新疆典型流域冰雪洪水对气候变化的响应机理与适应性管理对策研究

Snow and ice water resource is an important part of the water resources in Xinjiang, glacier floods, snowmelt floods and ice jam flood are mainly disasters kinds of extreme hydrological disaster events in Xinjiang, and frequencies and intensities observed of snow and ice floods have an enhancing trend during the last decades. In recent decades, glacial lake outburst floods and glacial floods in the Tarim River Basin of the southern Xinjiang, and spring snowmelt floods and ice jam floods in the northern Xinjiang have brought great damage to the lives, property, socio-economic development, and increasingly risk issues relatively to water resources security, disasters for the local authorizes of Xinjiang. We selected the four typical studied basins of the southern slopes of the Altay, the northern slopes of the Tianshan Mountains, the Ili River basin and the Tarim River Basin, and build information database of the snow and ice floods based on the field investigation, hydrological and metorological record data，documents review. Based on data analyses and modeling simulation, we would carry out the studies on impacts of climate change on intensities, frequency and spatial and temporal distribution of snow and ice floods, and to analyze the mechanism of causes of different kind of snow and ice floods, the distribution characteristics and flood hydrological process in the Xinjiang ,and make known the response mechanisms of the monthly distribution pattern of the flood hydrological process, flood frequency and intensity to climate change for different type of snow and ice supply river; proposed response measures of adaptive management to climate change, snow and ice flood safety, and to provide scientific supports for flood control and disaster mitigation and early warning.

冰雪水资源是新疆水资源的重要组成部分，冰川洪水、融雪洪水和冰凌洪水组成的冰雪洪水是新疆的主要的极端水文灾害事件，已观测到近十几年来冰雪洪水发生的频次和强度有加强趋势。近年来塔里木河流域的冰湖溃决洪水和冰川洪水及北疆春季的冰凌和融雪洪水已对当地的生命财产和社会经济发展带来巨大危害，对新疆带来的水资源安全、灾害等问题日益凸显。选择阿勒泰山南坡、天山北坡、伊犁河流域和塔里木河流域的典型冰雪洪水发生流域，采用野外调查、水文气象资料整编、文献回顾，建立冰雪洪水资料数据库，通过数据分析和模型模拟，开展气候变化对冰雪洪水的强度、频率及时空分布影响研究，分析新疆不同冰雪洪水的成因机理、分布特征和洪水水文过程，揭示不同冰雪补给类型河流的洪水水文过程年内分布特征、洪水频次和强度对气候变化响应的机理；提出应对气候变化下冰雪洪水安全的适应性管理对策，为防洪减灾和预警提供科学支撑。

冰川和积雪融水在新疆水资源构成中占有重要的地位，其对气候变化的响应使得河流水文过程发生明显的变化，对新疆干旱区的水资源利用和管理产生重大影响. 随着新疆气候向暖湿转变，高山流域的水文过程对气候变暖和积雪增加产生明显的响应：积雪为主补给的河流，水文过程对气候变化变暖的响应表现为最大径流前移，夏季径流减少明显；以冰川融水补给的河流，径流响应表现为6-9月汛期径流量明显增大，汛期洪水增多，年流量增加. 冰川、积雪在其融水补给河川径流的同时，也常伴有冰川洪水、融雪洪水、冰湖突发洪水、冰川泥石流、冰雪崩和风吹雪等冰雪灾害发生. 新疆的冰川洪水和冰湖突发洪水灾害主要发生在塔里木河流域的喀喇昆仑山、昆仑山以及天山南坡西部一带，融雪洪水灾害主要发生在新疆北部的阿勒泰地区、塔城地区和天山北坡一带. 随着全球气候变暖，尤其是新疆从1987年开始的气候由暖干向暖湿的转型，冰川退缩加剧，融水量增大，冰川洪水和冰川泥石流灾害随着冰川融水径流的增加而增多；而融雪洪水、雪崩和风吹雪随着气候变化引起的冬季积雪增加和气温升高，其灾害强度在增强. 在新疆地区，冰雪灾害主要表现为冰雪洪水，已观测到近十几年来在气候变化影响下冰雪洪水发生的频次和强度有增加的趋势，塔里木河流域的冰湖溃决洪水和冰川洪水及北疆春季的冰凌和融雪洪水已对当地的生命财产和社会经济发展带来巨大危害. 随着气候增温引起的冰雪融水径流的增加，相关的冰雪灾害增多，因而增加了冰雪灾害的风险程度，并可能形成若干新的灾害点. 面对气候变化诱发的众多冰川、积雪灾害，目前还缺乏对灾害监测、预测预警方面的适应对策. 因此, 在全球气候变化不断加速的趋势下, 冰雪洪水灾害应引起有关方面的足够重视, 加强气候变化对冰雪灾害的影响评估和适应性管理对策研究.