秦岭金钱河流域土地利用景观格局变化特征研究

Changes of Landscape Pattern of Land-use at Jinqianhe River in Qinling Mountains

[目的]为揭示流域土地利用方式与气候变化的响应机制,并制定气候变化的适应策略。[方法]以2000和2015年金钱河流域的遥感影像为数据源,利用遥感影像处理方法对影像进行分类,采用叠置分析得到2000和2015年的土地利用方式转移矩阵;利用Fragstats软件在景观格局分析中采用了景观格局数量分析方法,在类型水平和景观水平上分别选取不同景观指数,系统分析了金钱河流域土地利用方式景观格局变化的时空特征。[结果]近15年来金钱河流域的土地利用类型均发生明显变化,草地、林地、建设用地的面积增加,分别增加了620.33、386.58、45.32 km^2,而水域、未利用地和耕地面积分别减少了555.34、452.71、44.17 km^2。景观格局分析结果表明,林地和水域面积始终占据优势,耕地和建设用地面积明显增加且破碎程度降低,分布呈现集中化,水域周边的景观要素增多。[结论]流域内水域面积减少明显,其主要原因是降水变化以及人为活动的影响;草地面积增多,主要转入类型为水域,多为断流的河流以及变小的河道;林地面积的增多以及耕地面积的基本平衡与政府施行的退耕还林、林地耕地保护政策有很大关系,因此短时间内政府政策的导向是土地利用变化的主要驱动因素。在景观格局的数量分析上研究区的破碎程度降低,景观呈均衡化趋势发展。

[Objective]To reveal the response mechanism of basin land use and climate change,and to make the adaptation strategy of climate change.[Method]Using the remote sensing images in 2000 and 2015 in Jinqianhe River basin as the data source,image classification was carried out by remote sensing image processing method.Overlay analysis was used to obtain the land use transfer matrix in 2000 and 2015.Fragstats software was adopted to analyze the landscape pattern by the method of quantitative analysis.Different landscape indices were selected at the type level and landscape level,and the spatial and temporal characteristics of land use pattern change in the land use pattern of money river basin were analyzed systematically.[Result]In the past 15 years,the land use types in the river basin had changed obviously.The area of grassland,forest land and construction land increased by 620.33,386.58 and 45.32 km 2 respectively.While the water,unused land and arable land decreased by 555.34,452.71,44.17 km 2,respectively.The results of landscape pattern analysis showed that the area of forest land and water area were always dominant,the area of cultivated land and construction land was obviously increased and the fragmentation degree was reduced,the distribution was concentrated,and the landscape elements in the water area were increased.[Conclusion]The water area in the basin decreased obviously,the main reason was the change of precipitation and the influence of human activities.The grassland area increased,mainly to types of waters,mostly dry rivers and small rivers.The increase of forest land area and the basic balance of cultivated land area and the government's policy of returning farmland to forest and forest land were very significant.Thus,the guidance of government policy was the main driving factors of land use change.In the quantitative analysis of landscape pattern,the degree of fragmentation in the study area was decreased,and the landscape was balanced.