新疆地区干旱灾害风险评价

发布时间：2018-01-25 02:23

本文关键词： 干旱灾害 AHP层次分析法 GIS 风险评估新疆地区　出处：《西北农林科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：全球范围内的气候变暖已成趋势,气候变暖将影响全球水循环以及各区域水分平衡。气候变暖导致水资源的时空分布发生变化、降雨的时空分布更加不均匀,进而导致极端气候频繁发生。新疆地区地处西北内陆干旱区,水资源总量严重缺乏,因为干旱造成的水资源短缺是制衡新疆地区生态平衡和制约新疆地区国民经济持续、稳定发展的关键因素。因此,新疆地区干旱灾害风险等级的划分,对今后新疆地区防灾减灾、农业结构调整、农业用水规划及生态环境的建设具有重要的参考价值。本文基于新疆地区1961-2013年53年间50个气象站逐月降水数据,通过计算降水距平百分率、降水Z指数、SPI,查阅《新疆统计年鉴》得到农业、经济指标。根据干旱灾害风险指数模型理论,选取了降水距平百分率、降水Z指数、SPI、作物、人口密度、废水排放量、GDP和有效灌溉面积八个指标对旱灾情况进行风险评价。将基础数据进行标准化处理,通过反距离权重插值得到面积权重,结合AHP层次分析方法和熵权重法赋予指标因子权重,选取最优分割法等级化计算过程和GIS的干旱评估模型和风险评估方法,将新疆地区划分为低风险区、较低风险区、一般风险区、较高风险区、高风险区5个等级,初步提出新疆地区旱灾风险区划分方案。主要得到以下结果:(1)近10年即2004-2013年新疆地区降水距平百分率差异从-38.52~51.63不等。新疆地区不同时期不同的旱涝情况具有明显的时空分布特征,且区域性较强,从总体上看,东北部与东南部降水呈现减少趋势,西南部呈增高趋势。(2)新疆地区总体旱涝十分不稳定,降水Z指数、SPI总体呈现上升趋势。1961-2013年间发生旱灾17次,发生涝灾15次,即旱涝发生的频繁且分布基本平均,但发生偏旱的频率明显大于其他级别的旱涝事件。新疆地区降水在未来呈增加趋势,人口密度、废水排放总量、GDP和有效灌溉面积呈不同速率的增长。(3)从新疆地区旱灾风险区划分方案可以看出新疆地区干旱风险存在明显的地域差异。干旱灾害的高风险区主要集中在新疆西南部地区,和田地区、喀什地区和柯尔克孜自治州整体接近高风险区。该区域全年降水稀少,蒸发量高,具有极高的危险性,故评价结果为高风险区。中部地区农业发达,人口众多,降水量充足,其防灾减灾能力较强,故评价结果为一般风险区域。北部地区和中南部地区尽管有着相当的危险性和暴露性,但是由于人口和耕地普遍较为稀少,因此暴露性和防灾减灾能力都很低,故评价结果为较高风险区。
[Abstract]:Global warming has become a trend, global warming will affect the global water cycle and regional water balance. The Xinjiang region is located in the northwest inland arid region, and the total water resources are seriously lacking. The shortage of water resources caused by drought is the key factor to balance the ecological balance and restrict the sustainable and stable development of the national economy in Xinjiang. In the future, the agricultural structure of Xinjiang will be adjusted for disaster prevention and mitigation. The planning of agricultural water use and the construction of ecological environment have important reference value. This paper is based on the monthly precipitation data of 50 meteorological stations in Xinjiang during 1961-2013. By calculating precipitation anomaly percentage, precipitation Z index SPI, looking up the Xinjiang Statistical Yearbook to obtain agricultural and economic indicators. According to the drought disaster risk index model theory, the precipitation anomaly percentage is selected. Precipitation Z index SPI, crop, population density, waste water discharge, GDP and effective irrigation area were used to evaluate the drought risk, and the basic data were standardized. The area weight is obtained by the inverse distance weight interpolation, and the index factor weight is given by combining the AHP analytic hierarchy process and entropy weight method. Selecting the optimal segmentation method grade calculation process and GIS drought assessment model and risk assessment method, Xinjiang area is divided into low risk area, low risk area, general risk area, higher risk area. 5 grades in high risk areas. A preliminary plan for the division of drought risk areas in Xinjiang is put forward. The main results are as follows: 1). The difference of precipitation anomaly percentage in Xinjiang in recent 10 years is from -38.52 to 51.63. The drought and flood in different periods in Xinjiang have obvious spatial and temporal distribution characteristics. . On the whole, the precipitation of northeast and southeast shows a decreasing trend, and the southwest shows an increasing trend.) the total drought and flood in Xinjiang are very unstable, and the precipitation Z index is very unstable. There were 17 droughts and 15 waterlogging in the period of 1961-2013 in SPI, that is, the occurrence of drought and flood occurred frequently and the distribution was basically average. However, the frequency of partial drought is obviously higher than other levels of drought and flood events. The precipitation in Xinjiang will increase in the future, the population density, the total amount of wastewater discharge. GDP and effective irrigation area increased at different rates. From the division of drought risk areas in Xinjiang, we can see that there are obvious regional differences in drought risk in Xinjiang. The high risk areas of drought disasters are mainly concentrated in the southwest of Xinjiang. Hotan area, Kashi area and Kirgiz Autonomous Prefecture are close to high risk area. The region has rare precipitation, high evaporation and high risk, so the evaluation result is high risk area. Because of its large population, abundant precipitation and strong ability of disaster prevention and mitigation, the evaluation results are general risk areas, although the northern and central and southern regions have considerable risks and exposures. However, the population and cultivated land are generally scarce, so the exposure and the ability of disaster prevention and mitigation are very low, so the evaluation results are high risk areas.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S423

【参考文献】