Hydrology
Mahnaz Rezaei; Somaiyeh Khaleghi; Mohammad Mahdi Hosseinzadeh
Abstract
Considering the importance of the subject, in this research, the factors affecting the hydrological changes of the Taleghan River have been investigated. Descriptive-analytical methods have been used in this research. The most important data of the research included Landsat 5 and 8 satellite images, ...
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Considering the importance of the subject, in this research, the factors affecting the hydrological changes of the Taleghan River have been investigated. Descriptive-analytical methods have been used in this research. The most important data of the research included Landsat 5 and 8 satellite images, the SRTM 30-meter height digital model, Taleghan synoptic station climate information, and regional discharge information. Also, the most important tools used in the research were ArcGIS, ENVI, and SPSS. According to the subject of the study, this research has been done in several stages. In the first stage, the evaluation of land use changes, in the second stage, the evaluation of changes in climatic elements, and in the third stage, using IHA indicators, has been paid to evaluate the hydrological changes of the Taleghan River. The results of this research have shown that during the years 2000-2017, the average temperature of the region has increased and the area covered by snow has decreased. Also, under the influence of population growth, the use of artificial areas has increased and the use of gardens and pastures has decreased. Also, the total results of this research have shown that the discharge of the Taleghan River under the influence of natural and human changes, in terms of all IHA indicators, has had a significant decreasing trend. Also, among the stations in the region, the Glink station, which is located downstream of other stations, has faced more changes, which can be considered as the result of human activities and climate changes.
hydrogeology
Sina Ziaye Shendershami; Abazar Esmali Ouri; Raoof Mostafazadeh; Ardavan Ghorbani
Abstract
The aim of this study was to investigate the factors affecting the decrease and change of groundwater level in Ardabil plain in two periods 1995 to 2005 and 2005 to 2015. The monthly precipitation data of Ardebil, Nir, Namin, Abi baglo, Hir, Samiyan stations in the Ardabil plain during the statistical ...
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The aim of this study was to investigate the factors affecting the decrease and change of groundwater level in Ardabil plain in two periods 1995 to 2005 and 2005 to 2015. The monthly precipitation data of Ardebil, Nir, Namin, Abi baglo, Hir, Samiyan stations in the Ardabil plain during the statistical period of 1995-2015 and monthly data of the height of the station in 24 Piezometric well ring were chosen for the plain. Landslide OLI and TM satellite imagery was used to prepare land use map for the target periods in June 1993, 2005, and 2015. The results of land use changes in the years 1993, 2005, and 2015 in the Ardabil plain showed the highest watery agriculture with 48156.26, 50678.66, and 58356.68 and area water level, respectively, were with 168.75 ,88.65 and 380.95 ha, lowest level Which indicates the high level of agricultural land involvement in the decline of agricultural land in the Ardebil plain. The study of the process of Piezometric Wells showed that in the plain of Ardabil, the maximum height of the surface of the station (1437 m) is related to the southern parts of the plains around the village - Noshahr-Kargan and the minimum height (1300 m) is related to the village of Khalifaulo Sheikh. The highest level of cultivation is also focused on user plans in these areas.
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 ...
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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.
Abazar Esmali Ouri; Fatemeh Kateb
Abstract
1- IntroductionIn recent years, concerns regarding the impact of changing patterns of land-use owing to deforestation and agricultural development or elimination have led to numerous crises in the quality of water and soil resources (Lam et al., 2018). Alterations in land use resulting from human activities, ...
