基于土地利用变化的典型喀斯特城市流域生态系统服务功能研究

Ecosystem Service Functions of a Typical Karst Urban Basin based on Land Use Change

揭示喀斯特城市流域土地利用对生态系统服务功能的影响机制,对喀斯特地区的社会经济发展与生态环境保护具有重要意义。本研究以贵州典型喀斯特城市流域—南明河流域为例,基于Arc GIS技术平台揭示了2000–2020年3个时期流域的土地利用时空演变规律,采用In VEST模型对流域不同土地利用类型的生态系统服务功能进行了系统评价。结果表明:(1)流域土地利用以林地、耕地和草地为主,土地利用变化方式主要表现为建设用地的增长,增长了13.07%;(2)流域水源涵养功能显著提升,碳储存功能略微减弱,空间上两者的物质量均呈现东北高、西南低的分布特征;(3)林地对流域水源涵养和碳储量的贡献率均超过57%,林地转为建设用地,耕地转为林地分别是生态系统服务功能减弱和增强的两种土地利用变化形式。本研究可为喀斯特生态脆弱区土地利用结构优化、水土资源开发和生态系统可持续管理提供重要数据支撑与科学参考。

Revealing the mechanism by which land use influences ecosystem service function in karst urban watersheds is of great significance for social and economic development and ecological environmental protection.In this study,the Nanming River Basin,a typical karst basin in Guizhou Province,was used as an example.The spatiotemporal dynamic changes in land use in the basin during three periods from 2000 to 2020 were analyzed using ArcGIS,and the ecosystem service functions of the different land use types in the basin were evaluated using an integrated valuation of ecosystem services and tradeoffs(InVEST)model.This analysis led to three outcomes.(1)Forest,cultivated land,and grassland make up most of the land uses.The land use change was mostly dependent on the growth of construction land,which expanded by 13.07%.(2)The watershed's water conservation function was significantly boosted during the study period.In contrast,the carbon stock function became slightly impaired,and the physical quality of both was regionally distributed as high in the northeast and low in the southwest.(3)The contributions of forest to total water conservation and carbon stock of the watershed are always the greatest,exceeding 57%,and the conversions of forest to construction land and cultivated land to forest are the two primary types of land use change in which the ecosystem service function was impaired and strengthened,respectively.The results of this study can provide important data support and scientific reference for land use structure optimization,soil and water resource exploitation,and sustainable ecosystem management in ecologically fragile areas.