洞庭湖流域中上游地区景观格局变化的水文响应

Analysis on hydrological responses to changes of landscape patterns in the middle and upper reaches of Dongting Lake Watershed

将洞庭湖流域中上游地区1980、1995和2000年的LandsatMSS和TM卫星照片解译所得的景观数据,与经过最大似然估计法"消噪"的湘、资、沅、澧四水入湖水文站的年内最高洪峰水位、最大瞬时流量、年入湖径流量和年入湖泥沙量数据进行Paneldata模型处理,并对处理后的景观和水文数据进行灰色分析和主成分分析。结果表明:研究区最高洪峰水位的变化受景观格局变化影响最大,入湖泥沙量的变化受景观格局变化影响最小。对最高洪峰水位变化影响最大的是山地水田、水库坑塘和灌木林地疏林地景观面积的变化,影响指数值分别达-48.5、-48.1和45.2;对最大瞬时流量变化影响最大的是水库坑塘、水田(山地水田除外)和灌木林地疏林地景观面积的变化,影响指数值分别达-41.9、41.2和41.2。有林地景观因林分差和林种结构单一,对各水文特征指标变化的影响较小,影响指数值分别仅为-10.1、-13.5和-14.5。

The landscape data used was interpreted from the Land MSS and TM satellite imagary for the middle and upper reaches of Dongting Lake watershed in 1980, 1995, and 2000. With the Maximum Likelihood method, noise, concealing trends which the hydrological indices represented, was eliminated. Hydrological indices include the yearly peak stage, the peak discharge, the yearly amount of runoff, and the yearly amount of sediment, values for which came from the hydrological stations located in the lake inlet of Xiang River, Zi River, Yuan River, and Li River. After being treated by the Panel Data Model, these landscape and hydrological data were analyzed by the method of Gray Connection analysis and the principal component analysis. The results showed ： change of the peak stage is affected mostly by the landscape pattern change, and yearly sediment amount has impacted little affect. The peak stage change, lay on the increase or reduction of the landscape types, such as the mountain paddy fields, reservoirs and ponds, and shrub land and open forest land, whose influence values were - 48.5, - 48.1, and 45.2, respectively. The yearly peak discharge change is affected by the change of landscape types, including reservoirs, ponds, paddy fields （except mountain paddy fields）, and shrub land and open forest land, whose influence values are - 41.9, 41.2, and 41.2, respectively. Because the structure of the forest ages is not clear and the kinds of trees are simple, the effect of forest land on the change of hydrological characteristic indices is small, and the influence values are only - 10.1, - 13.5, and - 14.5, respectively.