近30a来白洋淀土地利用变化规律及驱动力分析

分析土地利用变化规律对提高土地开发利用效率和推动生态环境保护工作具有重要意义。针对白洋淀的土地利用演变,为探究其变化趋势,以白洋淀湿地为例,采用30 a来8期Landsat TM/OLI遥感影像为数据源,结合遥感和地理信息系统方法,分析白洋淀湿地土地利用的时空变化特征和驱动力。结果表明:(1)1986—2018年,主导的土地利用类型是耕地和水域。耕地变化最为明显,减少了60.3%,水域变化次之,增加了24.1%。水生植物面积大致呈"增多—减少—增多"的趋势,居民地面积持续增加。(2)分析土地利用动态度得出,1986—2018年间水生植物和水域面积的单一动态度较大,综合动态度(L_C)从0.267%下降到0.117%,呈现缓慢下降趋势,说明白洋淀土地利用到后期的变化速度变慢,土地利用状态趋于稳定。(3)白洋淀土地利用类型变化的驱动因子为气候、人类活动和国家宏观政策。研究成果有利于区域进行土地利用决策,也可作为土地可持续利用和生态环境保护的科学依据。

Analysis on land use variation law and its driving force of Baiyangdian Lake since recent 30 years

It is of great significance to analyze the law of land use change to improve the efficiency of land development and utilization and promote the ecological environment protection． Aiming at the land use evolution of Baiyangdian Lake，the temporalspatial variation characteristics and the driving force of the land use of the wetland of Baiyangdian Lake are analyzed herein through adopting the LandsatTM/OLI remote sensing image of eight phases since recent 30 years as the data sources in combination with the methods of remote sensing and GIS ( geographic information system) by taking the wetland of Baiyangdian lake as the study case，so as to explore its variation law． The study result shows that: ( 1) From 1986 to 2018，the dominant types of land use are cultivated land and water areas． The variation of cultivated land is most significant with a decrement of 60. 3%，while the variation of water area is the secondary with the increment of 24. 1%． The area of aquatic plant generally exhibits a trend of increasing-decreasing-increasing，while the area of residential land continues to be increased． ( 2) It is obtained from the analysis made on the dynamic degree of land use that the single dynamic degrees of aquatic plant and water area are relatively large from 1986 to 2018，while the comprehensive dynamic degree ( LC ) decreases from 0. 267% to 0. 117% with a slowly decreasing trend， which is indicates that the variation speed of the land use of Baiyangdian Lake slows down in the later period and the land use status tends to be stable． ( 3) The driving factors of the land use type variation of Baiyangdian Lake are climate，human activities and national macroscopic policies． The study results are not only conducive to the regional land use decision-making，but can also be taken as a scientific basis for the sustainable land use and ecological environmental protection therein．