Spatial Analysis of the Chemical Regime of Groundwater in the Karatal Irrigation Massif in South-Eastern Kazakhstan

Abstract

Understanding the groundwater chemical regime on irrigated lands is relevant for assessing hydrogeological and reclamation processes. Water chemistry, natural and climatic conditions, and drainage characteristics define the complex hydrochemical connections which are formed between irrigation waters, soil, and water of the unsaturated zone and groundwater. This research paper presents the results of studies of seasonal changes in the chemical composition of groundwater in the Karatal irrigated massif. A detailed analysis of the salt regime and chemical composition of groundwater have been performed based on a large number of samples for 2019. Besides, data related to the Karatal River and drainage waters quality inside the basin have also been analyzed. Results demonstrate that the salinization processes in the massif are determined by hydrogeological conditions and drainage availability. In the north-eastern part of the massif, a high risk of soil salinization has been observed as a consequence of all the salinization processes which are determined by its hydrogeological conditions and drainage availability. Data analysis over soil samples and irrigation and drainage waters show that the hydrochemical regime of groundwater on Karatal irrigation massif is influenced by the presence of saline soil-forming rocks, the groundwater depth, the volume, and the quality of irrigation waters, the characteristics of the natural drainage, and evaporation processes.