SPATIAL ZONING OF THE SOIL HYDROPHYSICAL CONDITIONS OF WATERLOGGED AREAS

Abstract

This study examines the effects of changes in moisture content on the hydrophysical state of soils, using the left-bank area of Astana (Kazakhstan) as an example. The research is based on an analysis of data from 141 engineering-geological boreholes, grouped across 12 development sites. The main parameters used are natural soil moisture, the liquidity limit, the plasticity limit, and the liquidity index. To assess spatial changes in soil conditions, spatial modeling methods and Spline interpolation were applied in the ArcGIS Pro environment. Simulations were performed for the baseline water saturation scenario and a synthetic scenario, in which moisture values were increased by 20–50% to simulate potential waterlogging in the event of utility leaks and/or a rise in the groundwater level. Moisture distribution maps and zoning of the study area based on the liquidity index were created. The results showed that under baseline conditions, the area was characterized by predominantly stiff soil consistency, whereas an increase in moisture led to the formation of extensive zones of plastic and liquid consistency. The most potentially unfavorable conditions were identified in the southeastern and northwestern parts of the study area. At the same time, the proportion of the area with normal soil conditions decreases from 97.0% to 21.5%, while the risk and waterlogged zones increase to 56.1% and 22.4%, respectively. The proposed approach enables a spatial assessment of changes in the hydrophysical state of soils across large urban areas and can be used in engineering-geological surveys and the monitoring of building and facility foundations, including those in operation.