海口市农用地格局时空变化分析
Spatial-temporal changes of agricultural land landscape in Haikou City
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摘要: 【目的】从时空上对海口市农用地各用地类型的演变进行分析,为海口市农用地景观格局分析和农用地利用变化趋势分析提供科学依据,并为农用地适宜性评价提供前期研究基础。【方法】采用海口市1991、2001、2010年3期Landsat TM/ETM+和ALOS遥感影像数据,利用ENVI 4.4和ArcGIS软件对3期遥感影像数据进行分类,通过土地利用变化率得到海口市农用地在时间序列上的变化规律,并在ArcGIS中通过空间叠加分析获得海口市农用地转移矩阵和空间转化特征。【结果】1991~2010年海口市耕地、园地、林地、坑塘水面和牧草地的土地面积变化率分别为:-0.551%、0.480%、-0.701%、0.195%、-0.005%。从时间上看,1991~2010年海口市农用地面积减少较快,其中林地减少速度最快,其次是耕地,减少最慢的为牧草地,园地和坑塘水面面积均不同程度增加;从空间上看,农用地转化为建设用地的区域主要集中在建成区的外围地区,耕地和园地互相转化的区域分布均匀,其中中西部林地主要转化为园地,在东海岸和东寨港附近部分耕地和红树林转化为坑塘水面。【建议】应实现耕地占补平衡、切实保护耕地,加强林地保护、扩大植树造林面积,集约利用土地资源,实现农用地信息化管理,以降低人地矛盾,促进海口市农业可持续发展。Abstract: ObjectiveSpatial-temporal changes of agricultural land landscape in Haikou City were studied to provide refer-ences for analyzing agricultural land landscape , determining variation trend of agricultural land utilization and evaluating agricultural land suitability. MethodAccording to ENVI4.4 and ArcGIS, the LandsatTM/ETM and ALOS remote sensing im-age data of 1991, 2001 and 2010 were classified. The change law of agricultural land time series in Haikou City was studied using the change rate of land utilization. Agricultural land transition matrix and space conversion characteristics of Haikou City were obtained using spatial overlay analysis in the ArcGIS.ResultThe land use change rate of farmland, garden plot, forest land, aquafarm and pastureland was-0.551%, 0.480%,-0.701%,0.195%and-0.005%,respectively. In time domain, the area of agricultural land reduced quickly in 1991-2010, in which forest land reduced fastest followed by farmland and pastureland. Garden plot and aquafarm area increased in varying degrees. In space domain, the location of agricultural land into construction land mainly scattered in the periphery of the built up area. The mutual conversion area of farmland and garden plot was u-niformly distributed. The midwest forest land mainly changed to garden plot. Part of the farmland and mangroves changed into aquafarm near east coast and Dongzhai harbor. SuggestionThe government should protect the farmland and make balance between the occupied farmland and supplement. The mangrove forest and the state reserve should be strictly pro-tected. The land resources should be saved and information management of farmland should be implemented to lower the contradiction between man and land and promote the sustainable development of agriculture in Haikou City.