石羊河流域冰川资源的脆弱性机制及其适应对策研究

Glacier is an important kind of fresh water resources in arid inland river basin. Glacier recession resulted by climatic warming has a serious impacts on hydrological process and eco-enviornment. The Shiyanghe basin, as one of the most closely concerned area in Hexi Corridor, there is small quantity of glaciers in Qilian Mountains. Shortage of water resources and deterioration of the Ecological Environment are closely intertwined in Shiyanghe basin. For this reason, the research project will focus on this basin with vulnerable ecosystem depending on remote sensing and field measurement. The main research contents in this field include: (1) study on characteristics of glacial change, to know the influence factors of affecting glacier change, (2) scientific assessment on vulnerable of glacier system and ecosystem influenced by glacier change, to disclose the mechanism of environmental fragility under the same climate trends, (3) give suggestions to ecological environmental protection and adaptive strategy of human activity to vulnerable. The research on Shiyanghe basin, is scientific to understand climate change, and is in accordance with major strategy to national ecological security barriers experimental area of Gansu province, current national directory of comprehensive management of Shiyanghe basin as well.

冰川是干旱内陆河流域重要的水资源，气候变暖引起的冰川剧烈萎缩势必对流域水文过程及生态环境产生重要影响。当前石羊河流域的水资源短缺和生态环境退化问题交织在一起，在气候变暖驱动下，该流域冰川系统及受冰川变化影响的生态系统极度脆弱。搞清楚冰川变化及脆弱性机制并进行科学评价，为山区生态屏障建设和区域可待续发展提供科学依据。鉴于此，本项目针对生态系统非常脆弱的石羊河流域源头，以遥感手段结合野外调查方法在以下三个方面开展研究：（1）研究气候变暖背景下该源区冰川变化特征，揭示小冰川变化的影响因子；（2）对冰川系统及受冰川变化影响的生态系统脆弱性进行科学评价，揭示相同气候条件下冰川脆弱性机制；（3）根据评价结果，给出生态环境保护和人类活动脆弱性适应对策。本项目的研究，既具有追踪气候变化时代性，又符合当前建设甘肃省国家生态安全屏障综合试验区生态工程的重大战略，以及石羊河流域综合治理的国家目标。

石羊河流域是河西走廊人地关系最为突出的流域，受全球气候变暖和城填化进程的影响，石羊河流域生态环境极端脆弱，冰川水资源成为区域关注的焦点问题。项目基于石羊河流域冰川变化及冰川脆弱性评价研究，厘清冰川变化现状，确定冰川变化的驱动因子，并提出人类活动适应冰川脆弱性的对策。研究成果要点如下：1）冰川年均面积变化率由1973~1995年的-1.27%•a-1变为2015~2016年的-2.87%•a-1，消融有加快的趋势；2）坡度、朝向、最高海拔、最低海拔在不同程度上解释了冰川变化的空间差异性。海拔是冰川变化空间分异的最重要的控制因素，其次是朝向，最后是坡度。任意两个地形因子对冰川变化的交互作用均大于其叠加作用，属于非线性增强关系；3）2002~2015年间，石羊河流域冰川系统的脆弱性逐渐增强，研究区大部分处于重度脆弱和极重度脆弱。东部地区海拔较低，脆弱性等级较高且冰川的破碎度比较大；4）冰川脆弱性受多种综合因素的影响，主要的影响因素是冰川朝向、坡度、最高海拔、冰川厚度、气温、面积和冰川类型。冰川对气候变化异常敏感，是其脆弱性的重要影响因子。