Projected Exploitable Groundwater Resources in the Dagestan Piedmonts

摘要

The projected exploitable underground freshwater resources (PEUFR) on the territory of a hydrogeological structure of the third order, a small artesian basin system (SABS), was determined with allowance for the water shortage in the Dagestan piedmonts under the conditions of an acutely arid climatic regime. Geologically, the study area belongs to the Tertiary folding, where work has been carried out over the past decades to search for, explore, and evaluate reserves and predicted resources for the use of fresh groundwater for domestic and drinking water supply. The previous studies were generalized, and promising hydrogeological regions were identified with calculation of the predicted resources for the use of fresh groundwater, especially wide, deepened river valleys that turn into alluvial fans and form foothill plumes. The data on the meteorological, hydrogeological, and geological knowledge of the territory, the chemical composition of groundwater, and the lithology of the cover and aquifers have been processed; prospective sites for groundwater exploration and areas of their supply, transit, and discharge were identified to develop a design scheme. The work of existing water intakes on the approved reserves was analyzed, and the potential to increase the PEUFR outside the fields was considered. The hydrogeological conditions of the region and the SABS and a brief description of previously explored groundwater deposits are given; promising areas for groundwater exploration are identified, and their projected exploitable resources are calculated. The PEUFR for the limited synclinal structures of the Upper-Middle Sarmatian deposits was determined with the condition of precipitation infiltration. Its value was 25 600 m(3)/day for synclinal artesian intermountain basins and for Chokrak, Chokrak-Tarkhan, and Konk-Karagan sandy-argillaceous deposits.