Hafez Mirzapour; Ali Haghizadeh; Naser Tahmasebipour; Hossein Zeinivand
Volume 6, Issue 20 , December 2019, , Pages 79-99
Abstract
1- IntroductionAccurate detection of changes land use in Accurate and timely, Basis for a better understanding of the relationships and interactions of human and natural phenomena to manage and provides better use of resources. Principal land use management requires accurate and timely information in ...
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1- IntroductionAccurate detection of changes land use in Accurate and timely, Basis for a better understanding of the relationships and interactions of human and natural phenomena to manage and provides better use of resources. Principal land use management requires accurate and timely information in the form of a map. Regarding the widespread and unsustainable changes in land use, including the destruction of natural resources in recent years, Investigating how landslide changes during time periods are essential for satellite imagery. Since conservation of natural resources requires monitoring and continuous monitoring of an area, Land-use change models are now used to identify and predict land-change trends and land degradation one of the most widely used models in predicting land use change is the Auto-Markov cell model. the aim of present study is to monitor land use changes in the past years and predict changes in the coming years in Badavar-Nurabad watershed in the Lorestan province with an area of 71600 hectares. 2- MethodologyThe Markov chain method analyzes a pair of land cover images and outputs a transition probability matrix, a transition area matrix, and a set of conditional probability images. The transition probability matrix shows the probability that one land-use class will change to the others . The transition area matrix tells the number of pixels that are expected to change from one class to the others over the specified period (Ahadnejad 2010). Automatic cells are models in which adjacent and continuous cells, such as cells that may include a quadrilateral network, change their state or attributes through simple application of simple rules. CA models can be based on cells that are defined in several dimensions. The rules for changing the state of a cell from one mode to another can be either a combination of growth or decrease, such as a change to a developed cell or without development. This change is the source of the change that occurs in the adjacent cell. Neighborhood usually occurs in adjacent cells or in cells that are close together(Ghorbani et al, 2013). In order to detect land use changes in the studied area, TM , ETM+ and OLI satellite images of Landsat were used during three time periods of 1991, 2004 and 2016. After applying geometric and atmospheric corrections to images, the land use map for each year was prepared using the maximum probability method. The Kappa coefficient for the classified images of 1991, 2004 and 2016was 0.81, 0.85 And 0.90 obtained. Then, to model land use changes using the Auto-Markov cell model for 2028 horizons, First, in the Idrisi Selva software using Markov chain, the map was selected as input from the years 1991 and 2004, the 12-year prediction of the changes was considered by 2016 to determine the likelihood of a change in application. Then, using the CA-Markov method, the data from the Markov chain and the map of 2016 were used as input data for the automated-Markov cell method. 3- ResultsAssessment of the match between simulated and actual map of 2016 with 0.97 kappa index showed that this model is an appropriate model for simulating of land use change. The results from monitoring satellite imagery that in 1991 to 2016, the extent of residential areas, land is Dry farming, garden and irrigated farming land added in front of vast pastures, shrubbery and other is reduced. After verifying the model's accuracy, a 2028 map was prepared to predict the changes over the coming years. Well as the results show that the vast pastures of the forecast is reduced in the amount of 659.89hectares and 395.47 hectares will be added to the extent of irrigated farming. 4- Discussion and conclusionThe results of the Auto-Markov cell model showed that if the current trend continues, the size of the ranges will decrease sharply. Comparison of simulated map of 2016 by model and actual map with Kappa index showed that Auto-Markov cell model is a suitable model for predicting land use change and can accurately assess the future status of land use and vegetation to predict. Therefore, it is suggested protective measures and make appropriate management decisions to control non-normative changes continue to apply more than ever.
Amir Saffari; Mariyam Jan Ahmadi; Monireh Raeati Shavazi
Volume 2, Issue 3 , January 2017, , Pages 81-97
Abstract
Nowadays, one of the main problems that the societies encounter is discharging of the ground waters and the lack of suitable substitution for that. In Bushkan Plain vast use of agricultural lands has caused a drop in groundwater level. One of the suitable solutions to reduce this crisis is artificial ...
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Nowadays, one of the main problems that the societies encounter is discharging of the ground waters and the lack of suitable substitution for that. In Bushkan Plain vast use of agricultural lands has caused a drop in groundwater level. One of the suitable solutions to reduce this crisis is artificial feeding of groundwaters. To this end, the most important step in the floodwater spreading plan is suitable zonation for water spreading and forcing the water to penetrate into underground water tables. In this study, a hybrid AHP-Fuzzy method in Geographic Information Systems (GIS) and 8 parameters of the slope, alluvium thickness, electrical conductivity, geology, land use, drainage density, conductivity and altitude are used. First, these layers were converted to Fuzzy and then were evaluated using Analytical Hierarchy Process (AHP) and Expert Choice software. The values achieved in ARC GIS 10/2 on fuzzy layer were multiplied to Fuzzified layers by using Raster calculator and were combined with Fuzzy overlay command and the final maps were then prepared. The results show that gamma value of 0/9 has the best overlapping and eventually, the optimal gamma was found on 5 classes as high improper, improper, average, proper and high proper in the plain. 7/11 percent of the study area was calculated within high improper class, and 11/1 percent of the study area belonged to the high proper class. The southwestern parts of the plain, where pasturage density is low, are the best areas for flood spreading.
Mahtab Safari Shad; Mahmoud Habibnejad Roshan; Karim Solaimani; Alireza Ildoromi; Hossein Zeinivand
Volume 4, Issue 10 , June 2017, , Pages 81-98
Abstract
Climate change has altered the earth’s hydrologic cycles, especially its temporal and spatial distributions. Therefore, prediction of its future changes is very important. This study investigated the effects of climate change onthe precipitation, minimum temperature, maximum temperature, and runoff ...
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Climate change has altered the earth’s hydrologic cycles, especially its temporal and spatial distributions. Therefore, prediction of its future changes is very important. This study investigated the effects of climate change onthe precipitation, minimum temperature, maximum temperature, and runoff in three sub watersheds in Hamadan, Bahar Watershed. To this end, the WETSPASS model was used to estimate runoff and the LARS-WG model was used to predict climate variables between the years of 2014 and 2043. The results showed that the HadCM3 model with the largest weighting coefficient and the lowest error has the highest efficiency in simulation of precipitation and temperature. According to the scaled down measurements, in the next period, the average minimum and maximum temperatures will respectively increase up to 1.22 ºc and 0.9 ºc and the total rainfall will decrease about 8%. The results of the impact of the climate change on the future of the watershed's hydrology showed that runoff volume for all three sub-watersheds under the A2 scenario and the first and second sub-watersheds under the B1 scenario is going to decrease. For the third sub-watersheds, in contrast, it is going to increase. In addition, while total runoff input to plain will decrease by 36 % under A2 scenario, it will increase by 8 % under B1 scenario which will affect the watershed's water resource system changes. The remarkable thing is the reduction in rainfall in the winter and in the spring, disassembling the temporal distribution of the rainfall, and increasing the temperature. Accompanied by land use changes, it can have a significant negative effect on the future water resources management.
Abolghasem goorabi; Mojtaba Yamani; Seyyed Javad Hoseini
Volume 5, Issue 16 , December 2018, , Pages 81-100
Abstract
Abstract
Introduction
Rivers' pattern is seldom stable and is always subject to change. Rivers' banks have long been the most important areas of population settlement, especially in the semi-arid regions of Iran. This has made the recognition and assessment of the geometric deformation of rivers an ...
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Abstract
Introduction
Rivers' pattern is seldom stable and is always subject to change. Rivers' banks have long been the most important areas of population settlement, especially in the semi-arid regions of Iran. This has made the recognition and assessment of the geometric deformation of rivers an important applied topics. Alluvial beds of a river are divided into two groups of stable and unstable. While in a stable bed, the walls and the floor are stabilized, in the unstable bed, the walls and the floor are not constant and have a changing state. Zanjanrood is regarded as the natural bio-economical artery of Zanjan province. In the present study, by recognizing the temporal and the spatial hydro-geomorphological changes of Zanjanrood during the years 1955 and 2011, and in the western part of the river, which is more important for agriculture, the amount of morphological changes is calculated and presented in the form of a map.
Methodology
The method of the study was analytical by spatial-local comparison based on the direct and the indirect observations using satellite images, aerial photos, and maps.
