气候变化和人类活动对中亚地区水文环境的影响评估

中亚地区是我国天气的上游区,生态环境异常脆弱,必须要保证该地区生态环境和资源安全,水资源安全首当其冲.研究和评估气候变化和人类活动对中亚地区水文环境的影响,具有重要的战略意义.近百年来中亚地区气候有暖湿化趋势,气温增温持续时间较长且增温幅度较大,近50a增暖更加明显(0.47℃·(10a)^-1),其中冬季增温最快,预估未来会延续变暖的态势;同时20世纪80年代之后降水量持续波动上升.气候变化对该地区水资源的时空分布及湖泊变迁造成了重大影响,人类活动加剧了水资源短缺,近50a来锡尔河和阿姆河入咸海径流量均呈减少的趋势,20世纪70年代之后拦水蓄水水库等水利工程的建设,加上灌溉用水的增加,导致两河入咸海水量骤减;而1987年之后两河入咸海水量回升,主要是气温回暖、降水增多,加速了常年积雪和冰川融化,使得进入河道的径流量增加.同时,湖泊水位下降,面积收缩,水质恶化.中亚水资源问题主要是跨国水资源分配和水环境恶化问题,要做好水资源评估和用水规划工作,建立覆盖全区域的水资源环境监测网络.中亚国家需要共同参与制定一套完整的、综合考虑人口、社会经济、生态环境等因素的水资源管理政治立法决策体系,构建中亚各国人水和谐、互利共存的水资源新秩序,以水资源可持续利用来支持经济与社会的可持续发展.

Evaluation of the impacts of climate change and human activities on the hydrological environment in Central Asia

Central Asia is the upstream of synoptic of China, and has significant strategic importance in relation to the safety of the region ecological environment and resources, especially water resources safety. Research and assessment of climate change and human activities affecting the hydrological environment in Central Asia has vital significance. Over the past century, in Central Asia there was a tendency of wetting and warming, with temperature increase of long duration and large amplitude. In the last 50 years, temperature has increased with the rate of 0.47 ℃·(10a)^-1, and faster in winter. It was estimated that the warming will continue. After the 1980s, precipitation has increased wavelike. Climate change and human activities have a huge effect on the space-time distribution of water resources in the region, human activities have aggravated the water resources and changed lakes. In the last 50 years, Syr Darya and Amu Darya have reduced the runoff into the Aral Sea. Since the 1970s, water conservancy project construction has increased, coupled with the increase of irrigation water, resulting in sharply decrease of the water from the two rivers into the Aral Sea. After 1987, water from the two rivers into the Aral Sea has risen again, mainly because of precipitation increasing and temperature warming, which accelerates snow and ice melting, and then runoff increasing. At the same time, lake surface has gone down, lake area has shrunk, and water quality has deteriorated. Ice is a main water resources. In recent 50 years, glaciers in Central Asian have retreated in a speed of 0.2%~1% a year, and those in Pamir have retreated 14%~30%; glacier retreat is mainly controlled by significant increase in summer temperature. According to the regional climate changing characteristics, medium and small glaciers would retreat more. Central Asia water problems are mainly international allocation of water resources and international struggle against water environment deterioration. It is necessary to do a good job in water resources assessment, water planning and to establish water environment monitoring network for the whole region. Central Asian countries need to participate to set up a set of complete strategy framework, comprehensive considering population, social economy and ecological environment factors, such as political legislation decision-making system of water management, to build a harmonious coexistence of Central Asia new order of water resources, sustainable utilization of water resources to support economic and social sustainable development.