Landscape analysis of runoff and sedimentation based on land use/cover
change in two typical watersheds on the Loess Plateau
Abstract
Understanding sedimentation and runoff variations caused by land use
change have emerged as important research areas, due to the ecological
functions of landscape patterns. The aims of this study were to
determine the relationship between landscape metrics (LMs), runoff, and
sedimentation and explore the crucial LMs in the watersheds on the Loess
Plateau. From 1985 to 2010, Grassland (GRA) was the dominant landscape
in the Tuweihe (TU) and Gushanchuan (GU) watersheds. Unused land (UNL)
and farmland (FAR), respectively, experienced the greatest
transformations. The landscape in the study area tended to become
regular, connected, and aggregated. The landscape stability of the TU
watershed was higher than that of the GU watershed. Annual runoff and
sedimentation gradually decreased and significant relationship was found
between them (P <0.01). Due to larger FAR area and lower
landscape stability in the GU watershed, the sedimentation of the two
watersheds were similar, even though the runoff in the TU watershed was
greater. The LMs had more significant effects on runoff than that on
sedimentation yield. Shannon’s evenness index and the patch cohesion
index had the greatest effects on runoff and sedimentation, making them
the key factors of influencing water and soil loss. which could provide
a scientific basis for the prevention and treatment of soil erosion.