Hydrology
Mohammad AKBARINASAB; Faezeh Abbasi; Nadia Talebpour
Abstract
Floods play an important role in the flow of rivers, so their investigation and analysis are importance. Studying the dynamics of floods and the water discharged into the sea (plume) is very important in the fields of fisheries, sedimentation, transportation and environment. Babolrud-River originates ...
Read More
Floods play an important role in the flow of rivers, so their investigation and analysis are importance. Studying the dynamics of floods and the water discharged into the sea (plume) is very important in the fields of fisheries, sedimentation, transportation and environment. Babolrud-River originates from the south of Babol city and flows into the Caspian-Sea after traveling about 67 kilometers. In this research, the expansion of the plume entering from the Babolrud-River to the Caspian Sea during the spring flood of 2018 has been investigated. For this purpose, firstly the images of Sentinel-2 satellite were taken, then the required pre-processing including geometric and radiometric correction was applied. According to the spectral behavior of muddy and clear waters, in the spectral range of wavelengths of 0.4 to 0.78 micrometers, this phenomenon can be distinguished. As a result, by using this feature and the optimal index factor (OIF), the best color combination with the largest information was detected. The combination bands of 3, 4 and 8, with the OIF of 0.19, was defined as the best band combination. In the next step, NDVI, NDFI, and MNDWI were applied, and thresholds were applied to the defined indices for better separation of muddy and clear waters. These thresholds were identified by drawing spectral profiles at the plume of river and checking their histograms. Finally, by building the decision tree with all these indicators and applying the thresholds, the amount of muddy water from the flood entering the Caspian Sea from the Babolrud-River was revealed.
Ziba Kounani; Alireza Ildoromi; hossien zenivand; Hamid Nouri
Abstract
1-Introduction Due to the importance of climate change and the effects it can have on runoff, developing a suitable model for simulating the present and future conditions of the catchment areas is of great importance (Rajabi et al, 2012). Nowadays, the LARS-WG and SDSM models are used to downscale environmental ...
Read More
1-Introduction Due to the importance of climate change and the effects it can have on runoff, developing a suitable model for simulating the present and future conditions of the catchment areas is of great importance (Rajabi et al, 2012). Nowadays, the LARS-WG and SDSM models are used to downscale environmental parameters in climate change studies nowadays. Studies show that the SDSM model has less uncertainty and a more complex simulation process, and the LARS-WG model with simpler process and faster performance is more efficient (Aghashahi et al., 2012). Considering that many of Iran's watersheds lack hydrometric stations, it is of great importance to use those methods that can estimate the amount of runoff obtained from the rainfall. Therefore, the present study aimed to investigate the role of climate change in estimating runoff from the Silakhor-Rahimabad basin of Lorestan using a rainfall-runoff model (SIMHYD). 2-Methodology Silakhor-Rahimabad basin is in the catchment area of Dez Dam in Borujerd, Lorestan Province, which is located between N 33º 45¢ and 34º 7¢ and E 48º 29¢ and 48º 57¢. First, the baseline data including observation data of minimum temperature, maximum temperature, precipitation and sunshine during the period 1990-2014, and rainfall-runoff data including evaporation, rainfall and flow data, which were available, were received from the General Department of Aerology and Regional Water Authority of Lorestan Province, respectively. In this study, the daily data from Borujerd metrological synoptic station were used as the basis because they were complete and the elevation of the station was equal to the average of other stations’ elevations. For the evapotranspiration variable, the mean daily data from Rahimabad, Borujerd, and Silakhor stations were used, the mean daily data from the six rain-sensing stations for the rainfall variable. Moreover, Rahimabad hydrometric station at the outlet was used as the base station to observe the runoff variation in the basin. 3-Results and Discussion The results of the evaluation of criteria show that the LARS-WG model has a good ability to simulate rainfall parameters, minimum temperature, and maximum station. The simulated precipitation is in good agreement with the observed values (Table 1 and 2). After assuring the ability of the LARS-WG model to produce the rainfall data, minimum and maximum temperatures of Silakhor-Rahimabad Basin, the output of the HADCM3 model was downscaled under the scenarios A2 and B1, the parameters were predicted and compared with their values in the period 1990-2014 (Figures 2, 3 and 4). The results of the LARS-WG model indicate a decreasing trend of precipitation and temperature rise under both scenarios A2 and B1 for the period 2046-2065. The average amounts of annual rainfall predicted under the scenarios A2 and B1 are 451.445 and 4.420 mm, respectively. If the annual rainfall is 453.8 mm in the base period, the study area will observe a decrease in precipitation from 51.0 to 20.7 percent. The results obtained in the SDSM model under the two climate scenarios A2 and B2 for the future period indicate that the average air temperature is increasing and in the period 2050, the monthly average temperature, compared to the 1990-2014 period, increases in most months of the year. Also, rainfall has a decreasing trend in this period (Figure 5). Investigations show that the model efficiency has a direct correlation with the recharge coefficient, infiltration coefficient and soil moisture storage capacity. The effects of climate change on runoff are presented in Figures 9-16. In the period 2046-2065, the amount of runoff in the studied basin will decrease compared to the 1990-2014 period. This decrease in runoff rate can be attributed to the increase in temperature, followed by an increase in evaporation and a decrease in rainfall. Regarding the study of temperature and rainfall for the future period and monthly runoff, it is observed that the amount of runoff will decrease in the future period. 4-Conclusion In recent decades, the increase in greenhouse gases and thereby, the rise in temperature, have made Earth’s climate system imbalanced and caused massive climate change in most parts of the planet. Therefore, it seems necessary to apply climate predictions in national macro plans, especially in relation to natural disasters. The results indicate the decrease in precipitation and temperature rise in both SDSM and LARS-WG models. Also, in the present study, the SDSM model showed more variations than the LARS-WG model. Finally, the results obtained in both statistical downscaling models indicate the decreased amount of runoff in the studied basin is in the future period. In the study of the effect of climate change on runoff in the studied area, according to the values of Nash-Sutcliff coefficient and the coefficient of determination obtained at the calibration step (0.63 and 0.779, respectively) and the verification step (0.61 and 0.61, respectively), it is observed that the SIMHYD model has acceptable performance in the studied basin. These results are consistent with the findings of Aghashahi et al. (2012), Rajabi et al. (2013), Zolgharnein et al. (2013), Zhang et al. (2014).
Geomorphology
Amirhosein Ghorbani; Raoof Mostafazadeh; Mohsen Zabihi; Masoud Jafari Roodsari
Abstract
Landslide, as an important natural hazards, causes damage to infrastructure and leads to economic, social and human losses. In this regard, determining the critical zones of landslides occurrence can be used in planning for damage reduction. The aim of the current research is analyzing and identifying ...
Read More
Landslide, as an important natural hazards, causes damage to infrastructure and leads to economic, social and human losses. In this regard, determining the critical zones of landslides occurrence can be used in planning for damage reduction. The aim of the current research is analyzing and identifying landslide hot spots using Getis-Ord algorithm in Gharnaveh watershed, Golestan province. Therefore, the frequency and characteristics of landslides has been analyzed in different classes of slope, aspect, soil and land uses. The area, length, width, depth and height of the precipice of landslide features have been considered as the basis in hot spot analysis. The results showed that the landslide hot spots are located in the eastern part of the study area, which includes high altitude classes, rangelands and moderate slopes. Results showed that the rangeland and forest land uses, loess soils and 50-75% slope class and the northern aspect had the highest number of landslides. Also, the non-significant landslide points using the Getis-Ord method and considering landslide area criterion located in the middle and downstream of Gharnaveh watershed. Determining the landslide hotspots and affecting factors through the spatial analysis in GIS provides the defining thresholds in the landslide’s occurrence. The analysis of the landslide hotspots can be a basis for spatial planning, and risk reduction. The implemented approach can be used in the evaluation of the spatial autocorrelation of natural hazards, and in combination with the areas prone to multiple environmental hazards can predict the risk and severity of damages in the future.
