Evaluation of the Impacts of Land Use in Water Quality and the Role of Nature-Based Solutions: A Citizen Science-Based Study

Julia Calderón Cendejas,Martín Merino Ibarra,Alejandro Chino Téllez,Jorge Ramírez Zierold,Julio Díaz Valenzuela,Santiago Morató Sánchez De Tagle,Lucía Madrid Ramírez

doi:10.3390/su131910519

Abstract

The present study explores the impact of different land uses on water quality in a Mexican basin and addresses key mitigation measures, with key measurements made by citizen scientists. The Amanalco-Valle de Bravo Basin reservoir is the major freshwater supply for Mexico City. By measuring physical-chemical and bacteriological parameters in creeks over 21 months and correlating them to land use areas, it was possible to understand the impacts of different land uses (urban, forest, riparian forests, and different agricultural systems) in water quality. The results show that the concentration of E. coli, nitrates, nitrites, total phosphorus, total nitrogen, and total suspended solids were higher than the recommended reference levels, and that average oxygen saturation and alkalinity were lower than the recommended reference levels in most sites. The analysis of the Pearson correlation coefficient showed a strong relationship between water pollution and urban and agricultural land uses, specifically a higher impact of potato cultivation, due to its intensive use of agrochemicals and downhill tilling. There was a clear positive relationship between total forest area and riparian vegetation cover with improved water quality, validating their potential as nature-based solutions for the regulation of water quality. The results of the present study indicate the opportunities that better land management practices generate to ensure communities’ and water ecosystems’ health. This study also highlights the benefits of citizen science as a tool for raising awareness with regard to water quality and nature-based solutions, and as an appropriate tool for participative watershed management.

Highlights

Restoring the ecosystem services provision in basins is key to ensuring a sustainable water supply to growing cities in the world
Several studies have investigated the relationship between land use and water quality parameters that have broadened the understanding of the environmental impact of different land uses
Based on the previous studies, this work aims to strengthen the knowledge about the relationship between land uses and water quality by adding another variable that has not been considered in these previous works

Summary

Introduction

Restoring the ecosystem services provision in basins is key to ensuring a sustainable water supply to growing cities in the world. It is necessary to deepen our understanding of the dynamics around human activities, land use systems, and their impacts on water quality, as well as the appropriate solutions to these problems. Among the various chemical substances dissolved in water, phosphorus (P) and nitrogen (N) are important for the management of riverine systems. These two macronutrients are essential components of all organisms and are closely linked to the aquatic carbon cycle, determining both the primary production and the microbial mineralization of organic matter in aquatic systems [1].

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Conclusion