南水北调中线工程途经区生态服务价值的时空变化

Abstract

南水北调中线工程是我国迄今为止最重要的跨流域调水工程，为沿线二十四个大中城市提供了紧缺的生产和生活用水。但是，迄今为止人们对调水影响下南水北调中线工程途径区生态服务价值的动态变化过程所知甚少，阻碍了人们对该工程生态效益的科学评估与沿线土地资源的合理利用。南水北调中线工程建成前后的生态服务价值变化研究有助于沿线土地的合理规划和科学利用。为此，首先基于改进的当量因子法分析了2000、2005、2010、2015、2018年研究区生态服务的静态价值时空变化，然后利用优先指数重构了研究区生态服务的动态价值并探讨了其时空演变的特征。结果表明：① 2000—2018年，研究区生态服务的总价值先减后增，2018年达到峰值。研究区生态服务价值的增长在一定程度上归因于南水北调中线工程的影响。② 研究区水文调节功能价值占总价值的比例最高，约占30%，养分循环功能的价值占比最低，约为1%；各年份林地、草地、耕地和水体均为研究区生态服务总价值的主要构成部分。③ 2000—2018年，研究区生态服务价值空间分布存在明显差异，自西部向东部递减，调水后北京市和天津市的高值区增加。④ 研究区生态服务的动态总价值（1.38×10¹²元）只有静态总价值（2.58×10¹²元）的一半，主要是由于动态与静态生态服务的价值系数差别较大。因此，应重视土地利用类型变化和薄弱生态服务功能对生态服务总价值的影响，优化土地利用结构，对南水北调中线工程沿线周边开展针对性保护，以稳步提升整个区域生态服务的总价值。;The Middle Route of the South-to-North Water Diversion Project (MRSNWDP) is the most important inter-basin water diversion project in China so far, and provides the scarce production and domestic water for 24 large and medium-sized cities along the route. However, the dynamic change process of the ecosystem service value of the project was studied so inadequate that hindered the scientific evaluation of the project ecological benefits and the rational use of land resources. The study on changes in the value of ecological services before and after the completion of the MRSNWDP is helpful to the rational planning and scientific use of land along the route. This paper analyzed the temporal and spatial changes of the static value of ecological services of the project in 2000, 2005, 2010, 2015 and 2018 based on the improved equivalent factor method, and then reconstructed the dynamic value of its ecological services with the priority index, and discussed its temporal and spatial evolution characteristics. The results showed that:① from 2000 to 2018, the total value of ecological services in the study area first decreased and then increased, and reaching its peak in 2018. The increase in the value of ecological services in the study area can be attributed to the impact of the MRSNWDP to a certain extent. ② The value of the hydrological regulation function was the highest, accounting for 30% of the total value, and that of the nutrient cycle function was the lowest, accounting for only 1%. The forest land, grassland, cultivated land and water body were the main components of the total value of ecological services in the study area in each year. ③ The spatial distribution of ecological service values in the study area was significantly different from 2000 to 2018, which decreased from the west to the east. The high-value areas in Beijing and Tianjin increased after water diversion. ④ The total dynamic value of ecological services in the study area was 1.38×10¹² Yuan, which was lower than the static total value of 2.58×10¹² Yuan, due to the value coefficient of dynamic and static ecological services is quite different. Therefore, we should pay attention to the impact of changes in land use types and weak ecological service functions on the total value of ecological services, optimize the structure of land use, and carry out targeted protections along the MRSNWDP to steadily improve the total value of ecological services in the entire region.