In this method, the intervals were classified into distinct parts based on the morphology-hydrodynamic similarity. Then, by applying spatial analysis on the raster maps, the pattern and variation of the changes were estimated by plotting tangential transects on the extension and restriction areas in the right and left sides. By determining the extension and restriction areas in river sides, the type and amount of stream’s variation in various reaches was determined. Afterwards, the total areas of extension and restriction on both sides of the stream were computed. Transects are rectangles with constant angles whose area variations indicate the changes of the river banks in different time ranges. This technique was used to determine the area dominated every progression and regression area in order to analysis and assess of the main factor(s) affecting this change.
Result
The results of the study showed that the outcome of the action-reaction of the factors affecting Znjanrood changes in the studied area had been a stable trend over the past 56 years. The most important factors involved in this trend were the development of the agricultural activities, the increase of management actions to stabilizing the river for agriculture and infrastructure proposes, and dam construction. However, the effect of slope and geological conditions (neo-tectonic) should not be neglected as well.
Discussion and conclusion
The results indicated that the overall trend was to reduce the width of the channel to its axis. However, the process has increased from the first period (1955-1985) to the second (1985-2011) and the third periods (1985-2011), so that at the end of the given time intervals, there was an increase in the relative stability of the stream. The change in flow to the outlet reduced the erosion power of the river flow and increased the stability and relative stabilization of the bed. The development of the fairly stable gardening activities dispersed on the flood bed played an important role in the stability of the stream in the studied area, so that the gardens and fields on the stable river main bed sides exhibited great changes in the images and photographs.
The role of the human factors in the Zanjanrood Basin due to its relative geographical position (east to northwest transit), has been the basis for the development and launch of several road construction projects (railways, roads and freeways) during the period of 1955 to 2011 in Zanjanrood and caused the change of Hydro-geomorphological-Hydrodynamic systems. A quantitative assessment of the Zanjanrood river bed changes shows that the rate of change, overcoming the general trend of stability and stabilization, has increased from the first period to the last period. Indeed, while the stabilization rate in the first period was 0.16 km2, in the second and final periods, it was respectively 1.91 and 2.01 km2. Progressions are concentrated in the beginning and end of the research (Transects 1, 2, 6, and 9 to 13), which affects the lands of the villages of Nikpey, Darelik, Dolanab, Naji, Idalou, and Baghloja and Saifabad. The recessions are also focused on transects 3 to 8, excluding transect number 6. Based on the results, Zanjanroud shows the overall stability trend. The adjacent area of the upper and lower parts of the studied research (the areas around the villages of Nikpey and Baghloja) are among the most sensitive areas of the research.
Masumeh Rajabi; Kazem khoshdel
Volume 2, Issue 5 , January 2017, , Pages 83-99
Abstract
Dr. M. Rajabi[1], K. khoshdel[2] Abstract The study area is Ahrchay upstream basin. Because of the mountainous region is a sensitive area in terms of ...
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Dr. M. Rajabi[1], K. khoshdel[2] Abstract The study area is Ahrchay upstream basin. Because of the mountainous region is a sensitive area in terms of erosion. Most parts of the basin, are permanent. When Ahrchay branches arrive the flat area, the river meanders be converted. Ozomdel Varzeghan Plain, as a result of blockage by volcanic activity has occurred near the village of Sghendel. Digging trenches and sediments of the seabed by Ahrchay cause appears to have been made. In spring and late winter rainfall and melting snow caused river flooding is causing erosion and transportation of sediments found there by the river. In areas where the slope is to slow the stream sediment deposition. The material in foothill and lowland areas has formed alluvial terraces. In this study the geomorphic characteristics of the terrace deposits is investigated. For this study, 15 out of deposits terraces for grain harvested. Charts on different parameters such as (MD), (MZ), (QI), (SKG) and (SKI) is extracted and were analyzed separately. Grading of terraces and other characteristics of sediments show also features river terrace. 1 Professor of Geomorphology, University of Tabriz mrajabi@tabrizu.ac.ir 2 Geomorphology Ph.D. student, University of Tabriz Khoshdel8@tabrizu.ac.ir
Vahid Nourani; Saleh Mohsenzadeh
Volume 4, Issue 11 , September 2017, , Pages 83-103
Abstract
Introduction
In this study, the MPSIAC model was used to consider the effects of the dominant factors in sediment production in order to estimate the rate of the erosion and sediment load in sub-basins of the Aji Chay River. Since the sediment rate of this model is the annual average, the variations ...
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Introduction
In this study, the MPSIAC model was used to consider the effects of the dominant factors in sediment production in order to estimate the rate of the erosion and sediment load in sub-basins of the Aji Chay River. Since the sediment rate of this model is the annual average, the variations of the nine fold factors of this model was examined in order to calculate the sediment for each year. Then, the annual and monthly sediment rates were quantified using a cascading method.
Methodology
In order to estimate the sediment production and the relationship between the degree of the sediment yield and the amount of production, equation (1) which was based on determining the scores of the factors considered in the PSIAC model and obtaining their total scores in each hydrological unit was used
38.77e0.0353R = Equation(1): QS
Qs=sediment yield (m3/km2/year) R= sedimentation rate
The PSIAC model specifies some variations for each factor, which is somewhat selective and requires an expert judgment. Johnson and Gombard (1982) have made the nine-fold factors for this method as numerical equations.
The estimated sediment rate using MPSIAC method is based on the annual average. Therefore, the variations of the factors of MPSIAC model were examined and compared to estimate the sediment for each year. Due to the fact that sediment is not the same throughout the year, it was not possible to equally consider annual sediment for all months of the year. Thus, for the purpose of the quantification of the monthly sediment, the cascading micro-scale was used through verifying the existing data and filling the deficiencies of the data. In the process of disintegration, the sediment, which was the annual sediment in the initial intervals, was sequentially broken into smaller surfaces with specific coefficients and calibrated.
Equation(2): SNij = Sij
Equation(3): SijNky = Sk
Results and discussion
In this paper, the annual sediment rate was estimated using remote sensing, GIS techniques, and the application of the experimental model of MPSIAC in hydrological units and its zoning in the area. Then, by inserting the DEM into the GIS environment and by modifying the ups and downs, the flow direction, the network of waterways, and the primary and secondary sub-basins were produced. As a result, the production rate of the sediment and the scores of the each of the factors in the sub-basins were calculated using the equations presented in the MPSIAC model. The results showed that there was a high correlation between the estimated sediment load with the MPSIAC model and the observed and recorded results.
The results of the MPSIAC model for the estimated sediment rate were based on the annual average, so the existing data and nine-fold factors of MPSIAC model, which were time-consuming, were used for the monthly sedimentation. To measure the amount of the precipitation and runoff for different months of each statistical year and to study the amount and manner of changes in vegetation and land use in the studied area, the annual precipitation and annual erosion were calculated for each statistical year. Then, sub-scaling was done through the calculation of the sub-scale coefficients of annual to monthly sediment.
Conclusion
The estimated sediment rate using MPSIAC model and observational and measured data of the sediment in the hydrometric stations of the Aji Chay basin has high accuracy and acceptable correlation. In addition, by comparing and verifying the available and measured data in the hydrometric stations of the AjiChay basin at low scales with extractive data of this method, it turns out that the sediment values can be estimated at low scales by specifying the sub-scale coefficients and calculating the sediment for each year.
Aghil Madadi; Elnaz Piroozi; Leila Aghayary
Volume 5, Issue 17 , March 2019, , Pages 85-102
Abstract
Introduction
One of the most striking natural hazards in the world is flood which generates a lot of financial and human losses every year. It can be said that in comparison with other natural hazards, it occurs with high abundance and in vast expanses. Some of its causes can be severe or prolonged ...
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Introduction
One of the most striking natural hazards in the world is flood which generates a lot of financial and human losses every year. It can be said that in comparison with other natural hazards, it occurs with high abundance and in vast expanses. Some of its causes can be severe or prolonged rainfalls, melting, breaking the dam and landslide, high waves, channel closure, rainfall intensity, type of rainfall, time and volume of rainfall, previous river conditions, drainage basin, inappropriate use, and falling of forest trees in the sources of the rivers. Knowing susceptible areas to floods is one of the basic measures in natural resource management and development planning. One of the most important flood management methods is flood zoning. The zoning of potential flooding is to identify and describe areas with potential for surface runoff. The Khiyav Chay Watershed Basin, with an area of 318 km2, is located in Meshgin shahr. Due to the specific circumstances of the region, such as topography, slope, and climatic conditions (sudden precipitation and spring precipitation, melting, flooding of rivers in the spring), there is a high potential for flood occurrence. Therefore, the purpose of this research was to study the area's potential for flood occurrence.
