生态服务价值视角下湖北省长江流域防洪能力研究

以我国洪涝灾害最为严重的地区之一——湖北省长江流域为研究对象,从生态服务价值的视角,利用流域1996年和2009年两期土地利用数据,测算与流域防洪功能相关的水土保持和滞洪蓄洪生态服务价值的变化情况,并结合土地利用/覆盖变化(LUCC),分区域对其变化的原因及所带来的影响进行分析。研究结果表明:(1)流域的整体防洪调蓄能力在1996~2009年有所增强,滞洪蓄洪和水土保持两项生态服务价值都有所增加;(2)局部地区存在较大问题,主要是:防洪重点地区江汉平原荆江段和鄂东沿江平原地区的滞洪蓄洪能力显著降低,其主要原因是湿地被大量侵占;水土保持重点区域鄂东沿江平原的北岸黄冈地区的水土保持生态服务价值则由于林地的减少而显著降低;(3)应借鉴生态服务功能保持较好地区的经验,坚持执行退耕还林和退田还湖政策,并建立湿地及森林自然保护区,以行政和法律的手段保护地区生态环境,提高流域防洪能力。

STUDY ON FLOOD CONTROL CAPACITY OF YANGTZE RIVER BASIN OF HUBEI PROVINCE FROM THE PERSPECTIVE OF ECOLOGICAL SERVICE VALUE

The Yangtze River basin of Hubei Province is one of the most seriously flood threatened areas. Soil and water conservation and flood storage are two kinds of ecological service functions that are directly related to the flood control capacity . From the perspective of ecosystem service value (ESV), the flood control capacity can be measured quantitatively. Land use/cover change (LUCC) is one of the main driving forces of the change of ecosystem services value. Based on the land use data of the Yangtze River Basin of Hubei Province in 1996 and 2009，this paper estimates ecosystem service value in each subdivision according to “equivalent value per unit area of ecosystem services in China” and explores the association between the ESV evolution and the land use changes. The results showed: (1) During the period 1996-2009, the flood control capacity of the study area had been enhanced, the values of these two kinds of ecosystem service values including soil and water conservation and flood storage function have been increased. (2) Due to the substantial growth of the woodlands, the soil and water conservation service value of The Three Gorges region and East Hubei plain along the Yangtze River increased during the study period. It is worth noticing that the growth of the soil and water conservation service value in East Hubei plain along the Yangtze River is mainly due to the surge of the ecological service value in Huangshi at the southern bank, whose range is greater than the decrease of the ecological service value in Huanggang at the north bank of the area. (3) Due to the shrinkage of the wetlands, the flood storage service value of the Jianghan plain and East Hubei plain along the Yangtze River decreased during the study period. It reveals that it is in lack of Sustainability for Returning farmland to forest. As important agricultural regions, the cultivated lands of these two areas has been effectively guaranteed, at the price of wetland encroachment in some areas, which destroyed flood control capacity of the region. However, there are positive aspects in other regions, such as Honghu and Wuhan. The wetlands have been effectively protected thanks to some ecological restoration policies. The flood storage service value of these regions increased during the study period. From the perspective of land use planning, these results suggest that: more attention should be paid to ecological lands, such as wetlands and woodlands. Only in this way, the ecological service function of various land use can be protected effectively