Anthropogenic load effect on formation of hydrogeological conditions of the Shirvan steppe of the Kura-Aras lowland in Azerbaijan

Abstract

Relevance. Azerbaijan water and soil resources are limited and subject to technogenic impacts more and more every year. Use of water and demand for water in the republic are growing at a higher rate every year. On the other hand, global climate changes have a serious impact on formation of hydrogeological processes. In such circumstances, it is very important to study the formation situations of hydrogeological conditions under the influence of natural and anthropogenic factors, to use the available water resources efficiently and economically, and to take preventive measures against negative processes. Aim. To study the regularity of formation of the hydrogeological conditions of the Shirvan steppe of the Kura-Araz lowland in the Republic of Azerbaijan under the influence of natural and anthropogenic processes over a long period time. Object. Subsoil waters of the Shirvan steppe of the Kura-Araz Lowland in the Republic of Azerbaijan. Methods. Based on the results of the studies (1977 to 2020) of perennial average level of groundwater and degree of mineralization, the rate of soil salinization, the regime of groundwater and based on the materials collected in this direction, the regime types of groundwater were separated and correlative dependence was found by the method of least squares between regime types and regime-shaping factors – atmospheric sediments, river networks, irrigation water, irrigation canals, drainage, etc. The genetic types of the regime were selected according to the factors creating the regime and the synchronicity of the groundwater level change. Results. Under the influence of natural and anthropogenic factors, the level of groundwater, degree of mineralization, chemical composition, salinity and chemical composition of soils have changed. From 1958 to 2020, due to the irrigation melioration, the groundwater level of the area rose by 4.1 m, due to the infiltration of surface water and removal of mineralized water through drainage, their mineralization rate decreased by 16.2 g/l. Based on the results of the research on changes in the level, degree of mineralization and chemical composition of groundwater, soil salinity and chemical composition, and based on the analysis of archival materials collected in this direction, groundwater regime types were selected and correlative dependence between regime types and regime-creating factors by the method of least squares was defined. Due to the synchronicity of regime-creating factors and groundwater level changes, the genetic types of the regime were selected – climate, hydrological, irrigation, irrigation-watering, drainage, irrigation-watering and the fields of their distribution areas were determined.