浑河上游新宾县土地利用演变对水源涵养能力影响评价

Evaluation of the Impact of Land Use Evolution on Water Conservation Capacity in Xinbin County,Upper Reaches of Hunhe River

[目的]阐明水源保护区浑河上游新宾县土地利用变化与水源涵养功能的关系,指导当地或类似地区土地利用和水资源优化管理。[方法]基于ArcGIS平台,采用土地利用转移矩阵研究新宾县1995年、2000年、2005年、2010年和2015年土地利用变化;在此基础上,运用InVEST模型评估1995—2015年区域及不同土地利用类型的产水功能和水源涵养功能。[结果](1)1995—2015年新宾县土地利用类型始终以林地和草地为主,21年来,林地、其他用地(湿地为主)、水域和建设用地的面积均增加,其中林地面积增加最大,耕地和草地的面积在减少;(2)1995—2015年,林地、其他用地、建设用地和水域面积的增加来源于耕地和草地;(3)新宾县多年平均产水量为1.564×10^(9)m^(3),水源涵养量为6.2×10^(8)m^(3),作为重点水源涵养区域,新宾县平均水源涵养能力193.62 mm,多年来呈现波动变化趋势,产水量的变化与分布、土地利用直接影响着区域的水源涵养量大小;(4)1995—2015年不同土地利用类型的水源涵养量变化明显,不同地类年均水源涵养能力大小依次为林地>其他用地>草地>水域>耕地>建设用地。[结论]林草覆盖率高是该地区维持水源涵养功能的基础。作为新宾县水源涵养总量贡献最大的林地与面积最小却具有极强水源涵养能力的其他用地(以湿地为主),应予以特别关注,同时建设用地的扩展对林草地面积和质量造成的负面影响也要引起注意。

[Objective]The relationship between land use changes and water conservation function in Xinbin County in water conservation area of upper reaches of Hunhe River was charified in order to guide the optimal management of land use and water resources in local or similar areas.[Methods]Based on ArcGIS platform,land use transfer matrix was used to study land use changes in Xinbin County in 1995,2000,2005,2010 and 2015;on this base,the InVEST model was applied to evaluate the water production function and water conservation function of the region and different land use types from 1995 to 2015.[Results](1)From 1995 to 2015,the land use type of Xinbin County had always been dominated by woodland and grassland.In the past 21 years,the areas of woodland,other land(mainly wetland),water bodies and construction land had increased,among which the area of woodland had increased the most,and the areas of cultivated land and grassland were decreasing.(2)From 1995 to 2015,the increase of woodland,other land,construction land and water bodies came from cultivated land and grassland.(3)The average annual water yield of Xinbin County was 1.564×10^(9)m^(3),water conservation capacity was 6.2×10^(8)m^(3).As a key water conservation area,the average water conservation capacity of Xinbin County was 193.62 mm,showing a fluctuating trend of first decreasing,then increasing and then decreasing over the years.The change and distribution of water yield and land use directly affected the water conservation capacity of the region.(4)From 1995 to 2015,the water conservation capacity of different land use types changed significantly,and the order of average annual water conservation capacity of different land types was woodland>other land>grassland>water area>cultivated land>construction land.[Conclusion]High forest and grass coverage is the basis of water conservation in this area.Special attention should be paid to the forestland with the largest contribution to the total amount of water conservation in Xinbin County and the other land with the smallest area but strong water conservation capacity(mainly wetland).Meanwhile,attention should also be paid to the negative impact of the expansion of construction land on the area and quality of forest and grassland.