Irrigation
N. Haj Seyed Ali Khani; H. Saeediyan
Abstract
Introduction Control and extraction of water using underground dams in arid regions has been of interest to researchers since not too long ago. Construction of underground dams does not require surface water storage and does not change land use. Therefore, they are environmentally suitable. The ...
Read More
Introduction Control and extraction of water using underground dams in arid regions has been of interest to researchers since not too long ago. Construction of underground dams does not require surface water storage and does not change land use. Therefore, they are environmentally suitable. The lack of groundwater resources on the one hand and indiscriminate and unscientific harvesting on the other hand, and the increasing needs associated with population growth, will cause scientific communities to revise and provide appropriate solutions for managing the exploitation of groundwater aquifers and creating new resources or renewable reservoirs in the country. Nowadays, in many countries of the world, the construction of underground dams has been considered as a new method for utilization of water resources. Several criteria such as physical, socio-economic and hydrological criteria are involved in the location of underground dams. Underground dams have wide applications for feeding groundwater aquifers and water storage, as well as preventing soil erosion and increasing groundwater quality. Due to the limitation of water resources and the lack of equality of the world's share in exploiting this divine gift, it is anticipated that most countries will soon suffer from severe water shortages, so that it is firmly believed that if this problem continues, many international conflicts will be over water for centuries to come. One of the strategies to deal with water shortage is to extract water from new resources, especially the discovery of underground, which can be done by constructing different underground dams and with the knowledge of the world.Materials and Methods In this study, to determine the susceptible areas of underground dam construction using field visits was selected Pashueeyeh watershed. To communicate between effective criteria and save time and money, a method based on combining maps in GIS and RS system has been used. In the first step, investigations were carried out to identify suitable areas for the construction of underground dam. For this purpose, data extracted from basic maps, findings in this field and expert opinions were used.Results and Discussion Therefore, a combination of new sciences such as GIS, RS and geoelectrics was used in determining the susceptible areas of underground dam construction, which in turn is a valuable research that provides the situation for creating other combined researches in different climates of the country, stating that a combination of different sciences in addition to the sciences mentioned in this research can increase the quality of studies related to underground dams and even large groundwater discovery are effective and in case of mild to severe droughts can be a way to solve the country's problems in the field of using quality water and lower extraction costs. The results showed that Pashueeyeh watershed is not a susceptible place for underground dam construction in Lut desert region for water storage. According to the results of geoelectric sodages and field evidences, the bedrock at the proposed location has dense clay that have many salts and the depth of impact on the bedrock varies between at least 2.6 meters and a maximum of 7 meters. On the bedrock is a river alluvial layer consisting of two wet and dry horizons. Also, the river alluvial layer consists of sequences of layers with different aggregation and permeability. The results show that the electrical resistance of different layers rarely reaches more than 30 ohms per meter; this is due to fine grain texture and high density of sediments as well as water salinity.Conclusion One of the strategies to deal with water shortage is to extract water from new resources, especially the discovery of underground aqueous, which can be done by constructing different underground dams and with the new knowledge of the world. Underground dams in the world are expanding in different climates, especially in arid and semi-arid regions, which are likely to become one of the most important sources of water extraction in the future years, especially if they are associated with new technologies and combination of GIS, RS and geoelectric. the results showed that the combined role of GIS, RS and geoelectric in determining the susceptible areas of underground dam construction makes the accuracy of proper site construction of underground dams and even the discovery of underground aquifers much higher and achieved valuable results.
Irrigation
H. Saeediyan; Hamid Reza Moradi
Abstract
Introduction: Erosion and sediment production studies along with other natural resources studies in decision making and success and efficiency of watershed plans are of great importance. In order to plan and be aware of the destructive situation of the watershed, it is necessary to have erosion and sediment ...
Read More
Introduction: Erosion and sediment production studies along with other natural resources studies in decision making and success and efficiency of watershed plans are of great importance. In order to plan and be aware of the destructive situation of the watershed, it is necessary to have erosion and sediment production from each watershed. The information about sediment load of basins can show the prospect of erosion. Sediment scatter from the soil surface by the impact of raindrops and shear force of runoff and is transported to downstream by spraying from raindrops and mainly by runoff. Also, the stress characteristics of soil particles are important in the process of effective transport. In recent decades, soil erosion has been intensified due to the human interference, inappropriate land management and land use. This is much more important in developing countries, because soil erosion is a serious risk to sustainable development in these countries. Soil erosion on farmland occurs due to the interaction between nature and human activities that have been being intensified in recent years. Estimation of sedimentation in watersheds, dealing with sediment accumulation risks in water structures and reservoirs of dams are the main objectives in water resources management that leads to sustainable development. One of the most erodibility of Iran is the Gachsaran formation. Gachsaran formation is about 1600 meters thick. A viewpoint of lithology is consisting of salt, anhydrite, colorful lime, and some shale. Gachsaran formation age is lower Miocene. Materials and Methods: In this study, in order to determine sediment estimation by using different erosion components in different land uses of Gachsaran formation deposits, a part of Kuhe Gypsum watershed of Izeh city with an area of 1202 hectares was selected. In this study, the relationship between produced sediment and different erosion components such as runoff,soil permeability,runoff, and erosion threshold in different land uses of Gachsaran formation was determined by multivariate regression. Then, sampling of erosion different components was done at 6 points with 3 replicates and at rainfall different intensities of 0.75, 1 and 1.25 mm/min in three land uses of rangeland, residential area and agricultural using rain simulator. SPSS and EXCEL softwares were used for statistical analysis. Results and Discussion: The results showed that sediment estimation using different erosion components presents acceptable results and can be used for other watersheds. The results also showed that in sediment estimation by erosion different components, runoff and erosion threshold had the most positive and negative effect and in eight cases played a role in modeling. Then, soil permeability has the average effect of positive and negative and has played a role in modeling in seven cases. In addition, runoff has not played a role in modeling in any of the three different land uses and intensities of precipitation. Conclusion: Sediment estimation by erosion different components, the runoff and erosion threshold had the highest effect. Soil permeability had a moderate influence and runoff rate has not played a role in modeling in any of different land uses and precipitation intensities, it indicated the much more important role of runoff and erosion threshold and soil permeability in this modeling method in estimating sediment production. Finally, sediment estimation method by using erosion different components showed that it could be more applicable in sediment estimation in hard-to-reach watersheds in the future and be more effective in soil conservation and erosion reduction with appropriate and rational estimates in more appropriate implementation of watershed projects.
