Quantification of land cover change and its impact on hydro-geomorphic processes in the Upper Yangtze using multi-temporal Landsat imagery: an example of the Minjiang area

The Landsat MSS, TM and ETM+ data acquired in the year of 1975, 1989 and 2001 were used to quantify land cover change in the Minjiang area. Knowledge-based stratified classification was performed for each image and change detection was analysed. Profound changes in land cover, including widespread deforestation and extension of agricultural land, have been observed, notably along the river valley. Such a large reduction in forestland cover might be expected to lead to a significant impact on hydro-geomorphic processes. An attempt was made to identify gully erosion, one of the severe geomorphic processes after reduction in vegetation cover, using the Landsat image.