چکیده:
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.
خلاصه ماشینی:
In arid and semi-arid environments that include more than 40% area of land surface in global scale (Deichmann and Eklundh, 1991), low vegetation cover, special soil features, and scant water resources are major characteristics.
This paper aims to review some of the key issues related to applications of remote sensing data to mapping and monitoring of important properties of soil in arid and semi-arid regions by a set of recent papers selected.
In other words, the motivation for this review is increasing demand for desert-related information to address a wide range of societal issues (for example water scarcity, food security, dust storm, soil degradation, and economic sustainability), the availability of unique earth observations from many new satellite-based remote sensing instruments, and the advancement of analysis and modeling techniques.
In the past two decades, as a result of increasing recognition related to ecological importance of biological soil crusts in desert regions, some studies have been conducted to investigate spectral characteristics of biological soil crusts or its species components and use of remotely- sensed data to classify or map biological soil crusts (Ager & Milton, 1987; Graetz & Gentle, 1982; Jacobberger, 1989; Karnieli & Sarafis, 1996; Karnieli & Tsoar, 1995; Karnieli et al.
3. Temporal changes Suitable timing relates to passive remote sensing data acquisition and must be taken into account in studying soil properties in arid and semi-arid regions (Metternicht and Zinck, 2003).
Detection of soil salinity changes and mapping land cover types based upon remotely sensed data.