Groundwater
sayyad Asghari Saraskanrood; Maryam Riahinia
Abstract
Today, due to population increase, industrial development, excessive exploitation, droughts, exploitation of underground water has multiplied. Therefore, identifying areas with underground water as one of the important sources for providing drinking water, agriculture, and various industries is considered ...
Read More
Today, due to population increase, industrial development, excessive exploitation, droughts, exploitation of underground water has multiplied. Therefore, identifying areas with underground water as one of the important sources for providing drinking water, agriculture, and various industries is considered to be one of the important and necessary issues in water resources management. The purpose of this research is to investigate and zonate the areas with underground water in Khorram Abad plain located in Lorestan province using convolutional neural network method. For this purpose, maps of nine factors affecting underground water were first prepared in the ArcGist environment. In the convolution method, the number of samples was determined as the ratio between the training set and the test set was 70:30, and the convolution neural network framework was used as 2 convolution layers and 2 integration layers, 2 complete connections. layers and finally the sigmoid layer was used for classification from the 3-3 convolution kernel, the Relu function as the activation function and the cross entropy function as the loss function. The obtained maps were classified into 5 classes: very good, good, average, low and very low. Confusion matrix was also used to validate the results of the model. 30% of the real data was used for evaluation, which resulted in an overall accuracy of 92%, that is, the model was able to correctly identify 92% of the data as underground water and 93% as the absence of underground water. The analysis of the groundwater potential map of the convolutional neural network model shows that about 57% of the area is in low groundwater conditions and 43% of the area is in good groundwater conditions.
Hassan Khavarian; Maryam Aghaie; Raoof Mostafazadeh
Abstract
1-IntroductionLand use change has significant effects on hydrological and ecological processes at different temporal and spatial scales. Many hydrological models have been developed based on the characteristics of the basin, available data and purpose of the study. To predict the characteristics of river ...
Read More
1-IntroductionLand use change has significant effects on hydrological and ecological processes at different temporal and spatial scales. Many hydrological models have been developed based on the characteristics of the basin, available data and purpose of the study. To predict the characteristics of river flow, we need to develop the rainfall-runoff model to predict the flow for a long period of time. This study has been carried out for the modeling of monthly runoff using Temez model and then the effects of the different land use change scenarios on runoff components have been assessed.2-MethodologyIn this study the OLI-Landsat 8 satellite imageries, a digital elevation model (DEM) as well as meteorological and hydrological data were used for the modelling purpose. The land use classification was carried out using a support vector machine (SVM) method to create a map with 6 land use classes: dry farming, forest land, water body, pasture, built-up and irrigated agriculture. Then, the 10 management scenarios have been developed based on the field observations and taking into account the field characteristics, changes trend in the land use pattern, and the suitability of the study area for different land uses. In order to simulate the runoff, the Temez monthly hydrological model was employed. A 10-year (2002 to 2012) daily precipitation, temperature and runoff data were aggregated to monthly time scales. The calibration and validation steps were performed based on observed data. For calibration of the model, the first 6 years data and for model validation 4 years data were used. The parameters of the Temez model were calibrated based on the values obtained from the literature. First, the appropriate coefficients were found for each land use in the watershed and then the area of land uses in all scenarios were computed. Finally, the weighted average was calculated for the coefficients and appointment in Temez model. 3-Results and DiscussionThe accuracy of the land use map was quite high. A Kappa coefficient of 0.95 and an overall accuracy of 0.975 was obtained. The accuracy of the modeled runoff was presented using R2 coefficient, which was 0.77 and 0.65, for calibration and validation stages, respectively. The results of considering the land use change scenarios on the monthly runoff showed that land use reclamation scenarios of 3, 4 and 5 had a decreasing effect on the runoff by 3.4, 3.3, and 4.1 percent, respectively. Also the land use scenarios of degradation condition, 9 and 10 scenarios, caused an increasing effect on the monthly runoff to 15.24 and 4.5 percent, respectively.4- ConclusionThe monthly hydrological Temez model showed relatively good performance in estimating monthly runoff values based on the data used. The results can be considered in predicting the development and degradation conditions in the study area. Keywords: Land Reclamation, Land Degradation, Kouzehtopraghi Watershed, Land use Change Scenario, Monthly Runoff Feature, Temez Model5-ReferencesArceo, M.G.A.S., Cruz, R.V.O., TiburanJr, C.L., & Balatibat, J.B (2018). Modelling the hydrologic responses to land cover and climate changes of selected watershed in the Philippines using soil and water assessment tool (SWAT) model, DLSU Business & Economics Review, 28, 84-101.Andrade Abe, C., Lucialobo, F.O., Berhan Dibike, Y., Farias Costa, M.P.D., Dos Santos, V., & L.M Novo, E.M (2019). Modelling the effects of historical and future land cover changes on the hydrology of an Amazonian basin, Water, 10(932), 1-19.Feki, M. R., G. Gepple, A. Mille, G. Mancini, M (2018), Impact of infiltration process modelling on soil moisture content simulations for irrigation management, Water, 10(850), 1-20.Garg, V., Nikam, B.R., Thakur, P.K., Aggarwal, S.P., Gupta, P.K., & Srivastav, S.K. (2019). Human-induced land use land cover change and its impact on hydrology, HydroResearch, 1, 48-56.Gumindoga, W., Rwasoka, D.T., Ncube, N., Kaseke, E., & Dube, T (2018). Effect of land cover/land-use changes on water availability in around Ruti dam in Nyazvidzi catchment, Zimbabwe, Water, 44(1), 136-145.Hyandye, C.B. Worqul, A., Martz, L.W., & Muzuka, A.N.N. (2018). The impact of future climate and land use/cover change on water resources in the Ndembera watershed and their mitigation and adaptation strategies, Environmental System Research, 7(7), 1-24.Jain, S.K. (1993). Calibration of conceptual models for rainfall-runoff simulation, Hydrological Sciences Journal, 38(5), 431-441.Onate-Valdivieso, F., Bosque-Sendra, J., Sastre-Merline, A., & Ponce, V.M. (2016). Calibration, validation and evaluation of a lumped hydrologic model in a montain area in Southern Ecuador, Agrociencia, 50(8), 945-963.Temez, J.R (1977(. Modelo matematico de transformacion. Precipitacion. Aportacion. Asociacion de Investigacion Industrial Electrica ASINEL, 1-10.
Mohammad Hossein Rezaei Moghaddam; Davoud Mokhtari; Majid Shafieimehr
Abstract
Floods are one of the most common natural hazards, causing significant loss of life and property each year. The purpose of this study is to determine the risk areas of floods in Shahr Chai Miyaneh watershed. To implement this model, different layers such as slope, aspect, elevation, distance from river, ...
Read More
Floods are one of the most common natural hazards, causing significant loss of life and property each year. The purpose of this study is to determine the risk areas of floods in Shahr Chai Miyaneh watershed. To implement this model, different layers such as slope, aspect, elevation, distance from river, river density, land use, vegetation, lithology, rainfall and soil were used. The final analysis and modeling was performed using the Vikor model. The results showed that rainfall, slope and distance from the river have the greatest impact on the occurrence of floods in this watershed. Also, according to the obtained results, 5.2 and 1021.7 square kilometers, respectively, are located in a very high-risk and high-risk area. Dangerous and very dangerous areas are mainly located along the main river and mountainous in the steep logic. Due to the high slope and height of the region, it plays an effective role in the amount of runoff and flow peak floods. Also, in the catchment area of Miyaneh Chai city, 2.2, 27.2, 1099.6, 1021.7 and 10.2 square kilometers, respectively, are in a very low risk, low risk, medium, high risk and very high risk area.
Mojtaba Yamani; Hamid Ganjaeian; Lila Garoso; Mahnaz Javedan
Abstract
1-Introduction Today, geomorphic studies are considered as the base of studies on natural resources. Recognizing the processes and active mechanisms on these landforms and their characteristics, as well as understanding the type of use of these units in using the natural environment and sustainable development ...
