基于InVEST模型的杭州市典型年份年产水量时空变化特征及其影响因素

Temporal and spatial variation characteristics of annual water yield and its influencing factors in Hangzhou based on InVEST model

【目的】自然因素和土地利用变化是引起生态系统服务改变的两大驱动因素。研究年产水量时空变化特征及两大驱动因素对年产水量的影响,对维持或提升城市水源涵养、保持水土具有现实意义。【方法】以浙江省杭州市为研究对象,采用景观格局分析、空间梯度分析、相关性分析等方法,综合应用InVEST、ArcGIS、Fragstats、SPSS等工具,识别杭州市土地利用和气象因子变化特征,评估并分析年产水量时空变化特征及其与气象因子、景观格局指数的相关性。【结果】2000—2015年杭州市年产水量呈先下降后上升趋势。在空间上表现为东北高、西南低,随着远离城市中心先增大后减小,于10 km处达到最大值。建设用地的产水量最大。2000—2015年杭州市土地利用变化最剧烈的是耕地与建设用地之间的转化。景观总体呈现更强烈的破碎化和异质性趋势,在距离城市中心10~20 km处达到峰值。年降水量先降低后升高,年均气温波动上升,年实际蒸散量处于波动状态。离城市中心50 km内年降水量变化不显著,年均气温显著下降,年实际蒸散量先减小后增大。杭州市年产水量与气象因子的相关性大于其与景观格局指数的相关性,其中与气象因子中降水量正相关性最强。【结论】气象因子的变化是引起杭州市年产水量变化的主要因素,但景观格局的影响仍值得关注。距离城市中心10 km处是年产水量变化的拐点。图4表7参34。

[Objective]Natural factors and land use changes are important driving factors of ecosystem services change.The analysis of temporal and spatial variation characteristics in annual water yield and its main driving factors have practical significance for maintaining or improving urban soil and water conservation.[Method]This study took Hangzhou as the research object,adopted methods of landscape pattern analysis,spatial gradient analysis,and correlation analysis with the support of the InVEST model,ArcGIS,Fragstats,SPSS and other tools,identified the characteristics of land use and meteorological factors of Hangzhou,evaluated and analyzed the temporal and spatial variation of annual water yield and its correlation with meteorological factors and landscape pattern indices.[Result]The annual water yield in Hangzhou showed a first decline and then an upward trend from 2000 to 2015.The water yield is spatially high in the northeast and low in the southwest,and increased first and then decreased with distance from the city center,reaching the maximum at 10 km.Construction land had the largest water yield.The most dramatic change in land use in Hangzhou from 2000 to 2015 was the conversion between cultivated land and construction land.On the whole,the landscape showed a stronger trend of fragmentation and heterogeneity,reaching a peak at 10-20 km from the city center.The annual precipitation in Hangzhou decreased first and then increased.The annual average temperatures fluctuating increased and the annual actual evapotranspiration fluctuated.The annual precipitation does not change significantly within 50 km of the city center.The annual average temperature decreased significantly as it moved away from the urban center,while the annual actual evapotranspiration first decreased and then increased.The correlation between water yield and meteorological factors was greater than that of landscape patterns indices.Water yield had the strongest positive correlation with precipitation in meteorological factors.[Conclusion]The change of meteorological factors was the main factor causing annual water yield change in Hangzhou,but the impact of landscape pattern was still worthy of attention.The 10 km distance from the city center was the turning point of annual water yield.[Ch,4 fig.7 tab.34 ref.]