关中地区干旱预警与应急水源配置研究

发布时间：2018-07-25 13:50

【摘要】：自古以来关中地区就是我国农业最为发达的地区之一,在秦、汉、唐时期更是全国的政治、经济、文化中心,但由于地处半干旱地区,属于资源型缺水区,人均占有水资源量和亩均占有水量分别只有全国平均水平的17.3%和15%。加上本地区蓄水工程较少,调蓄能力差,供水保证率低,干旱缺水严重,旱灾十分频繁,是制约该地区农业生产、阻碍经济发展、困扰人民生活的严重自然灾害。为改变长期以来被动、盲目应对干旱灾害的局面,减少干旱灾害造成的损失,及时消除干旱对社会经济的不良影响,加强干旱预警研究,并据此对干旱的应急水源进行合理配置已成为当务之急。本文在野外调查、资料收集的基础上,采用统计分析、遥感解译、模糊分析等方法研究了关中地区的干旱特征,探索了干旱的遥感监测方法,建立了关中地区干旱预警系统,并制定和计算了不同干旱等级下的供用水方案和缺水量,为应急水源配置奠定了基础,取得下述研究成果:(1)通过对关中地区降水、地表水和地下水的动态变化规律进行研究,总结分析了该地区水资源时空分布特征,对研究区水资源总量和可利用水资源量进行了评价。关中地区气候干燥,水资源时空分布差异较大。从地理分布来看,降水由南向北、由西向东呈递减趋势;地表水以渭河为界,渭河以南显著丰富于渭河以北;地下水水位受地形地貌影响,由南北山前向中部渭河逐渐减小。从时间分布来看,降雨和地表水的年内分布基本一致,降水量的60~75%、地表水径流量的50—65%集中于汛期(6~9月)4个月,且多年来地表水来水量有衰减的趋势。(2)运用数理统计方法分析了1949年至1995年关中地区的历史干旱资料,计算出关中地区各区县干旱频次,并采用K-means方法对其进行了聚类分析,绘制了关中地区干旱灾害频次分布图。干旱频次分析表明关中地区干旱十分频繁,几乎年年有旱,在统计的47年中,发生的小区干旱达到280次,四季中夏季发生旱灾的比例最高,达到35.8%。干旱发生的空间特点为东西两头极重、中北部次之、中部再次之、中南部最轻。以粮食产量为基础数据,通过引入旱灾累计程度概念,计算了各区县20年来因旱损失程度,反映了各区县抗旱能力的差异,绘制了关中地区各区县旱灾累计程度分布图,展现了在相似气候条件下,人类活动对于旱灾结果的影响。(3)基于遥感技术的干旱监测具有监测尺度大、时效性强和监测成本低廉的优点,论文采用美国地球观测系统(EOS)中分辨率成像光谱仪(MODIS)500m精度数据,进行关中地区遥感干旱监测研究。结合归一化植被指数(NDVI)和归一化水体指数(NDWI)的优势,应用归一化干旱指数(NDDI)实现了对关中地区2014年伏旱的遥感干旱监测并进行了结果分析。并利用MODIS影像分析结果,获得各区县的受旱面积和受旱程度。(4)论文以模糊可变集理论为基础,建立了关中地区干旱预警系统。该系统综合考虑了关中地区干旱灾害发生频次指标、干旱灾害程度累计指标、连续无雨天数指标和MODIS遥感干旱监测等级指标,通过分析各指标的阈值,构建标准矩阵和可变区间矩阵,实现了不同层次、不同纬度影响因素的标准化考量和综合评估,完成对关中地区的干旱状态评价,并根据评估结果发布相应的干旱预警警报。(5)以行政区县为单位,综合考虑当地水利设施、水源储备情况和用水情况,逐月分析了各地区水资源供需矛盾。结合多年降雨数据和渭河来水超越机率,计算出不同来水频率下各区县的逐月可供水量和不同来水频率下的缺水量,并提出了重旱和极旱状态下的供用水方案,为决策者在不同预警级别下做出正确决策提供了科学依据。
[Abstract]:Since ancient times, Guanzhong area is one of the most developed areas of agriculture in China. In the period of Qin, Han and Tang Dynasties, it was the political, economic and cultural center of the whole country. But because of the semi arid area, it belongs to the resource based water shortage area. The per capita amount of water resources and the average amount of water per mu is only 17.3% of the national average and 15%. plus the water storage in the region. Less engineering, poor storage capacity, low water supply guarantee rate, serious drought shortage and frequent drought is a serious natural disaster that restricts the agricultural production, hinders economic development and plagued the people's life. In this paper, on the basis of field investigation and data collection, the characteristics of drought in Guanzhong area are studied by means of statistical analysis, remote sensing interpretation and fuzzy analysis on the basis of field investigation and data collection, and the methods of remote sensing monitoring for drought are explored. The drought warning system in Guanzhong area was established, and the water supply scheme and water shortage under different drought levels were formulated and calculated, which laid the foundation for the allocation of emergency water sources. The following achievements were obtained: (1) through the study of the dynamic changes of the precipitation, surface water and groundwater in Guanzhong area, the water resources in this area were summarized and analyzed. The distribution characteristics of water resources and the amount of available water resources in the study area are evaluated. In Guanzhong area, the climate is dry and the spatial and temporal distribution of water resources is different. From the geographical distribution, the precipitation is from the south to the north and from the west to the East, the surface water is bounded by Weihe, and the south of Weihe is rich in the north of Weihe; the groundwater level is affected by the topography. The effect of geomorphology is gradually reduced from the north and South Mountains to the