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1- IntroductionIn recent years, concerns regarding the impact of changing patterns of land-use owing to deforestation and agricultural development or elimination have led to numerous crises in the quality of water and soil resources (Lam et al., 2018). Alterations in land use resulting from human activities, such as deforestation, agriculture and urban growth among other activities, can have far-reaching and long-term consequences such as reduced biodiversity, increased surface runoff, soil erosion, increased greenhouse gases, global warming and energy imbalance on the surface of the ground (Mokhtari et al., 2020). Undoubtedly, all human activities in nature eventually lead to change of land use. Over the past three decades, the evolvement of human needs has led to a significant increase in change of land-use and damage (Hazbavi et al., 2018). Landscape is defined by focusing on the role that humans play in creating and influencing ecological patterns and processes. Therefore, it should be noted that man has always sought to change the appearance of environments where he feels dominant, hence replacing natural spaces with artificial ones in the process, itself leading to environmental instability (Nazarnejad et al., 2017). Landscape measurement criteria is the best way to compare the landscape of a land and different land uses (Akin et al., 2013; Wang et al., 2014). According to the Food and Agriculture Organization (FAO) of the United Nations, 3 million hectares of agricultural lands are lost annually due to erosion. The total annual sediment volume of basins should be evaluated for soil conservation projects, erosion control and sediment reduction methods, as well as the volume of reservoir dams. Estimation of erosion, annual sedimentation and subsequent preparation of landscape for soil erosions are of paramount importance in controlling soil erosion and maintaining mechanical and biological performance. Direct and indirect methods are two general tools employed for measuring soil erosion. In the direct method, the rate of erosion and sedimentation of different instruments is measured. In indirect methods, the rate of erosion and the level of sediments are measured based on experimental models and other parameters. It is difficult to prepare models with detailed information on local watersheds due to the lack of sediment measuring stations in most watersheds. Therefore, the use of experimental models is inevitable, but the main problem with the experimental models is the inaccuracies in processing and large amounts of data that must be first digitized by the GIS system and analyzed by mathematical models.The purpose of this study was to evaluate the changes in land-use measures at the level of class and landscape in Sharif Beiglou watershed for the development of the catchment area in line with the needs of the region. Due to the existence of Sharif Beiglou Reservoir Dam in the above basin, identification of sensitive and critical areas of erosion is necessary to carry out further conservation activities. Also, one of the obvious problems in this basin is the presence of excessive sediment due to the lack of suitable vegetation upstream of the basin. Examining this relationship can provide a good tool for monitoring land change and decision making in management.2- MethodologyIn this research, land-use map was prepared using images from Google Earth 2020, mostly owing to its high resolution and appropriate interpretation of the watershed. Image analysis was performed using ArcGIS 10.3 software. After preparing the land-use map for the area in ArcGIS 10.3 and converting it to raster format, Fragstats 4.2 was used to quantify the land-use measurements at the scope and class level for the watershed. Soil erosion sensitivity coefficient was calculated with EPM model for Shari Beiglou watershed. Then, the data from calculating the measures and the severity of soil erosion were inputted SPSS, determining a significant relationship there between.3- Results and DiscussionThe basis for calculating land-use metrics is land-use map at the level of landscape and class. The analysis of quantitative measures of land-use were performed at two levels of class (the level of each class being unique) and the landscape. According to the results, the maximum number of spots was witnessed in agricultural use, the minimum of which was related to the water body. This finding is not consistent with that of Madadi and Ashrafzadeh (2015), in which the most destruction was reported in the water body. The average spot density of the study area was 0.23, and the maximum value of the spot distance was related to agriculture and pasture, garden, residential and water body, respectively. This shows that human manipulation and interference in this use has been high over time. The value for the index of the largest spot in the study area was 80.65 for the rangeland, and the smallest value was zero assigned to the water body. Increasing the shape of the spot is associated with increasing the irregularity of the shape of the spots. In this regard, Karami et al. (2012) studied and compare the use of North and South Zagros lands with the ecological approach of the land of Kurdistan, Kohgilooyeh and Boyer-Ahmad provinces, and reported that the most and the least are related to agricultural lands and water bodies, respectively. The maximum and minimum total margins for Sharif Beiglou watershed at the level of class, were 68080.023 and 1345.224, respectively. The average total margin for the studied watershed was 50338.672 meters. Similar results have were previously by Kiani and Fiqhi (2015) for northern Iran, in which the margin density was the highest for the rangeland and the lowest for the water body. The spot shape index for all uses was more than 