The Disasters Prevetion And Reduction In Haiyuan Region, Ningxia Province Based On The Ecological Risk Assessment

Based on the ecological risk assessment and regional ecological security theory and methodology, and by utilizing the remote sensing information, history records, investigation data and GIS technology synthetically, this paper studied the main ecological risk source, namely drought, in Haiyuan region, Ningxia province. Thus, in this region, not only the general ecological risk assessment and the risk classification regionalization have been accomplished, but also the idiographic ecological reconstruction program has been brought forward, and finally the disasters prevention and reduction system has been established.Results of the risk classification regionalization are as follows:The first-class risk zone locates the northern study area, including most or part of Xingren town, Xutao town, Xinglong town, Songchuan town, etc. In detail, most of Xingren town belongs to this zone, while the rest 3 towns are only part of this zone with excluding the inhabitant spots and medium coverage grass land. The second-class risk zone mainly locates the southern and middle area of sloping croplands. The third-class risk zone locates the southern and middle area of plain land, dam land, river-beach land, ditch land, table land and the low and medium coverage grass land. The forth-class risk zone locates the southern and middle area of shrub land, open woodland and the medium coverage grass land. The fifth-class risk zone locates the southern and middle area of forested land and high coverage grass land. And finally, the sixth-class risk zone mainly locates the construction land (towns, inhabitation spots, etc.), unused land and some water areas.Based on the above results and regional ecological security theory, and through analyzing the special characteristics of different regionalization, it has put forward corresponding ecological reconstruction program in order to establish the disasters prevention and reduction system ecologically & safely.The first-class risk zone, which is mainly plain land, should pay its attention to 2 aspects. Firstly, it is supposed to strengthen its environment construction, increase its vegetation coverage rate, extend the economic woods' planting area in dry lands moderately and improve the local rain water utilizing rate and its relative economic benefit. Secondly, it is ought to strengthen the new catchments materials' application in inhabitant spots, improve the efficiency of rain water flow, increase the flow quantity, extend the cartilage economical scale and construct some sluice establishments like water vaults. The sloping lands here should develop stockbreeding and plant grass as much as possible.There are 2 general utilizing modes of sloping lands and corresponding industrial development programs for the second-class risk zone. In detail, they are firstly arbor-shrub-herbage ecological &...