Read More
1-Introduction Today, geomorphic studies are considered as the base of studies on natural resources. Recognizing the processes and active mechanisms on these landforms and their characteristics, as well as understanding the type of use of these units in using the natural environment and sustainable development is important. Many of Iranian towns and villages are on plains and alluvialfans and as a result, exploitation of the plains has become diverse and growing; but there are problems and limitations in the use of these areas. For a successful farming, consideration of climatic and environmental conditions is of tremendous importance. Therefore, the designation of geomorphic units is a suitable method for detailed studies of natural resources planning and management and environmental hazards. According to some experts, the assessment of environmental power is an instrument for identifying a land for activities such as agriculture and forestry (Quang minh et al, 2003). The agricultural sector of Sanandaj Province is especially important among the economic sectors of the province since in terms of production and employment, it is ranked second after the services sector. The geographical and climatic conditions and abundant water resources provide the potential benefits of agricultural production in the city. In recent years, with the adoption of new software and hardware methods, many efforts have been made to determine the capability and management of land leading to fruitful results. 2-Methodology The purpose of this study is to assess land suitability for agricultural activities in Sanandaj based on hydrogeomorphological parameters. To this end, the research method is based on descriptive-analytic methods. Research data includes statistical information (information on the status of groundwater and climate parameters), information layers, information extracted from satellite imagery (land use), as well as library information. Software used in the research includes ARCGIS (providing information layers, fuzzy, final output), IDRISI (implementation of the OWA model), Google Earth (validation of results), and SuperDecisione (weighting to criteria). The data layers of this research are soil, land type, geology, slope, altitude, precipitation, river, temperature, groundwater status, and groundwater chemical quality. Since the value and importance of the parameters are not the same for the desired purposes, the parameters were evaluated using expert opinion (5 geomorphic experts) by the ANP method and fuzzy by using the fuzzy function in ArcGIS software. Afterwards, standardized layers are entered into the IDRISI software and then combined with the ANP model using the OWA model based on the obtained values. Finally, the final map is made. After drawing up the final map to verify the results, 50 random samples were used to validate the result. 3-Results and Discussion In this research, ten parameters have been used for the development of agricultural lands in Sanandaj. The parameters are assigned in three clusters: Geomorphologic parameters (elevation, slope and geomorphology units), hydroclamite (river, underground water, chemical water quality, temperature and precipitation), and land cover (soil and lithology). In this research, after providing information layers, these layers are standardized using ARCGIS software. The geomorphological parameters are standardized in such a way that the altitude, the lower height means that the pixel is worth more And also in terms of slope, areas with a lower slope are worth more. In terms of geomorphology units, the lake and mountain units are of the lowest value. In terms of hydro-climatic parameters, regions with higher rainfall and temperatures near the river have lower groundwater depths and areas with lower EC values are of higher value. In addition, the areas with inspetisol are of higher value and lithologically, the areas with alluvial lithology are more valuable. The value of the criteria was then calculated using the ANP model. Finally, the obtained value was applied to the layers and in the end, using the OWA model, the final map is obtained. 4- Conclusion(S) Since agriculture makes a major contribution to the economy of Sanandaj, and given the great potential of the city in terms of water resources, it is necessary to make proper planning and location in this area. In the present study, according to studies conducted and hydrogeomorphological survey related to the study area regarding zoning the area for the development of agricultural lands, it has been attempted to identify suitable areas for the desired purposes. The results of zoning using integrated network analysis and sequential weighted averaging model have been verified using integrated network analysis model and random sampling method is verified. The confirmed results indicate that the final map has 86 percent accuracy. The results of the present study indicate that the major part of Sanandaj does not have the proper level of agricultural activities so 1587 km2 of the city area is in the inappropriate class and the relatively suitable and suitable class area is 801 and 579 square kilometers, respectively. According to the results, about 53% of Sanandaj area is not suitable for agricultural activities, especially for water crops.
hydrogeology
Mahshid Moavi; heeva elmizadeh
Abstract
From the point of view of fractal behaviors, the property of replication over time creates patterns in the bed of the basin that show unique performance during the maturity of a basin, depending on the reproductive characteristics and how they change. For this reason, in this study, investigates the ...
Read More
From the point of view of fractal behaviors, the property of replication over time creates patterns in the bed of the basin that show unique performance during the maturity of a basin, depending on the reproductive characteristics and how they change. For this reason, in this study, investigates the bifurcations of drainage networks of the Ramhormoz basin using Tokunaga model and fractal dimension correlation, has been done. Ramhormoz River is one of the sub-basins of Jarahi basin located in the southwest of the country. This river originates from 50 km southeast of Izeh and flows to the southwest. In this study, river networks were extracted from Arc GIS software, and then input data were entered into the software to calculate two-dimensional fractal numbers using correlation function. In this regard, first Ramhormoz basin is divided into eastern and western parts and then using the Tokonaga method, irregular network and curve of Ramhormoz river are drawn in a regular, geometric and corresponding tree form. According to the length of the streams, the fractal dimension was calculated for both parts of the Ramhormoz basin. The fractal dimension of the correlation between the Ramhormoz basin and its eastern and western parts has been calculated between (1.42 to 1.68) with a high correlation coefficient, which indicates a relatively high turbulent behavior of the basin and its parts. The calculated fractal dimension represents the average bifurcation ratio and the short time to reach a constant flow.
Mehdi Hayatzadeh; Sahar Amini; Ali Fathzadeh; Maryam Asadi
Hydrogeomorphology
ahad habibzadeh; Massoud Goodarzi; Malek Rafiei
Abstract
1-IntroductionThe common method of supplying water for agricultural purposes is flood irrigation used in semi-dry areas from past times. Flood utilization has long been one of the common water supply methods among farmers in dry areas of the world due to inaccessibility to sustainable surface or underground ...
