Assessment of spatial distribution of soil loss over the upper basin of Miyun reservoir in China based on RS and GIS techniques

Abstract

Soil conservation planning often requires estimates of the spatial distribution of soil erosion at a catchment or regional scale. This paper applied the Revised Universal Soil Loss Equation (RUSLE) to investigate the spatial distribution of annual soil loss over the upper basin of Miyun reservoir in China. Among the soil erosion factors, which are rainfall erosivity (R), soil erodibility (K), slope length (L), slope steepness (S), vegetation cover (C), and support practice factor (P), the vegetative cover or C factor, which represents the effects of vegetation canopy and ground covers in reducing soil loss, has been one of the most difficult to estimate over broad geographic areas. In this paper, the C factor was estimated based on back propagation neural network and the results were compared with the values measured in the field. The correlation coefficient (r) obtained was 0.929. Then the C factor and the other factors were used as the input to RUSLE model. By integrating the six factor maps in geographical information system (GIS) through pixel-based computing, the spatial distribution of soil loss over the upper basin of Miyun reservoir was obtained. The results showed that the annual average soil loss for the upper basin of Miyun reservoir was 9.86 t ha(-1) ya(-1) in 2005, and the area of 46.61 km(2) (0.3%) experiences extremely severe erosion risk, which needs suitable conservation measures to be adopted on a priority basis. The spatial distribution of erosion risk classes was 66.9% very low, 21.89% low, 6.18% moderate, 2.89% severe, and 1.84% very severe. Thus, by using RUSLE in a GIS environment, the spatial distribution of water erosion can be obtained and the regions which susceptible to water erosion and need immediate soil conservation planning and application over the upper watershed of Miyun reservoir in China can be identified.

Soil Conservation by Vegetative Systems in Oil Palm Cultivation

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Spatial modelling of soil erosion susceptibility mapping in lower basin of Subarnarekha river (India) based on geospatial techniques

“…R factor signifies the erosivity happening from rainfall and runoff at a particular location (Pan and Wen 2014;Chen et al 2011b). The estimated R factor is portrayed in Fig.…”

“…For LS calculations, the slope length and slope steepness can be used (Chen et al 2011b). The percent of slope was determined from ASTER DEM, while a grid size of 30 m was used as field slope length (k).…”

Soil erosion of Hungary assessed by spatially explicit modelling

“…Lahloi, Rhinane, Hilali, Lahssini, and Khalile (2015) used the USLE with remote sensing for potential erosion risk calculations in Morocco. USLE, and its revised version RUSLE, are used mainly for estimation of the yearly amount of soil loss in tonnes per hectare per year (t/ ha/y) (Chen et al, 2010;Doğan et al, 2015;Fantappiè, Priori, & Costantini, 2014).…”