黄河流域湿地景观时空演变格局分析

Spatio-temporal evolution pattern of wetland landscape in the Yellow River Basin

湿地景观的时空演变及其驱动因素研究是湿地生态恢复与保护的重要参考,本文利用1980—2015年7期黄河流域土地利用数据构建黄河流域湿地矢量数据集,基于景观格局指数对黄河流域湿地的时空演变特征进行定量和定性分析;采用转移矩阵对每两个时期湿地资源的转移类型和数量进行计算与分析。研究结果表明,(1)1980—2015年,黄河流域湿地率为3.5%,其中自然湿地率约为2.0%,即黄河流域的湿地类型以自然湿地为主。(2)斑块面积结果显示,黄河流域湿地总面积减少了312.74 km^(2),表现为人工湿地增加,自然湿地减少;自然湿地中沼泽湿地呈增加状态,主要是在2005—2010年增加了979.22 km^(2),滩地呈减少状态,减少了1 218.19 km^(2),主要发生在1990—1995年和2005—2010年。斑块密度结果显示,随着河渠和滩地受人为活动影响程度的加大,两者的斑块破碎化程度逐渐加大。最大斑块指数结果显示,水田是黄河流域的主导湿地类型,沼泽和湖泊是自然湿地中的主导湿地类型。(3)黄河流域湿地类型与非湿地之间转换是黄河流域景观转换的主要组成部分,其中沼泽与滩地是面积发生变化的主要湿地类型。

The study on the spatio-temporal evolution of wetland landscape is an important reference for the follow-up wetland ecological restoration and protection. This paper uses the land using data of the Yellow River Basin from 1980 to 2015 to construct the wetland vector data set in the Yellow River Basin, and analyzes the spatio-temporal evolution characteristics of the wetland in the Yellow River Basin quantitatively and qualitatively based on the landscape metrics. The transfer matrix is used to calculate and analyze the transfer type and quantity of wetland resources in each two periods. The research results shows that:(1)From 1980 to 2015, the wetland rate of the Yellow River Basin was 3.5%, in which the natural wetland rate was about 2.0%, which means that the wetland type of the Yellow River Basin is mainly natural wetland.(2) The results of patch area showes that the total area of wetland in the Yellow River Basin is decreased by 312.74 km^(2), represented by the constructed wetland increased and the natural wetland decreased. The marsh wetland increased in natural wetland, mainly in 2005—2010, increased by 979.22 km^(2), and the beach decreased by 1 218.19 km^(2), mainly occurred during 1990—1995 and 2005—2010. The results of PD showes that the degree of patch fragmentation increases gradually with the increase of human activities. The results of LPI show that paddy field is the dominant wetland type in the Yellow River Basin, swamp and lake are the dominant wetland types in the natural wetland.(3) The transformation between wetland type and others is the main component of landscape transformation in the Yellow River Basin, in which marsh and floodplain are the main transferred types with others.