1, indicating the irregularity of the spots at the field level. The maximum and minimum values of this index were witnessed in agriculture (8) and water body (1.27) respectively. The maximum and minimum values for the average spot size were respectively 313.66 and 6.92, (Mokhtari et al, 2020). Moreover, the results showed that the average size of forest spots has increased from 1987 to 2018. The minimum and maximum value for the landscape rupture of the studied watershed was equal to 1 and 0.34, respectively pertaining to residential use, and water body and rangeland. The maximum and minimum values for fragmentation rate was determined to 376.889 and 1.53, respectively. Also, on the surface of Sharif Beiglou watershed 49 spots were identified, with spot density of 1.15, largest spot index of 80.64, total margin of 7558.008, average margin of 17.75, spot shape index of 4.56, and average spot size of 86.79, while the landscape rupture was calculated to be 0.34 and fragmentation rate was calculated to be 1.52. According to the results obtained from the study basin (Esmali and Abdollahi, 2011), agricultural land-use has high erosion, rangeland and garden land uses have moderate erosion, residential land-use has low erosion and water body has partial erosion. In the southwestern part of the basin, owing to agricultural activities, the intensity of erosion is high, while the intensity of soil erosion in the northeastern part is moderate. Owang et al. (2010) examined the watershed upstream of the Yellow China River from 1977 to 2006 and reported that factors including the continuous expansion of bare lands, water areas and agricultural lands has significantly increased soil erosion. Analysis of the results at the spot level confirmed that the amount of sediment transport from the edge of the spot has also increased due to the increase in the margin of the spot. Obtaining and employing such information will definitely help curb regional and local environmental pollution. Also, the landscape of Koozeh Topraqi watershed is composed of pastures, agriculture, rocky outcrops and residential areas with the shares of 29.13%, 64.77%, 3.50% and 0.80%, respectively (Alaei et al., 2019). The data from calculating the measures and the intensity of soil erosion were inputted to SPSS software and the significant relationship there between was determined according to Pearson correlation test. The results indicated that only the fragmentation index (SPLIT) is statistically significant with a negative correlation and is thus an effective measure that can be employed in methods of reducing the severity of soil erosion.4- ConclusionThe results showed that in the study basin, agricultural applications have high erosion, rangeland and garden applications have moderate erosion, residential applications have low erosion while water body has partial erosion. At the level of landscape, for Sharif Beiglou basin, the number of spots was 49, the spot density was 1.15, the largest spot index is 80.64, the total margin was 75508.008, the margin density was 17.75, the spot shape index was 4.56, the average spot size was 86.79, and landscape rupture was 0.34 and fragmentation was determined to be 1.52. At the class level, the amount of fragmentation in the water body was the highest. Therefore, it can be concluded that its relationship with their assemblies has been severed. Finally, with the intervention of changes in land features, the study of soil erosion was optimally performed, in that the erosion potential map indicated that areas with high erosion are affected by the measurement indicators and the hydro-geomorphological properties used.Keywords: Land use, Land degradation, Landscape, EPM, Sharif Beiglou. 5- References Akın, A., Erdoğan, A., Berberoğluc, S. (2013). The Spatiotemporal Land use/cover Change of Adana City. International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 7, 11-17.Alaei, N., Mostafazadeh, R., Esmali Ouri, A., Sharari, M., & Hazbavi, Z. (2019). Assessing and comparing the continuity of the landscape in the Koozeh-e-Topraqi watershed, Ardabil province. Applied ecology, 8 (4): 34-19.Esmali, A., & Abdullahi, K. (2011). Watershed management and soil protection. Mohaghegh Ardabili Publications, 574 p.Hazbavi, Z., Jantiene, B., Nunes, J.P., Keesstra, S.D., & Sadeghi, S.H.R. (2018). Changeability of reliability, resilience and vulnerability indicators with respect to drought patterns. Ecological Indicators, 87, 196-208.Kiani, W., Jurisprudence, J. (2015). Investigation of the cover / use structure of Sefidrood watershed using ecological criteria of the land feature. Environmental Science and Technology, 17, 141-133.Karami, A., Fiqh, J. (2012). Monitoring and comparing the use of North and South Zagros lands with the ecological approach of the land landscape (Case study: Kurdistan, Kohgiluyeh and Boyer-Ahmad provinces). Land Management, 4 (6), 34-5. Lam, N.S., Cheng, W., Zou, L., & Cai, H. (2018). Effects of landscape fragmentation on land loss. Remote Sensing of Environment, 209, 253–262.Madadi, H., Ashrafzadeh, M. (2010). Investigation of land cover changes in the area of Bamdaj wetland with the ecological approach of land appearance. Journal of Science and Technology, 9 (1): 51-61.Mokhtari, M., Abedian, S., & Qolpour, M. (2020). Detection and modeling of forest land use change trends in Qarahsu watershed using land features. Applied ecology, 8 (4): 18-1.Nazarnejad, H., Hosseini, M., & Irani, T. (2018). Using Landscape Measurements in Assessing Landscape Structure Changes in Qarahsoo Watershed in Kermanshah. Geography and Environmental Hazards, 26, 36-23.Wang, X., Blanchet, G.B., & Koper, N. (2014). Measuring habitat fragmentation: An evaluation of landscape pattern metrics. Methods in Ecology and Evolution, 5, 634–646.
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.
