重庆龙溪河流域水生态系统服务时空演变及对土地利用变化响应

探究区域水生态系统服务时空变化状况及其与土地利用的关系,有利于区域水生态环境保护和国土资源合理开发利用,帮助决策者通过合理的土地利用方式提高区域生态系统服务能力,平衡区域生态功能与农业生产功能。选择位于长江上游重要生态屏障的重庆市龙溪河流域作为研究对象,利用InVEST模型,对龙溪河流域近20年产水、水质净化、土壤保持服务等水生态系统服务的时空变化特征和其受不同土地利用类型的影响进行了研究。结果表明:(1)近20年龙溪河流域水生态系统服务总体呈增强变好的趋势,但存在一定的空间差异性。虽然产水与水源涵养服务在整个流域空间上相差不大,但水质净化服务在流域林地密集区较场镇和工业集聚区强,土壤保持服务在流域中部南北向水域、建设用地、农地集中区较流域东西两侧坡地强。(2)不同土地利用类型对流域水生态系统服务贡献呈现较大差异性。产水服务由强到弱表现为耕地>林地>建设用地>草地>水域,水源涵养能力表现为耕地>草地>水域>林地>建设用地,水质净化服务表现为林地>草地>建设用地>耕地>水域,土壤保持服务表现为水域>建设用地>耕地>林地>草地。(3)为平衡供给与调节服务,宜以乡镇为单元将龙溪河流域划分为生态修复区、农业生产区、城镇发展区,并针对各分区采取相应生态措施。

Spatiotemporal Changes of Water-related Ecosystem Services and the Responses to Land Use Changes of the Longxi River Basin, Chongqing

Exploring the spatial and temporal changes of regional aquatic ecosystem services and their relationship with land use is conducive to the protection of regional aquatic ecological environment and the rational development and utilization of land resources, and helps decision makers to improve the regional ecosystem service capabilities and balance the regional ecological functions and agricultural production functions through reasonable land use methods. Longxi River Basin (LRB) in Chongqing, an important ecological barrier in the upper reaches of the Yangtze River, was selected as the research object. The InVEST model was used to study the temporal and spatial variation characteristics of water ecosystem services such as water production, water purification and soil conservation services in the Longxi River Basin in recent 20 years and their effects on different land use types. The results showed that: (1) In the past 20 years, the water ecosystem services of the LRB in Chongqing were generally enhanced and improved, but there were some spatial differences. Although the water yield and water source conservation services of the whole basin had little difference, the forest-intensive area in basin of the water purification services was stronger than that of farm town and industrial agglomeration area. The soil conservation services in basin of water area, construction land and forest land in the central and north-south was stronger than the sloping land on the east and west sides of the basin. (2) Different land use types had different contributions to water ecosystem services. The order of the water yield services from strong to weak as follows: cultivated land > construction land > forest land > grassland > water area. The water conservation capacity from strong to weak as follows: cultivated land > grassland > water area > forest land > construction land. The water purification services from strong to weak as follows: forest land > grassland > construction land > cultivated land > water area. Soil conservation services from strong to weak as follows: water area > construction land > cultivated land > forest land > grassland. (3) In order to balance the supply and regulation services, it was appropriate to take township as a unit to divide the Longxi River Basin into ecological restoration area, agricultural production area and urban development area, and take corresponding ecological measures for each partition.