中华水塔面临的挑战与应对战略

Challenges and coping strategies of China's Water Tower

传统的“中华水塔”范围是指青藏高原东部黄河、长江、澜沧江的三江源地区,多年平均产水量为499亿m^(3),而整个青藏高原面积257万km2,多年平均产水量约7780亿m^(3),孕育了流出高原的大中型河流20条。受气候变化及人类活动影响,青藏高原冻土退化、冰川消融和蒸发增加,对资源、生态与环境等造成重大影响,保护好“中华水塔”是“国之大者”。本文提出将“中华水塔”范围由三江源扩展到整个青藏高原,有助于推进青藏高原生态保护的关键工程建设,以遏制水源涵养功能的加速退化;有助于构建涵盖雅鲁藏布江、怒江、澜沧江的国家水网,以应对中低海拔冰川消融和冻土释水消失后北方地区的缺水危机;有助于加强青藏高原地区饮用水安全保障,以应对生源要素改变与病原微生物进入水体带来的水环境风险。

Traditionally, ‘China’s water tower’ refers to the Sanjiangyuan area covering the source area of the Yellow, Yangtze and Lancang Rivers in the east of the Qinghai-Tibet Plateau.The Sanjiangyuan area has an average annual water yield of approximately 49.9 billion m^(3),whereas the Qinghai-Tibet Plateau covers an area of 2.57 million km^(2) with an average annual water yield of 778 billion m^(3) and 20 large or medium-sized rivers originating from the plateau.Due to climate change and human activities, glaciers and frozen ground on the plateau melt and the evaporation rate increases, severely affecting resources, ecology and the environment.Therefore, protecting ‘China’s water tower’ is of vital importance to the country.In this paper, the defined range of ‘China’s water tower’ is expanded from the Sanjiangyuan area to the entire Qinghai-Tibet Plateau, which has the following advantages.First, it facilitates the construction of key projects for the ecological protection of the plateau, thus curbing its accelerated degradation and maintaining its role in conserving water resources.Second, it aids in establishing a national water network covering the Nu, Yarlung Zangbo and Lancang Rivers to solve the water shortage crisis in the northern region when glaciers and frozen ground melt at middle and low altitudes.Third, it helps guarantee safe drinking water on the plateau by eliminating the risks associated with changes in biogenic elements and the mixing of pathogenic microorganisms in the water environment.