基于多源数据的岷江上游生态系统服务价值动态评估

Dynamic Evaluation on Ecosystem Service Value of the Upper Reaches of Minjiang River Based on Multi-Source Data

为深入了解四川省重要生态屏障—岷江上游地区的生态系统服务功能,在RS,GIS技术的支持下,综合运用RUSLE模型、CASA模型以及水源涵养模型结合影子工程法、碳税法、造林成本法、能量替代法等环境经济方法,对岷江上游的生态系统服务价值进行了科学评估,揭示了生态系统服务价值的时空变化格局及其驱动机制。结果表明:(1)2003—2013年,岷江上游生态服务价值总值呈现先增加(2003—2007年)后减小(2007—2013年)的趋势。(2)2007年单位面积生态服务价值相对于2003年呈现较大程度增加,而2013年比2007年的单位面积生态服务价值有所减少。(3)岷江上游各项生态系统服务价值均在10月份达到最小值,而土壤保育价值和水源涵养价值在8月份达到最大值,基于NPP的固碳释氧、有机质生产和营养物质循环价值则在7月份达到最大值。(4)2003—2007年,松潘县的生态系统服务价值总值增加幅度最大,2007—2013年,各县的生态系统服务价值总值均表现为一定程度的减小,其中汶川县的减小幅度最大。相关研究成果不仅可以为岷江上游的生态环境保护提供技术支持,还可以为区域经济建设和生态补偿提供决策参考。

The Upper Reaches of Minjiang River,as a typically fragile eco-system zone,is an important ecological protection region of Yangtze River.Utilizing the geographic information system and remote sensing,we have obtained the evaluations of the soil conservation,carbon sequestration and oxygen release,nutrient cycling,organic production and water conservation in 2003,2007,and 2013 with the models of regional water balance,RUSLE and CASA based on multi-source data(remote sensing images,meteorological observations,land-use types,and so on).Then the spatial and temporal change patterns of ecosystem service values of the Upper Reaches of Minjiang River were analyzed.The results showed that:(1)during 2003—2013,there were an increasing,trend in the gross of ecosystem service value for 2003—2007 and a decreasing trend for 2007—2013,respectively;(2)in 2007,the ecosystem service value of unit area increased compared with that of 2003 while there was a slightly decreasing change during 2007—2013;(3)each part of ecosystem service in the Upper Reaches of the Minjiang River reached the minimum value in October,while the values of water conservation and soil conservation reached the maximum in August;meanwhile,the values of carbon sequestration and oxygen release,the organic production,and nutrient recycling derived from net prima-ry productivity(NPP)reached the maximum in July;(4)during 2003—2007,the ecosystem service value of Songpan county had the largest increase while that of Heishui County was the smallest;on the contrary,there was a decreasing trend in ecosystem service value for all five counties,among which the Wenchuan County had the largest reduction during 2007—2013;(5)compared with other land use types,the forest had higher capacities of soil conservation,net primary production,and water conservation.Therefore,it was of great importance to improve the condition of forest for raising the ecosystem service value of the Upper Reaches of Minjiang River.The main driving forces of ecosystem service value changes were composed of natural factors(such as earthquake,landslide,debris flow,vegetation,and climate fluctuations)and human disturbances(such as deforestation,land overuse,unreasonable economic structure).The improvement of ecosystem service value can reduce soil erosion and protect the farmland in the Middle and Lower reaches,which is of great significance for the sustainable economic development in the Upper Reaches of the Minjiang River.The results can not only provide the basis for the ecological environment management,but also strengthen the concept of environmental protection.