Developing method of vegetation fraction estimation by remote sensing for soil loss equation: a case in the Upper Basin of Miyun Reservoir

Vegetation fraction is an input parameter to scale, the vegetation cover on the ground for soil loss equation. In order to calculate the yearly volume of losing soil in the Upper Basin of Miyun Reservoir in the north of Beijing, China, it is necessary to develop a model to estimate vegetation fraction using remote sensing technology. Based on the analysis on the existing methods of measuring vegetation fraction, an improved Dimidiate Pixel Model was developed to estimate vegetation fraction from normalized difference vegetation index (NDVI) derived from Landsat TM images, and a new method was also brought forward to quantify NDVI thresholds of soil and vegetation. The. vegetation fraction data have been estimated using improved model in the study area, and was validated with the field survey data. The result shows that the improved model could satisfy with the need for quantifying vegetation cover parameter front TM imagery for soil loss equation