Meysam Yari; Somayeh Soltani-Gerdefaramarzi; Mohsen Ghasemi; Rouhollah Taghizadeh
Volume 6, Issue 21 , March 2020, , Pages 203-225
Abstract
1-Introduction Given the growing population and the increasing need for food, water and soil conservation are of great value. In the context of conservation of soil and water resources, information on the amount of runoff production and erosion to achieve sustainable development is the basis for planning ...
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1-Introduction Given the growing population and the increasing need for food, water and soil conservation are of great value. In the context of conservation of soil and water resources, information on the amount of runoff production and erosion to achieve sustainable development is the basis for planning and decision making. Therefore, careful investigation of surface runoff and floods is an important and key step in planning and managing optimal water resources. One of the factors affecting the characteristics of surface runoff is land-use changes at different basin levels (Melesse and Shih, 2002). Land use is influenced by two components of human needs and environmental processes. Inaccurate land-use changes will disrupt the water cycle from natural equilibrium, resulting in devastating floods, including economic damage, loss of life, loss of water, and consequently reduced water resources (Jakeman et al., 2005). During the last two decades, the Qhareh-su watershed, particularly its downstream, has been experiencing rapid growth in the construction and expansion of residential structures. Human activities and changes in the basin have affected the natural arrangement of stream processes that transmit water and sediment from upstream to downstream. Human interventions are one of the major hazardous issues in this basin that causes changes in the pattern of surface currents and natural conditions of the catchments and encroachment on rivers and streams. In this regard, the present study aimed to investigate the role of land-use change on runoff in a part of Qhareh-su watershed in Ardebil province over a period of almost 20 years due to the availability of information and access to satellite images of different time periods. 2-Methodology The study area consists of a part of Qhareh-su watershed located in Ardabil province with an area of 2162.6283 km2. The minimum and maximum elevation of the mentioned watershed are 1280 and 3829 m respectively, and its average slope is 11.57%. Land use in this area often includes dry and irrigated agriculture, pasture, forest, and residential areas. The aim of the current research is to study the effect of different land uses and its changes during the years 1992-2012 on the surface runoff in a part of Qhareh-su, Ardabil watershed. At first, the maps of land use and curve number in the mentioned years were gathered and the area of each of the units was extracted. In the following, the process of land-use changes in the cases of the study period and its effect on changing the specific retention (S) and curve number were calculated and the height of runoff was estimated using the SCS method. 3-Results The results showed that during the case of the study period, area of forest, water farming, and wasteland land uses were decreased by 2.54%, 16.69%, and 1.19% respectively and the area of the rangeland, dry farming, and urban land uses were increased by 5.74%, 12.39%, 2.29% respectively. These changes have caused the increase of curve number from 78.57 to 79.77 in the years 1992 and 2012, respectively and following the decrease of the specific retention (S) from 69.28 mm in the year 1992 to 64.42 mm in the year 2012. Also, runoff height has increased from 263.4 mm in the year 1992 to 297.07 mm in the year 2012 (11.33%). Calculation of correlation coefficient between different land uses and curve number and runoff height showed that these variables have a direct relationship with rangeland, dry farming, and urban land uses while they have an inverse relationship with the forest, water farming, and wasteland. 4-Discussion and conclusion In the present study, the results of the study showed that land-use change due to its effect on the curve number of the studied basin causes a change in the surface runoff. During this 20-year period, land use has changed and this land-use change has tended to decrease from 1992 to 2012 land use including residential, pasture and dryland areas increased by 2.29%, 12.39% and 5.74% respectively, as well as forest, water and wastewater land use decreased by 2.54%, 16.69% and 1.19%, respectively. As a result, its curve number has increased, followed by a runoff height of 11.33%. This shows that in a natural ecosystem, land use and environmental changes, especially vegetation and land use affect the hydrological responses such as flooding and erosion and sedimentation rate in the area. Ultimately, it will cause severe economic and social damages. Changes in the total volume of runoff and changes in hydrological balance are the most important effects of land-use change on watershed hydrology.
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.
Mahin Naderi; Alireza Ildoromi; Hamid Nouri; Soheila Aghabeigi Amin; Hossein Zeinivand
Volume 5, Issue 16 , December 2018, , Pages 61-79
Abstract
Abstract Intr4oduction Changing the environmental conditions of a natural ecosystem influences the hydrological responses such as flooding and the extent of erosion and sedimentation of the area. One of the models used to investigate the effect of land use change and climate change on runoff is SWAT ...
