高分辨率遥感影像在水土流失定量评价中的应用探讨——以Quickbird影像为例

我国是世界上水土流失最严重的国家之一,水土流失是我国的头号环境问题。从20世纪80年代起,我国开始将GIS技术应用于水土保持领域,主要是将GIS与通用水土流失方程结合来估算坡面土壤侵蚀,方程中的作物管理因子(C)和水土保持措施因子(P)主要是基于中低分辨率影像来获得的;对于沟蚀,目前主要采用GPS测量或实地调查等方法进行小尺度上的研究,对于大尺度范围上的研究甚少。针对上述两个问题,将高分辨率影像Quickbird与GIS相结合,探讨高分辨率遥感图像在水土流失定量评价中的应用,提出新的计算C、P因子的方法,较大地提高了C、P因子的准确度;同时,获得了研究区的侵蚀沟密度空间分布图,探讨了依据侵蚀沟密度空间分布图可以进行的相关工作。这都将为水土流失定量评价提供有益参考。

Application of High-resolution Images on Soil Loss Quantitative Estimation——A case of QuickBrid

Soil loss in China is very serious and it has become the top environment problem in China.Since 1980,GIS has been used to the domain of soil and water conservation.In our country,the most applications are to combine GIS and USLE to count the hillslope soil erosion.Especially,for the C and P factor,it often takes coarse-resolution images as data resource to get the value of C and P factor.But to some extent,this leads to mistakes on precision.At present,for the research on gully,it is often based on the measure of GIS or field investigation and pay more attention to the small scale.This paper,by using high-resolution image,provides new methods to acquire C,P which improve the precision of C,P.At the same time,the spatial distribution of gully are acquired and this will provide a new view to the larger spatial scale.All these works give some beneficial suggestion to the soil loss quantitative estimation.