Challenges in relating land use to sediment yield in the Upper Yangtze

Observations of the spatial pattern of sediment yields within the Upper Yangtze basin have suggested the importance of agricultural land as a major source area. The paper attempts to examine the relationship between land use and sediment yield by incorporating land cover types, derived from AVHRR data, into a multivariate analysis of factors controlling sediment yields. The extraction and analysis of catchment variables is undertaken in a GIS framework. Relationships between indices of agricultural land and sediment yields are highly scattered and the precise influence of land use on regional sediment yields remains rather inconclusive. There is a tendency for catchment areas with high proportions of arable land to exhibit high sediment yields but the individual catchments generating the highest sediment yields within the Upper Yangtze appear to relate to specific conditions such as landsliding or loess cover.