Read More
1-IntroductionThe common method of supplying water for agricultural purposes is flood irrigation used in semi-dry areas from past times. Flood utilization has long been one of the common water supply methods among farmers in dry areas of the world due to inaccessibility to sustainable surface or underground water resources. In North America, Indians have used simple flood irrigation methods for centuries (Hudson, 1975). The studied area is located at 110km from the center of the province, north of Uremia Lake and the drainage basin surrounding Tasoj city at 45°18' to 45°33' eastern longitude 38°20' to 38°24' northern latitude. The area includes ten sub-basins overlooking the city of Tasuj and the villages of Angashtjan and Amstajan, and its area is 9616.79 ha. The average height of the area is 1700m with an average rain of 271mm in 20 years and an average annual temperature of 13.4°C. The region is climatically affected by polar air from the north, polar sea from the northwest, tropical climate from the south. The region's climate is cold semi-arid, and the rainfall regime is in the Mediterranean. The main feature of this regime is intense rainfall, spring rainfalls, and intense snowing in winters, along with several months of drought in summer and late spring. The land use of this region includes farming gardens 938ha, irrigated aquaculture 2050ha, and dry farming 420ha. The cultivation pattern of farms and gardens mostly includes apple, walnut, Elaeagnus Angustifolia, almond, cherries and alfalfa, wheat, barley, and chickpeas that are the farming lands with aridity problems. Angoshtjan and Amstejan ponds and watersheds have two U.R.F upper Miocene geologic formations and the equivalent formations of Qom with marl, limestone, and sandstone deposits that produce high sedimentary floods (Habibzadeh, 2018). One of the main objectives of flood distribution projects is the improvement of the status of natural resources in flooding plains on the alluvial fans of the outflow of the problematic watershed, the storage of precipitation, supply of underground sources, supply of required water for crop and farming, quantitative and qualitative changes of vegetation, changes in plant composition and increase of plants for feeding and increase of soil fertility. Lashanizand et al. (2010) studied the changes in surface water quality of Kashkan basin due to periods of water scarcity and watery and for this purpose, 12 parameters of water quality and discharge statistics of eight hydrometric stations in 30 years and concluded qualitative changes from The ascending and descending trends follow the periods of watery and aridity. The purpose of this study, while presenting a qualitative analytical method of floods, is to use floods in agricultural water supply in the agricultural plains north of Lake Urmia.2-MethodologyThe research project investigating the effects of incoming flood quality on flood spreading performance was carried out by the author to create model areas for flood exploitation for agriculture, promotion, and development of flood distribution systems in arid and semi-arid regions. Samplers were installed along the flood paths of the Angoshtjan and Amstejan sub-basins at the entrance of the plain and in three locations of impoundment system, above and below these systems with gages. After the installation of samplers, the flood sampling was done to this end, sampling was performed three times in 2011, two times in 2012 and one time in 2014; the number of samples to be taken was determined based on the flood discharge and the height of samplers and sent to the laboratory for analysis. The results related to the differentiation of the sampling location have been classified using Model and Wilcox diagram (Habibzadeh, 2017).3-Results and DiscussionThe main limitation in agriculture, especially in arid and semi-arid regions, is the supply of water needs. In such areas, water is the basis for planning for agricultural development. Every year, much water flows out of reach in the form of runoff or floods and causes much damage to agricultural lands, residential lands, and roads (Mesbah and Negahdar, 2015). According to the purpose of the research, it was necessary to prepare information about the amount of rainfall and floods in the region. For this purpose, the amount of flood extraction was calculated and collected based on 20-year statistics of rainfall and floods in the region. The average monthly rainfall and flood storage are shown in Table 1. Flood samples were sent to the laboratory for qualitative analysis during six floods over three years. Laboratory analyzes including salinity, acidity, anions, and flood cations were performed. The lowest salinity, or EC, is related to the flood of the Amstajan river with 345 μm /cm, and the highest is related to the flood of the Angoshtjan river with 799μm / cm. Table (1): Average monthly flood rate in Tasuj study catchments (2000-2020)MonthPrecipitationmmFlood storagem3Flood%April39.653054.039.1May51.751005.237.6June13.82875.02.1July6.4865.70.6August4.11432.71.1September9.328.60.0October11.72134.21.6November35.55432.14.0December25.40.00.0January14.20.00.0February28.20.00.0March29.618698.713.8 269.5135526.2100.04-Conclusions In this project, to access the 2.5 million m3 outflow flood of Amstejan and Angoshtjan villages, the qualitative analyses of flood samples have been done based on Wilcox, Piper, and Stiff hydro-chemical diagrams. The mean electric conductivity in Amstejan sub-basin floods is 350mho/cm, and for Angoshtjan, the sub-basin is 600 mho/cm. The floods have relatively alkali acidity or neutral. The highest values, 8.06 and 8.04, are related to the inflow flood of the reservoir of flood collection. The quality of floods in terms of irrigation water classification of Wilcox method, where salinity and sodium rate are the most important criteria, is mostly in the C2S1 area. In terms of classification of irrigation water, C2, water with medium salinity that can be used for plants with medium tolerance to salinity, S1 is low sodium water which is good for irrigation of all types of soils and is not risky; therefore, they are good waters for agricultural purposes.
Mohammad Hossein Rezaei Moghaddam; asadollah hejazi; Mehdi Mezbani
Abstract
In this study, in order to identify the spatial distribution of soil erosion and sediment production in Sarab Sikan basin, the RUSLE model, GIS and remote sensing technology are used. First, using meteorological data, soil and digital elevation model with a size of 10 meters, each of the factors of erosion ...
Read More
In this study, in order to identify the spatial distribution of soil erosion and sediment production in Sarab Sikan basin, the RUSLE model, GIS and remote sensing technology are used. First, using meteorological data, soil and digital elevation model with a size of 10 meters, each of the factors of erosion erosivity (R), erodibility (K), slope and slope length (LS) and soil protection (P) in the Arc GIS was calculated in Arc GIS. Sentine2 satellite sensor was also used to extract and prepare the vegetation factor of the basin (C) in ENVI 5.3 software environment. Finally, by combining these factors, the amount of basin erosion was calculated and the amount of sediment produced in the basin was obtained by different methods of sediment delivery ratio (SDR). The results showed that the amount of erosion in the basin is varies from 0.003 to 248.4 t ha-1y-1 and the average erosion in the basin is 22.3 t ha-1y-1. Among the model factors, LS factor with a correlation coefficient of R2 = 0.92 showed the highest share in soil erosion. Also, the SDR ratio was calculated by different methods between 0.12 and 0.36, which after combining with the erosion map, the sediment yield of the basin was estimated. The average sediment yield by Boise method is 2.8 t ha-1y-1, which is closer to the amount of station sediment with an average of 1.65 t ha-1y-1 compared to other methods.
Sayyad Asghari Saraskanrood; Mostafa Omidifar; Ehsan Ghale
Abstract
Identification of landforms and the way of their distribution is one of the basic needs in applied geomorphology and other environmental sciences and landform maps show the shapes of the earth's surface. This project aims to identify the landforms of the Qaranqu catchment area using object-oriented classification ...
Read More
Identification of landforms and the way of their distribution is one of the basic needs in applied geomorphology and other environmental sciences and landform maps show the shapes of the earth's surface. This project aims to identify the landforms of the Qaranqu catchment area using object-oriented classification methods including nearest neighbor algorithm and thresholding. Landsat satellite imagery for 1990 (TM) and 2020 (OLI) was used for this purpose. First, to apply the classification, atmospheric and radiometric corrections were applied to the images, then to better identify and extract the phenomena, principal component analysis (PCA), and MNF algorithms were used to classify satellite images using classification methods. Object-oriented, which included the nearest neighbor method and thresholding was used. For the accuracy of the maps produced using the two methods of Kappa index and the overall accuracy of the use, the results revealed that the nearest neighbor method is more accurate than the thresholding method. The classification results showed that the highest rate of decreasing changes during 1990-2020 is related to dense rangeland because it has decreased by 12.49 percent and the highest rate of incremental changes is related to irrigate agriculture which is 10.83 percent. The most important reason for this increase is the construction of Sahand Dam over time. In the absence of well-organized planning and the adoption of appropriate policies, the destruction of rangeland will continue and turning it into arable land, which leads to irreparable environmental and economic losses in the region.
Mohammad Hossein Rezaei Moghaddam; Davoud Mokhtari; Nasrin Samandar
Abstract
Land use change is one of the important factors in changing the hydrological flow, basin erosion and biodiversity destruction. Therefore, knowing the effect of land use change on discharge and suspended load is an inevitable necessity. The main purpose of this study is the efficiency test of the model ...
Read More
Land use change is one of the important factors in changing the hydrological flow, basin erosion and biodiversity destruction. Therefore, knowing the effect of land use change on discharge and suspended load is an inevitable necessity. The main purpose of this study is the efficiency test of the model and its usability as a simulation of the process of land use change on discharge and sediment is from the soil and water assessment model (SWAT) and SUFI2 program. Model simulation was performed for 29 years from 1987 to 2015, the first 5 years of which were selected for model calibration and the last 5 years for model results validation. Four statistical indices, r_factor, P_factor Nash-Sutcliffe (NS) and coefficient of determination (R2), the ratio of squared root-to-standard deviation (RSR) and the percentage of skewness (PBIAS) were selected monthly to evaluate the model. The accuracy of monthly simulation using NS evaluation index in the calibration and validation stage for flow and suspended load is equal to 0.65 and 0.49, respectively. The results of the study were considered acceptable according to the interpretive domains used in previous studies and indicate the satisfactory efficiency of the SWAT model in simulating the components of the impact of land use change on sediment and discharge in the Ojan Chay Bostanabad watershed. The results showed that the height of surface runoff increased by 1.15 mm and the sediment concentration increased by 1.5 tons per hectare per year.
Hydrogeomorphology
Fariba Karami; Davoud Mokhtari; Farnush Ahmadi
Abstract
The aim of this study is to estimate the rate of soil erosion and its relationship with landforms of Zonuzchay catchment in Marand city. In this study to estimate the rate of soil erosion and sediment production, the modified global model of soil loss (RUSEL), geographic information system (GIS) and ...
