松嫩平原湿地演变及其驱动因素分析

湿地是生态系统的重要组成部分，在维系区域生态安全中扮演着重要角色.利用1975、2000和2018年的Landsat遥感影像数据，获取3期湿地解译数据，采用动态度分析、差异性分析、转移矩阵等方法对近50年来松嫩平原地区湿地的时空变化特征进行分析，为研究和保护松嫩平原地区湿地生态系统提供一定的理论依据.研究表明：湿地面积由1975年的20 189.81 km2上升至2018年的29 456.79 km2，整体上呈增加的趋势，具体表现为1975—2000年天然湿地的大幅度下降和2000—2018年人工湿地的大规模增加.分析认为：蓄水工程、河道防洪堤和湿地围垦是天然湿地减少的主要因素；降水量变化、气温上升、蒸发量增加是天然湿地变化的次要因素；受经济效益为中心理念驱动，水田改扩建增加是人工湿地增加的主要因素.

WETLAND EVOLUTION AND ITS DRIVING FACTORS IN SONGNEN PLAIN

As an important part of ecosystem, wetland plays a significant role in maintaining regional ecological security. Based on the Landsat remote sensing image data in 1975, 2000 and 2018, the interpretation data of wetland during the three periods are obtained to analyze the spatiotemporal variation of wetland in Songnen Plain in nearly 50 years with the methods of dynamic degree, difference analysis and transfer matrix, which provides certain theoretical basis for the research and protection of wetland ecosystem in Songnen Plain. The results reveal that the wetland area shows an overall increasing trend from 20 189.81 km² in 1975 to 29 456.79 km² in 2018, manifested by the substantial decrease of natural wetland during 1975-2000 and large-scale increase of constructed wetland during 2000-2018. It is concluded that water storage project, floodwall and wetland reclamation are the main factors causing the decrease of natural wetlands, followed by precipitation reduction, temperature rise and evaporation increase. Driven by the economic benefit, the paddy field reconstruction and expansion mainly contributes to the increase of constructed wetlands.