基于GIS的江西于都崩岗侵蚀空间分布研究

GIS-Based Research on Spatial Distribution of Slope Disintegration in Yudu County of Jiangxi Province

崩岗是沟蚀和重力侵蚀结合的一种特殊形式,是我国南方丘陵区水土流失的一种特殊类型,于都县是江西省水土流失较为严重的县份之一,水土流失面积843.82 km2,中度以上流失占流失面积的64.01％,尤以崩岗侵蚀为强烈.借助Aremap 10地理信息系统建立了江西于都崩岗侵蚀的数据库及影响崩岗的相关图层,将崩岗分布图层分别与影响图层叠加分析,从而得到研究区崩岗的分布规律.研究表明：于都县有崩岗4 062处,绝大多数崩岗正处于侵蚀发育旺盛期,侵蚀严重,崩岗类型以条型、瓢型、混合型为主,三者占崩岗数量的86.9％.崩岗主要发育分布在海拔200 m左右、坡度10°～30°、花岗岩发育的红壤区域.崩岗在全县23个乡镇均有分布,但在崩岗数量及侵蚀面积均具有北多南少、从西北向东南递减的空间分布特点.

As a combination of gully erosion and gravitational erosion, slope disintegration is a special type of soil erosion in hilly areas of south China. Soil erosion in Yudu County is relatively serious in Jiangxi province, with a soil erosion area of 843.82 km2 , and 64.01% moderate soil loss. Slope disintegration erosion is particularly serious in this area. By employing Arcmap 10 geographic information system, we established a database of slope disintegration and its relevant layers that influence the behaviour of disintegration for Yudu County of Jiangxi Province. The distribution of slope disintegration is obtained by analyzing the superimposition effect of disintegration distribution layers and influencing layers. Result shows that there are 4 062 slope disintegrations in this county, most of which are in vigorous erosion development. The slope disintegration mainly consists of bar type, ladle type and mixed type, which in total accounts for 86.9% of the slope disintegration. Slope disintegration mainly develops in the granite- grown red earth area at an altitude of about 200m with Slope degree from 10° to 30°. Slope disintegration distributes in 23 townships of this county. The number of disintegration and the erosion area both diminish from north to south and northwest to southeast.