贵州省黄家坝万亩大坝土地覆被及景观格局变化

为实现贵州省万亩大坝土地资源可持续利用,运用GIS技术、景观格局指数和主成分分析方法,通过对比湄潭县黄家坝大坝2000年ETM、2005年ASTER、2010年ALOS遥感影像,分析其土地覆被和景观结构的动态变化。结果表明:2000—2010年,大坝耕地持续减少,林地、城镇建设用地、农村居民点、道路、水域等面积持续增加,灌木林地呈先减后增的趋势,耕地主要转化成城镇建设用地、农村居民点和道路,大坝景观格局的破碎度和多样性指数增加,优势度减小,景观结构趋于多样和均匀化。耕地的稳定性值较低,林地的稳定性值较高,坝子土地覆被变化受人口、经济效益和产业结构因素的影响较大,政策因素也有一定的驱动作用。

Water cycle evolution in the Haihe River Basin in the past 10000 years

The water shortage problem in the Haihe River Basin is the most severe in China, and has restricted its economic development. Over-extraction of groundwater has been very severe in the past 30 years. To solve this problem, scientific decisions should be made from a historical perspective. It is important to describe water cycle evolution in the Haihe River basin over the past 10000 years. Datasets of paleoclimate, paleogeography, palynoflora, historical record, isotopic abundance ratio and content were collected for research on different time scales. Some interesting conclusions were drawn by a comprehensive analysis method. First, radiation was the intrinsic force driving the evolution of water cycle. Generally, precipitation increased with temperature. Second, precipitation was high during 8 ka-5 ka B.P., the so-called Yangshao warm period of the Middle Holocene, which recharged the major part of the Quaternary groundwater. Third, heavy floods during this period transported sediment to the seaside, forming the Coastal Plain where cities such as Tianjin, Huanghua, Cangzhou are now located. In the last 3000 years, intermittent moderate floods did not have enough energy to transport sediment to the sea. Rivers usually overflowed in the piedmont region of the Taihang Mountains, and sediment deposited there formed the Piedmont Plain, where locate Shijiazhuang, Xingtai, Handan, Baoding and other cities. Precipitation had a high correlation with temperature in Haihe River Basin in the past 10000 years: the high temperature usually coupled with high precipitation. Today precipitation in the Haihe River Basin is relatively low, owing to low temperature. This study reveals the relationship between temperature, precipitation and river networks in the past 10000 years in Haihe River Basin, which has great scientific and practical importance in understanding the current water circulation and water shortage.

贵州省大坝土地利用变化及驱动力分析

选取贵州省万亩（1亩=1／15hm2）以上的坝子为研究对象，以GIS为技术支撑，通过空间叠加分析，提取研究区10a来的土地利用／覆被信息，并结合相应的社会经济统计数据，进一步分析引起变化的驱动力影响因子。结果表明：（1）2000～2005年、2005～2010年两个时段，耕地面积一直在持续减少，第二时段的变化比第一时段更剧烈；林地、城镇建设用地、农村居民点、水域、道路在两个时段都不同程度的增加，其中城镇建设用地、农村居民点在第二时段比第一时段增加的速度更快，其它3种地类增加的速度有所减缓；灌木总体变化是出现先减后增的趋势；（2）耕地在2000~2005年的流向主要是林地，在2005-2010年流向主要是居民点和城镇建设用地；（3）研究区土地利用变化受人口、经济效益、政策的影响。