赣江上游的土地利用类型对山洪灾害的敏感性

目的]分析赣江上游的土地利用类型和地形条件的山洪灾害敏感性,为非工程性减灾工作的开展提供理论支持。方法]基于GIS技术,使用Landset影像获取土地利用数据和Aster的DEM数据,以小流域为最小研究单元,计算不同坡度、不同土地利用的山洪灾害敏感性,分析土地利用和坡度影响下的山洪灾害敏感性。结果]城镇建设、耕地建设等人工生态系统会增加山洪灾害发生,而森林、灌丛、草地等自然生态系统可以减缓山洪灾害发生。在坡度大于25°区域,耕地和城镇建设用地的敏感性显著增加,会显著促进山洪灾害发生。结论]研究区通过生态建设开展防灾减灾工程,应该增加自然生态系统的覆盖面积。此外,坡度大于25°的不适合开发区域,应尽量减少城镇开发和耕地开垦行为。

Sensitivity of Flood Disaster to Land Use Types in Upstream of Ganjiang River

Objective] The purpose of this study was to analyze the flood susceptibility to land use type and mountain terrain condition in the upstream of Ganjiang River, and to provide theoretical support for the undertaking of non-engineering hazard mitigation efforts. Methods] Based on GIS technology, data of land use types and Aster DEM were elicited from Landset images. Flood sensitivity was calculated in different slopes and land use types in a unit of small watershed. Results] The construction of towns, farmland, and other artificial ecosystem components could increase floods disasters; whereas forests, shrub lands, grasslands and other natural ecosystems components could scale floods disasters down. The sensitivity of farmland and urban construction land in slopes over 25 degree significantly promoted the occurrence of floods disasters. Conclusion] Disaster prevention and mitigation efforts should be carried out via ecological construction. The efforts should increase the coverage area of natural ecosystems. In addition, slopes more than 25 degrees are not suitable for development, where urban development and farmland reclamation were also not appropriate.