1964—2015年海南省八门湾红树林湿地及其周边土地景观动态分析

Dynamic analysis of landscape changes in Bamen port and the surrounding lands of Hainan Province from 1964 to 2015

以海南省文昌市八门港红树林湿地及其周边土地为研究对象,采用6期遥感影像为主要的数据来源,建立起研究区域内1964、1972、1988、2000、2009、2015年50年的景观数据库,利用土地转移矩阵和表征景观破碎化过程的景观指数系统阐述了八门湾红树林湿地及其周边土地的土地利用/覆被变化以及景观破碎化的过程,探讨八门湾红树林湿地及其周边土地土地利用/覆被变化与景观破碎化过程之间的相互关系。结果表明:(1)1964—2015年间,研究区域内建筑用地、养殖水面面积持续增长面积比重分别上升了7.72%、12.55%,耕地、林地、红树林面积所占比重分别下降了7.01%、9.16%、9.74%。(2)1964—2015年间,研究区域内斑块数量增加了685个,平均斑块面积缩减了39.12%,聚合度下降了3.5%,最大斑块面积缩减了28.38%,蔓延度下降了9.26%,斑块平均形状破碎化指数和面积加权平均形状破碎化指数分别上升了0.0148、0.0207,斑块密度从1964年的0.0653个/hm^2上升到2015年的0.1073个/hm^2。(3)八门湾红树林湿地及其周边土地的土地利用/覆被变化与景观破碎化过程的相关关系主要体现在养殖水面、建筑用地面积变化对研究区域景观破碎化指数的影响上。养殖水面、建筑用地面积变化对研究区域景观破碎化过程的影响主要体现在聚合度、斑块数量、蔓延度的作用上。其中,养殖水面面积变化对研究区域景观破碎化过程的影响主要体现在其对红树林面积的侵占,使得红树林面积占研究区域总面积的比例由15%下降到5.25%,红树林由大面积连续集中分布趋向于小面积孤立分散分布。建筑用地面积变化对研究区域景观破碎化过程的影响主要体现在城市的快速发展、交通设施大量的建设。50年来,八门湾红树林湿地各地类之间的转化主要表现为红树林面积转化成养殖水面,林地和耕地面积转化为建筑用地,由此可见,人类活动能力的增强以及影响范围的不断扩大是引发八门湾红树林湿地景观破碎化的主要原因。

This paper took mangrove wetland of Bamen port in Wenchang of Hainan Province as the area of research. Six period remote sensing images, including the 50-year period （1964, 1972, 1988, 2000, 2009, 2015） , were used as the main data source to establish the regional landscape database and analyze the landscape dynamic changes of the study area, using a land transfer matrix and l0 kinds of relevant landscape indices. The results showed that （ 1 ） the built-up and surface areas of the raising water in Bamen port increased by 7.72% and 12.55%, respectively, from 1964--2015. At the same time, the proportions of the cultivated, forest, and mangrove areas decreased by 7.01%, 9.16%, and 9.74%,respectively. （2） The number of plaques in the study area increased to 685, the average patch area was reduced by 39.12%, the degree of polymerization decreased by 3.5%, the largest patch area decreased by 28.38%, and the CONTAG decreased by 9.26% from 1964 to 2015. During the same period, the mean patch-shape fragmentation index and area- weighted average patch-shape fragmentation index increased by 0.0148 and 0.0207, respectively, and the plaque density increased from 0.0653/hm2 in 1964 to 0.1073/hm2 in 2015. （3） The relationship between the land use/cover changes and their surrounding lands and landscape fragmentation in Bamen port mangrove wetland was mainly reflected in the influences of aquaculture water surface and construction land area on the study-area landscape fragmentation index. The influences of the changes of aquaculture water surface and construction land area on the landscape fragmentation process were mainly reflected in the degree of polymerization, number of plaques, and role of CONTAG. Among them, the influences of the changes in aquaculture water surface area on landscape fragmentation were mainly reflected in the encroachment of mangrove area. As a result, the proportion of the mangrove area accounting for the total research area decreased from 15% to 5.25%, and the mangrove forest showed a transformation from the large-area continuous concentration to the small-area isolated distribution. The influences of the changes in construction land area on landscape fragmentation were mainly reflected in the rapid development of the city and transportation facilities. The transformation of various types of mangrove swamps in Bamen port mainly embodied on that the mangrove areas were transformed into the aquaculture water, and the building area was converted from the woodland and cultivated land in the past 50 years. Thus, the primary reason for the fragmentation of mangrove wetland in Bamen port was the enhancement of human activity and the expanding scope of its influence