Methodology
In this study, ten factors of slope, height, rainfall, CN, runoff height, distance from the river, soil, lithology, vegetation, and user-use were identified as effective factors for flood formation in the region. Using Landsat 8 images including OLI and TIRS sensors and the Maximum Likelihood supervised classification method, in the ENVI 5.3 environment, the land use map was obtained. Then the user map was compared with the index table and integrated with the hydrologic group data, and the CN curve number was prepared. In the next stage, with mean precipitation and CN, and by using SCS method, ARC GIS software and Arc-Hydro and Arc CN-Runoff subtraction, the runoff height of the range was calculated. Also, the NDVI index, one of the most widely used indices for vegetation monitoring, was undertaken to prepare a vegetation map of the basin. Then, the other layers of information were provided in the GIS environment. The weights of the layers using the Critical method based on the correlation, interference, and standard deviation of the factors were determined. The final analysis and modeling was done using the WLC model as one of the methods of multi-criteria analysis techniques.
Discussion
By studying the zoning of the potential flood area of the study area and comparing it with each of the standard maps, it was concluded that the high risk areas were mainly in the hilly and mountainous areas of the area (slope over60%). Due to the slope and elevation of the area, the main role was with runoff, flood discharge, penetration, precipitation losses, and flow and water velocity. In these high risk areas, due to the fact that most of the formations belong to the formation of volcanic activity in the late third and early fourth centuries, the degree of permeability was very low but the runoff and CN amount were high. Secondly, areas with potential hazard were located within the urban boundaries of Meshkinshahr. In the city of Meshgin Shahr, on the east side, is the deep valley of khiyave chay, where the khiyave chay River flows. Two other radial valleys in the natural pathway formed the surface water stream, along which residential neighborhoods were developed that were subject to flood and extreme flow of surface water. Due to the fact that most of the city is made up of asphalt and residential surfaces, the permeability was very low, in contrast to the amount of runoff (99%) and CN (curve above 8).
Conclusion
According to the results of weighing, height factors with weight coefficients (0.173), lithology with weight coefficients (0.163), slope with weight coefficient (0.139) and rainfall with weight (133/0) were the most important factors on flood formation in the region. The results of the study showed that 13.33% and 22.88% of the study area were in high risk and high class. According to the final map, high-risk areas, in the first priority, were mainly in the hilly and mountainous regions of the region, but in the second priority they were within the urban boundaries (especially in the central regions of the city due to lower construction and permeability). The results of the study also indicated that due to the high potential of the study area in terms of the risk of flood, water protection and protection measures at the basin level should be considered. In addition, the simultaneous use of remote-sensing and GIS and using the SCS-CN model could be useful in preparing a flood zoning map.
Maryam Bayati Khatibi; Fariba Karami
Volume 3, Issue 7 , October 2016, , Pages 87-106
Abstract
Maryam Bayati Khatibi[1]* Fariba Karami[2] Abstract slope susceptibility is very vary to water erosion in geographical regions and climatic conditions .In recent time, losses of soils by gully erosion is serious work on geomorphological, hydrological and man aspect. Delivery of losses slope is ...
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Maryam Bayati Khatibi[1]* Fariba Karami[2] Abstract slope susceptibility is very vary to water erosion in geographical regions and climatic conditions .In recent time, losses of soils by gully erosion is serious work on geomorphological, hydrological and man aspect. Delivery of losses slope is treated farmer lands. gullies -as one main erosion form- is made on steep slopes and on susceptible surface material to erosion in Atashbeig Catchment (located at 37° 00' to 37° 20' E and from 46° 45' to 47° 15' N). Runoff is delivered materials to foot slopes at short time. In this paper is analysis rate erosion and rate of soil lose at single of gully by use of quantitative methods. In first step ,is investigated condition of region for gully form by use of Hydrotermal index(HTK). Then is studied runoff property taking into movement time and rate of sediment that is delivery to river by single gully(Dg) .The results of these studies show that is vary of erosion rate at throughout of Atashbeig catcment.Erosion is very intensive in middle part of this catchment .HTK show that is favorabel land of stady area at 5 month for gully erosion. Also the results suggessted that rate erosion is high in all part of area . [1]- Professor in Gegraphic Research Group; University of Tabriz; (Corresponding author), Email:m5khatibi@yahoo.com [2]- Associte Professor in Gegraphic Research Group; University of Tabriz.
Nasrollah Kalantari; Mehran Mehdipour; Valiollah Hamrayan Azad
Volume 3, Issue 9 , March 2017, , Pages 87-112
Abstract
Gardab spring with an average annual discharge of 330 lit/s is counted as one of the important Karstic springs in the Andimeshk City. The aim of this study is surveying geological structures, morphological features and determination of factors affecting the manner of appearance, recharge and turbidity ...
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Gardab spring with an average annual discharge of 330 lit/s is counted as one of the important Karstic springs in the Andimeshk City. The aim of this study is surveying geological structures, morphological features and determination of factors affecting the manner of appearance, recharge and turbidity of the Gardab spring. In this regard stratigraphic studies, lithology, structural and morphological works have been done. The data obtained show that fractures, the Balarud faulting zone, faults in the region and the Chalab doline have basic roles in occurrence, recharge, turbidity and water transmission from the Chaoni Mountain and a part of the northwest of the Kooshab anticline to the Gardab (Mongereh) spring. Though, the topography and gradient of the Chaoni mountains are towards the Mongreh spring and convey water in the direction of it, but the main parameter governing water convey and turbidity are the Mongreh, Chareh and Verna faults. Based on gathered information, turbidity of the Gardab spring during rainfall is due to the Chalab doline.
yaser hoseini
Volume 6, Issue 21 , March 2020, , Pages 87-107
Abstract
1-IntroductionFlood discharge is of high importance in studies regarding water resource exploitation, flood control, construction of dams, basin management, and hydrologic studies (Alzahrani et al, 2017). Therefore, to a large extent the accuracy of these studies and the safety of water constructions ...
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1-IntroductionFlood discharge is of high importance in studies regarding water resource exploitation, flood control, construction of dams, basin management, and hydrologic studies (Alzahrani et al, 2017). Therefore, to a large extent the accuracy of these studies and the safety of water constructions depend on flood study methods. Flood is a natural phenomenon that threatens the life and properties of a large number of people all over the world, and it is impossible to manage water resources in basins without the accurate determination of the peak flood discharge (Badri et al, 2017). The advances in flood estimation techniques have made it possible to use rainfall-runoff models to assess the hydrographic properties of the flood in watersheds and decrease the risks of the flood. Therefore, this study was carried out to compare the SCS unit hydrograph and Uniform methods in determining the peak flood discharge with WMS model in Amughin basin of Ardabil province.2-MethodologyAmughin basin with an area of approximately 78 km2 is located in the northwest of Iran. The physiographic features were extracted using the basin map (scale: 1:25000) and WMS model. This study applied Arc GIS 9.2 and Idrisi32 software to obtain the properties of the studied basin using DEM (Digital Elevation Map) of the National Cartographic Center, NCC. Remote sensing methodology was utilized to study the geographical land use changes occurred during the study period. Landsat images of TM and ETM+ of Amughin basin area were collected from the USGS Earth Explorer web site. After image preprocessing, un-supervised and supervised image classification were performed to classify the images into different land use categories. In general, soil hydrologic groups were divided into three subgroups of B, C, and D and CN value of 78.7 was estimated for the Amughin basin based on the geological examination, permeability, vegetation, and hydrologic conditions of the basin soil.3-ResultsThe model calibration results showed that the simulated peak discharge and flow volume were in good correspondence with the observed values (RE%= 7.17, RMSE= 0.44). Thus, the calibration results were used for optimum values of parameters. The model was validated using two rainfall events and the model performance indices were acceptable in both cases (RE%= 2.51, RMSE= 0.0042) in SCS method. To evaluate and test model validation, two rainfall events, were used. That the model performance indices were acceptable. Distribution of CN amount in the area showed that the upstream flow had higher CN values and consequently increased flood volume in these areas. Based on the values of obtained CN, the amount of peak flood discharge was calculated for return periods of 25, 50, and 100 years.4-Discussion and conclusionAccording to the results, the SCS model has good agreement with experimental results among the different methods used for estimating flood discharge in the northwest of Iran. In fact, this model requires calibration in the study region. In small watersheds in the northwest of Iran, the SCS model yields better results than the Uniform method because the conditions required for using this model are satisfied in these basins. Moreover, the results obtained from this method can be closer to actual values provided that the watershed concentration time is calculated more accurately. Our results also showed that the SCS model has a high sensitivity to rainfall distribution across the region and that the rainfall across the region needs to be analyzed to obtain desirable results. Besides, the rainfall distribution and its time distribution should be close to the corresponding values in the region. A comparison between the obtained results of peak discharge from the SCS and Uniform methods in return periods of 25, 50, and 100 years revealed that the average estimates of the Uniform were approximately 5% higher than the SCS method. According to paired T-test, the difference between Uniform and SCS values were not significant at a confidence level of 0.01. Overall, the results obtained from this method can be closer to actual values if the watershed lag time is calculated more accurately using the floods occurred in the studied basin.
