地球信息科学学报 ›› 2019, Vol. 21 ›› Issue (5): 781-788.doi: 10.12082/dqxxkx.2019.180643.

• 遥感科学与应用技术 • 上一篇    下一篇

基于Landsat影像的斯里兰卡内陆湖库水体时空变化分析

李健锋1,2,3(), 叶虎平2,3,5,*(), 张宗科2,3, 孔金玲1, 魏显虎2,3, Somasundaram Deepakrishna2,3,4, 王法溧2,3,4   

  1. 1. 长安大学地球科学与资源学院,西安 710054
    2. 中国科学院遥感与数字地球研究所,北京 100094
    3. 中国科学院中国—斯里兰卡水技术研究与示范联合中心,北京 100085;
    4. 中国科学院大学,北京 100049
    5. 中国科学院地理科学与资源研究所资源与环境信息系统国家重点实验室,北京100101
  • 收稿日期:2018-12-06 修回日期:2019-02-21 出版日期:2019-05-25 发布日期:2019-05-25
  • 通讯作者: 叶虎平 E-mail:ljf_chd@163.com;yehp@radi.ac.cn
  • 作者简介:

    作者简介:李健锋(1994-),男,陕西富平人,硕士生,主要研究方向为定量遥感。E-mail: ljf_chd@163.com

  • 基金资助:
    中国科学院中国—斯里兰卡水技术研究与示范联合中心项目,中国科学院中国-斯里兰卡联合科教中心;中国科学院战略性先导科技专项(XDA2003030202);国家发改委财政专项(2017ST000602)

Spatiotemporal Change Analysis of Sri Lanka Inland Water based on Landsat Imagery

Jianfeng LI1,2,3(), Huping YE2,3,5,*(), Zongke ZHANG2,3, Jinling KONG1, Xianhu WEI2,3, Deepakrishna SOMASUNDARAM2,3,4, Fali WANG2,3,4   

  1. 1. School of Earth Science and Resources, Chang'an University, Xi'an 710054, China
    2. Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing 100094, China
    3. China-Sri Lanka Joint Research and Demonstration Center for Water Technology, Chinese Academy of Sciences, Beijing 100085, China
    4. University of Chinese Academy of Sciences, Beijing 100049, China
    5. State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
  • Received:2018-12-06 Revised:2019-02-21 Online:2019-05-25 Published:2019-05-25
  • Contact: Huping YE E-mail:ljf_chd@163.com;yehp@radi.ac.cn
  • Supported by:
    China-Sri Lanka Joint Research and Demonstration Center for Water Technology, China-Sri Lanka Joint Center for Education and Research, Chinese Academy of Sciencese;The Strategic Priority Research Program of the Chinese Academy of Sciences, No.Xda2003030202;State Development And Reform Commission's Special Financial Projects, No.2017ST000602.

摘要:

斯里兰卡是海上丝绸之路沿线重要节点,降雨量丰富但时空分布不均匀,存在明显季节性缺水,其内陆湖库水体面积变化监测对水资源开发利用具有重要指导作用。为了解斯里兰卡湖库水体空间分布特征与时间变化规律,本文基于Landsat系列影像数据,对比分析不同水体提取模型在影像上的水体提取精度,确定最优算法;选取典型湖库分析其面积年际和年内的动态变化特征。以1995、2005和2015年为基准研究年份,采用最优水体提取模型对全岛内陆湖库水体进行提取,利用面积将湖库分为4个等级,统计各年份不同等级湖库的数量和面积数据,分析其时空变化特征。研究结果表明:① 基于大津法(OTSU)的归一化水体指数(NDWI)水体提取模型提取水体的精度最高,总体精度在97%以上,误提率和漏提率最低,适合于斯里兰卡地区水体的提取;② 1988-2018年同期8月的典型水库面积总体呈现波动增加的趋势,1992年水库面积最小,2013年水库面积最大;水库面积年内变化较大,其中2017年最大面积出现在2月,最小出现在9月,与雨季和旱季结束月份基本一致,且2月面积是9月面积的2.24倍;③ 1995-2015年同期,斯里兰卡全国4个等级湖库的数量和面积不同幅度的增加,湖库水体资源量呈递增的趋势。研究结果可为斯里兰卡水土资源优化配置及水资源管理与规划提供科学依据。

关键词: 斯里兰卡, 湖库, 海上丝绸之路, 水体提取, 时空变化, 大津法(OTSU)

Abstract:

Sri Lanka is an important node on the Maritime Silk Road, where rainfall is abundant in quantity but uneven in terms of spatiotemporal distribution. There is obvious seasonal water shortage. Monitoring the changes of water cover area in inland lakes and reservoirs is important for guiding the development and utilization of water resources. To understand the spatial distribution characteristics and temporal variations of lakes and reservoirs in Sri Lanka, this paper, based on Landsat series imagery, analyzed and compared the precision of different water extraction models on the images, following which the optimal algorithm was determined. A typical reservoir was chosen to analyze the interannual and monthly variations of the water cover sizes. The optimal water extraction algorithm was applied to the inland lakes and reservoirs in 1995, 2005, and 2015. Lakes and reservoirs were divided into four grades by area. The number and area of lakes and reservoirs of different grades in each year were counted, and their spatiotemporal variation characteristics were examined. Conclusions can be made according to the results as the following statements: (1) The water body extraction model based on the Normalized Difference Water Index (NDWI) with threshold value from the Otsu method (OTSU) had the best accuracy and was suitable for the water body extraction in Sri Lanka. The overall classification accuracy is above 97% and it has the lowest mis-extraction rate and the missing rate. (2) The water cover area of typical reservoir showed a fluctuatingly increase trend in Augusts from 1988 to 2018. The smallest water cover area occurred in 1992, and the largest was in 2013. The water cover area of reservoir was also of large intra-annual fluctuations. In 2017, the biggest water cover area appeared in February, while the smallest appeared in September, with a discrepancy of 2.24 times between the cover area in February and September, exactly the ends of local rainy season and dry season, respectively. (3) From 1995 to 2015, the number and area of lakes and reservoirs of different grades increased to some extent, and the trend of lake and reservoir water resources was increasing. Findings of the research will provide necessary data support for the management and planning of soil and water resources in Sri Lanka.

Key words: Sri Lanka, lakes and reservoirs, Maritime Silk Road, water body extraction, spatiotemporal change, OTSU