Geography and plan
ehsan Hosein-Nezhad-Makki; mehdi bashiri; hamid-reza moradi
Abstract
Population growth, along with the development of industry and agriculture, has led to an increase in water consumption. Limited surface water resources have led to over-harvesting of groundwater aquifers and has had irreparable consequences for the country's water resources and environment, including ...
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Population growth, along with the development of industry and agriculture, has led to an increase in water consumption. Limited surface water resources have led to over-harvesting of groundwater aquifers and has had irreparable consequences for the country's water resources and environment, including the subsidence phenomenon, which has covered most of the country's plains. The present research aims to identify the effective factors and areas at risk of subsidence in Fadafan village of Kashmar. For risk zoning, during 2019, the lithology, land use, Petrology, aquifer Extraction rate, Distance from the stream, Fault, exploitation wells, springs and aqueducts factors as well as geomorphological factors including slope, direction and height studied and each factor turned into an information layer, then modeling and evaluation were performed using random forest algorithm in R software. Then, to determine the areas prone to subsidence, risk zoning maps in five classes were extracted using two methods of information value and area density in ArcGIS environment. The results showed that in the methods of area density and information value, 97.01 and 91.04% of subsidence were in the very- high and high-risk class, respectively. Therefore, both methods have been successful in risk zoning. Also, the aquifer extraction and land use factors are most important in subsidence. Also based on the ROC curve, random forest algorithm with very high accuracy (93%) has provided good results in prioritizing and the importance of effective factors in subsidence. The southern part of the region with rangeland use, has the highest and irrigated agriculture in the region has the lowest risk in the spatial development of land subsidence.As a result, aquifer recharge management by spreading floods and reducing water extraction in the southern part of the region can be effective and practical in reducing the risk of occurrence and development of subsidence.
Geography and plan
amir salari; Maryam heydarzadeh; nasim Ghashghaeizade
Abstract
Continuous monitoring of the quantity and quality of groundwater resources is essential due to the excessive dependence of employment on these resources. The present study was conducted with the aim of quantitative and qualitative study of groundwater resources in the villages of centeral part of Bandar ...
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Continuous monitoring of the quantity and quality of groundwater resources is essential due to the excessive dependence of employment on these resources. The present study was conducted with the aim of quantitative and qualitative study of groundwater resources in the villages of centeral part of Bandar Lengeh city. After quantitatively estimating the groundwater balance, taking into account all components of the aquifer inlet and outlet, level hydrogeological maps and groundwater level changes based on the average of the lunar data were at least in GIS software (10.3 version). By quantitative and qualitative monitoring of groundwater resources in the study area, using water quality statistics of 35 wells that were registered by the Regional Water Company during the statistical period of 2003-2018, groundwater curves were drawn and plotted. The results showed that the groundwater balance of Pedlmezan, west Dezhgan and east Dezhgan aquifers were 5.94, 0.64 and 3.24 million cubic meters per year, respectively, and the amount of allowable withdrawal from the mentioned aquifers were 5.60, 0.64 and 0.64 million cubic meters per year, respectively. Annual drop of -0.03, -0.08 and -0.07 meters of water level of Pedlmezan, west Dezhgan and east Dezhgan indicates the favorable conditions of the aquifer water balance. The qualitative results of the basin showed that the average electrical conductivity of Pedlmezan aquifer has decreased from 6935 μs⁄cm in 2007 to 5654 μs⁄cm in 2003. In Dezhgan plain aquifer, it was found that the average electrical conductivity of the aquifer has increased from 7410 μs⁄cm in 1998 to 10424 μs⁄cm in 2007. Decreasing the amount of electrical conductivity in Pedlmezan aquifer and increasing it in Dezhgan basin is directly related to fluctuations in rainfall in the relevant basin in this period. The general result of this research is that the integrated management of water resources and the measures and planning of the regions have maintained the relative balance of water balance in the region, but in order to prevent the reduction of the quality of water resources with high salinity of the basin, the ban on further exploitation of the water resources of the basin should continue.