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Abstract Intr4oduction Changing the environmental conditions of a natural ecosystem influences the hydrological responses such as flooding and the extent of erosion and sedimentation of the area. One of the models used to investigate the effect of land use change and climate change on runoff is SWAT model which is a hydrological simulator and a continuous and semi-distributive time-space model with a physical base. Understanding the relationship between land use change and its causative factors and its secondary effects on hydrologic regimes provides essential information for land use planning and sustainable management of natural resources. Investigating the amount and trend of the changes and its effect on the hydrological processes in the basin is a way to predict the state of future changes and provide more effective plans for the sustainable development of the water resources in the basin. The construction of the Garin Dam in the Garin Basin, the risk of filling the sediment reservoir with sediment, reducing its useful life due to seasonal floods, and the effect of basin land use and climate change were the reasons for choosing this area for this research. The purpose of this study was to study the land use and climate change in the studied watershed and determine the effect of these changes on the runoff rate of this watershed in order to better it correctly. Garin Dam is located in the Zagros in the province of Hamedan. It includes the catchment area of the Sarab Gamasiab River to the Garin Reservoir Dam and its area is up to the 22,000 m2. The Garin land basin is mainly mountainous and its range of height ranges from 1833.9 to 3429.2229 m above sea level. Materials and Methods SWAT model input data included climatic and hydrological data (daily precipitation, maximum and minimum temperature, relative humidity, wind speed, dew point, and solar radiation). In this study, the ten year data of Nahavand synoptic station was uased. Topographic maps, digital elevation model (DEM), soil and land use were also used as the input of the model. A digital elevation model (DEM) was extracted using a topographic map of 1: 250,000 of the Garin River basin. SWAT CUP software was used for the calibration and validation of the SWAT model. The calibration data was from the years 2002 to 2007, but the validation data was from 2008 to 2010. In order to determine the degree of the sensitivity of the flow parameters in the SWAT model, SUFI2 software SWAT CUP were used and the sensitivity of the selected 24 parameters were measured. The Elimination of the parameters which had less sensitivity, was based on the calibration process. According to the P-value and T-Stat criteria, the sensitivity of the parameters were determined. The land use maps of 1986, 2000, and 2014 were prepared at the previous stages, and the Markov chain and the CA Markov filter were used to map the land use in 2042. In this research, the outputs of the Hadcm3 model were used to predict Garin's future climate. In addition, the SDSM statistical method was used to fine-scale the output of the general atmospheric circulation models. The SWAT model was also used in the range of calibrated parameters to simulate runoff caused by climate change in Garin basin under two A2 and B2 scenarios. After micro-sampling, the SWAT model was converted and t analyzed for the scenarios. Then, the results of the model implementation with different scenarios and the results of model implementation with the current climate conditions were compared Results and Discussion Regarding the results of the statistical indices, NS index was 0.95. P and R factors were respectively 0.47 and 0.03, and the coefficient of determination (R2) for observed and simulated floodguns was 0.6. Accordingly, the results were confirmed in the calibration phase. The validation phase was conducted to verify the correctness of the selection of the parameters during the calibration period between 2008 and 2010. Given that the Nashatcliff coefficient for Garin's catchment area at the calibration and validation stages were respectively 0.95 and 0.66, , the results were satisfactory and the SWAT model was able to simulate surface runoff in Garin River Basin. In general, due to an increased forest use, an increased permeability and water drainage to the surface and deep water aquifers, and an increased evaporation and transpiration, the amount of runoff has decreased. Regarding the results of temperature, rainfall, and runoff of the next period, it can be seen that in months when rainfall is reduced and the temperature increased, the amount of runoff in the coming period also decreases. The main reasons for this discrepancy can be attributed to the difference in the intensity of land use change as well as the extent of the altered land area, which, given the mountainous nature of the area in the Garin land basin, can be compared to other areas with flat lands with agricultural uses. It is concluded that the effect of climate change in the Garin dam basin is greater than the change in land use due to its mountainous nature. Conclusion The results of the study of the effect of land use change on runoff in the Garin basin indicated that there was a daily and monthly decline in the amount of runoff. The results of the study of the effect of climate change on runoff in the Garin western basin also indicated that there was a daily and monthly decline in the amount of runoff. In both A2 and B2 scenarios, the monthly average temperature, especially in the first and last months of the year, had an increasing trend and rainfall decreased in the spring and winter. It can be attributed to the increased temperature and evaporation, and decreased rainfall. It can also be seen that there was a decline in the average monthly runoff in January, February, April, May and December, with a decreased rainfall, but there was an increase in the average monthly runoff in June, July, August and September, with an increased rainfall. In addition, the effect of land use change on the reduction of runoff in the upcoming period is lower compared to the change effect under A2 and B2 scenarios. It will affect the climate change of the runoff more flatly and the reduction of runoff is more affected by climate change. According to the information obtained from these predictions, it is possible to properly manage the watershed and adopt appropriate management measures in accordance with the conditions of this watershed, prevent unauthorized land use changes, and reduce the damage caused by the phenomenon of the climate change.
