摘要
采用CA-Markov模型方法,研究挠力河流域不同时段土地利用对湿地景观格局干扰强度的差异性。结果表明:(1)流域湿地景观格局变化显著。1967—2000年,挠力河流域湿地类型景观最大斑块指数逐渐减小,耕地和水域斑块的面积周长分维数逐渐减小,而沼泽和居民地的散布与并列指数变大,草甸和耕地聚集度指数增大;湿地景观破碎化程度增加;湿地景观空间分布逐渐由流域周围高地势区向中心河流廊道退缩。(2)流域土地利用变化明显。耕地和居民用地数量迅速增加,耕地趋于集中连片分布,土地利用呈由自然湿地逐渐转化为耕地的变化过程,耕地成为主导的土地利用类型。(3)流域土地利用强度存在阶段差异。1967—2000年,流域内人类活动对湿地景观的干扰强度逐渐加剧,人为景观面积比例由1967年的26.5%上升至2000年的67.8%。土地利用影响强度指数由1967年的1.690上升至2000年的2.394。2000年模拟的流域土地利用影响强度比2000年实际土地利用影响强度小,由此可以识别1983—2000年人类对湿地景观的干扰强度比1967—1983年有所增大;利用居民地和沼泽面积的变化可以识别流域人口增长和排水活动对土地利用影响的时段差异性。
With the aid of the CA-Markov model, impacts of land use on the wetland landscape pattern of the Naoli River Watershed was analyzed. Results show (1) the wetland landscape pattern varied significantly, with the largest patch index (LPI) of wetland landscape, and the perimeter-area fraetal dimensions (PA-FRAC) of cultivated land and water body declining gradually, while the interspersion & juxtaposition index (IJI) of marsh and residential land, the aggregation index (AI) of wet meadow and cultivated land, and the fragmentation degree of cultivated land landscape increased ascending gradually, leading to shrinkage of the wetland landscape from lands of high relief in the circumference of the basin to the narrow corridor alongside the central river from 1967 to 2000; (2) variation of the land use was significant, reflected in rapid expansion of farmland and residential land, and mergence of farmlands in distribution; and dominance of the landscape shifted from by wetland to by farmland ; and ( 3 ) variation of the intensity of land use between time phrases were remarkable. Disturbance of the wetland landscape by human activities increased in intensity in the period from 1967 to 2000, leading to rise of the proportion of artificial landscape in area from 26.5% to 67.8%, and of the intensity of land use impact from 1. 690 to 2. 394. The simulated impact intensity of land use on the basin was lower than the actual data in 2000. It is, hence, concluded that the disturbance intensity in the period of 1983 - 2000 was higher than in the period of 1967 -1983. Based on variation of the areas of residential land and the wetland, temporal differences in contribution of population expansion and drainage activity to the impact of land use on the wetland landscape pattern can be distinguished in the Naoli River Watershed.
出处
《生态与农村环境学报》
CAS
CSSCI
CSCD
北大核心
2009年第1期1-7,31,共8页
Journal of Ecology and Rural Environment
基金
国家自然科学基金(40471003)
高等学校博士学科点专项科研基金(20070319001)