Samira Zandifar; Maryam Naeimi; Zohre Ebrahimi Khosfi
Volume 27, Issue 1 , April 2020, , Pages 144-158
Abstract
The most important structural factor that contributes to desertification is the appearance of salt domes. Due to its solubility and also the effect it can have on the quality of water and soil resources in the surrounding areas, its study is of special importance in agricultural projects and natural ...
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The most important structural factor that contributes to desertification is the appearance of salt domes. Due to its solubility and also the effect it can have on the quality of water and soil resources in the surrounding areas, its study is of special importance in agricultural projects and natural resources because it will reduce soil fertility and expand deserts. In this study, it has been tried to determine the quality of surface and groundwater and also to study the factors of geology, morphology, salt dynamics, and tectonic fractures around the Dashti salt dome and its relationship in desertification. The thickness of the salt column in the Dashti salt dome has been estimated at approximately 2,800 meters, and salt glaciers are affected by the topography of the dome (northeastern-southwest) from both sides and laid on the surrounding rocks. For this reason, low sediment is constantly threatened with contamination. Examining the dynamics of the dome, it was found that the balance between the amount of supply and the lack of salt in the desired salt dome is always established and plays an active and permanent role in the expansion of the desert around it. The flow of groundwater in the aquifers of the region is mainly controlled by the permeability of tectonic joints and faults around the dome and confirms the effect of the dome on the salinity of groundwater. Close activity to the surface of the Dashti salt diapir before the orogeny of Zagros is an important and fundamental factor in the destruction of the Kangan anticline soils and the expansion of desertification.
Hamidreza Abbasi; Mohammad Darvish
Volume 11, Issue 2 , August 2019, , Pages 163-178
Saeed Barkhori; Rasoul Mahdavi; Gholamreza Zehtabian; Hamid Gholami
Volume 25, Issue 2 , August 2018, , Pages 355-365
Abstract
The aim of this study was to investigate the temporal and spatial changes trend of groundwater quality for drinking purposes in Jiroft plain. The role of land use and geological formations in the groundwater quality was also investigated. In this study, the parameters of electrical ...
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The aim of this study was to investigate the temporal and spatial changes trend of groundwater quality for drinking purposes in Jiroft plain. The role of land use and geological formations in the groundwater quality was also investigated. In this study, the parameters of electrical conductivity, sodium adsorption ratio, pH, calcium, chlorine, magnesium, sodium, and sulfate were used and the zoning of qualitative data was done by the geostatistical method of Kriging in ArcGIS9.3 software; then, the classification of the region was done using Schoeller diagram. Results showed that in 2001, southern parts of the study area had a lower quality of groundwater but in 2014, northern parts had a lower quality. According to the results, the groundwater quality decreased overtime and the decreasing trend spread from the south to the center and the north of the region. Also, the land use map showed a low quality of groundwater in agricultural lands. The geology map showed a low quality of groundwater in central and southern parts. In general, it can be concluded that the water quality of the study area for drinking is decreased over time and influenced by land use and geological formations; thus, to improve the quality of groundwater resources the role of human factors (land use and agricultural activities) need be taken into account.
alireza mahmoudi; marzieh mokaram; fatemeh Abedi
Volume 24, Issue 3 , October 2017, , Pages 646-657
Sara Nakhaie Nejad; Gholamreza zehtabian; Arash Malekian; Hassan Khosravi
Volume 24, Issue 2 , July 2017, , Pages 268-279
Abstract
Nowadays, due to water scarcity in the country, especially in arid and semi-arid areas, optimal management of groundwater resources is necessary. This study investigates the quality and quantity of underground water of the Sarayan plain in the northwest of South Khorasan Province in a 14-year period ...
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Nowadays, due to water scarcity in the country, especially in arid and semi-arid areas, optimal management of groundwater resources is necessary. This study investigates the quality and quantity of underground water of the Sarayan plain in the northwest of South Khorasan Province in a 14-year period (1998-2012) using statistical methods. The number of samples studied included 20 wells, six qanats and three springs. Then, using GS + software, appropriate statistical methods were selected. Results showed that Kriging method was suitable for zoning of the factors. Using interpolation methods, appropriate spatial maps for each of the groundwater quality parameters (EC, TDS, and SAR) were obtained in three years (beginning, middle and end of the fourteen-year period). The results of the spatial variations of the TDS and SAR showed that the reduction of these two parameters was more severe in the middle and southern parts of the study area. To evaluate changes in groundwater depth in the plains, the depth maps of the ground water resources were prepared during the study period by the use of the results of measuring the depth of water in each of the observation wells. Results showed that in 1998, in the eastern and southern plains, the water was at a closer distance to the ground and with the advance toward the West and especially to the north, water was available in deeper parts of the ground. In the study area, the average amount of rainfall is less than the average amount of the whole of Iran and groundwater resources in agricultural water supply plays a fundamental role. Therefore, the sustainability of water resources is affected by sustainable management of underground water resources in the agricultural sector.
