InVEST模型水源涵养模块实地应用的可行性验证

Feasibility verification with field application of a water conservation module using the InVEST Model

以浙江省杭州市临安区水涛庄水库集水区为研究对象,在研究区2015年森林类型勘测分析的基础上,基于水量平衡法、综合蓄水法和InVEST(Integrated Valuation of Ecosystem Services and Trade-offs)模型对研究区水源涵养功能进行评价,并分别用总量数据和样点数据对InVEST模型水源涵养模块在研究区的可行性进行验证。结果表明:根据森林主林层优势树种可将研究区的森林可分为11个类型。基于出入库水量监测数据计算可知研究区2015年总水源涵养量为2 738.31×10~4m^3,基于综合蓄水法计算可知研究区2015年森林水源涵养量为3 498.86×10~4m^3。基于InVEST模型计算可知研究区2015年总水源涵养量为3 193.90×10~4m^3,模拟值精度达83.36%;森林水源涵养量为3 189.73×10~4m^3,模拟精度为91.27%;各林型水源涵养量精度为89.86%。以基于综合蓄水法计算的样点水源涵养量为基准,对InVEST模型的各样点模拟值进行回归验证, R2为0.635 4,模型精度为74.15%。由此可知,利用InVEST模型对研究区水源涵养进行测算是可行的,具有较高的推广价值。

Water conservation,one of the most important types of ecosystem services,not only reflects the ability of an ecosystem to maintain a water supply,but also shows how much water humans use.Although the InVEST model has been used in China for a long time,there is still a lack of feasibility verification of the results.To verify the feasibility of the model and assist in water source protection planning,evaluation and simulation of water conservation were studied in the Shuitaozhuang Reservoir Watershed.The water conservation capacity of the research area was calculated by monitoring data and by using a comprehensive storage method,and then these two methods were used to verify the correctness of the InVEST Model using a precision analysis and a regression analysis.Results showed that according to monitoring data,in 2015 the total water conservation capacity of the research area was 2 738.31×104 m3;whereas,with the comprehensive storage method the forest water conservation capacity was 3 498.86×104 m3.The InVEST Model calculated that in 2015 the total water conservation was 3 193.90×104 m3,and the forest water conservation capacity was 3 189.73×104 m3.Compared with monitoring data,the accuracy of the InVEST Model was 83.36%.Based on the water conservation capacity of sample points measured by the comprehensive storage method,the InVEST Model simulation value was verified by regression analysis(R2=0.635 4).Thus,the InVEST Model was accurate for this area and could be effective in water conservation to provide a reference for optimization and promotion of forest water conservation in Zhejiang and even subtropical areas.