Modeling the Impact of Water Hyacinth on Evapotranspiration in the Chongón Reservoir Using Remote Sensing Techniques: Implications for Aquatic Ecology and Invasive Species Management

The proliferation of water hyacinth (Eichhornia crassipes) in the Chongón Reservoir, located within the Parque Lago National Recreation Area in Guayaquil, Ecuador, poses significant challenges to the local aquatic ecosystem and water resource management. This study assesses the impact of water hyacinth coverage on evapotranspiration rates over a 20-year period from 2002 to 2022 using remote sensing data and geospatial analysis. The Normalized Difference Vegetation Index (NDVI), derived from Landsat satellite imagery, along with meteorological records, was utilized to model the spatial and temporal dynamics of water hyacinth coverage and its effects on evapotranspiration. Our results indicate that water hyacinth coverage fluctuates significantly between rainy and dry seasons, increasing from covering 10.42% of the reservoir area in 2002 to a peak of 42.33% in 2017 during the rainy seasons. A strong positive correlation (r=0.92, p<0.001) was found between water hyacinth coverage and net daily water loss due to evapotranspiration. The evapotranspiration rates associated with water hyacinth were significantly higher during the rainy season (mean of 2309.90 mm/year) compared to the dry season (mean of 1917.87 mm/year). These elevated evapotranspiration rates contribute to increased water loss from the reservoir, potentially impacting water availability for municipal and agricultural use. Controlling the spread of water hyacinth is therefore crucial for preserving the reservoir’s ecological integrity and ensuring sustainable water resource management. The findings of this study provide valuable insights for informing management strategies aimed at mitigating the effects of invasive species on freshwater resources and maintaining aquatic ecosystem health.