THE APPLICATION OF THE NEW METHODS ON LAND DEGRADATION STUDY A CASE STUDY ON DONGXI RIVER BASIN, WESTERN FUJIAN, CHINA
土地退化方法应用初步研究：以闽西沙县东溪流域为例

The attempts which apply the alternative methods for estimating rapidl soil erosion rates to elusidate the relationship between the land use types and land degradation has been made. The 137Cs measurement, magnetic susceptibility, aggregate stability, and the soil properties have been employed in Dongxi River Basin, a mountainous area of western Fujian. The results reveal that: (a)A plot of 137Cs inventory(Y) against slope angle(X) showing a strong inverse log log relationship(r=-0 83) indicates that much stronger soil erosion occurs on steeper slopes;(b)average soil loss(in thichness of top soil per year) in the past 30 years for arable slope crest, arable slopes and tea plantation slopes are 1.6, 10.4 and 8.0 mm/year respectively; (c)the surface layer enrichment factor of magnetic susceptibility(Y) in soil also shows an inverse log log relationship(r=-0 63) which indicates a similar tendency with the relationship between the 137Cs inventory(Y) against slope angle(X); and (d)the physical and chemical properties of soil among different land use types show different degraded characteristics at different significance levels.