Physical dynamics of Lake Victoria over the past 34 years (1984-2018): Is the lake dying?
Physical dynamics of Lake Victoria over the past 34 years (1984-2018): Is the lake dying?
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DOI：
10.1016/j.scitotenv.2018.12.051
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发表时间：
2019-03-25
影响因子：
9.8
通讯作者：
Kexiang, H.
中科院分区：
文献类型：
--
作者：
Awange, J. L.;Saleem, A.;Kexiang, H.
了解湖泊(如区域和海岸线)物理动态的变化，对于在极端气候(如洪水和干旱)期间为政策、规划和管理提供信息十分重要。维多利亚湖是世界第二大淡水湖，从面积66,400-69,485千米(2)，长度300-412千米，宽度240-355千米，海岸线3300-4828千米的引证来看，其物理动态和相关变化并未得到很好的了解。其庞大的规模和地区政府承诺的研究资源的缺乏阻碍了观测。这一贡献利用了过去34年(1984-2018年)的一套遥感产品；Landsat、Sentinel-2、MODIS、Google Earth Pro、CHIRPS、多变量厄尔尼诺-南方涛动指数和高度计数据以及37份出版物(1969-2018年)的物理参数，以(1)研究湖泊的动态并建立其当前(2018年)状态，(2)确定和分析发生显著动态变化的热点，以及(3)研究气候变化和人类活动对这些动态的贡献。利用人工数字化、MNDWI、NDVI和PCA方法，研究表明，该湖的平均表面积为69,295平方公里(即，比37份出版物的面积增加812公里(2)或1.2%)，2018年的面积为69,216平方公里(即，与37份出版物的733公里(2)(1.1%)相似)。至于湖泊是否正在消亡，与1984年的价值相比，它缩小了203公里(2)(0.3%)，这主要体现在四个热点海湾(Birinzi 40%，Winam 20%，Emin Pasha 38%和Mwanza 55%)。相应地，纳鲁巴勒大坝的扩建(2002-2006年)使面积分别减少了31%、10%、21%和44%。季节分析表明，在暴雨季节(3-5月)，湖区面积增加了9公里(2)，而ENSO使面积增加了0.23%(2007年)和0.45%(2010年)。因此，很明显，气候多变/变化和人为活动都在对热带最大的淡水区造成损害，因此有必要制定谨慎的开发和管理计划。(C)2018爱思唯尔B.V.保留所有权利。
Understanding changes in the physical dynamics of lakes (e.g., areas and shorelines) is important to inform policies, planning and management during climate extremes (e.g., floods and droughts). For Lake Victoria, the world's second largest freshwater lake, its physical dynamics and associated changes are not well understood as evidenced, e.g., from the citations of its area 66,400-69,485 km(2), length 300-412 km, width 240-355 km, and shorelines 3300-4828 km. Its sheer size and lack of research resources commitment by regional governments hamper observations. This contribution employs a suite of remotely sensed products for the past 34 years (1984-2018); Landsat, Sentinel-2, MODIS, Google Earth Pro, CHIRPS, Multivariate El' Nino-Southern Oscillation Index and altimetry data together with the physical parameters from 37 publications (1969-2018) to (i) study the lake's dynamics and establish its current (2018) state, (ii) identify and analyse hotspots where significantly dynamic changes occur, and (iii), study the contributions of climate change and anthropogenic activities on these dynamics. Utilizing manual digitisation, MNDWI, NDVI and PCA methods, the study shows the lake's mean surface area to be 69,295 km2 (i.e., 812 km(2) or 1.2% more than that of the 37 publications) and its 2018 value to be 69,216 km2 (i.e., similar to 733 km(2) (1.1%) more than that of the 37 publications). As to whether the lake is dying, it shrunk by 203 km(2) (0.3%) compared to its 1984 value, a decrease noted mainly in four hotspot Gulfs (Birinzi 40%, Winam 20%, Emin Pasha 38% and Mwanza 55%). Correspondingly, the expansion of Nalubaale Dam (2002-2006) decreased the areas by 31%, 10%, 21% and 44%, respectively. Seasonal analysis shows an increase of 9 km(2) in the lake's area during the heavy rainy season (March-May) while the ENSO enlarged the area by 0.23% (2007) and 0.45% (2010). It is evident, therefore, that both climate variability/change and anthropogenic activities are exerting a toll on the tropical's largest freshwater body thereby necessitating careful exploitation and management plans. (C) 2018 Elsevier B.V. All rights reserved.