永定河上游流域水生态系统服务价值评估

张家口市是首都的水源涵养区和生态功能支撑区,流经该区域的永定河上游流域发挥着保育水资源的重要作用。为全面认识永定河上游流域水资源生态价值,对流域水生态各项服务功能开展定量评价。以2017年为基准年,综合采用InVEST模型与市场价值法系统评估研究区的水源供给量,以空间和货币的手段直观地表达该地区的水源供给情况;对于空间数据较难获取的地区,采用当量因子法评估水土保持与生物多样性价值;采用分摊法计算水生态旅游价值。结果表明：其总价值量为55.14亿元,约占张家口市各区县平均GDP（81.87亿元）的67.35%。其中,水源供给价值、水力发电价值、水产品生产价值、休闲娱乐价值等直接使用价值为28.64亿元,土壤保持、河流输沙、生物多样性等间接使用价值为26.50亿元,水源供给、休闲娱乐和水土保持功能对研究区域水生态系统价值提升和发展具有重要作用。研究区单位面积的生态价值和经济效益分别为0.35亿元和0.23亿元,生态价值远高于经济效益。本文因地制宜的综合评价方法提升了价值评估的科学性和可靠性,对于基础数据较为缺乏的地区,有一定的参考意义。

Evaluation on the ecosystem services value of the upper reaches of Yongding River

Zhangjiakou city is the water conservation area and ecological function supporting area of Beijing, the capital of China. The upper reaches of Yongding River in Zhangjiakou play an important role in preserving water resources. In order to get a better understanding of the ecological value of water resources in the study area, various water ecological service functions were quantitatively evaluated in this study. With 2017 as the base year, and the InVEST model and market value method, the water supply in the study area was comprehensively evaluated and intuitively expressed by means of space and currency. In the study area, where spatial data were difficult to obtain, soil and water conservation and biodiversity values were evaluated with the equivalent factor method. The aquatic ecotourism value was calculated with the apportionment method. The results show that the total value is ¥ 5.514 billion, accounting for about 67.35% of the GDP (¥ 8.187 billion) of Zhangjiakou city. The water supply value, hydropower generation value, aquatic product production value, leisure and entertainment value and other direct service values reach ¥ 2.864 billion. Soil conservation, river sediment transport, biodiversity, and other indirect service values reach ¥ 2.650 billion. Water supply, recreation, and soil and water conservation functions play an important role in enhancing the value of regional aquatic ecosystems. The ecological value and economic value per unit area of the study area are ¥ 35 million and ¥ 23 million, respectively, and the ecological value is much higher than the economic value. At the same time, the comprehensive use of the above assessment methods has improved the reliability of the evaluation method and has certain reference significance in the areas without enough basic data.