Ecological responses of three urban watercourse stretches after implementation of one-off recovering interventions: an integrated assessment

Abstract

Faced with the anthropic activities of urban streams stretches through rectification with concrete, there is a concern about the modifications of the aquatic habitats and consequent ecological damages to the ecosystems. Based on biophilic engineering, there is a great opportunity to idealize and test interventions to revitalize such hampered ecosystems. Hence, we verified the performance of biological and organic factors, after the implementation of one-off interventions in three rivers using biophilic handmade materials and structural elements in their fixation. We carried out the project in urban stretches of concrete bed streams, located in Sorocaba-SP, Southeast of Brazil. In two years, we conducted biweekly in situ and laboratory measurements to characterize the study sites, idealize, scale, implement the projects, and, evaluate the ecological responses of the implementations. We collected sampling in two points: upstream and downstream interventions. We evaluated the performance of the interventions through the analysis of SWOT (Strengths, Weaknesses, Opportunities, and Threats) factors and by using the Analytic Hierarchy Process (AHP). We presented the results through a decision-making matrix for stakeholders, which indicated that our ideas are of low cost and easy to implement. Then, we got the following scenario of SWOT priorities: opportunity (58.55%), strength (24.71%), threat (10.74%), and weakness (6.00%). They demand constant efforts for maintenances and they need adjustments to a better understood by residents and the watershed management. We concluded that the strengths observed in the project turn our idea replicable in any part because it attaches the idea of caring about the environment through biophilic techniques, and the weaknesses are liable to modifications (improvements) in future projects that consider such proposal.