Mirali Mohammadi; Farnaz Mohammadi; Ahmad Fakherifard; Sajad Bijanvand
Abstract
1- Introduction Mainly the flood is caused by the surface runoff resulted from the properties of precipitation and river basin. The reduction of flooding by the effect of vegetation and soil in a small basin is less than a basin with a large area. Hence, to have a flood zoning map, the first step is ...
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1- Introduction Mainly the flood is caused by the surface runoff resulted from the properties of precipitation and river basin. The reduction of flooding by the effect of vegetation and soil in a small basin is less than a basin with a large area. Hence, to have a flood zoning map, the first step is studying economic flood management and flood control projects. This paper focuses on Baranduz-chay River as a case study, located in the Urmia lake basin. The river reach having 3 km long, was studied between two hydrology stations namely Bibakran at the upstream and Dizaj at the downstream. The annual peak discharge data of Baranduz-chay has surveyed during the years from 1974 to 2013, where the appropriate Manning roughness coefficient, n, by averaging 0.0325 as an upstream coefficient and 0.0301 as a downstream coefficient were both implemented in the HEC-RAS software and its result including floodplain zones elevation extraction by the Muskingum-Cunge method, based on the floods with different return periods obtained. After converting these zones to their corresponding risk for each return period time, it has been delineated in Arc-Map software through HEC-geo-RAS extension, floodplain zones were then defined. The maximum inundated area is 97.34 Hectares and belongs to 1000 years return period which has the most risk as 63.58% within 3 years of useful periods. The Rule Curve is obtained by inundated areas with both different return and useful periods from the risk formula in which the general Area-Period-Risk formula was extracted. Basically, the magnitude of the floods and their repetition over time is subject to rainfall intensity, permeability, and topographic conditions in the area. The occurrence of floods as one of the natural disasters that cause many financial losses in many parts of the world. The first step in economic studies of flood management or flood control is flood zoning. Flood zoning means the extent to which the flood covers the area. Today, via modern science and technology, human beings are trying to optimize designs and to reduce these costs. Therefore, it seems that flood zoning study in the permanent and seasonal rivers path appears to be of great importance by conducting case studies in vulnerable areas. ShahiriParsa et al. (2016: 55-62) used the integration of the HEC-RAS one-dimensional model and the two-dimensional CCHE2D model on the Sungai Maka river in the state of Kelanten, Malaysia. They concluded that in this case, some important factors are: Manning’s flow resistance coefficient, n, the geometric profile of the river section and the choice of the most suitable flood return period. The mentioned parameters have a major role in providing flood zoning outcome, which has caused the most changes in the geometric shape of the river section. Their results showed that the greatest difference between the models was 6% in the location of the meandering rivers. The results of both models were also consistent in most of the transverse sections, and, due to the difference in the shape of the rivers, the greatest difference was the difference between the two models. Sung et al. (2011: 1-12) used the Maskingum method to process unqualified basins by analyzing the HEC-HMS hydrologic model and the HEC-geo-HMS geo-hydrologic model, the extraction of sub-basins and characteristics of the basin was extracted. The results showed that the percentage of flood events proportional to the maximum discharge errors of a moment of less than 20% and a runoff volume of less than 10% to reaches 100%. 2- Methodology Baranduz-chay river as the main river and permanent water catchment area of the study area. It originates from the highlands of Iran and Turkey border. The catchment area of this riverside in Saatlu is about 666 square kilometers and in Babarood is 1012 square kilometers. This research was associated with a similar risk due to the risk relationship with different return periods for the restricted areas around the river, based on different return periods. To determine risk areas or certain return periods, peak discharges were fitted with the best statistical distribution and through that, peak discharges were then calculated with different return periods and each of them was determined along the river and its expansion area. 3- Results and discussionFig. 3, shows the risk versus area (A, RISK), the risk with a downward trend, which means that the area risk is decreasing with the area covered by the risk area. By fitting a variety of exponential, linear, logarithmic, polynomial and power statistical functions, among those functions as shown in Fig. 3, risks with different useful lives are plotted simultaneously and from among functions, the power function was selected as a suitable fit function in order to obtain the general probabilistic distribution function and its parameters based on different useful life. Fig. (3) Risk diagram versus area (Rule Curve) with a different useful life 4- Conclusions For the Manning roughness coefficient, n, in the hydraulic model, the Manning’s n for the upstream and downstream stations were computed. The roughness coefficients, n, were then obtained for the upstream and downstream stations as 0.0325 and 0.0301, respectively. In order to obtain the corresponding risks for the areas covered by a flood of 3 km long from the Baranduz-chay between the upstream Bibakaran station and the lower reaches of the Hoerl's model, which is a type of power function. The risk-space-period curve for the specified periods is 2, 3, 5, 10, 25, 35 and 75 years (for more details, see Mohammadi, 2016).
Samaneh Poormohammadi; Mohammad Taghi Dastorani; Alireza Massah Bavani; Hadi Jafari
Volume 4, Issue 12 , December 2017, , Pages 89-110
Abstract
Extended Abstract Introduction Climate change has a huge impact on all aspects of human life. Some of its impacts can be reduction in the surface and ground water resources of the country, changing the amount, timing, and type of precipitation, and influencing water quality. It can also lead to the increased ...
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Extended Abstract Introduction Climate change has a huge impact on all aspects of human life. Some of its impacts can be reduction in the surface and ground water resources of the country, changing the amount, timing, and type of precipitation, and influencing water quality. It can also lead to the increased droughts, increased demand for water, changes in the management of water resources, sea level rise and its complications, and extreme maximum and minimum temperatures. The aim of the present study was to evaluate the impact of the climate change on rainfall and minimum and maximum temperatures using 15 atmospheric general circulation models under two scenarios, including A1B and B1, between the years 2011-2039. Methodology For this purpose, through the use of beta statistical distribution of rainfall changes and based on the probability of 20, 50 and 80%, the minimum and maximum temperatures, were calculated from 15 general circulation models. Standard errors, absolute errors, and Nash-Sutcliff coefficients were determined for simulated data on the base and the upcoming periods. Next, of the 15 climatic models, the minimum temperature changes (ΔTmin), the maximum temperature changes (ΔTmax), and rainfall variation ratios (ΔP) for A1B and B1 scenarios for 12 months were extracted from the Lars model. The introduction of the climatic scenarios in the family scenarios of the A1 group, a rapidly growing economy and the growth of the population that will peak in the mid-21st century and decline thereafter introduces new and more efficient technologies. In this family, economic issues are more emphasized and opinions are rather global rather than regional. Three different subgroups for group A1 are based on the type of technology used in the 21st century, the intensification of the use of the fossil fuels (A1FI), the use of non-phosphate energy sources (A1T), and the use of fossil and non-fossil sources in a balanced manner (A1B). Results and discussion The results showed that, with the probability of 20 to 80% and under both A1B and B1 scenarios, the minimum and maximum temperatures are rising and the rain is falling. In addition, the increase in the minimum and maximum temperatures under A1B was more than that of the B1 scenario, but the reduction in the precipitation under B1 was more than A1B. The results also showed 19 to 22% decrease in precipitation, minimum temperature of 13 to 20%, and a maximum temperature of 2.4 to 6.4% compared to the baseline of the Tuyserkan catchment. In Table 1, the percentage change in climatic parameters under the influences of A1B and B1 scenarios and in relation to the base curriculum is presented. Under A1B scenario, and with the probability of the occurrence of 80%, there is 19.1% decrease in precipitation, 4.6% increase in maximum temperature, and 20% increase in minimum temperature in future periods. In addition, under B1 scenario and with the probability of occurrence of 80%, there is 22% decrease in precipitation, 13% increase in minimum temperature, and 4.2% increase in maximum temperature. Table (1) Assessment of the percentage change in climate parameters relative to the base curve Scenarios Probability of occurrence Precipitation (%) T_max (%) T_min(%) A1B 20 -3.8 1 7.2 50 -13.7 2.8 14.5 80 -19.7 4.6 20 B1 20 1.5 -0.9 7 50 -20 1.5 7.7 80 -22 4.2 13 Conclusion Generally, it can be argued that the climate change in future periods will increase the minimum and maximum temperatures and reduce the rainfall in Tuyserkan Plain. Consequently, these changes in temperature and precipitation will affect plain water resources. The most important of change is the change in the seasonal precipitation pattern and temperature rise in cold seasons. These changes will also have a significant impact on the region's cropping pattern, as the dryland cultivation is limited, due to the reduced rainfall, and its time will vary with time variations.
