remote sensing application in evaluation of soil characteristics in desert areas

soil is one of the most important natural resources covering a large area of the land surface. soil plays a vital role in biosphere processes, such as energy balance, hydrology, biochemistry, and biological productivity. it supports plants that supply foods, fibers, drugs, and some other human needs. conversely, desert regions include about one third of earth lands and these regions have increased caused by desertification, which is one of the main three world challenges in 21st century in global scale. thus, it is important to monitor and map soils (especially in desert regions) and understand how these resources should be utilized, managed, and conserved properly to aim at implementing ecological role. remote sensing has improved from traditional methods for assessing soils to informative and professional rapid assessment techniques to monitor and map soils. previous studies have shown the utility of digital aircraft and satellite remote sensor data in the pedologic and geologic mapping process. remote sensing offers a potential to provide information about soil characteristics over large regions. however, the intent of this paper is to focus on discussion about remote sensing applications to study desert regions. in this review, at first, we would discuss about the remote sensing applications to research on soil properties including soil salinization, crusting, moisture, texture, mineralogy, approaches, and techniques used to classify soils. in second section, we would argue about constraints tied on remote sensing applications data gathering usually conducted about investigation on soil characteristics in arid and semi-arid regions.