Geoenvironmental approach to investigate surface and groundwater pollution-related problems in water-sensitive regions.

Abstract

The desert environment is a clean, dynamic system due to its remoteness from human interventions. Yet, sometimes it is approached by anthropogenic activities that change its balanced ecosystem. The present study states that the non-planned construction of wastewater plants has affected the environment and led to water resource deterioration. The presented approach is based on the integration of hydrogeologic data together with remote sensing and GIS applications as well as statistical, chemical, biochemical, and bacteriological analyses of water samples. The groundwater showed high salinity values (up to 13,236mg/l) where it is extracted from two coastal aquifers; the Middle Miocene aquifer represents the main one, while the Pleistocene aquifer is of limited use. The obtained results reveal the existence of pollution indicators in both stored rainwater and groundwater where the colony bacteria, NO3, chemical and biological oxygen demands, and total organic carbon exceed the permissible limits. The satellite images acquired between 2003 and 2021 demonstrated a land use change through the construction of a wastewater plant with two forests that led to the spreading of the partially treated water over the Marmarica Plateau. The photogeological lineaments are extracted where the plateau is affected by many faults (NE-SW, NW-SE, and E-W) that facilitate surface-groundwater interaction. The results indicate that the studied groundwater becomes vulnerable to the existing pollution sources, with the possibility of being affected by climate change and saltwater intrusion. Therefore, this integrated approach is presented to assess the current environmental problems and suggests a strategy to mitigate the pollution hazards.