Determination of Soil Characteristics and Degradation Using Geospatial Technologies in the Al Ahsa Oasis

Abstract

Soil degradation associated with wind and water erosion and physical and chemical deterioration is increasing at an alarming rate worldwide. This research identified soil characteristics and spatial distribution of soil degradation risks in the Al Ahsa Oasis. Several quantitative analytical approaches used geospatial techniques, namely, ArcGIS, Erdas Imagine10, and ENVI 5.3. Six selected remote sensing indices were used, i.e. the salinity index (SI), normalised difference salinity index (NDSI), brightness index (BI), normalised differential vegetation index (NDVI), vegetation soil salinity index (VSSI), and soil adjusted vegetation index (SAVI) software. Field verification monitored the degradation of different types of soil. Samples were collected in May 2019 and processed using satellite images and mechanical and chemical laboratory analysis for 36 samples. The Universal Soil Loss Equation and climatic data were used to measure the annual soil loss rate in the Al Ahsa Oasis. Integration of these datasets resulted in a map of soil degradation values. The results show that the sampled oasis soils have degraded physically, chemically, and biologically. The average physical degradation was 9.93 g/cm3/year, the average biological degradation was 2.93%/year, and the average chemical degradation was 36.36 mmhos/cm.