中国土地覆盖时空变化未来情景分析

在对HLZ (Holdridge life zone) 分类系统与土地覆盖类型分类系统之间的差异性进行对比分析的基础上,根据土地覆盖类型与HLZ生态系统类型的最大对应概率,构建了基于栅格的土地覆盖边际转换模型。采用基于HadCM3 A1FI、A2a、B2a等三种未来气候变化情景数据模拟获得的中国HLZ生态系统时空变化的系列栅格数据,运行模型后获得相应时段中国未来土地覆盖时空变化情景系列数据。引入土地覆盖类型景观指数及平均中心系列模型和构造平均中心偏移距离及偏移方向的计算模型,对中国未来土地覆盖的景观指数变化及其平均中心的偏移距离、偏移方向及偏移趋势进行综合分析。基于HadCM3 A1FI、A2a、B2a三种情景模拟结果分析表明：在2000~2099年间耕地、草地、湿地、水域、冰川雪被等土地覆盖类型面积逐渐减少,林地、建设用地、荒漠等土地覆盖类型面积逐渐增加,沙漠面积有所减少。其中,林地增加速度最快 (平均每10年增加2.34%),裸露岩石减少速度最快 (平均每10年减少2.38%)。

Spatial and Temporal Distribution of Land Cover Scenarios in China

The differences of classification systems between HLZ and land cover are compared in this paper. Based on the conversion probability of each HLZ type to every land cover type, a marginal conversion raster model of land cover is created. This model wins through the difficulty of converting between the two classification systems. After the raster data of HLZ spatial distribution on the basis of the climate change data of HadCM3 A1FI, A2a, and B2a, respectively, being simulated, the marginal conversion model were run with these data, so the scenario data of land cover change of China in 2039, 2069 and 2099 are simulated. Moreover, some landscape index models, as the land cover diversity index and patch connectivity index, are introduced to analyze the landscape changes of land cover in China in the future. The mean center model is introduced to construct a model to calculate the shift distance and direction of the mean center of each land cover type, thus to study the shift trend of the mean centers of the future land cover in China. These results show that: with temperature continuously rising and precipitation keeping increasing, the areas of cultivated land, grassland, wetland, water body, ice and snow cover, and bare rock would decrease; the areas of forestland, construction land, desertified land would increase; especially, the increased rate of forestland is high (2.34% per ten years) and the decreased rate of bare rock is high (2.38% per ten years); the desert area would reduce partly; the land cover diversity and patch connectivity would continuously decrease and increase, respectively.