Read More
The aim of this study is to estimate the rate of soil erosion and its relationship with landforms of Zonuzchay catchment in Marand city. In this study to estimate the rate of soil erosion and sediment production, the modified global model of soil loss (RUSEL), geographic information system (GIS) and remote sensing (RS) was used. To implement the model, rainfall erosivity factors (R), soil erodibility factor (K), slope length-gradient factor (LS), support practice factor (P), and cover-management factor (C) in Arc GIS environment calculated and Then a soil erosion map was drawn. Topographic position index (TPI) was used to classify and map the landforms of the basin. Then, the role of different landforms in relation to soil erosion rates was investigated by combining relevant maps. The results showed that the values of soil erosion in Zonuzchay basin vary between 0 and 50.20 tons per hectare per year. Valleys and cuts located on heights and slopes have the highest rate of erosion and low-slope domains and flat areas and plains include areas with low and very low erosion. In Zonuzchay basin, soil erosion is mostly on the builders of Flysch type deposits, red and gray conglomerates with Marny layers and alluvial terraces. Investigation of regression relationships between (RUSLE) model factors and soil erosion of Zonuzchay basin showed that the slope length-gradient factor has the greatest effect in calculating the rate of erosion of Zonuzchay basin. .
Hydrogeomorphology
Alireza Ildoromi; nasrin hassanzadeh; fariba hedayetzadeh
Abstract
Sustainable quality of rivers water has become one of the main concerns in developing countries, so monitoring the water quality of these resources for various uses is essential to formulate a public health and environmental management policy. The purpose of this study is to evaluate the water quality ...
Read More
Sustainable quality of rivers water has become one of the main concerns in developing countries, so monitoring the water quality of these resources for various uses is essential to formulate a public health and environmental management policy. The purpose of this study is to evaluate the water quality of Karun and Dez river systems in Khuzestan province and to analyze the suitability of their water quality for drinking and agricultural purposes. To this end, various techniques, indicators and statistical analyzes are used to evaluate spatio-temporal changes in the interpretation of large and complex datasets of 12 water quality parameters collected from the Karun and Dez river basins over a period of 17 years (2003-2019).Evaluation of the trend of water quality changes in the study period also showed that according to WQI, the water quality of Karun and Dez rivers from 2003 to 2007 are in the category of "very poor"and "poor", and from 2008 to 2018 in the "unsuitable" and "very poor"category, respectively. Regarding irrigation parameters, the lack of a clear trend in their values can indicate the lack of effect of river water quality from natural factors and their obedience with human factors. Overall, this study highlights the importance of using water quality indicators that provide a simple interpretation of monitoring data to help improve water quality, because based on these indicators and PCA, it can be concluded that related human activities along the banks of the Karun and Dez rivers, especially in recent years, affect their water quality.
Hydrogeomorphology
ali abdolmaleki; amjad maleki; ali khazai
Abstract
In addition to damaging structural effects, earthquakes also have adverse environmental effects, including polluting water resources. In this article, the quality changes of surface water resources due to earthquakes are monitored. In the present research, in order to achieve the above goal, by using ...
Read More
In addition to damaging structural effects, earthquakes also have adverse environmental effects, including polluting water resources. In this article, the quality changes of surface water resources due to earthquakes are monitored. In the present research, in order to achieve the above goal, by using various data from Sunnynell 1 satellites, optical data from Landsat 8, and Madis satellite images, the data has been unified in such a way that they can be used together in the form of a dataset for processing. be placed In this research, by using the combination of satellite images (radar and optics), the Starfam algorithm, the spectral signature of Sentinel 1 data and the use of remote sensing indicators (MNDWI, NDVI and RGB color combination), water resources The studied area was identified and then the quality changes of surface water resources affected by the earthquake were obtained in the environment of ARC GIS and SNAP SANTINEL software. The results show that the earthquake caused shaking and displacement of the surface and subsurface layers of the earth and due to the karstic location of the studied area, it caused an increase in the concentration of dissolved anions and cations in water. In the studied area, the role of faults is very obvious. According to the geological structure of Zagros, Sarpol-Zahab city has numerous faults and the most changes of water resources are located in the main path of the faults and follow the fault lines of the region. Also, in terms of geology,
Nahideh Parchami; Raoof Mostafazadeh; Abazar Esmali Ouri; Rasol Imani
Abstract
During the occurrence of hydrological drought, the river flow will be reduced and the quality of the river ecosystem will be degraded. Determining the temporal and spatial variations of the hydrological drought makes it possible to plan for the optimal use of river water. In this study, temporal and ...
Read More
During the occurrence of hydrological drought, the river flow will be reduced and the quality of the river ecosystem will be degraded. Determining the temporal and spatial variations of the hydrological drought makes it possible to plan for the optimal use of river water. In this study, temporal and spatial changes of river flow index (SDI) in watersheds of Ardabil province were evaluated. In this regard, daily flow time series of 28 hydrometric stations in Ardabil province were analysed. River flow drought index was calculated using DrinC software and then hydrological drought characteristics were analyzed and spatial variations of SDI index were determined in 1-month, 3-month, 6-month and annual temporal scales in GIS software. 1-month SDI values (short-term droughts) showed that severe droughts were more common in rivers with low discharge values. However, most rivers with low and high amounts of river flow discharge have experienced severe seasons. The annual (long-term) hydrological drought index in most stations was in the range of -1.5 SDI greater than or equal to -1, which indicates the occurrence of mild drought. Spatial changes of SDI showed that the spatial variations of drought index on a 1-month scale are completely different from the annual scale. The lowest occurrence of hydrological drought was in upstream stations and flowing rivers in Sabalan hillsides. Severe and very severe droughts occur in low discharge rivers. The higher the river discharge, the lower the incidence of severe droughts, and the greater its flow stability than low-discharge rivers.
Geomorphology
mehdi feyzolahpour
Abstract
Glacier cirques show the characteristics of past glaciers and climates. In this research, the analysis of 39 glacial cirques in the catchment area of Jajrud River was done. For this purpose, Arc GIS software and Google Earth images were used. The parameters of length, width, height of the top of the ...
Read More
Glacier cirques show the characteristics of past glaciers and climates. In this research, the analysis of 39 glacial cirques in the catchment area of Jajrud River was done. For this purpose, Arc GIS software and Google Earth images were used. The parameters of length, width, height of the top of the circus, height of the floor of the cirques , area, perimeter, ratio of length to width, ratio of length to height of floor and ratio of width to height of floor were used to check the morphometry of cirques. For each of the morphometric parameters, statistical factors of coefficient of variation, standard deviation, average, maximum and minimum were calculated and estimated in Excel. Then R2 values or coefficient of determination were estimated for each of the parameters and a scatter diagram was drawn. Finally, the correlation matrix was estimated using the Pearson correlation coefficient for all factors. The highest abundance of cirques is located in the southwest direction. The maximum height of the cirques is 3800 meters and belongs to the geographical direction of the south.The highest correlations between length and width parameters were observed at the rate of 0.9936. The results show that the cirques in the north-facing slopes have a lower height. This indicates the high nutrition of these cirques and their significant volume in the Pleistocene period. Investigations showed that more developed cirques have more area, less height and less length to width ratio than less developed cirques .
Mehdi Teimouri; Omid Asadi Nalivan
Abstract
1- Introduction Underground water is one of the most important water resources that plays an important role in providing water for agricultural and drinking activities in arid and semi-arid regions (Usamah and Ahmad, 2018, Wu et al., 2019, Kumar et al., 2019). Awareness of the quality of water resources ...
