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

摘要

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 fac-tors.The result show that:1)farmlands dominated in 1985,1990,1995,2000,2005,2010,and 2015 cov-ering about 1530.59km2,1388.88km2,1388.15km2,1121.88km2,1166.48km2,1017.07km2 and 883.15km2 respectively,although farmland has been in a downward trend.2)From 1985 to 2015,the for-est area and grass land has shown a rising trend,the rising rate of forest is 15.78km2 every five years,the rising rate of grass land is 9.23 km2 every five years.3 )The cultivated land area change is in a rapid de-cline trend in nearly 30 years,decline rate is 103.8km2 every five years.The building land area in 2015 is about three times of 1985,increase rate is 83.00km2 for every five years.The water area is in decline too, decline rate is 4.1 1 km2 every five years.4)Expansion of cities and towns are the main factors influencing the ecological environment of the lower reaches of Luanhe river.%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15.78km2／5a；草地上升速率为9.23km2／5a。3）耕地面积变化呈持续高速下降趋势，下降速率为103.8km2／5a。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83.00km2／5a；研究区水域面积呈波动下降的趋势，年变化率为－4.11km2／5a。4）城镇扩张是影响滦河下游生态环境的主要因素。