人类活动对亚洲中部水环境安全的威胁

主要依赖河流出山口的径流量维系山地-绿洲-荒漠间脆弱生态平衡的亚洲中部干旱区,其水分循环过程完全不同于湿润区。平原区不产生径流,地表水和地下水同源于山区,一个流域就是一个以地表水和地下水相互依赖的生态功能单元,其中河流是纽带,连接山区径流形成区与平原径流散失区或消耗区,以水分循环为主体,并与生物、生态系统紧密相联系,构成一个独特而又完整的內陆水分循环体系。自然要素的变化,特别是人类的参与或介入,改变了水分循环的规律,对亚洲中部干旱区水和环境的形成具有很大的威胁。用多年的观测数据来讨论人类活动的影响,并提出维系和保持干旱区水环境的建议。

Threat of Human Activities to Hydrological Regime in Central Asia

In the arid climate areas in Central Asia, the low-land area and plains hardly generate any surface runoff due to inadequate precipitation, yet relatively sufficient precipitation in the mountains forms streams flowing to the plains. These streams are the primary sources of surface water in oases and deserts, redistribute the limited surface water resources, recharge groundwater in the plains, and sustain the fragile and unique ecosystems in the oases and deserts. Such ecosystems have been under the serious pressure from human activities in recent decades. Expansion of farmland, cities and towns increases the consumption of surface water and groundwater, disturbs the natural hydrological regime, and threatens the sustainability of ecosystems in the arid areas in Central Asia. In this paper, the impacts of human activities on hydrological regime and ecosystem health in the arid areas in Central Asia are discussed based on the multi-year observed data, and some mitigation strategies are suggested.