1956年以来9个时期湖南省湿地动态研究

在遥感和地理信息系统技术支持下,利用湿地调查资料、地图和遥感影像数据,获得1956~2016年期间9个时期湖南省的湿地数据;采用景观分析方法,系统地分析了9个时期湖南省的湿地分布及其变化特征和湿地景观格局变化及其影响因素。研究结果表明,与1956年相比,2016年湖南省的湿地面积减少了955.4 km^2,其中,永久性淡水湖泊和河流面积明显减少,水产养殖场面积明显增加;湿地的景观结构也相应地发生了改变,1986年湖南省的湿地的破碎化程度最严重;1956~2016年期间,湿地景观类型分布不均衡程度在不断加剧;永久性河流和永久性淡水湖泊是湖南省的优势湿地景观类型,且永久性淡水湖泊的最大斑块指数都远大于其它类型湿地;围垦和退耕还湿活动是影响湿地变化的主要因素。

Dynamics of Wetlands in Hunan Province for 9 Periods since 1956

The study on the long-term changes and their trends of wetlands in Hunan province could provide theoretical instructions for wetland protection and decision-making in management within the area. With the support of remote sensing, geographic information system technology and landscape analysis methods, the related data about the wetlands including wetland survey data, maps, and remote sensing images collected and processed;and a spatial-database were built up with wetland data of Hunan province for 9 periods from 1956 to 2016. Landscape analyses were systematically conducted. Characteristics of wetland distribution, wetland landscape patterns and corresponding influencing factors were studied and concluded. The results showed that the area of wetlands in Hunan province in 2016 decreased by 955.4 km^2 compared with that in 1956, and the area of permanent freshwater lakes decreased and area of aqua-farms increased obviously. The fragmentation of the wetland landscape was the most serious in 1986. The diversity of the wetland landscape increased during 1956-2001, and decreased during 2001-2016. The unevenness on the distribution of the landscape types increased throughout the study period. Permanent rivers and permanent freshwater lakes were the dominant wetland types in Hunan province, and the maximum patch index of permanent freshwater lakes was much larger than other types of the wetlands. Reclamation and activities of returning farmland to wetlands were the main factors affecting the wetlands.