Estimating soil erosion and analyzing its spatio-temporal characteristics in Guij iang river basin,Guangxi
CHEN Ping
LIAN Yan-qing
JIANG Zhong-cheng
QINXiao-qun
Abstract：The Guij iang river basin is situated in China’s southwest karst area.It is well-known for the Li-jiang river,which has the most scenic karst landforms in the upper reaches of the basin.The Guijiang river is a major tributary of Xijiang river in the Pearl river basin.Research on soil erosion in the Guijiang river basin, hence,has practical significance for conservation of the aquatic ecology and security of the Pearl River Delta. In addition,the soil erosion model developed for this study is fundamental to research on the carbon budget of this karst area.The Revised Universal Soil Loss Equation (RUSLE)was utilized to calculate the soil loss rate and soil loss amount in the Guijiang river basin,Guangxi.The spatial distribution of soil erosion was an-alyzed,and the natural and human factors associated with soil erosion discussed.It was shown that about 51.8% of the land area of the Guijiang river basin underwent soil loss to differing degrees.The Guijiang river basin had an average-annual soil loss of up to 2.95×106 tons and the average soil erosion rate was 153.5 t/km2 ,identified as medium erosion.85% of the total area of the study basin had micro-slight and medium soil erosion.Strong or greater soil erosion was found in 1 5% of the study area,mainly in the north of the basin, the high-elevation south and northwest mountain areas of the Gongcheng river.The seasonal distribution of rainfall in the basin determined similar temporal distribution of soil erosion.Soil erosion intensity and total soil loss peaked in the second quarter,because the ratio of rainfall erosivity from April to June is highest in a whole year.This is followed by the third quarter,which accounted for one third of the total annual soil loss. Soil loss reached a maximum in the hilly and mountainous areas with elevations ranging from 30m to 600 m. Soil loss in the karst areas was nearly all derived from areas of no or slight karst rocky desertification.The intensity of soil erosion was enhanced following increases in the degree of karst rocky desertification from no to medium,and the soil erosion in areas of slight or medium karst rocky desertification reach strong degree. Soil losses calculated by the RUSLE model developed for the Guijiang river basin were basically in accord with sediment discharge data from past literature,indicating that RUSLE can be properly used to estimate soil erosion intensity and soil loss in karst river basins.
Keywords：Guijiang river basinsoil erosionRevised Universal Soil Loss Equation(RUSLE)rocky deserti-fication
Publication Date：2014-10-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：10( 473-482 )