基于InVEST模型的岷江上游生态系统水源涵养量与价值评估

Assessment of Ecosystem Water Retention and Its Value in the Upper Reaches of Minjiang River Based on InVEST Model

岷江上游是中国长江上游生态屏障的重要组成部分,更是成都平原的重要水源生命线,该文使用InVEST模型与影子工程法,对其生态系统水源涵养量与价值进行量化评估与空间制图,可为当地水源地保护与生态补偿机制的建立提供依据。结果表明:岷江上游小流域水源涵养量多年平均值为219.36 mm,总量为49.19亿m^3,价值为40.83亿元,并且存在明显的空间差异,高值区主要分布在汶川中南部,低值区多集中在松潘县与茂县境内。受评估方法的限制,不同学者对该流域的相关研究结果差异较大,可比性较差,但是岷江上游生态系统具有巨大的水源涵养价值。空间化评估结果可直观的反映水源涵养量与价值的空间差异,在流域生态补偿机制构建、补偿效益分析等方面具有重要应用价值。

The upper reaches of Minjiang River is not only an important part of the ecological barrier in the upper reaches of the Yangtze River, but also a vital water source lifeline for the Chengdu plain. InVEST model and shadow engineering method were used to assess the ecosystem water retention and its value in the upper reaches of Minjiang River, and this work had important significance for water conservation planning and establishment of payment for ecosystem service mechanism. The results showed that the average annual water retention amount of sub watersheds in the upper reaches of Minjiang River was 219.36 mm, the total water retention amount was 49.19 billion m^3 and the water retention value was 4.083 billion Yuan. Water retention amount and its value in our study area displayed some obvious spatial variation with high value areas mainly distributed in south central Wenchuan County and low value areas relatively concentrated in the regions of Songpan and Maoxian County. Due to the limitation of the evaluation method, the relevant findings of this watershed were obviously different and had poor comparability. However, it is sure that the upper reaches of the Minjiang River has huge water retention value. The quantitative assessment results and mapping can directly reflected the spatial variation in water retention and its value. It had strong applied value in the establishment of payment for ecosystem service mechanism and compensation efficiency analysis etc.