基于多源遥感的广东镇海湾红树林演变分析

利用4 期多源遥感数据（包括1970 年的美国间谍卫星DISP KH-9 数据、1999 年的SPOT-2 全色数据、2007 年的ALOS 多光谱数据和2015 年国产的资源三号数据），结合红树林湿地资源的空间分布特征及先验知识，基于面向对象的多尺度分割提取红树林植被斑块，采用目视解译获取多时相红树林空间分布精确信息。结果表明：1970、1999、2007 和2015 年镇海湾红树林有林地面积分别为931.4、615.3、678.5 和783.7 hm²，红树林面积呈现出先减少后增加的趋势。1970―1999 年，该区域以原生红树林被破坏为主，仅有5.7%的原生林被保存下来。1999―2015 年，红树林的人为破坏与人工修复现象并存，但总体上破坏程度有所降低；其中1999―2007、2007―2015年间红树林面积分别增加了63.2 和105.2 hm²。养殖塘侵占和人工恢复种植的综合影响，以及海岸线周边人为活动变化是驱动红树林有林地时空变化的主要因子。最后，提出了一系列有针对性的红树林保护与发展的措施，为合理地开发和更好地保护红树林资源提供决策支持。

Analysis on Mangrove Resources Changes of Zhenhai Bay in Guangdong Based on Multi Source Remote Sensing Images

A large area of mangrove wetland has been preciously conserved in Zhenhai Bay of Jiangmen City, Guangdong Province. However, scholars and local government have not paid much attention to this area yet. In this paper, multi-source remote-sensing images of four periods (namely Declassified Intelligence Satellite image acquired in 1970, KH-9, SPOT-2 image obtained in 1999, ALOS multi-spectral image in 2007, and the ZY-3 image captured by domestic satellite in 2015) were used. Integration of spatial distribution characteristics of mangrove forest and objected-oriented multi-scale segmentation, visually interpreted approach were combined for accurate classification of mangrove forest. Results demonstrate that the areas of mangrove forest in Zhenhai Bay were 931.4, 615.3, 678.5 and 783.7 hm² in 1970, 1999, 2007, and 2015 respectively, showing a declining trend in the former 10 years and later an upward tendency. Specifically, during the period from 1970 to 1999, the change of mangrove forest in this area was mainly due to the destruction of original forest, when only 5.7% of original forest was preserved. Later, during the period of 1999-2015, the interruption of people and artificial remediation coexisted, but on the whole the degree of the damage decreased. The area of mangrove forest increased 63.2 and 105.2 hm² during 1999-2007 and 2007-2015, respectively. Hence, the primary driving factors that affect mangrove’s temporal and spatial change were the combined influences of the sprawl of aquaculture ponds and the artificial recovery of plants. Therefore, in this paper, we propose a series of measures for targeted protection and development of the mangrove wetland (e.g. protecting the suitable land, developing the ecotourism and realizing the dynamic monitoring on mangroves), so as to provide decision support for rational exploitation and better protection of mangrove forest resources in the area.