Analysis of the invasion of the water lily (Eichhornia crassipes) in the Cointzio dam

Abstract

Objective: to analyze the growth dynamics of the water lily (Eichhornia crassipes) in the Cointzio dam due to the availability of water.

Design/Methodology/Approach: a monthly series of 45 Sentinel 2 and Landsat satellite images was used, with which the percentage of invasion of the water lily in the total area of the reservoir was calculated. The relative coverage of the lily was analyzed looking for growth patterns over time, as well as precipitation data, total reservoir area over time, and water storage data in the 2010-2020 period to broaden the context.

Results: Three ascending and two descending patterns of the water lily cover were identified; a 15-month upward growth pattern with slight inland slope changes; decreasing patterns are associated with decreased storage. The largest lily covers were found in critical storage stages during the 2010-2020 period.

Study limitations/implications: faced with climate change conditions, the filling pattern of the dam could change, aggravating problems related to water supply.

Conclusions: containment/mitigation efforts have a reduced effect because the lily recovers the covered area easily, growing about 400% between October 2017 and June 2018, so it is necessary to implement a containment strategy using the biophysical interactions of the basin in conjunction with social, political, economic and governance interactions.