’98洪水对鄱阳湖区生态系统服务的影响研究被引量：9

Impact of the 1998 Flood on Ecosystem Services in the Poyang Lake Region,China

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摘要 1998年长江流域性洪涝灾害驱使鄱阳湖区开始实施退田还湖工程,对湖区土地利用产生了重大的影响,进而影响了各项生态系统服务功能。本文对1998年流域性特大洪涝灾害对鄱阳湖区土地利用及生态系统服务功能的影响进行了研究。研究结果表明:在此次特大洪涝灾害的驱动下,鄱阳湖区土地利用结构产生了重大变化。其中,耕地面积减少了2.2%,为201.5km2,水域面积增加5.5%,为206.0km2。洪涝灾害发生后,研究区的生态系统服务功能整体提升了8.5%,其中湖泊面积的增加提高了湿地的水源涵养、洪水调蓄以及提供生物栖息地功能,湖泊对整体提升贡献率为92.4%;而水田、旱地等生态系统服务功能有所降低。湖区整体水源涵养、废物处理、生物多样性和娱乐文化功能分别提升了8.2%,6.6%,2.1%与6.5%,而食物生产和原材料生产功能分别降低了1.8%与0.4%。此外,对鄱阳湖洪水调蓄功能价值的计算表明,鄱阳湖区洪水调蓄功能也有所提升。 Due to monsoon climate characteristics and long-term reclaiming of wetlands as farmlands,the Poyang Lake region,the largest fresh water lake of China in the middle reaches of the Yangtze River,suffered from frequent flood hazards.In particular,the 1998 flood resulted in tremendous losses of property and life,which further urged the implementation of the Returning Farmland to Lake Policy launched by the Chinese central government.The implementation of this policy in the Yangtze River basin has shown a great impact on land use in the Poyang Lake region, which further affected ecosystem services thereof.Current studies focus mainly on the direct loss induced by natural hazards instead of variations in ecosystem services caused by flood hazards. This study explored the integrated impacts on both land use change and variations in ecosystem services by the 1998 flood and the returning farmland to lake policy.By using the Landsat Thematic Mapper（TM）/Enhanced Thematic Mapper Plus（ETM＋）images before and after the 1998 flood,land use change was quantified.Results show that the land use patterns of the Poyang Lake region changed greatly due to the 1998 flood and the implementation of the policy.Farmland decreased by 2.2%and had an increased area of 205.98 km2,whereas water area increased by 5.5% and the increased area was 206.0 km2.The ecosystem services value was calculated based on unit area ecosystem services and the specific coefficient of correction.It was suggested that the total ecosystem service function increased by 8.5%.Water surface area increase contributed 92.4%to the total function improvement.Water storage,flooding regulation,and habitat provision enhanced greatly by the increased water surface area.Alternatively,ecosystem services provided by paddy land and dry land decreased.On the basis of the ecosystem services value unit area of China’s terrestrial ecosystems,nine varieties of variations in ecosystem services value were evaluated. Results show that taking the region as a whole,the ecosystem services of water storage,pollution control and detoxification,biodiversity,as well as recreational and cultural functions increased 8.2%,6.6%,2.1%,and 6.5%,respectively.However,food provision and raw materials provision decreased by 1.8%and 0.4%,respectively.In addition,the calculations show that the flooding regulation function was also greatly improved due to the increased water surface area of the Poyang Lake,which were 479×106 Yuan,1 378×106Yuan,and 2 339×106 Yuan at water levels of 20.50 m,21.68 m and 22.59 m,respectively.