Damtie Yilebes Addisu, Mengistu Daniel Ayalew, Meshesha Derege Tsegaye
Institute of Disaster Risk Management and Food Security Studies, Bahir Dar University, P.O. Box 5501, Bahir Dar, Ethiopia.
Faculty of Social Sciences, Bahir Dar University, Bahir Dar, Ethiopia.
Heliyon. 2021 Oct 19;7(10):e08196. doi: 10.1016/j.heliyon.2021.e08196. eCollection 2021 Oct.
The introduction of water hyacinth poses a serious threat to economic viability of Lake Tana and its environments. This study aimed to capture the spatial coverage of water hyacinth and its effect on water loss in Lake Tana using quantitative research methods. Four satellite images representing each season of 2019 were downloaded from USGS. In addition, pan evaporation data were taken from the National Meteorological Agency. ArcGis 10.4, Envi 5.3, Qgis 3.12.1 plug in CSP and Excel used to manage land use land cover classification and water loss estimation analysis. The seasonal coverage of water hyacinth was 15.35, 4.14, 11.82 and 13.59 km in winter, autumn, summer and spring 2019 respectively representing 0.63 and 0.17 percent of the Lake as a maximum and minimum coverage. The mean daily evaporation of Lake Tana was 5.14 mm/day, but this increased to 18.85 mm/day due to the presence of water hyacinth. The mean net daily water loss due to water hyacinth at Lake Tana was 0.14 km while 52,62 km in 2019. The study concludes that water hyacinth caused enormous negative impact on the water volume reduction in Lake Tana. Management of the Lake Tana environment and control of the water hyacinth weed are recommended to sustain the Lake.
凤眼蓝的引入对塔纳湖及其周边环境的经济可行性构成了严重威胁。本研究旨在运用定量研究方法，获取塔纳湖凤眼蓝的空间覆盖范围及其对湖水流失的影响。从美国地质调查局下载了代表2019年每个季节的四张卫星图像。此外，蒸发皿蒸发数据取自国家气象机构。使用ArcGis 10.4、Envi 5.3、Qgis 3.12.1插件CSP和Excel来管理土地利用土地覆盖分类以及湖水流失估算分析。2019年冬季、秋季、夏季和春季凤眼蓝的季节性覆盖面积分别为15.35平方公里、4.14平方公里、11.82平方公里和13.59平方公里，分别占湖泊面积的0.63%和0.17%，为最大和最小覆盖比例。塔纳湖的日均蒸发量为5.14毫米/天，但由于凤眼蓝的存在，这一数值增加到了18.85毫米/天。2019年，塔纳湖因凤眼蓝导致的日均净湖水流失量为0.14立方千米，全年总计52.62立方千米。该研究得出结论，凤眼蓝对塔纳湖的水量减少造成了巨大负面影响。建议对塔纳湖环境进行管理并控制凤眼蓝杂草，以维持湖泊生态。
