论文部分内容阅读
中国是滑坡和泥石流灾害频发和灾害损失严重的国家,滑坡和泥石流灾害风险评价对区域防灾减灾意义重大。以1 km×1 km栅格为基本评价单元,在GIS技术支持下,对比分析2000年和2010年中国滑坡和泥石流灾害风险分布及其空间变化。结果表明,2000年滑坡和泥石流灾害风险大致以黑河—腾冲人口密度分界线为界,界线西部以低度风险区为主,界限东部以中度和高度风险区为主。2010年低度风险区仍以此为界主要分布在中国西部,但高度风险区已明显越过界线向西扩展。10年跨度间,中度风险区、高度风险区和极高风险区面积均有增加,尤其以高度风险区面积比例增加最大。反之,低度风险区面积则大为减少并转变升高为中度风险区,中度风险区是各风险等级中变化面积最大、最不稳定且最为敏感的区域。由于高度风险区所占面积和比例较小,因此,除局部地区以外,整体上中国目前尚不属于滑坡和泥石流灾害高风险地区。随着未来10年中国经济的中高速发展,灾害易损度进一步升高,地区间经济差距逐步缩小,高度易损区与高度危险区重叠部分将逐步增大,因此中国滑坡和泥石流灾害风险将会继续升高,灾害风险变化总体形势趋于严峻。
China is a country where landslide and debris flow disaster are frequent and disaster losses are serious. Landslide and debris flow disaster risk assessment is of great significance to regional disaster prevention and mitigation. Taking the 1 km × 1 km grid as the basic evaluation unit, the risk distribution and its spatial variation of landslides and debris flow hazards in China in 2000 and 2010 were compared and analyzed with the support of GIS. The results show that the risk of landslide and debris flow disaster in 2000 is roughly bounded by the Heihe-Tengchong population density demarcation line, the western part of the demarcation line is dominated by low-risk areas, and the eastern part of the demarcation is dominated by medium and high-risk areas. Low-risk areas in 2010 are still mainly for this sector in western China, but the high-risk areas have been significantly expanded westward beyond the boundary. Over a span of 10 years, the area of moderately risky areas, highly risky areas and extremely high risk areas have increased, especially in areas with high risk areas. On the contrary, the area of low-risk areas is greatly reduced and transformed into moderately-risk areas, which are the areas with the largest, the most unstable and the most sensitive changes among the risk levels. Due to the small area and proportion of high-risk areas, China does not currently belong to high-risk areas such as landslide and debris flow disasters as a whole, except for some areas. With the rapid economic growth in China in the next 10 years, the degree of disastrous disasters will further increase, the regional economic gap will gradually narrow, and the overlap between highly vulnerable areas and highly dangerous areas will gradually increase. Therefore, the risk of landslides and debris flow disasters in China will Will continue to rise, the overall situation of disaster risk changes tend to be severe.