【作者】 翁白莎；

【导师】 王浩； 练继建； 严登华；

【作者基本信息】 天津大学 ， 水文学及水资源， 2012， 博士

【摘要】 作为水循环过程的一类极值过程，干旱随着气候变化和人类活动影响的深入，呈现出广发频发态势，危及到流域的水安全和生态安全。干旱事件的发生具有确定性和随机性的双重特性，需在遵循自然—人工二元水循环原理的基础上，采用风险模式进行应对。本文从水资源系统的角度，提出广义干旱的内涵及定量化评价方法；结合自然气候变化、人为气候变化、下垫面条件改变、水利工程调节等对干旱事件的影响特性，构建广义干旱演变的整体驱动模式，并定量识别其驱动机制；结合干旱事件演变的确定性和随机性特征，提出广义干旱风险评价方法与基于3S技术的广义干旱风险区划方法；从节流与开源两方面提出流域广义干旱风险应对措施，并评估措施的实施效果。在上述理论与技术的支撑下，选取干旱事件频发的东辽河流域进行实证研究。通过识别东辽河流域广义干旱的驱动机制可知，流域广义干旱在1960~1981年主要受自然气候变化、下垫面条件改变和水利工程调节的影响，在1982~2010年主要受自然气候变化、人为气候变化、下垫面条件改变和水利工程调节的影响。从水资源系统的角度构建东辽河流域广义干旱评价指标，指标的计算结果与梨树县和公主岭市典型场次的实际旱情较为一致，且该指标在东辽河流域的模拟效果要优于标准化降水指标、Palmer干旱指标和缺水率指标。采用广义干旱评价指标分析东辽河流域广义干旱的时空分布情况可知，1960~2010年流域各评价单元的广义干旱次数、持续时间、强度有较大的差异；各评价单元的广义干旱次数、持续时间和强度在不同年代间亦发生了较大的变化；不同年代流域广义干旱次数、持续时间和强度的重心在空间上发生了明显的转移。通过评价东辽河流域广义干旱风险且绘制流域广义干旱风险区划图可知，流域高风险区主要分布在流域上游的金满水库、八一水库、椅山水库、安西水库、三良水库的供水范围内，以及下游的南崴子灌区、秦屯灌区、梨树灌区和双山灌区。人为气候变化、下垫面条件变化（主要是土地利用变化）、水利工程的调节均在一定程度上使得东辽河流域广义干旱高风险区的面积减少，而低风险区的面积增加。通过从提高农田灌溉水利用系数、减少田间土面蒸发和流域外调水三个方面提出了东辽河流域广义干旱风险应对方案且评估方案的实施效果可知，提高灌溉水利用系数，可使部分评价单元广义干旱风险值降低，同时又提高了另一部分评价单元的广义干旱风险值；减少田间土面蒸发，可使流域大部分评价单元的广义干旱风险值得到大幅度的降低；实行流域外调水后，可以降低流域水利工程供水范围内的评价单元的广义干旱风险值。通过本研究，将进一步发展变化环境下干旱应对理论与技术，并为东辽河流域干旱综合应对提供科学依据。更多还原

【Abstract】 Drought is the extreme event in water cycle. With the increasing impact of climatechange and human activities, drought happens in more area with higher frequency, andnow it endangers the water and ecology security in river basin. The occurrences of droughtevents usually contain dual characteristics: determinacy and randomness. A risk modelbased on "natural-artificial" dualistic water cycle theory should be taken to cope with thisproblem.From the perspective of the water resources system, this article proposed aconnotation and a quantitative evaluation method to generalized drought. The drivingfactors of natural climate variability (NCV), anthropogenic climate change (ACC),underlying conditions change (UCC) and hydraulic engineering regulation (HER) can alterthe impacts of drought events. The unitary driver model of generalized drought evolutionwas built. After combining the dual characteristics of drought events, the methods ofgeneralized drought risk assessment and generalized drought risk division were proposedbased on3S technology. Some measures were put forward to cope with generalizeddrought risk, and their effects were evaluated. Based on the above theories andtechnologies, Dongliao River Basin with high frequency of drought events was taken foran example.According to the identification of the driving mechanism of generalized drought inDongliao River Basin, it could be seen that the generalized drought was affected by NCVand HER during1960to1981, and affected by NCV, ACC and HER during1982to2010.The results simulated by generalized drought assessment index were comparativelyunanimous to the drought disasters happened in Lishu and Gongzhuling of Dongliao RiverBasin actually. The results simulated by the generalized drought assessment index werebetter than that of Standard Precipitations Index, Palmer Drought Severe Index and Rate ofWater Deficit Index. The generalized drought frequency, duration and severity differwidely between assessment units in Dongliao River Basin from1960to2010. They werealso different in different years, and their centers of gravity transferred obviously in thespace.The risk values of the assessment units of Jinman Reservoir, Bayi Reservoir, YishanReservoir, Anxi Reservoir, Sanliang Reservoir, Nanwaizi Irrigated Area, Qintun IrrigatedArea, Lishu Irrigated Area and Shuangshan Irrigated Area were higher than other assessment units. The areas with high risk were decreased, and the areas with low riskwere increased by the impacts of ACC, UCC and HER.Some response strategies of enhancing the coefficient of farmland irrigating water use,decreasing the soil evaporation and implementing inter-basin water transfer project wereproposed to cope with generalized drought in Dongliao River Basin. The risk values ofsome assessment units were decreased, and some assessment units were increased byenhancing the coefficient of farmland irrigating water use. Nearly all assessmentunits risk values were reduced by decreasing the soil evaporation. The risk values of theassessment units of reservoirs were decreased by implementing interbasin water transferproject.Based on this research, both theories and technologies to cope with the droughtproblems in changing environment will be further developed, and provide scientific basisto deal with drought problem in Dongliao River Basin in the meantime.更多还原