1985—2015年滦河下游典型区域土地覆盖/土地利用时空变化及其影响因素分析

The Spatio-temporal Changes on Ecological Environment of the Lower Reaches of Luanhe River from 1985 to 2015

为探究滦河下游典型区域土地覆盖/土地利用时空变化规律及其影响因素,利用1985—2015年每隔5年的遥感影像及其他辅助数据,采用监督分类的最大似然法提取不同时间段各土地类型,分析了滦河下游土地覆盖/土地利用的时空变化规律和影响因素。结果表明:1)耕地面积近30年呈高速率下降的趋势,但仍是滦河下游的主要土地覆盖类型。2)总体上,从1985—2015年林地与草地变化表现上升趋势,林地上升速率为15.78km2/5 a;草地上升速率为9.23 km2/5 a。3)耕地面积变化呈持续高速下降趋势,下降速率为103.8 km2/5 a。建筑用地呈上升趋势,2015年建筑用地面积为1985年的3倍多,其近30年来的整体增加速率为83.00km2/5 a;研究区水域面积呈波动下降的趋势,年变化率为-4.11km2/5 a。4)城镇扩张是影响滦河下游生态环境的主要因素。

In order to study the spatio-temporal changes on ecological environment and influence factors of the lower reaches of Luanhe river,we collected the remote sensing image（1985—2015）and other ancil-lary data,and used supervised classification method to extract the dynamic change of ecological factors.The result show that：1）farmlands dominated in 1985,1990,1995,2000,2005,2010,and 2015 covering about 1530.59km^2,1388.88km^2,1388.15km^2,1121.88km^2,1166.48km^2,1017.07km^2 and 883.15km^2 respectively,although farmland has been in a downward trend.2）From 1985 to 2015,the forest area and grass land has shown a rising trend,the rising rate of forest is 15.78km^2 every five years,the rising rate of grass land is 9.23 km^2 every five years.3 ）The cultivated land area change is in a rapid decline trend in nearly 30 years,decline rate is 103.8km^2 every five years.The building land area in 2015 is about three times of 1985,increase rate is 83.00km^2 for every five years.The water area is in decline too, decline rate is 4.1 1 km^2 every five years.4）Expansion of cities and towns are the main factors influencing the ecological environment of the lower reaches of Luanhe river.