Geophysics
Marzie Shabani; Abolfazl Rezaei; Zohre Masoumi
Abstract
The water table in the Zanjanrood catchment has severely declined recently. Therefore, determination of the groundwater potential zoning map is of great importance for optimal management of water resources. Here, we used seven effective criteria including lithology, slope, drainage, lineament, rainfall, ...
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The water table in the Zanjanrood catchment has severely declined recently. Therefore, determination of the groundwater potential zoning map is of great importance for optimal management of water resources. Here, we used seven effective criteria including lithology, slope, drainage, lineament, rainfall, spring density and landuse to asses groundwater potential. The analytical hierarchical analysis process was used for weighting the criteria. Overlay analysis was implemented using TOPSIS model to prepare the groundwater potential map in four categories of priority including very-good, good, low and poor. In general, the very-good category corresponds with the first priority while the lowest potential of groundwater match with the fourth priority. The high-discharged production wells and the geoelectrical investigations (resistivity and induced polarization) were applied to verify the model. The spatial distribution of the high-discharge production wells has completely coincided with both the very-good and good priorities in the area. The results of resistivity and IP models also are in good agreement with those from the TOPSIS model. Overall, the results suggest there is no rich aquifer in mountains of the Zanjanrood catchment. Furthermore, the most important aquifer in the Zanjanrood catchment is located around the Zanjanrood River where a severe water table decline has occurred.
Geophysics
zahra hajeb; zahra mousavi; zohreh masoumi; Abolfazl Rezaei
Abstract
The arid and semi-arid climate with a low rainfall along with the population growth has been lead to overexertion from groundwater resources over recent two decades in Iran. This over-extraction has been led to the significant groundwater depletion and water level decline in most parts of Iran as well ...
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The arid and semi-arid climate with a low rainfall along with the population growth has been lead to overexertion from groundwater resources over recent two decades in Iran. This over-extraction has been led to the significant groundwater depletion and water level decline in most parts of Iran as well as to the significant land subsidence in many aquifers throughout Iran. In this study, we investigated the subsidence occurred over the Jafarabad and Qanavat in Qom plain using the radar interferometry technique in conjunction with hydrogeological measurements. We used ENVISAT ASAR images from 2003 to 2010, in descending orbits to produce interferograms. Once all interferograms are corrected from topographic and flatten phase, we obtain the mean velocity map of the Qom plain region based on SBAS time series analysis method. The mean velocity map reveals 35 and 28 mm/yr of going away deformation in the line of sight direction in Jafarabad plain and Qanvat plain, respectively. Zoning map of subsidence resulted from the InSAR analysis in conjunction with the water level measurements and the thickness of fine-grained sediments (clay and silt) across the aquifers indicated that the maximum subsidence occurred in the places that not only have a higher water level decline but also have the thicker thicknesses of fine-grained sediments. This work clearly highlights the influences of mismanagement of water resources and over-extraction of groundwater in the arid areas.