Read More
1- Introduction Underground water is one of the most important water resources that plays an important role in providing water for agricultural and drinking activities in arid and semi-arid regions (Usamah and Ahmad, 2018, Wu et al., 2019, Kumar et al., 2019). Awareness of the quality of water resources is one of the most important requirements in managing, planning, and developing, protecting, and controlling water resources. Using multivariate statistical techniques helps researchers identify the most important factors affecting the quality of water systems and is a valuable tool for water resources management (Pasandidehfard et al., 2019). On the other hand, geostatistical methods are also capable of zoning water quality at the watershed level and can play an important role in completing the assessment of water quality (Ahmadi et al., 2019). The aim of this study is to evaluate the quality of groundwater used for drinking and farming in Hable-Rood Basin, analyze and interpret the quality of these resources using ArcGIS, and perform statistical tests to determine the role of land use and geology formations in water quality. 2-Methodology To do this research, 132 water sources including wells, springs, and Qanats were used during the statistical period of 2008-2018. The watershed can be divided into fifteen main categories in terms of geology. Hable-Rood watershed has 11 main land uses, which has the largest area of the watershed for pasture and the smallest area of the dams. The main components were analyzed (factor analysis) to understand the most important parameters affecting the water quality. This method weighs the components and expresses a special value for each of them (Finkler et al., 2016). Factor analysis has three stages of producing a correlation matrix from all variables (Pearson correlation method), extracting the main factors, and interpreting the results. Duncan's test was also used to check the significance level of parameters among land uses and the type of formations. Geostatistical methods were used for zoning water quality for drinking and farming purposes in the GIS. The spatial relationship of a random variable in the geostatistics was determined by the semivariogram (software GS +). The root mean square error (RMSE) method was used to assess the geostatistical methods and select the best method. It should be noted that the Schoeller diagram and Wilcox diagram were used for the drinking water zoning and agricultural water quality zoning, respectively. 3-Results and Discussion The results showed that the Cl, EC, TDS, Na, Ca, TH, and SO4 vary significantly in different land uses. The highest average was related to industrial areas within the watershed due to the release of industrial materials and the spread and diffusion of groundwater pollution. Also, the parameters of Cl, EC, TDS, TH, and SO4 differed significantly in varied formations. The trend of water quality changes shows the water quality impact of land use, and water quality has decreased sharply in the industrial area, low-yielding land, saline lands, agriculture, and residential areas. The EC parameter showed the highest correlation with TDS at 5% significance level, which is due to a high correlation with the effect of increasing EC on TDS. The pH parameter did not correlate with the other parameters. The factor analysis on the basis of water quality characteristics showed that 88.16% of the water quality variations among land uses were controlled by a single factor (TDS with a weight of 0.99). The factor analysis on the basis of water quality characteristics showed that 91.59% of water quality changes in the formations were determined by two factors (the first and the second factors with weight loads of 0.95 and 0.95 belonged to the TDS and EC parameters, respectively), and the variance percentages of each of factors 1 and 2 were 77.29 and 14.3%, respectively. 4- Conclusion In this research, the effects of geology and land use on groundwater quality were evaluated using multivariate statistical methods and geostatistical methods in ArcGIS. It was determined that some of the groundwater quality parameters were affected by land use and some of the other parameters were under the influence of the geology in the watershed. In general, however, it can be stated that in the first priority, the land use factor and human activities, and in the second priority, the geological factor affecting groundwater quality have the most significant effects. In the formation part of the geology, the dissolution of calcareous and dolomite formations, the chemical processes of salt dissolution, and evaporative formations are the main factors controlling groundwater chemistry in the region. Based on the results, multivariate statistical techniques and geostatistical methods have the ability to recognize factors affecting groundwater quality and the zoning of water quality for different uses and are, therefore, suggested for similar research.
Sayyad Asghari; Rasool Hasan zadeh; Soheil Raoofi
Abstract
1-Introduction Instability of natural slopes is one of the geological and morphological phenomena that has a significant role in changing the form of surface of the earth, and when it affects human activities, it can become a dangerous phenomenon (Esfandiari, 2006: 113). Landslides as geological events ...
Read More
1-Introduction Instability of natural slopes is one of the geological and morphological phenomena that has a significant role in changing the form of surface of the earth, and when it affects human activities, it can become a dangerous phenomenon (Esfandiari, 2006: 113). Landslides as geological events related to the transportation of soil / heavy rock materials and assessment of its sensitivity, is an important task for local authorities to plan and reduce the land (Xialong Deng, 2017: 2). Therefore, many attempts have been made to assess the dangers of mass movements, and it is suggested to have its reduction methods based on the key characteristics of the slip, including scope and extent, volume, startup mechanism and recurrence, and subsequently, make decisions (Kuo Jeong Chank et al., 2018: 700). (Hemati and Hejazi 2017: 24-7) evaluated the landslide hazard zonation of Lavasanat watershed using logistic regression statistical methods and the result was stated in this way that in the studied area, areas with high risk of zoning, had a large share of the area amount of the region. Aliabad basin with the southwest - northeast trend in the geographical coordinates of - located in the east and - located in the north latitudes of the northeast of East Azarbaijan Province and southeastern part of Horand County.(Figure1) Figure (1): Geographic location of Aliabad watershed 2-Methodology 1- Topographic map (1: 50000) and geological map of Kaleybar region (1: 100000). 2- Landsat satellite images of 8 OLI sensors 3- GPS devices 4- Maps of the faults, slopes, isohyet, isotherm, evaporation, land use, elevation and hydrology 5- Envi 5.3 software 6- Statistical software of SPSS, version 16. For zoning the risk of rock falls, nine layers of information including slope, hypsometry of the region, isohyet, isotherm, evaporation, distance from the fault, distance from the river, land use and lithology were used as independent variables and to prepare the layers in Arc GIS, 1,500,000 topographies and 1.100000 geology maps were utilized, and Landsat 8 satellite imageries were used with the OLI sensor to produce the land use layer. So, after preparing the considered data, the layers were classified as raster, and in their descriptive table, a column called the standard weight was added and the classes related to each layer were calculated using a sum ranking method. In this research, the rock fall layer was considered as the dependent variable and the 9 presented layers were considered as independent variables and all layers had been evaluated in the normalization of the weight between zero and one per pixel; based on the proportion table method, each layer, having 500 weighted pixels that overall included 5000 pixels, was entered into the SPSS environment and regression analysis was performed thereof. Independent variables, including 9 variables, consisting of three PhDs in geomorphology and two Phd in geology were selected based on exports opinions considering their importance in creating and strengthening the dependent variable were weighted between zero and one numbers. 3-Results and Discussion The Chi square test for each of the independent variables, separately, showed that there was a significant relationship between the independent variables and the dependent variable, and the effects of these variables on the dependent variable was acceptable. The numerical value of R was 0.953, and if the R value was closer to one, it would indicate the high validity of the test. The numerical value of the coefficient of determination of the independent variables relative to the dependent variable was 0.909, which indicated the high validity of the significance of the test, because it was closer to number one. Of course, it is clear that the value of the determination coefficient in Pseudo R Square was determined to be good, so the adjusted coefficient of determination was considered whose numerical value was 0.907. These findings indicated that roughly 90 percent of rock falls occurred in the Aliabad basin have been affected by these 9 estimated independent variables. Given that the statistical analyzes confirmed the validity of the effects of independent variables on the dependent variable according to the weightings of the experts in terms of zero and one for each variable as well as the importance of the variables in relation to each other as a binary comparison, the zoning of the risk of rock fall for the Aliabad watershed of the Horand basin was done using Arc Gis software, and in this zonation, five falling risk classes were used including very high, high, medium, low and very low . 4- Conclusion lithology and the distance from the fault and river and foot slopes were the most important factors in the formation of rock falls since the drainage system of the basin exactly followed the fault zone. The reason for this issue can be analyzed in the way that the longitudinal distance of the highest parts of this region, from the basin to the Aliabad River was lower, which has caused the slope of the basin to perform deep slices to achieve a balance in the slopes and hydrology. The southern parts of the basin are considered as one of the most susceptible basins in the geomorphologic phenomenon of rock falls and destructive cones due to the existence of alluvial formations and the lack of proper slopes and the relative reduction of the fault to the northern and eastern parts despite having significant heights and very low and low status of zonation in the risk of rock falls, and in the southwestern part of the basin, a presence of rocky outcrops in the presence of permeable cones has been also observed. This issue should be addressed to the authorities in order to avoid serious damages to the lives of the inhabitants of the basin, so that the potential risks of this phenomenon could be controlled as much as possible including: threatening communication routes and threatening rural villages and damaging electrical and telecommunication facilities, therefore, infrastructure solutions should be applied in this regard.
erfan bahrami; Ali Shahidi
Abstract
were prepared as seven raster layers, and after ranking and weighing, the obtained DRASTIC index ranged between 45 and 115. Yet, as far as the model's major problem is applying expert opinions in ranking and weighing the variables, the main purpose of this study is to improve the DRASTIC model by using ...
