Análisis del costo-beneficio de la restauración ecológica en zonas con alta susceptibilidad de erosión en la subcuenca Casacay

Abstract

The Casacay Sub-Basin is the main source of water supply for the communities of Machala, Pasaje, and El Guabo. The water resource has been affected by erosion processes in the upper sub-basin generated by changes in land use and sediments transport. This research aims to analyze the cost-benefit of ecological restoration in areas with high erosion susceptibility in the upper sub-basin of the Casacay River. The Green-Gray Assessment methodology of the World Resource Institute was applied, considering a 30-year horizon, to determine the cost-benefit analysis related to the sediment load and turbidity in the raw and potable Water Treatment Plants of the "La Esperanza" Community Association. The results revealed that the Casacay upper sub-basin has a soil loss capacity of up to 60,000 tons/ha/year and, therefore, with strategic planning, it was determined that the priority areas for intervention are the channels immersed in the most susceptible areas to erosion. The ecological restoration project aims to restore the riparian ecosystem of these channels with the Buddleja coriacea specie, in around 29,06 hectares and 123.505 plants, with a sediment retention efficiency of up to 90%. This project has a total capital of $1,243,062.22 USD with economic benefits of up to $11,523,731.65 USD, and an initial capital recovery of 5 years and 5 months, making it completely viable and profitable, even considering high and low risk scenarios.