Robab Razmi; Narges Hesami; Zahra Rabiea; Karim Amini Nia
Volume 5, Issue 14 , June 2018, , Pages 91-111
Abstract
Introduction
The variations of amount, intensity and type of precipitation variable are transformed through spatial and temporal dimensions. Flooding precipitation as a dangerous natural hazard is caused of such variations. The annual heavy precipitations are triggered many hazardous floods over the ...
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Introduction
The variations of amount, intensity and type of precipitation variable are transformed through spatial and temporal dimensions. Flooding precipitation as a dangerous natural hazard is caused of such variations. The annual heavy precipitations are triggered many hazardous floods over the most of catchments in northern Iran. Hence, investigation of the generation and evolution mechanism of synoptic circulation patterns triggering of flooding and heavy precipitations could play a key role during risk management and mitigation measures of such natural hazards.
In this study, we aimed to investigate and analysis of synoptic condition of perceptible systems in Babol-Rud catchment. Two main questions were as below: how do the annual heavy precipitations follow the occurrences cycles? and how do the synoptic factors impact on annual heavy precipitations in Babol-Rud catchment?
Data
In this paper, both type of ground level and remotely sensed data were used. Diurnal data were gathered from eleven rain gauge stations in addition of a hydrometric station named as Quran-Talar. Number of days with heavy precipitation were considered by confidence level of P=95%. Atmospheric variations were collected as sea level pressure and geo-potential heights in 500 hPa with spatial resolution of 2.5*2.5 arch degrees. Water discharge of Quran-Talar hydrometric station was selected as monitoring indicator of the study area.
Methods
Spectral analysis is a proper procedure to extract of cycles in time series. Its merit is related to low-volume statistical operations based on Fourier transform. In order to extract the heavy precipitation and number of days with heavy precipitation, the percentile indices and the thresholds of US climate variability and predictability program (CLIVAR) were used. In this regard, equal to 435 days from 7305 total days in time series were selected as days with heavy precipitation in the study area. Based on clustering analysis, all temporal sequences were classified as three precipitation clusters.
Results
In this study, variations of annual heavy precipitation and water discharge data were investigated using synoptic and statistic techniques. Trends and occurrences cycles were investigated during temporal time series. Results revealed the significant annual and biennial curvilinear cycles in confidence level of P=95%.
Northern wards of Iran have been recorded as the prone of heavy precipitation and flooding events. The main aim of the present study was to investigate and analysis of synoptic condition of perceptible systems in Babol-Rud catchment. For this purpose, the heavy precipitation and number of days with heavy precipitation were extracted within time series. Thereafter, the synoptic conditions of perceptible systems were analyzed through sea level and height of 500 hPa. By assigning three clusters for heavy precipitation patterns in the study area, results revealed that the generation of short waves inside the main Rossby troughs is an important factor of heavy precipitation in Caspian coastal regions including the study area.
Fariba Esfandiyari Darabadi; Ebrahim Beheshti Javid
Volume 3, Issue 8 , December 2016, , Pages 93-111
Abstract
Received: 2015.12.13 Accepted: 2016.10.29 Fariba Esfandiyari Darabad[1]* Ebrahim Beheshti Javid[2] Abstract ...
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Received: 2015.12.13 Accepted: 2016.10.29 Fariba Esfandiyari Darabad[1]* Ebrahim Beheshti Javid[2] Abstract Landslide is one of the morphodynamic processes including significant hazards in terms of fatalities, financial casualties and the number of happening. In this research, Zoning of potential landslide occurrence is studied in Heyran Defile region. To do this the combination of multi-criteria (Analytical Network Process) and statistically (Bayes' theorem) models and accompanied by 12 natural and human parameters including, Slope, aspect, land use, lithology, precipitation, vegetation density index (NDVI), slope length (LS), topographic wetness index (TWI), stream power index (SPI), distance to road, distance to fault and distance to river were used. The layer of occurred landslides in the study area have been used to the obtaining weight of each landslide susceptibility parameters classes and validation of the final map which seventy percent of the landslide for running the model and another 30 percent is used to the model validation. The result is a map classified in five categories that respectively to be included Zones with very low, Low, Moderate, High and very High potential. According to the result map 26.3 percent of the area case study has been predicted as a region with high and very high potential for the landslide occurrence. These areas primarily to be included marginal areas of the Ardebil- Astara road. Most landslides also occurred in these areas because of the high construction in bordering the road, disrupt the natural slope of the land for the road construction and broaden it. Land use in these areas is mainly sparse forest, rangelands and agriculture which is located on the slopes. Evaluation of zoning map was done using 30 percent of the occurred landslide. According to the results of this evaluation and placement of a considerable percentage of landslides in the high and very high sensitivity classes (77.6 %), it can be concluded that the accuracy of used models in the landslides susceptibility zoning is acceptable. [1]- Associate Professor and Faculty Member of Mohaghegh Ardabili University, (Corresponding Autor), Email:fariba.darabad@gmail.com. [2]- Geomorphology Ph.D. student, mohaghegh Ardabili University (Corresponding Autor).
Volume 1, Issue 1 , January 2015, , Pages 93-109
Abstract
Abstract
The property of the surface materials in basins and environmental changes are among the important factors which can affect the quality of water. Human manipulation of slopes and industrialization are other factors that divert pollution into water and cause poor water quality. Injection of solid ...
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Abstract
The property of the surface materials in basins and environmental changes are among the important factors which can affect the quality of water. Human manipulation of slopes and industrialization are other factors that divert pollution into water and cause poor water quality. Injection of solid materials into water resources and increasing the ions viscosity are among the important reasons which decrease the quality of water. This might affect the human health and threat the food security directly or indirectly. Ahar River, as the main river at western slope of Sabalan mt., plays a crucial role in the irrigation of the surrounding fields and providing water for urban settlements and villages. In recent years the discharge patterns and quality of water in Ahar River have changed. This paper has studied the changes of water quality in Ahar River by utilizing TDS, SO4, Na index and Man-kendal method in long periods predicting trends of change till 1400. The results showed that there were increased TDS, SO4, and Na in the study period. This pattern is very dangerous and can be considered as a threat to the human health. The findings showed that the TDS was very high, and the high amount of solid material indicated pollution so the water consumption of the Ahar River can be a potential threat to the people who use it.
Mahnaz Bahrami; Ali Fathzadeh; Mohamad Ali Zaree Chahooki; Roohollah Taghizadeh Mehrjerdi
Volume 3, Issue 6 , January 2017, , Pages 95-113
Abstract
Mahnaz Bahrami[1] Ali Fathzadeh[2]* Mohamad Ali Zaree Chahooki [3] Roohollah Taghizadeh Mehrjerdi[4] Abstract Promotion of scale informaion quantity can improve the prediction of snow parameters. There are limited studies about the interaction on in the pizel size. The aim of this study is investigation ...