Read More
were prepared as seven raster layers, and after ranking and weighing, the obtained DRASTIC index ranged between 45 and 115. Yet, as far as the model's major problem is applying expert opinions in ranking and weighing the variables, the main purpose of this study is to improve the DRASTIC model by using the gene expression model, which as an intelligent model has shown a desirable performance. Also, in a mixed form, it can cope with other models to provide acceptable results. Thus, DRASTIC variables of a 20- year statistical period (1999-2009) were defined as the model input, and nitrate concentration was defined as its output. Data in GEP model were divided into two categories: training and experimentation. Moreover, using the statistical parameters (R2, RMSE, MAE and r), the simulation results of the gene expression model were evaluated. The results indicate the model's high ability in estimating nitrate concentration and its high capability in improving DRASTIC model. For validation and improvement of DRASTIC model, statistical parameters, R2 and r, were used, which were specified according to the error of the range model. Also, for each time combining the parameter with the GEP model, a score was gained during different stages and repeated performances of the weight ranking model using weighing rank model of each parameter. Finally, by removing two parameters, S and T, the modified formula of the DRASTIC index which was obtained based on weighing was 5D, 4R, 5A, 5I, and 4C.
RS
Mehdi feyzolahpour
Abstract
The purpose of this research is to investigate the relationship between LST and LULC in Heyran region. LULC indices consist of normalized difference of vegetation index (NDVI), normalized difference of built-up index (NDBI) and modified normalized difference of water index (MNDWI). The area of the studied ...
Read More
The purpose of this research is to investigate the relationship between LST and LULC in Heyran region. LULC indices consist of normalized difference of vegetation index (NDVI), normalized difference of built-up index (NDBI) and modified normalized difference of water index (MNDWI). The area of the studied area is 156.95 square kilometers, out of which in 1401, about 122.7 square kilometers are dedicated to forest area and only 33.2 square kilometers are dedicated to agricultural land. The values of the MNDWI index in the richest region in 2017 had an area equal to 12.27 square kilometers and faced a sharp decrease in 1401 and reached 1.68 square kilometers. Built-up areas (NDBI) increased until 2017 and decreased significantly until 1401. The maximum land surface temperature (LST) has reached from 35.42 degrees Celsius in 2013 to 39.04 degrees Celsius in 1401. The area with a temperature of 20 to 25 degrees Celsius has increased from 67.9 square kilometers to 124 square kilometers. Finally, Pearson correlation relationships showed that NDVI and MNDWI index had a negative correlation with LST index and there was a positive correlation between LST index and NDBI index. The highest positive correlation of 0.77 between LST and NDBI belongs to the spring of 2017, and the highest negative correlation of -0.71 belongs to the MNDWI and LST index, which was registered in the fall of 2017.
Gholam hassan jafari; Mina Avaji
Abstract
1-IntroductionEarth's climate is one of the most important structural factors. More natural and human trappings are affected by the weather. The coefficient of variation of less precipitation is reagent stability and steady time distribution (Fatahi, & Rezaei, 2009). The quaternary climatic changes ...
Read More
1-IntroductionEarth's climate is one of the most important structural factors. More natural and human trappings are affected by the weather. The coefficient of variation of less precipitation is reagent stability and steady time distribution (Fatahi, & Rezaei, 2009). The quaternary climatic changes have created different landscapes, such as glacial circus, glaciers, and especially erratic rocks, according to the first topography of Iran that found in high regions of Iran. Geomorphologists' permanent snowline altitude is determined to help the circus of mountain effects. The continuous snow line, altitude above which or latitude beyond which snow does not melt in summer (Ramesht, & Shah Zidi, 2011). The temperature conditions quaternary reconstruct based on a permanent snowline altitude temperature difference compared to today. They also estimate the maximum expansion of tabs by ice moraines, the erratic rocks, valleys of glacial sediments and granulometry, and its height to consider as ice and water equilibrium line altitude. The water and ice equilibrium line is where ice flows entirely replace the water ice flows wholly replacing the water. The quaternary climatic changes, according to particular topography of Iran, have inherited different figures and landforms such as glacial circus, glaciers, and especially wanderer rocks. We cannot analyze by changing one element changes made; a complex mix of elements change been led to changes in the process and enduring numerous landforms. Any anomalies in each component s will cause defects and commotion in the whole system. 2-MethodologyAccording to the geomorphological landform, the remaining lake last is one of the methods of forecasting and estimating their condition. The Climatic factors role has particularly essential in the current situation of the Iranian domestic water hole. We used to examine the relationship between climatic factors and its effect on local lakes, dewatering of the temperature and precipitation data of the 50-year-old Asfazari database in cells 15 x 15 km (Masoudian, 2012). In addition to measurements of temperature and precipitation of central tendency, indexes used of dispersion indexes in statistical processes (Standard deviation and Coefficient of variation). Since the standard deviation is not used to compare the distribution of both characteristic varies with different units, the coefficient of variation (CV) used. Since most time, the Earth's surface has a temperature higher than the surrounding air, in this study were rainfall receiving below two degrees Celsius on the Basin. The coefficient of snow by reducing the temperature was estimated. With put, the factors in its relations appropriate amount of heat and precipitation determined in the Quaternary cold periods. We expect the coefficient of snow and temperature changes and precipitation decrease of 3, 6, and 9°C temperature for sub-study briefly. We cannot continuously study the effect of all elements and factors related to Quaternary climate changes. Still, we are trying to interpret the lake volume fluctuation due to climate change as a system through changes in temperature, precipitation, the coefficient of rain below 2°C, the ratio of variation coefficient of variation of temperature and precipitation.3-Results and DiscussionThresholds obtained show that the basin con ensures the exit of the lake that to be the average temperature of less than 15.78, average annual rainfall more than 215 millimeters, snowy coefficient more than 13 percent, the coefficient of variation of precipitation less than 40 percent and the ratio of difference of temperature more than 7.43. All basins inside Iran changed to a temperature not fit in the Quaternary. Status and evidence there are of lakes dewatering in the Quaternary do not match whit precipitation double and decline of temperature 6-12 degrees compared to the current conditions. So that line equilibrium of water and land could be the effects of the Quaternary terrace lacks by reducing three, nine, and 12-degree temperatures and increased precipitation. Change the line equilibrium of water and land cannot interpret with a temperature and precipitation changes alone, and causality of these changes in the line equilibrium of lakes water and soil must search in changes of precipitation regime and geomorphology of the region4- ConclusionsTo investigate the impact of climate parameters on the dewatering amount of water, we used primarily average of them. Accordingly, they are receiving basins Maharloo (375), Urmia (372), and Meighan (314 mm) maximum and basins Yazd (92), Bafgh (95), and Ardestān (114 mm) minimum of basin precipitation average. The basin has a higher temperature water demand more. If they receive Precipitation equal, drought intensity increases, the average temperature of pond, and their condition are such that allocated the lowest temperature to the basins of Urmia, Meighan, Gavkhoni, and the highest temperature to the lakes Qom and basins Jazmurian, Lute, the Bafgh and Qatruyeh. Basins of Urmia and Meighan have the best conditions. The basins Bafgh and Yazd have the worst conditions dewatering in terms of combining two elements of climate, temperature, and precipitation. These parameters alone will not be able to estimate the dewatering basins' performance reliable be due to the difference in average temperature and precipitation in the basin. Therefore, we used other vectors such as the coefficient of variation of climate (temperature and precipitation) and the coefficient of rain below 2°C. Investigation and compared the ratio of precipitation below 2°C on precipitation full in fourteen basin studies represents that the basins Meighan 21%, Urmia 20.8% and Qom 20.4% allocated to the most extensive and basins Jazmurian 1% and Qatruyeh 0.6% accounted to the lowest percentage of precipitation in below 2°C. To estimate sufficient rainfall in dewatering lakes, we can put number 40 in equation (2) instead of CVp, and we expect threshold precipitation of the basins. Number 40 is a threshold effect coefficient of variation Precipitation in dewatering lakes.Keywords: Quaternary, Climate, line equilibrium of water and land, Interior Lakes of Iran. 5-ReferencesFatahi, E., & Rezaei, T. (2009). Pattern of Daily Climate Circulation on Iran, Journal of Geographical Research, Isfahan University, No. 93: 45-74Masoudian, A. (2012). Iranian Climate, Sharia Toos Publications, Isfahan.Ramesht, M., Shah Zidi, S. (2011). Geomorphology Application in National, Regional, Economic, Tourism Planning, Second Edition, Isfahan University Press.
