山西黄河流域水生态系统服务时空分析

Spatiotemporal analysis of water ecosystem services of the Yellow River Basin in Shanxi Province

生态系统服务是支撑经济社会发展和人类生存条件的要素,其中水生态系统服务对于维持人类生产生活以及生态环境等都具有重要意义。然而,目前对流域水生态服务研究相对薄弱。基于InVEST(Integrated valuation of ecosystem services and trade offs)模型量化了山西黄河流域2000—2020年的产水量、水源涵养和水质净化服务的时空分布格局。探讨了气候条件和土地利用与产水量、水源涵养和水质净化服务之间的关系。结果表明:(1)近20 a,流域的产水量出现了波动上升的变化,且高峰值的出现在2020年,达152.37 mm。在空间上产水量分布差异明显,高值区范围扩大,低值区范围缩小。土地利用和气候变化共同影响山西黄河流域产水服务时空变化。气候变化对流域产水服务的贡献率远大于土地利用变化。(2)近20 a,流域水源涵养量与产水量变化趋势基本一致,整体呈波动上升趋势。高峰值的出现在2020年,达100.32 mm。空间上,林地水源涵养量增加最多,其次为草地,降水量大且蒸散相对较小的地区水源涵养能力显著高于其他地区。相比土地利用,气候因素对水源涵养量的影响更大。(3)在水质净化方面,同时期流域N、P输出量呈现逐年递减的态势,在2020年N、P输出量均达到最低值,分别为0.4739 kg·hm^(-2)和0.0366 kg·hm^(-2)。空间上,山区和丘陵地区的N、P输出量显著低于平原和盆地。人类农业活动特别是对农业用地中化肥的广泛投入是造成水环境污染的主要原因,同时伴随城市化发展的不透水地面的扩张也会对研究区水质净化造成一定的影响。研究结果可为山西黄河流域水生态系统保护及生态补偿与流域科学管理提供参考。

Ecosystem services support economic and social development and human living conditions,with water ecosystem services being particularly significant for maintaining human production,life,and the ecological environment.However,research on water ecological services in the river basin is currently relatively weak.This paper applies the water production and quality purification module of the integrated valuation of ecosystem services and trade-offs model to quantify the spatial and temporal distribution patterns of water production,water source conservation,and water purification services of the Yellow River Basin in Shanxi Province from 2000 to 2020.It discusses the relationship between climate and land use and water production,water source conservation,and water purification.The results show that:(1)Over the past 20 years,water production in the basin has fluctuated and increased,with the peak value appearing in 2020 at 152.37 mm.The distribution difference of water production in space is noticeable;the range of high-value areas is enlarged,and the range of low-value areas is narrowed.Land use and climate change affect the spatiotemporal changes in water production and service of the Yellow River Basin in Shanxi Province.The water production capacity of different land use types varies from 2000 to 2020,and the contribution rate of climate change to water production services is significantly greater than that of land use change.(2)Over the past 20 years,the changing trend of water conservation and production has been the same,with the peak value occurring in 2020 at 100.32 mm.Water conservation in the basin has fluctuated and increased.Spatially,woodland has shown the most significant increase in water conservation capacity,followed by grassland,and areas with large precipitation and relatively small evapotranspiration have a significantly higher water conservation capacity than other areas.Climate factors have a greater influence on water conservation than land use type.(3)Over the past 20 years,nitrogen and phosphorus output in the basin has shown a yearly decreasing trend,reaching its lowest value in 2020 at 0.4739 kg·hm^(−2) and 0.0366 kg·hm^(−2),respectively.Spatially,the nitrogen and phosphorus output in mountainous and hilly areas is significantly lower than that in plains and basins.Human agricultural activities,especially the extensive input of fertilizer in agricultural land,are the leading cause of water environment pollution,and the urbanization-induced expansion of impervious ground will impact water purification in the study area.This study can provide a reference for water ecosystem protection,ecological compensation,and scientific management of the Yellow River Basin in Shanxi Province.