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Mahnaz Bahrami[1] Ali Fathzadeh[2]* Mohamad Ali Zaree Chahooki [3] Roohollah Taghizadeh Mehrjerdi[4] Abstract Promotion of scale informaion quantity can improve the prediction of snow parameters. There are limited studies about the interaction on in the pizel size. The aim of this study is investigation on the effect of spatial resolution on predicting snow depth through empirical test of the relationship between some digital elevation models and snow depth modeling using multi variate regression medel. First using Latin Hypercube Sampling (LHS) technique 100 snow depth data and 195 random data were collected. Then a base DEM with 10m resolution was selefcted and 25 terrain parameters were extracted from it as the ANN input. 9 DEMs with different pixel sizes were resampled from the base DEM. Finally effective parameters on sonw depth were estracted from 10 DEMs and their relationship between measured data was calculated usnig a multiple linear regression. The models were compared by RMSE, NMSE, MSE and MAE and the results showed that the DEM with 150m resolution was the best DEM for snow depth simulation. Thus this result can reduce costs and increase the accuracy of estimation of snow depth. [1]- Master Student of Watershed Management, Faculty of Agriculture and Natural Resources, University of Ardakan, Iran. [2]- Associate Professor of Faculty of Agriculture and Natural Resources, University of Ardakan, Iran. Email:afathzadeh@yazd.ac.ir [3]- Assistant Professor of Faculty of Agriculture and Natural Resources, University of Ardakan, Iran. [4]- Assistant Professor of Faculty of Agriculture and Natural Resources, University of Ardakan, Iran.
Amir Sasfari; Hamid Ganjaeian; Zahra Heidary; Mojdeh Fraidoni Kordestani
Volume 5, Issue 15 , October 2018, , Pages 95-114
Abstract
Wide areas of dry and non-glacier lands of the earth are covered with carbonate formations prone to karstic. Indeed, about 20 to 25% of the world's population live in karstic areas or get their water requirement from karstic water resources. Karstic areas are important because of the following reasons. ...
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Wide areas of dry and non-glacier lands of the earth are covered with carbonate formations prone to karstic. Indeed, about 20 to 25% of the world's population live in karstic areas or get their water requirement from karstic water resources. Karstic areas are important because of the following reasons. Firstly, they have an important role in providing and feeding aquifers. The karstic aquifers have also high heterogeneity and spatial diversity in terms of the development of karstic. In addition, they are formed in various forms and developed in karstic regions. For regions such as Iran which does not have enough water resources and 11% of its area covered with karstic, the issue is important. Due to the complex nature of karstic system, especially from the perspective of geomorphology, no models have been offered upon which all aspects of the system can be investigated. Due to the sensitive nature of a karstic system, in the planning of karstic areas, efforts have been made to develop the rate of change and sensitivity of karstic within the framework of the appropriate model or models. Accordingly, in this study using the OWA, fuzzy logic, and network analysis (ANP), the development of the processes and karstic aquifers are discussed in the Qaresou basin.
Methodology
This research was based on field, instrumental, and library techniques. Firstly, using the topographic maps, the basin area of the study was determined. The main data of the research were topographic maps of 1: 50000, geological maps of 1:100,000 and satellite imagery. In this research, 8 factors including lithology, fault, slope, aspect, elevation, river, rainfall, and climate have been used to determine the areas susceptible to Karstic development in the Qaresou Basin. For this purpose, the first step was to prepare information layers using some software. In the last step, considering the parameters, the potential of the region for the development of the processes and the development of karstic aquifers was evaluated. For this purpose, two models of fuzzy logic and sequential weighted averaging (OWA), as well as an analysis network (ANP) model, were used for the zoning and weighting the information layers.
Results and discussion
The 8 parameters of elevation, slope, aspect, lithology, fault, climate, rainfall, and rivers were used in order to evaluate the development of karstic in the study area. In the lithology and climatic condition layers, the first class had the lowest value in the development of karstic regions and the upper classes had the highest value. In the lithology layer, the first class had formations which had less potential for permeability and the sixth class was calcareous layer with a great potential in this regard. In the climate classes, the first class had a semi-arid climate and had a low score, but the fifth class had a wet climate with a high score. The distance from faults and rivers showed that the areas near faults had a high potential to develop the karstic processes. The pattern of the slope and aspect indicated that the regions with the lowest slope as well as aspects to the north had the highest score. The pattern of the height and precipitation also suggested that areas with significant elevation and more precipitation had great potential in the development of the karstic processes. The pattern of distance from the river showed that the areas away from the river had higher potential and score.
Conclusion
Considering the parameters that were considered in order to evaluate the development of the processes and the karstic aquifers, as well as considering the criteria and sub-criteria, the final maps were obtained. Based on the results of the effective factors in the development of the Karstic, the studied basin is divided into five levels of high, relatively high, moderate, low, and very low development.
The evaluation of the final maps indicated that in both maps of the north and northeast regions of the basin there is more development. In addition, due to the favorable climatic, geomorphological, and geological conditions, a large part of the region has a high development that is why the studied basin has a high potential for karstic water resources. Considering that there are differences in fuzzy logic and sequential weighted average (OWA) methods in integrating and combining information layers, the final results have differences in terms of class size. Indeed, in the OWA method because there is more moderation, the difference between the classes is less than the fuzzy logic method, but the general trend of the development in both methods is almost consistent and the extent of development reduces from the north and northeast to the south and southwest.
Mohammad Akhavan Qalibaf; Hamid Alipour; Elovsat Guliev; Marina Kurnova; Mohammad Hossein Mokhtari
Volume 6, Issue 18 , June 2019, , Pages 97-113
Abstract
Introduction The ability of a system to detect changes depends on its capacity to estimate variables on a scale. In any case, observing changes at successive times is the first step towards identifying the active processes and change forces. The assessment of land use change and land cover has been considered ...
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Introduction The ability of a system to detect changes depends on its capacity to estimate variables on a scale. In any case, observing changes at successive times is the first step towards identifying the active processes and change forces. The assessment of land use change and land cover has been considered as one of the main techniques of assessing environmental changes and has played a major role in environmental planning. Vegetation change and land use due to human activities are among important issues in regional and developmental planning. Given the advantages and capabilities of satellite data, this technology can help identify and discover these changes. Materials and methods In this research, the investigation of the land cover change of the Lake Urmia basin was based on the use of the MODIS Annual Coverage (MCD12Q1) with the HDF format and spatial resolution of 500 m. These images were categorized as Type I with 17 classes of land cover. Then, the image was taken annually by the mask region border and a geometric correction which Converted to UTM system Through entering the annual descriptive information tables into the Excel software, the change trend of land cover area was estimated between the years 2005 and 2016. Results and discussion The review of Tables 2 and 3 showed that there were significant variations in coverage over the period of 2005 to 2016. The area of the water zones had been declining since 2009. The grasslands had a relatively stable area between 2005 and 2015 and showed a decreasing trend over the last two years. Urban coverage during this period had not changed much, and the population growth seemed to be moderated by increasing urban densities. Between 2009 and 2014, water level changes were steeper than they were in previous years. In addition, since 2014, the slope had become even more intense. The area of the water zones in 2008 had a slight and noticeable decline compared to its following and preceding years. Conclusion According to the MODIS image information, the proportion of land area and water zones in 2016, compared to 2005, were respectively 1.39 and 0.69. Between 2005 and 2016, the greatest increase in the area of use was related to agricultural land and solid or dense floor coverings, respectively with an increase of 1648 and 837. The greatest reduction in the use of the area was related to water zones and desert cover, respectively with decreasing 1383 and 1159 km2. The results of the research showed that satellite images ha high potential for rapid decoupling of agricultural land, the preparation of map of different types of crops in the region, and determining under cultivation with a relatively accurate accuracy in a regional scale.
Volume 2, Issue 2 , January 2015, , Pages 99-115
Abstract
In order to use the best of any land patch, planners are often required to make decisions in short periods of time to create environmental and economic competitions which will lead to sustainable development. In this regard, a series of land use suitability maps would be very efficient. In the ideal ...