shahram roostaei; davood mokhtari; christin jananeh
Abstract
1-IntroductionMass movements of the earth's surficial materials downward the slopes is called slope instability, which is affected by the earth gravity, while the rate of material mobility increases by the presence of water in the sediments. Each year, slope instabilities cause enormous economic damages ...
Read More
1-IntroductionMass movements of the earth's surficial materials downward the slopes is called slope instability, which is affected by the earth gravity, while the rate of material mobility increases by the presence of water in the sediments. Each year, slope instabilities cause enormous economic damages to roads, railways, power transmission and communication lines, irrigation and watering canals, ore extraction, as well as oil and gas refining installations, infrastructures in cities, factories and industrial centers, dams, artificial and natural lakes, forests, pastures and natural resources, farms, residential areas and villages or threaten them. Nowadays, many instabilities are resulted by human intervention and manipulations. One of the human factors effective in the instability occurrence is the construction of roads. Road construction, especially in mountainous areas, increases the probability of occurrence of various types of instabilities, as it changes the natural balance of the slopes and causes deformations in the land. Each year, lots of casualties and financial losses are imposed by the occurrence of various types of instabilities in the slopes overlooking the roads, which also cause the destruction of many natural resources in the country. However, the construction of roads, highways and freeways is necessary and unavoidable in today’s life.The Karaj-Chaloos road and the Tehran-North highway are two routes that connect Tehran as Iran’s capital, with the southern shores of the Caspian Sea, although suffering frequent slope instabilities.2-Methodology This contribution aimed to study slope instabilities along these roads using logistic regression method. In this regard, layers of 14 effective factors were identified, comprised of elevation classes, slope, aspect, geology, land use, precipitation, distance from fault, river and road, normalized difference vegetation index (NDVI), climate, slope length (LS), stream power index (SPI) and topographic wetness index (TWI). Consequently, maps of the factors responsible for instabilities were prepared as separate layers in the GIS environment and transferred into the Idrisi software. The whole procedure included: (1) preparation of digital elevation model (DEM), river and fault layers based on the 1:25,000 topographic map of the area, as well as distance maps from rivers and faults, (2) creating slope and aspect maps from DEM, (3) preparation of land use and NDVI maps of the region based on unmatched classification of Landsat 8 image of OLI sensor, (4) preparation of geological map, (5) preparation of precipitation and climate layers based on the information obtained from the meteorological organization, (6) creating LS, SPI and TWI layers based on the DEM, (7) conversion of the distribution data of the regional instabilities using Landsat satellite and Google Earth images, (8) correlating the information layers with the regional instability map and calculating their density per unit area, and (9) performing the logistic regression model using Idrisi software.3-Results and Discussion Results obtained by applying logistic regression model showed that the most important factors affecting slope instabilities in the Karaj-Gachsar road area were the distance from river, climate and SPI, while those for the Tehran-Soleghan road area were the distance from fault and road and climate. 34.95 percent of the lands in the Karaj road area had medium to high potential for instability occurrence; 54.87 percent of the occurred instabilities corresponded to these areas. Moreover, 4.97% of the Karaj road area had a very high potential for instabilities, which correlated with almost 9% of the occurred instabilities. This was while 27.14% of the Soleghan road area possessed medium to high potential for instabilities, within which 86.26% of the instabilities have occurred. Furthermore, 4.57% of the Soleghan road area showed very high risk in terms of instability occurrence, encompassing 61% of the occurred instabilities. According to the prepared maps, the southern and middle parts of the Karaj-Gachsar road, as well as another part in the northwest of the study area had the highest potential for the occurrence of instabilities, whereas in the Tehran-Soleghan road area, the middle and southern parts and a small section in the north of the area had the highest potential for instability occurrence. By comparing these two areas, it was conceived that areas with medium to high potential of instability in the Soleghan road area were less than those of the Karaj road area (27.24% and 34.95%, respectively). However, the percentage of instabilities occurred in the Soleghan road area was much higher (86.26%) than the Karaj road area (54.87%). The high value of the ROC index and its proximity to the end value of 1 in both areas indicated that instabilities strongly correlated with the probability values derived from the logistic regression model. Additionally, the assessment of the instability potential map by the SCAI index showed that there was a high correlation between the prepared risk maps and the occurred instabilities, which have been confirmed by field surveys. The obtained results were in a good agreement with the general opinion that SCAI decreases especially in high and very high risk classes indicating a high correlation between the prepared risk maps and the occurred instabilities and field surveys in both areas.4-ConclusionThe results of this investigation showed that the logistic regression model was suitable for preparing the zonation of the probability of instability occurrence along the edges of the studied roads. Moreover, in addition to natural factors, the human-made factors and particularly unsystematic road construction can play an important role in the instability occurrences on the slopes overlooking the roads. In order to reduce the relative risks and increase the stability of the slopes, it is necessary to avoid manipulating the ecosystem and changing the current land use as much as possible, in addition to policy making for constructions in accordance with geomorphological and geological features of the area.Keywords:Instability, Logistic Regression, Tehran-North highway, Karaj-Chaloos road, Risk zonation.
Kaka Shahedi; mahtab forootan danesh
Abstract
Simulation of the rainfall-runoff process in a watershed is highly important from the point of view of hydrological issues, water resources management, river engineering, flood control structures and its storage. Rainfall-runoff estimation using a distributed hydrological model and the technique of GIS ...
Read More
Simulation of the rainfall-runoff process in a watershed is highly important from the point of view of hydrological issues, water resources management, river engineering, flood control structures and its storage. Rainfall-runoff estimation using a distributed hydrological model and the technique of GIS has become possible, practical and common. The Wetspa model is a distributed model simulating runoff and water balance that is performed at different time scales including hourly or daily basis. In this research, the discharge is simulated using Wetspa model in the Ghorichay watershed. This watershed (as one of the sub-watersheds of Gorganrood) with an area of 2481.5 ha is located in the south of Ramian city in Golestan province. The data used by the model are land use maps, soil texture, digital elevation model, precipitation, evaporation, temperature and discharge (for calibration and validation of the model). Calibration of 13 parameters was performed manually and automatically for 7 years at the beginning of the statistical period and model validation was performed for a period of 5 years. The results of the model evaluation show the accuracy of discharge simulation and very good agreement between the simulated data and observations based on the Nash-Sutcliffe criterion of 67.21% in the calibration period and 76.34% in the validation period. Also, the discharge calculated by the Wetspa model for the whole watershed was 28.31%, which in comparison with the observed discharge of 30.12% indicates a good simulation of the model.
