摘要
长江口九段沙是我国最重要的湿地之一,是国家级自然保护区。基于GF-2、Landsat以及GoogleEarth遥感影像数据,解译九段沙潮沟及景观类型空间分布,选取潮沟长度、曲率等10个潮沟特征参数以及斑块面积比、斑块密度等4种景观格局指数,探究九段沙潮沟特征参数与典型景观格局之间的关系。结果表明:U-Net卷积神经网络提取典型景观总体精度最高为93.15%,Kappa系数为0.94;长江口九段沙区域受人类活动影响较小,2011~2021年潮沟网络持续发育,逐渐扩大且复杂化,上沙与上沙潮沟长度分别增加52.821和133.467 km,与下沙相比,上沙潮沟发育网络连通性较好;在没有外来物种和人为干扰下,芦苇为九段沙上沙的优势物种,芦苇斑块面积比处于高值,互花米草为九段沙下沙的优势物种,互花米草斑块面积比处于高值;上沙潮沟长度、潮沟密度、潮沟曲率与芦苇斑块面积比呈较强正相关(p≤0.05),潮沟曲率与海三棱藨草破碎化程度呈一般正相关,与海三棱藨草斑块面积比呈较强负相关,下沙潮沟曲率与芦苇破碎化程度呈一般负相关,与芦苇斑块面积比呈较强正相关,γ指数与互花米草斑块面积比呈较强负相关,潮沟曲率与互花米草斑块面积比呈显著正相关(p≤0.01)。通过探究潮沟发育与湿地景观格局演变间的关系,可以为九段沙湿地保护工作提供理论依据。
Jiuduansha,the mouth of the Yangtze River,is one of the most important wetlands in China and is a national nature reserve.Based on GF-2,Landsat and GoogleEarth remote sensing image data,this study interpreted the spatial distribution of Jiuduansha tidal creeks and landscape types.Ten tidal creek characteristic parameters including tidal creek length and curvature,and four landscape pattern indexes including patch area ratio and patch density were selected to explore the relationship between Jiuduansha tidal creek characteristic parameters and typical landscape patterns.The results showed that:The overall accuracy of U-Net convolutional neural network of extracting typical landscapes was 93.15%,and the Kappa coefficient was 0.94.The Jiuduansha area was less affected by human activities.From 2011 to 2021,the tidal channel network continued to develop,expand and become complicated.The length of the upper sand and upper sand tidal channels increased by 52.821 km and 133.467 km,respectively.Compared with the lower sand,the upper sand tidal channel development network demonstrated a better connectivity.In the absence of alien species and human disturbance,Phragmites australis was the dominant species of sand on Jiuduansha,and the area ratio of Phragmites australis patch was at a high value.Spartina alterniflora was the dominant species of sand under Jiuduansha,and the area ratio of Spartina alterniflora patch was at a high value.There existed a strong positive correlation between the length of tidal creek,the density of tidal creek,the curvature of tidal creek and the area ratio of reed patches(p≤0.05).The curvature of tidal creek was generally positively correlated with the degree of fragmentation of Scirpus mariqueter,and negatively correlated with the area ratio of Scirpus mariqueter patches.The curvature of the lower sand tidal channel was generally negatively correlated with the degree of reed fragmentation,and was strongly positively correlated with the area ratio of reed patches.Theγindex was strongly negatively correlated with the area ratio of spartina alterniflora patches.The curvature of the tidal channel was significantly positively correlated with the area ratio of S.alterniflora patches(p≤0.01).By exploring the relationship between tidal creek development and wetland landscape pattern evolution,this research can provide a theoretical basis for the protection of Jiuduansha wetland.
作者
王岩
郑光辉
赵成义
WANG Yan;ZHENG Guang-hui;ZHAO Cheng-yi(School of Geographical Sciences,Nanjing University of Information Science and Technology,Nanjing 210044,China)
出处
《长江流域资源与环境》
CAS
CSSCI
CSCD
北大核心
2024年第3期510-524,共15页
Resources and Environment in the Yangtze Basin
基金
国家自然科学基金项目(41877004,42130405)。
关键词
长江口
九段沙湿地
潮沟
景观格局
演变规律
Yangtze estuary
Jiuduansha wetland
tidal trench
landscape pattern
evolutionary law
