黄河源区气候水文和植被覆盖变化及面临问题的对策建议

Climate, Hydrology, and Vegetation Coverage Changes in Source Region of Yellow River and Countermeasures for Challenges

        郑子彦(中国科学院大气物理研究所 中国科学院东亚区域气候-环境重点实验室 北京 100029)
        吕美霞(中国科学院大气物理研究所 中国科学院东亚区域气候-环境重点实验室 北京 100029)
        马柱国(中国科学院大气物理研究所 中国科学院东亚区域气候-环境重点实验室 北京 100029;中国科学院大学 北京 100049)

         黄河源区;气候变化;水资源;植被覆盖;对策建议

        source region of Yellow River;climate change;water resources;vegetation coverage;countermeasures

        黄河源区是黄河流域最重要的水源地和产流区，贡献了超过全流域37%的产流量，对流域中下游地区的水资源安全、粮食生产和生态环境有决定性的意义。明晰黄河源区近60年来的气候水文和近30年来的植被覆盖特别是草地退化的变化特征，不仅是深入理解黄河源区水文循环机理的前提，也是准确把握源区及中下游水资源状况和生态环境的关键，更是贯彻习近平总书记“黄河流域生态保护和高质量发展”要求的核心问题。从气候角度看，黄河源区自1951年以来经历了显著的暖湿化过程， 20世纪90年代有所回落。但从2000年以来，气温和降水以更快的速度增大，进而引发了冰川积雪消融加剧、蒸散发增加和冻土层退缩等一系列后果。然而，由于各个过程中水分损耗的加剧以及人类活动的影响，这种增湿并不能转换为有效的水资源，黄河源区的观测和天然河川径流量均呈现出减少的趋势。而不断退化的草地则使得区域水分涵养能力不断降低，生态环境不断恶化。面对黄河源区严峻的水资源和生态环境挑战，除了继续深入研究黄河源区水文循环机理外，建议应做到：（1）将生态环境保护放在首位；（2）水资源的有序开发利用；（3）社会生产与自然环境的和谐共存；（4）从战略高度贯彻实施有序适应气候变化。

        The source region of Yellow River is the most important water source and in contributing more than 37% of the total streamflow of the whole Yellow River, which makes great significance for water resources security, food production, and the ecological environment in the lower reaches of the river. Clarifying the changes in climatic hydrology and vegetation coverage, especially grassland degradation in the source region of Yellow River is not only a prerequisite for a deep understanding of the hydrological cycle mechanism of this region, but also an accurate grasp of the water resources and ecological environment in the source region and in the middle and lower reaches. Moreover, it is the core issue of implementing the requirements of President Xi Jinping's “ecological protection and high-quality development in the Yellow River Basin”. According to the meteorological datasets, the source region of Yellow River has experienced a significant warming and wetting process since 1951, and has declined in the 1990s, but the temperature and precipitation have increased at a faster rate since 2000, which has led to the melting of glacial and snow, the increased evapotranspiration, and shrinkage of frozen soil. However, due to the intensification of water loss in various processes and the impact of human activities, this humidification cannot be converted into effective water resources, and the observed and natural streamflow have shown decreasing trends. Moreover, the continuously degraded grassland has continuously reduced the regional water conservation capacity and the ecological environment has continued to deteriorate. Facing the severe water resources and ecological environment challenges of the source region of Yellow River, we recommend that (1) ecological environmental protection be given priority; (2) the orderly development and utilization of water resources; (3) the harmonious coexistence of social production and the natural environment; and (4) the implementation of an orderly adaptation to climate change as a strategic perspective.