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In order to use the best of any land patch, planners are often required to make decisions in short periods of time to create environmental and economic competitions which will lead to sustainable development. In this regard, a series of land use suitability maps would be very efficient. In the ideal case, these maps should be compiled and finally integrated through a complex process. Using instructions by FAO land evaluation and tables of soil and climate requirements for wheat production in the geographic information system (GIS), this study aims to evaluate the appropriateness of qualitative land suitability for the current and future production of dry land wheat in Shir Dar Kola watershed. The results indicated that the watershed’s climate, soil moisture regime, and soil hydrology, as the most important criteria for land suitability, and limiting features like rocky outcrops, steeps and slopes, and water erosion are high. The information obtained in the assessment of the current land suitability show that 12% of the land area is suitable for dry land cultivation (S1), 15% is moderately suitable (S2) and 73% is unsuitable (N2). For any future planning 19% of the land area were diagnosed to be suitable for dry land cultivation (S1), while 8% had average suitability (S2) and 73% were unsuitable (N2). The findings also show that the mountainous terrain has the ability to be used as pasture. Despite being mountainous the hills have the availability be become pastures as well. And all the upper terraced land has the potential for dry land and irrigated agriculture if the water supplies are provided.
Mousa Abedini; Mohammad Hossein Fathi
Volume 2, Issue 3 , January 2017, , Pages 99-120
Abstract
Flood is one of the most common natural worldwide hazards that causes enormous losses of life and property throughout the world. Therefore, the development of flood mapping forecast models is curial in decision making before the flood and for the after flood management. The aim of this study is to determine ...
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Flood is one of the most common natural worldwide hazards that causes enormous losses of life and property throughout the world. Therefore, the development of flood mapping forecast models is curial in decision making before the flood and for the after flood management. The aim of this study is to determine the flood hazard zones in the khiav Chai basin using the network analysis process. To implement this model in the area under study, various data such as rainfall, land use, slope-morphological characteristics such as convexity (profile curvature) convergence divergence slopes (plan curvature), steep slopes, vegetation index (NDVI), distance from major rivers and drainage network density were considered. The results obtained from the network Analyzer model shows the fact that more than 15 percent of the area affected by the floods with very high potential risk of occurrence are mainly located at the bottom of the basin. These levels are often less than 35% in slope, with low vegetation density profiles, converged areas with concave surfaces, and areas near rivers. Analysis of the final weights derived from the AHP in relation to flood risk shows that the slope of the geological formations operating by 0/99, and 0/822 value, have the highest impact and influence, regarding the high degree of control and influence they have on the amount of runoff and discharge of the surface area. The importance and influence of the SPI with 0/226 and 0/065 STI are of less important compared to other factors.
Ahmad Noheghar; Mohamad Kazemi; Seyyed Javad Ahamdi; Hamid Gholami; Rasool Mahdavi
Volume 4, Issue 10 , June 2017, , Pages 99-119
Abstract
Soil management is necessary in order to optimize utilization and decrease degradation. The present study aimed to measure the relative importance of the erosion rates and sediment yields of homogeneous units in land-uses and geological formations. Accordingly, Fargas, BLM models, and direct field measurements ...
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Soil management is necessary in order to optimize utilization and decrease degradation. The present study aimed to measure the relative importance of the erosion rates and sediment yields of homogeneous units in land-uses and geological formations. Accordingly, Fargas, BLM models, and direct field measurements of soil erosion were used. Then, the degree of homogeneous units' erosion on the map of land use and geology formation were extracted. In addition, the amount of the sediment caused by surface erosion, rill, and gully was measured. The total mean of sediments per land use and the geology information were measured. The areas including the participation of each of the produced sediments were also found. The results revealed that the highest amount of the sediment deposits in basin were for the range lands called B S33R42G21, C S34R43G32, and D S34R43G32 with the mean of 38.73(ton/ha) and for the Razak Information called C S43R42G21 and D s44R43G32 with the mean of 17.83(ton/ha). The highest amount of sediment deposits were also for the rangelands and Asmari formation, respectively, with the means of 64.9% and 55.43%. Bakhtyari formation and cultivation, in contrast, had the lowest relative importance in sediment yield of the Tange Bostanak watershed.
maryam khosravian; AliReza Entezari; Abolfazl Rahmani; Mohmmad Baaghide
Volume 4, Issue 13 , March 2018, , Pages 99-120
Abstract
Expanded Abstract
Introduction
It is very difficult and costly to collect information about the continuous changes of vegetation by conventional methods. With the development of the satellite technology, the satellite imagery has provided extensive access to information about ground sources. The detection ...
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Expanded Abstract
Introduction
It is very difficult and costly to collect information about the continuous changes of vegetation by conventional methods. With the development of the satellite technology, the satellite imagery has provided extensive access to information about ground sources. The detection of changes is one of the main factors in the study of the relationship between human activities and the environment. Most remote sensing products are used to evaluate and estimate the bio facial and biochemical parameters of plants from broad bands such as NOAA, AVHRR, SPOT, and TM / ETM. Landsat sensors often consist of three to seven bands. Vegetation indicators are mathematical transformations that are defined based on different gauges of the sensors and designed to evaluate and investigate plants in multi-spectral satellite observations. Lake Parishan Basin is located in Fars Province (Kazeroun city). In recent years, many environmental and human factors have had an adverse effect on its ecosystem. The interference of the agricultural lands with the marginal lands of this lake, the disposal of chemical fertilizers, the flow of pesticides from plant pests to the lake, burning of grasslands, and bogs of the surrounding countryside by profitable individuals in order to expand agricultural lands, are factors that affect its ecosystem. The purpose of this study was to investigate Lake level changes between the years 1989 and 2004.
Materials and Methods
Lake Parishan Basin is located in the geographic coordinates of 29˚ 25ˊ 12˝ to 29˚ 36ˊ 15˝ north latitude and 51˚ 40ˊ 50˝ to 51˚ 48ˊ 20˝ east longitude in Kazeroon, Fars Province. In this study, multispectral sensor data was used to investigate the changes in the lake level. Landsat ETM + 1: 50000 satellite and digital elevation data were used to carry out atmospheric and geometric corrections on satellite data. The Satellite data was interpreted and processed in ENVI 4.1 software and performed in ARC GIS 9.3 Cartographic Mapping Software. The datasets of this study were from Landsat satellite imagery of 1989 and 2004. There has been a very intense occurrence since 2004. The process of drying the lake so that nothing remains in 2007 can be checked using remote sensing techniques. The data processing process was carried out in three stages of pre-processing, processing, and post-processing. Regarding the necessity of geometric correction in detecting water level changes, the topographic maps of 1: 50000 and GPS-controlled points were collected. Using the reference grounding function in the PCI-Geomatica software environment on each image, the control points were made. The pixels were re-evaluated using the nearest neighbor method. In addition, images with an error of 0.39 and 0.42 RMS were correlated.
Results and Discussion
Different indices (SAVI), (NDWI), (NDMI), (MNDWI), (NDVI), and (AWEI) were separately extracted in order to identify distorted lake changes in the period of 1989-2008.The detection and identification of water level was done to study the relevant indicators of water level changes. The level of lake changes between the years 1989 and 2004 was evaluated and extracted in various indices. In addition, an algorithm was designed in ENVI software environment. The results showed that it was incapable of extracting the surface water of the lake. The NDMI index (with the lowest overall accuracy and kappa coefficient) was also considered due to its excessive sensitivity to blue areas.
Conclusion
The changes in the water level of the distressed lake using vegetation and water indices during the period of 1984-2008 were investigated. The results of this study showed that the normalized dispersion index (NDMI) with the lowest overall accuracy and kappa coefficient was unable to extract water from the surface, while the NDWI had the highest accuracy for the extraction of lake water level changes. Accordingly, the Normed Water Difference Index (NDWI) was used to model the spatial and temporal changes in the level of the disturbing lake in the period of 1989-2008. The results of this study also indicated that the decline in the lake water level between 2000 and 2004 was 19,160 m2. Moreover, the decline between 1989 and 1991 and between 1991 and 2000 were respectively 1344010 m2 and 1313000 m2. It was also estimated that the total changes in the water level of the lake amounted to 1494470 m2 between 1989 and 2004.