Naser Ahmadi Sani; Karim Solaimani; Lida Razaghnia; Raoof Mostafazadeh; Jalal Zandi
Volume 5, Issue 16 , December 2018, , Pages 139-158
Abstract
Abstract Introduction Due to population growth and human activities and increasing water demand, water availability will be critical and water resource assessment and planning for sustainable use become more complex. The dynamic and long-term laws of runoff are important and have practical value for ...
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Abstract Introduction Due to population growth and human activities and increasing water demand, water availability will be critical and water resource assessment and planning for sustainable use become more complex. The dynamic and long-term laws of runoff are important and have practical value for the sustainable development and planning of water resources. On the other hand, the traditional methods of runoff estimation should be improved regarding the accuracy and spatial variations. The application of GIS extensions is needed to provide water resource assessment data. Therefore, the application of such new techniques has greatly increased in recent years to estimate the runoff characteristics. The SCS method is the most commonly used method for estimating surface runoff, whose accuracy has improved through employing advanced GIS-based tools. The applicability of Arc-CN Runoff tool was tested in different internal and external studies which emphasized the quantitative evaluation of the model results. Methodology In this study, the accuracy of runoff estimation by Arc-CN Runoff tool was evaluated based on the land use map in two different time periods (1996-2011). The Landsat satellite images of 1996 and 2011 were processed and analyzed for land use mapping. Map of soil hydrologic groups was prepared in GIS environment using slope and soil texture maps. The annual rainfall calculations were done using rainfall daily data of several years for stations within the basin. The curve number map was used to estimate runoff using SCS method within ArcCN-Runoff tool in GIS environment. The runoff observations of Karehsang Station were calculated using daily flow data and the base flow was separated. Finally, the accuracy of the estimated runoff was assessed by estimating the percent relative error. Results and Discussion According to the accuracy assessment of land use maps using the ground-based map, the best overall accuracy and kappa coefficient were respectively 90% and 88%. The results showed that the maximum likelihood algorithm and the combination of main and synthetic bands, classified the land use classes of the study area with an acceptable accuracy. The highest percentage of the area was classified as range and dry farming (62.74%) in 2011. The percentage of rangeland, dense forest, and water zones decreased in 2011 compared with 1996.The map of the hydrological groups shown in this study, consisted of groups B, C and D, respectively covering 15.5, 44.5 and 40% of the study area. The average CN in the years 1996 and 2011 was estimated to be around 79.6 and 81.6. The average estimated rainfall of the study area using the arithmetic mean, inverse distance weighting, and kriging methods in 1996 were respectively 486.24, 424.4 and 486.1 mm. The estimated annual rainfall values were equal to 521.5 (arithmetic mean), 514.6 (inverse distance weighting) and 521.5 (kriging) mm. Runoff height was the highest in bare lands and residential uses, and the minimum of runoff height values were estimated in good and medium rangelands. Conclusion The mean values of total runoff, base flow, and surface runoff have increased in 2011 compared to 1996. The highest CN values in both periods consisted of bare lands and residential area. The runoff height in different land uses and the total runoff height increased in 2011 (11.38 mm) compared to 1996 (8.8 mm), which can be partly due to the degradation and land use change. The results of this study showed that the ArcCN-Runoff tool improved the accuracy of potential runoff estimations, while the relative error of runoff estimation in both periods was relatively low and acceptable. Thus, the implemented tool can be used to assess and estimate runoff height. The results showed that the relative error of runoff estimation in both periods was in agreement and the error amount was relatively low (10%). In addition, the used methods and tools were evaluated with 90% accuracy in both periods and can be used for runoff estimation in data-scarce watersheds.
