基于LUCC的鄱阳湖湿地生态效应分析

土地利用/土地覆盖变化(LUCC)是内陆湿地演变的重要因素之一,对湿地生态系统产生广泛的生态效应。2000年以来,鄱阳湖湿地土地利用方式和强度发生了较大变化,有必要探究由此引发的生态效应。利用2000-2013年共4个时期的遥感影像,借助RS和GIS工具研究了鄱阳湖湿地各时期的LUCC及其动态度和土地利用综合程度指数,通过景观指数计算,分析了总体景观格局和不同景观类型的变化特征;利用主成分分析和相关分析方法,探讨了总体景观格局指数主成分综合值及其与土地利用程度综合指数的相关性。结果表明,鄱阳湖湿地土地利用结构和方式发生了较大变化,水体和耕地面积逐年下降,林地、建设用地和沙滩地面积逐年增加,土地利用综合程度指数由2000年的249.08上升到2013年的251.41,土地利用强度持续增加;总体景观格局指数和不同景观类型均发生了较大变化,景观趋于多样化、复杂化和破碎化,连通性降低,稳定性变弱;土地利用程度综合指数与总体景观格局指数相关系数为0.927,呈显著正相关,土地利用强度的增加使鄱阳湖湿地景观格局趋于负面化。研究结果反映LUCC引发景观的破碎化和不稳定、鄱阳湖湿地面积的减少以及生物多样性降低等一系列负向生态效应。

Analysis of the Ecological Effects of LUCC in Poyang Lake Wetland

Land use/cover change (LUCC) is one of the important factors in the evolution of inland wetland, which has a wide range of ecological effects in the wetland ecosystem. Greater changes in the way of land use and land use intensity have taken place in the Poyang Lake wetland since 2000. This paper attempts to study the LUCC and its ecological effects of the Poyang Lake wetland. Four phases of remote sensing images in the same period of different years were utilized to study the LUCC in the Poyang Lake wetland with the help of RS and GIS tool; By calculating the landscape index, the paper analyzed the change features of the landscape pattern; Correlation analysis method was used to study the LUCC and landscape index etc, which is the main innovation of this paper. The results show that the comprehensive degree index of land use in Poyang Lake wetland increased from 249.08 in 2000 to 251.41 in 2013, and the land use intensity continued to increase; Landscape pattern had changed greatly, the landscape tended to diversification and fragmentation, connectivity decreased, and the stability became weak; The comprehensive index of land use degree was significantly positive correlated with the overall landscape pattern index. The results reflect the LUCC had caused a series of negative ecological effects, such as the fragmentation and instability of the landscape, the decrease of the wetland area and the reduction of biodiversity in the Poyang Lake wetland.