五个时期谷城汉江湿地的景观变化及其生态服务价值评估

Landscape Pattern Change and Evaluation on Values of Ecosystem Services of Hanjiang River Wetlands in Gucheng County for 5 Periods

南水北调工程是实施中国水资源优化配置和解决北方缺水问题的重大战略工程,它的修建将对汉江中下游流域湿地景观格局及价值产生重大影响。以汉江中游典型湿地——谷城汉江湿地为研究对象,应用遥感和地理信息技术,利用1991年、2000年、2007年、2013年和2017年的Landsat TM/ETM+/OLI影像,采用支持向量机和人工解译的分类方法,对研究区地物进行遥感分类,研究5个时期谷城汉江湿地的景观格局及其变化;采用修正的生态系统服务价值系数,估算了5个时期谷城汉江湿地的生态系统服务价值。研究结果表明,与1991年相比,2007年,谷城汉江湿地总面积减少,斑块数量增多,景观破碎度加大;与2007年相比,2017年,湿地面积在增大。谷城汉江湿地生态系统服务价值由1991年的4 813.98×10~4元减少至2007年的3 825.88×10~4元,2017年又增加至4 255.27×10~4元;在湿地的各种单项服务价值中,水文调节服务价值在5个时期中最大;在各种类型湿地中,河流生态系统的水文调节、废物处理、提供美学景观、维持生物多样性和食物生产服务价值都最大;江心洲的原材料生产和气体调节的服务价值都最大;河流和河漫滩气候调节的服务价值都较大;江心洲和河漫滩保持土壤的服务价值都较大。

In this study, the Hanjiang River wetlands in the Gucheng county was chosen as the research area. Using remote sensing and geographic information system techniques, landscape patterns of the study area and their changes were studied with the remote sensing images of Landsat TM/ETM+/OLI in 1991, 2000, 2007, 2013 and 2017. The values of ecological system services of the wetlands were estimated by the modified coefficients of ecosystem services' values for 5 periods. The results showed that the total area of the wetlands decreased from 1991 to 2017;especially the area of the ponds was significantly reduced. The number of landscape patches in creased with the increase of the landscape fragmentation. The total values of ecosystem services of the wetlands were 4 813.98xl0^4 RMB Yuan, 4 257.72x10^4 Yuan, 3 825.88x10^4 Yuan, 3 898.09xl0^4 Yuan and 4 255.27x 10^4 Yuan in 1991,2000, 2007, 2013 and 2017, respectively. The value of hydrological adjusting occupied the largest proportion of the total value for 5 periods, and the value of river ecosystem occupied the largest proportion in five types of the wetlands. It should be noted that the central bar was very important for raw materials and gas adjustment.