Mahin Naderi; Alireza Ildoromi; Hamid Nouri; Soheila Aghabeigi Amin; Hossein Zeinivand
Volume 5, Issue 14 , June 2018, , Pages 23-42
Abstract
Introduction
In a natural ecosystem, changing the environmental conditions of that ecosystem influences hydrological responses such as flooding and the extent of erosion and sedimentation of the area. One of the models used to investigate the effect of land use change and climate change on SWAT runoff, ...
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Introduction
In a natural ecosystem, changing the environmental conditions of that ecosystem influences hydrological responses such as flooding and the extent of erosion and sedimentation of the area. One of the models used to investigate the effect of land use change and climate change on SWAT runoff, the SWAT model is a hydrological simulator and a continuous and semi-distributive time-space model with a physical base. Understanding the relationship between land use change and its causative factors and its secondary effects on hydrologic regimes provides essential information for land use planning and sustainable management of natural resources. Investigating the amount and trend of the changes and its effect on hydrological processes in the basin is a way to predict the state of future changes and provide more effective plans for sustainable development of water resources in the basin. The construction of the Garin Dam in the Garin Basin and the risk of filling the sediment reservoir with sediment and reducing its useful life due to seasonal floods and the effect of basin land use and climate change on the reason for choosing this area for this research. The purpose of this study was to study the land use and climate change in the studied watershed and determine the effect of these changes on the runoff rate of this watershed in order to better manage it.
Study of Area
Garin dam dam is located in the province of Hamedan and is located in the mountain range of Zagros mountains. This area includes the catchment area of Sarab Gamasiab River to the Garin Reservoir Dam and its area is up to the 22,000-square-meter Garin Garin Dam, the Garinland basin is mainly mountainous and its range of elevation ranges from 1833.9 to 3429.2229 meters above sea level.
Materials and Methods
SWAT model input data include climatic and hydrological data (daily precipitation, maximum and minimum temperature, relative humidity, wind speed, dew point and solar radiation), which is ten years in the study of statistics related to the synoptic stations Skinheads Became Topographic maps, digital elevation model (DEM), soil and land use are also needed as model inputs. A digital elevation model (DEM) was extracted using a topography map of 1: 250,000 Garin River basin. Calibration and validation of the SWAT model in SWAT CUP software. The study used calibration data from 2002 to 2007 and 2008 to 2010 for validating the model. In order to determine the degree of sensitivity of flow parameters in the model SWAT using SUFI2 software SWAT CUP sensitivity analysis for 24 parameters election, the results of the sensitivity analysis on the Elimination of parameters that has the less sensitive they are, the calibration process decision It is accepted. According to the P-value and T-Stat criteria, the sensitivity of the parameters is determined. Land use maps of 1986, 2000, and 2014 were prepared in the previous stages, and the Markov chain and the CA Markov filter were used to map the land use in 2042. In this research, the outputs of the Hadcm3 model were used to predict Garin's future climate. In this research, the SDSM statistical method was used to fine-scale the output of the general atmospheric circulation models. The SWAT model was used in the range of calibrated parameters to simulate runoff from climate change in Garin basin under two scenarios A2 and B2. After micro-sampling, the SWAT model was converted and the model was analyzed for the scenarios. Then, the results of model implementation with different scenarios and the results of model implementation with the current climate conditions were compared
Discussion and results
Regarding the results of statistical indices, NS index is equal to 0.95, P factor and R factor were respectively 0.47 and 0.03 respectively, and the coefficient of determination (R2) for simulated and simulated floodguns was 60 / 0. Accordingly, the results were confirmed in the calibration phase. The validation phase was conducted to verify the correctness of the selection of parameters during the calibration period for the period 2008-2010. Given that the Nashatcliff coefficient for Garin's catchment area at calibration and validation stage was equal to 0.95 and 0.66, respectively, the results were satisfactory and the SWAT model was able to simulate surface runoff in Garin River Basin. In general, due to increased forest use due to increased permeability and water drainage to the surface and deep water aquifers and increased evapotranspiration, the amount of runoff has decreased. Regarding the results of temperature, rainfall and runoff of the next period, it can be seen that in the months when rainfall is reduced and the temperature increased, the amount of runoff in the coming period also decreases. The main reasons for this discrepancy can be attributed to the difference in the intensity of land use change as well as the extent of the altered land area, which, given the mountainous nature of the area in the Garinland basin, can be compared to other areas with flat lands with agricultural uses. It is concluded that the effect of climate change in the Garin dam basin is greater than the change in land use due to its mountainous nature.
