Analysis on ecological security in the soft rock area of Middle Yellow River - A case study of Changchuan watershed, Inner Mongolia, China

Ecological security of Chanchuan watershed in the soft rock area of Middle Yellow River was synthetically evaluated and multi-objective programming of land use was forwarded by using RS and GIS techniques along with systems analysis methods. Moreover, according to the landscape ecology theory, digitalized optimum spatial patterns and rational proportion of land use were obtained through computer-aided adjustment with GIS software to get visible images of land use pattern that guarantees ecological security at Changchuan watershed. The results of comprehensive evaluation on ecological security of land use at Changchuan watershed indicate that measures of soil erosion control, ecological and environmental construction has certainly improved the situation of ecological security of this region during past decades, but the current situation of ecological security was not satisfactory. The results of multi-objective programming of land use pattern based on the ecological security evaluation indicate the optimum land use structure should be 3.7% of woodland, 38.6% of brushwood, 49.4% of grassland and 6.3% of crop land. Their spatial distributions were also patterned in light of requirement of ecological security. The average ESI in this region is leveled at relative secure, figuring at around 0.85.