基于遥感影像和Canny算子的异龙湖形态特征变化

Morphological characteristics of Yilong Lake based on remote sensing image and Canny operator

基于Landsat 5 TM/Landsat 8 OIL影像,通过计算归一化差值水体指数,采用Canny算子自动提取湖岸线.在遥感和地理信息系统技术的支撑下,应用分形理论对近30a异龙湖的岸线动态变化特征进行分析,讨论环境和人类活动对湖岸线的影响及岸线变化对沿岸带生产力的影响.运用Pearson系数分析岸线复杂程度与周长、面积、周长面积比之间存在的潜在关系,定量探究岸线复杂程度与湖泊形状的关系.结果表明,Canny算子能有效地提取湖岸线,分形理论可以更好地对岸线进行定量描述.岸线复杂程度与周长、周长面积比强相关,与面积不相关几何学意义周长面积比的变化代表湖泊形状变化,当周长面积比值越高的时候,湖泊形状越复杂,岸线越曲折,其复杂程度越高,岸线发育系数越大,湖沿岸带的初级生产力越强。

Based on the Landsat 5 TM/Landsat 8 OIL image,the Canny operator was used to automatically extract the lake shoreline via a calculation of the normalized difference water index.Under the support of remote sensing and geographic information system technology,the fractal theory was applied to analyze the dynamic change characteristics of the shoreline of Yilong Lake in the past 30 years,the influence of the environment and human activities on the lake shoreline and the influence of the shoreline change on the productivity of the coastal zone were discussed.The Pearson coefficient was used to analyze the potential relationship between the complexity of the shoreline and the perimeter,area and perimeter-to-area ratio,and to quantitatively explore the relationship between the complexity of the shoreline and the shape of the lake.The results showed that the Canny operator could effectively extract the lake shoreline,and the fractal theory could better describe the lake shoreline quantitatively.The complexity of the shoreline was strongly correlated with the perimeter and perimeter-area ratio,but not with the area.In a geometric sense,changes in the perimeter ratio represented changes in the shape of the lake.When the perimeter area ratio was higher,the shape of the lake was more complex,the shoreline more zigzagged,the complexity higher,the lake shoreline development coefficient larger,and the primary productivity of the lakecoastal zone stronger.