central Weihe. From the time distribution, the annual distribution of rainfall and surface water is basically the same, the 60~75% of the precipitation and the 50 - 65% of the surface water flow are concentrated in the flood season (6~9 month) 4 months, and the water quantity of the surface water has a declining trend for many years. (2) the analysis of 1949 to 1 by mathematical statistics method The drought data of 995 years in Guanzhong area have been calculated and the frequency of drought in each district and county in Guanzhong area is calculated. The frequency distribution map of drought disaster in Guanzhong area is drawn by K-means method. The drought frequency analysis shows that the drought is very frequent in Guanzhong area and almost annual drought. In the 47 year of statistics, the drought area is drought. 280 times, the proportion of drought in the summer is the highest in the four seasons. The spatial characteristics of the drought in 35.8%. are the most heavy in the East and the west, the middle north part, the middle part of the middle and the middle south, the lightest in the middle and south parts. The drought damage degree in each district and county is calculated by introducing the concept of the cumulative degree of drought disaster and reflecting the county and county resistance. The difference of drought ability, drawing the distribution map of drought accumulative degree in each district and county in Guanzhong area, showing the influence of human activities on the drought results under similar climate conditions. (3) the drought monitoring based on remote sensing technology has the advantages of large monitoring scale, strong timeliness and low monitoring cost. The thesis adopts the American earth observation system (EOS). The remote sensing drought monitoring in Guanzhong area is studied by MODIS (500m) accuracy data. Combined with the advantages of the normalized vegetation index (NDVI) and the normalized water index (NDWI), the normalized drought index (NDDI) was applied to the remote sensing drought monitoring of the 2014 drought in Guanzhong area and the results were analyzed. And the MODIS image was used. On the basis of fuzzy variable set theory, the drought early-warning system in Guanzhong area is established on the basis of the fuzzy variable set theory. The system comprehensively considers the frequency index of drought disaster in Guanzhong area, the accumulative index of drought disaster degree, continuous no rain days index and MODIS remote sensing drought monitoring grade. Standard, the standard matrix and variable interval matrix are constructed by analyzing the threshold of each index, the standardization and comprehensive evaluation of different levels, different latitude factors are realized, the drought status in Guanzhong area is evaluated, and the corresponding warning warning is issued according to the evaluation results. (5) taking the administrative district as the unit, considering the local area. The contradiction between water supply and demand of water resources in various regions was analyzed month by month in water conservancy facilities, water source reserve and water use. The monthly water supply quantity and water shortage under different water frequency in different districts and counties under different frequency of rainfall were calculated. The water supply scheme under heavy drought and extreme drought condition was put forward. It provides a scientific basis for decision-makers to make correct decisions at different warning levels.
【学位授予单位】：长安大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：P426.616;TV213.4

【参考文献】