Conclusion
The results of the study of the effect of land use change on runoff in the Garin basin indicate that the amount of runoff is decreasing daily and monthly in this catchment area. Also, the results of the study on the effect of climate change on runoff in the Garinwestern basin indicate that the amount of runoff is daily and monthly in this catchment area. Considering that in both scenarios A2 and B2 the monthly average temperature, especially in the first and last months of the year, has an increasing trend and rainfall has decreased in the spring and winter, this decrease can be attributed to the increase in temperature which Following this, evaporation also increases and decreases in rainfall in this catchment area. Regarding the results, it can be seen that the average monthly runoff in months when rainfall decreased in January, February, February, April, May and December, and in the months when rainfall increased As of June, July, August and September, the amount of runoff will increase compared to the current period. It is also observed that the effect of land use change on the reduction of runoff in the upcoming period is lower compared to the change effect under A2 and B2 scenarios and will affect the climate change of the runoff more flatly and the reduction of runoff is more affected by climate change. According to the information obtained from these predictions, it is possible to properly manage the watershed and adopt appropriate management measures in accordance with the conditions of this watershed and to prevent unauthorized land use changes and reduce the damage caused by The phenomenon of climate change.
Bakhtiar Feizizadeh
Volume 4, Issue 11 , September 2017, , Pages 21-38
Abstract
Introduction
The modification of the Earth’s terrestrial surface by human activities is commonly known as the land use/land cover change (LULCC) around the globe. Although the modification of the land by humans to obtain livelihoods and other essentials has been a common practice for thousands ...
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Introduction
The modification of the Earth’s terrestrial surface by human activities is commonly known as the land use/land cover change (LULCC) around the globe. Although the modification of the land by humans to obtain livelihoods and other essentials has been a common practice for thousands of years, the extent, intensity, and rate of LULCC are far greater now than they were in the past. These changes are driving forces for local, regional, and global level unprecedented changes in the ecosystems and environmental processes. The empirical studies conducted by researchers from diverse disciplines have found that changes in the land use/land cover is a key to many diverse applications such as agriculture, environment, ecology, forestry, geology, and hydrology.
Satellite Remote Sensing and GIS are the most common methods for the quantification, mapping, and detection of the patterns of the LULCC, because of their accurate geo-referencing procedures, digital formats suitable for computer processing, and repetitive data acquisition. Technically speaking, the remote sensing based digital satellite images have a high capability for natural resources' management operations. Land use/land cover change detection is considered as one of the most important applications in the domain of the remote sensing satellite images. Related to this applicability, it will be possible to apply multi-temporal satellite images for the detection of the land use change. Based on the results obtained from the change detection operation and modeling of the further land use changes, one will be capable to makes better decision for natural resources' management. Based on this statement, the main objective of this research is to represent the applicability of the satellite images for the detection of the land use changes, particularly on the upper areas of the Allavian dam of the Sofi-chai basin.
Dataset and methods
The study area was the upper area of the Allavian Dam in Maragheh. The research was carried out based on the digital interpretations of the Landsat images (ETM+ and TM) of the years 1989, 2000, 2002, and 2015. Based on these images, the land use changes of this region were separately detected for 3 periods. It should be noted that the widely practiced operations such as image preprocessing, classification, and post processing with those related techniques were considered in this study. Indeed, it is widely known that preprocessing before the the change detection phenomenon is very important in order to establish a more direct relationship between the acquired data and the biophysical phenomena. Accordingly, atmospheric and geometric correction were applied as the first step on satellite images. In doing so, the LSLC classes were determined based on the spatial resolution of the satellite images. Then, image enhancement methods were applied to detect each LULC class on the satellite image. Next, GPS based training data was collected in the field operation and integrated with the satellite images. In addition, the supervised maximum likelihood was applied to derive LULC map for each year. The validation step was also part of this section for the accuracy assessment based on kappa coefficient and error matrix.
Results and Conclusion
After developing LULC maps, the results were transformed into GIS environment for the following steps and GIS analysis. The results indicated a significant changes in LULC of the study area. They also indicated that orchards cover had increased throughout the study periods but rich range lands widely converted into poor range lands because of losing the significant canopy of the native plants. Increasing the trend of the orchards area may be in relation with the population growth and this factor can be affected by ( have an effect on) range land degrading. The water supply out of Allavian dam might be another reason for increasing the orchard’s area. The results also acknowledged the capability of the remote sensing for the LULC and change detection analysis. The results of this research are of great importance for decision making authorities in governmental departments such as the ministry of agriculture and natural resources for the purposes of planning and decision making.