Sharam Roostaei; Davood Mikhtari; Zahra Hosseini; Mahdi Etmani Hagviran
Volume 2, Issue 4 , January 2017, , Pages 101-123
Abstract
Shahram Roostaei[1]* Davood Mokhtari[2] Zahra Hosseini[3] Mahdi Etmani Hagviran[4] Abstract The management of natural disasters requires locational information in order for prepareness against riske and perils and to decrease them. In this regard it is necessary to eualuate the occurance potential of ...
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Shahram Roostaei[1]* Davood Mokhtari[2] Zahra Hosseini[3] Mahdi Etmani Hagviran[4] Abstract The management of natural disasters requires locational information in order for prepareness against riske and perils and to decrease them. In this regard it is necessary to eualuate the occurance potential of land slides in region which is suseptable for landsliding due to its geographic situation and human construction operations. The case study locates in Dehloran city of Ilam provience in Zarinabad district with 33· 1΄ 30΄ to 33· 19΄ northern latitude. Mimeh river catchment because of having a particular Lithologic ,climate and land use conditions,enjoys young (new) roughness with high altitude variations and sensitive steep slops. On the other hand, human interferences has been increased in this region,therefor,more studies become a necessity. In the study of landslide occurances in the area of Mimeh river catchment,network analysis process (ANP) was applied. In this research some indicators like slop,slop side, lithology, land use, raining,distance form the river, distance form the road and levations were applied in order to determine prone areas. Methods based Analysis of standards in software Super Decision criteria in overlapping layers of information and then integrating the software ARCGIS and, network analysis process(ANP) and the overlap index. The findings showed that ANP has 81/69proportionate with transmittal map of landslides, also coefficients interpretation proved that raining, lithology,and elevation indicators play significant role in landslide. [1]-Professor; Faculty of Geomophology; University of Tabriz (Corresponding author), Email:tabrizu.ac.ir@roostaei. [2]- Associate Prof.; Faculty of Geomorphology; University of Tabriz. [3]- M.A Student; Faculty of Geomorphology; University of Tabriz. [4]- M.A Student; Faculty of Geomorphology; University of Tabriz.
Saeed Jahanbakhsh Asl; Yaghoub Dinpajouh; Mohammad Hossein Alinejad
Volume 2, Issue 5 , January 2017, , Pages 101-117
Abstract
Saeed Jahanbakhsh Asl[1] Yaghoub Dinpajouh[2] Mohammad Hossein Aalinejad[3]* Abstract In this study for the purpose of simulation of runoff originated from snowmelt in Shahrchay River basin two models namely SRM and HEC-HMS were used. For this purpose, entering the snow cover data, meteorological ...
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Saeed Jahanbakhsh Asl[1] Yaghoub Dinpajouh[2] Mohammad Hossein Aalinejad[3]* Abstract In this study for the purpose of simulation of runoff originated from snowmelt in Shahrchay River basin two models namely SRM and HEC-HMS were used. For this purpose, entering the snow cover data, meteorological variables and other needed parameters an input to SRM model the runoff from snowmelt was simulate. In HEC-HMS model, after derivation of watershed model using the HEC-GEOHMS software in GIS environment and derivation of meteorology model and entering the required parameters such as water losses, flow routing and snow melt was simulated. The coefficient of determination (R2) of SRM model was 0.9 and the percentage of volumetric error (DV) was equal to 1.96. On the other hand, the HEC-HMS model simulated snowmelt runoff was satisfactory (but less than SRM), so that the R2 and DV obtained for this model were as equal to 0.85 and 2.1%, respectively. Utilization of air temperature and precipitation data (neglecting the high accuracy of SRM) can be considered as advantages of HEC-HMS. In contrast, in SRM model in the snow covered area of region apart from the mentioned parameters satellite images of the region is also required. Results indicated that the total volume of runoff in the study area was 129.9×106 cubic meters for SRM, whereas it was 129.6×106 cubic meters for HEC-HMS. Comparing these values with that of the observed (i.e.134.4×106 m3) it can be concluded that SRM model performance is relatively better than the HEC-HMS. [1]- Professor, Department of Meteorological, the University of Tabriz. [2]- Associate Professor of Water Engineering, the University of Tabriz. [3]- M.A. student in Meteorological, the University of Tabriz (Corresponding author), Email:aalineghad63@yahoo.com.
Saeed Jahanbakhsh Asl; Majid Rezaee Banafshe; Hashem Rostamzadeh; Mohammad Hossein Aalinejad
Volume 5, Issue 16 , December 2018, , Pages 101-118
Abstract
Abstract
Introduction
Continuous simulation of rainfall-runoff is very important in many hydrological studies, including the effect of climate change on river flow, flood forecasting, and water resource planning. This phenomenon requires the identification of its components and formative variables. ...
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Abstract
Introduction
Continuous simulation of rainfall-runoff is very important in many hydrological studies, including the effect of climate change on river flow, flood forecasting, and water resource planning. This phenomenon requires the identification of its components and formative variables. One of the most important hydrological calculations for a basin is the determination of the relationship between rainfall and runoff. The amount of water conversion from rainfall to runoff volume depends on the climatic and the physical parameters of the basin. In the hydrological calculations of a basin, determining the relationship between rainfall and runoff is very important. Accurate calculation of precipitation and runoff at the basin level depends on the identification of its components, form-providing variables, and the use of an appropriate dependent model. The HEC-HMS software is a simulation-based hydrologic modeling software (with parameter optimization capability) developed by the US Army Hydrological Engineering Center whose first edition was presented in 1967 (Hydrologic Engineering Center, 2000: 4). In addition, in order to increase the accuracy of the input information entering into the HEC-HMS software, the HEC-GeoHMS has created an add-on called HEC-GeoHMS. One of the most important applications of this software is calibrating and estimating hydrological parameters in catchment areas. Due to the importance and the extent of using this software, many studies have been done.
Methodology
The catchment area of the city of Uremia is located in the western part of Lake Urmia. Its approximate area is 167.75 km2 and its geographical location is between 82 ° 44 'and 58 ° 44' eastern longitude and 32 ° 37 'to 48 ° 37' northern latitude. The height of the altimeter station is 1591 m and the maximum height of the basin (located on the border between Iran and Turkey) is 3574 m. Figure 1 shows the location of the Urmia Shahirchay basin in the watersheds of Iran and Lake Urmia. In this study, the HEC-HMS model was used to simulate surface runoff. In addition, the HEC-GEOHMS integration was used to map the basin model. For this purpose, the data of the temperature and the precipitation data of the synoptic station of Urmia and the daily flow rate of the river flow at the hydrometric station of the Bardesour (located at the outlet of the basin) were used.
Result
By obtaining the basin model by the HEC-GEOHMS add-on in ARCGIS software and creating climatological models, controlling and entering other necessary parameters of the model was implemented. In simulation of rainfall-runoff of Chacha basin by HEC-HMS model, in the period of 2004-2013, the best calibration and validation period was selected to minimize simulation error. The base course was divided into two calibration (2004-2010) and validation (2010-2013) periods. The calculation of this parameter is necessary for simulation in mountainous basins, which are mostly snowfall. In this study, the temperature index method, one of the complementary methods of day-to-day modeling of snow modeling, was used. One particular way is to consider the specific amount of snow melting for any temperature above freezing point. For this purpose, the catchment area was divided into altitudinal classes and the percentage of area of each sub-basin in each altitude region was introduced into the model.
Discussion and Conclusion
Based on the results of the simulation in the calibration and validation periods, as well as the evaluation criteria of the model, it was found that the HEC-HMS model had a high probability in rainfall-runoff simulation of Shahrchay basin. It should be noted that the use of the HEC-GEOHMS in the design of the basin model has played a large role in increasing its accuracy in rainfall-runoff simulation. In Yacoby's (2013) study, the accuracy of this model in the simulation of runoff was weaker than other models. It was probably due to not using the HEC-GEOHMS add-on and the lack of a synoptic station in the study area. Nevertheless, in other studies (e.g., Verenden et al., 2013; Borhani Daryan et al., 2016), the HECGEO-HMS add-on was a good result of the model's work, which is consistent with the current study. The results of this study indicate the ability of the HEC-HMS model to simulate the hydrologic behavior of the Chacha basin. In addition, the ability to use the GIS to accurately provide input for the model and view the output shows the efficiency of their integration. The present integration, with proper hydrometric data and precipitation, is able to accurately simulate rainfall-runoff phenomena.
