2.2. Data sources
Land use/cover data were acquired from LANDSAT
images in 1980 (MSS), 1988 (TM), 1994 (TM) and 2000
(TM). Using topographic contour data (1:10,000) of the
study area, a vector DEM was generated. For the purpose of
overlaying with some pixel data, such as land use and soil
type, etc., a DEM map at a resolution of 3030 m was also
obtained. Meteorological data including annual and monthly
precipitation (1953–2000), average precipitation and runoff,
annual maximum rainfall in 24 h (1954–1993) and
precipitation data of some typical rainstorms were obtained
from local meteorological station.