Yaser Ghasemi Arian; Hosein Azarnivand; Firoozeh Moghimi Nejad; Mohammad Jafary; Esmaiel Filekesh
Volume 21, Issue 3 , December 2014, , Pages 394-408
Abstract
This research was aimed to determine the rangeland suitability for sheep grazing in Chahtalkh-Sabzevar rangelands using FAO (1990) method. Initially, the DGN maps, including six sheets of 1:25000, topographic map of 1:50000, and geological map of 1:100000 of the study area were prepared and the vegetation ...
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This research was aimed to determine the rangeland suitability for sheep grazing in Chahtalkh-Sabzevar rangelands using FAO (1990) method. Initially, the DGN maps, including six sheets of 1:25000, topographic map of 1:50000, and geological map of 1:100000 of the study area were prepared and the vegetation types were detected. In each vegetation type, range condition, range trend and production were determined to produce the production suitability map. Then, the soil erosion sensitivity map was prepared using EPM method. To study the suitability of water, water sampling was done and the quantity of water was determined. Water samples were transferred to the laboratory to measure TDS, EC and Mg+2 for each sample. Finally, the suitability map of water resources was produced by combining the layers (provided for four slopes including 0-10%, 10-30%, 30-60% and >60%). The final model of rangeland suitability was prepared by overlaying the maps of production suitability, soil susceptibility to erosion and water. According to the obtained results, there is no suitability S1 class in the region and 23.7%, 18.92%, and 56.9% of the study area have S2, S3, and N suitability classes, respectively. Generally, it can be said that the conversion of rangeland to dryland, overgrazing and early grazing, formations susceptible to erosion, low vegetation cover, salinity, and improper distribution of drinking water sources for livestock are considered as the most important limiting factors for sheep grazing.
Marzieh Ghomishoun; Arash Malekian; Khosro Hosseini; Saeed Gharachelo; Mohammad Reza Khamoushi
Volume 19, Issue 3 , December 2012, , Pages 535-545
Abstract
Nowadays, water resources scarcity has become one of the most important issues in arid and semi arid regions including Iran which makes it necessary to optimize the utilization of these limited resources. This research surveyed the variations of EC, TDS, Cl-, SO4--, Na+ for an eleven-year period base ...
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Nowadays, water resources scarcity has become one of the most important issues in arid and semi arid regions including Iran which makes it necessary to optimize the utilization of these limited resources. This research surveyed the variations of EC, TDS, Cl-, SO4--, Na+ for an eleven-year period base on the data collected from selected wells of Semnan Plain. In order to select the appropriate model to fit to experimental variogram, Residual Mean Square Error was used. Several geostatistical approaches such as simple kriging, ordinary kriging, simple cokriging, and ordinary cokriging as well as other deterministic interpolation methods including Inverse Distance Weighing (IDW) with different powers were considered. Then, validation approach and Mean Absolute Error (MAE) criteria were considered to determine the most appropriate interpolation technique. Meanwhile cokriging method was selected as the fit method for qualitative parameters which illustrated the variations of groundwater quality in almost 67% of the cases. Comparison of quality parameters of spatial zoning maps showed that the rate of these parameters was developing in the core shape to the selected wells 15 and 13 and also, it had an increasing trend in plain boundaries for an eleven-year period. But there were no significant changes in the centers of plains. According to the results, lithology, unsustainable harvesting of wells, increased evaporation and thus reduced level of ground water and inappropriate methods of irrigation and agriculture were identified as the most effective factors.
Akbar Javadi; Hosein Arzani; Ali Salajeghe; Mahdi Farahpor; GHavam ... Zahedi
Volume 14, Issue 4 , February 2008, , Pages 513-523
Abstract
Proper use from water resources, especially in arid and semi arid rangeland are very important. Water is one of a valuable ecosystem component in rangeland management. In this study for surveying of water suitability, tree models including quality model, quantity and distance model made final model. ...
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Proper use from water resources, especially in arid and semi arid rangeland are very important. Water is one of a valuable ecosystem component in rangeland management. In this study for surveying of water suitability, tree models including quality model, quantity and distance model made final model. FAO (1991) method (recommended for land capability evaluation) was used for suitability classification. The study was conducted in Halvan region is located in Yazd province. According to the results, water resources distance and accessibility to water is the most declining factor for suitability. Quality factor is a limiting factor in part of the study area, too. Based up on, areas more than 15km far from water point are not suitable, but less than 6km are very suitable. Proper distribution of water resources increases water suitability and cause better and monotonous utilization of rageland.
Heshmatolah Agharazi
Volume 9, Issue 3 , September 2001, , Pages 1035-1046