Spatiotemporal Variation of Ecological Risk in Upper Reaches of Lijiang River by LandUse Change

Based on remote sensing images of upper reaches of Lijiang River, Guangxi, in 1986, 2000 and 2013, the land-use data were extracted andecological risk index was constructed. The characteristics of spatiotemporal variation of ecological risk were analyzed by spatial autocorrelation. Theresults showed that land use changed significantly from 1986 to 2013 in upper reaches of Lijiang River. Woodland and construction land increasedwhile farmland decreased. Ecological risk kept at a low level and decreased continuously in the research area. The spatial distribution of ecologicalrisk showed significant positive autocorrelation. Cities and towns had higher ecological risk along Lijiang River, mountain and forest in the northernand western of the research area had lower risk. The research demonstrated that ecological risk was low in upper reaches of Lijiang River, withincrease of areas, and small area has high ecological risk but increased quickly.