Water quality in Chile : the role of protected areas

Abstract

This paper examines the effect of protected areas on water quality, particularly water purification. We focus on the impact these areas have on the concentrations of four water-related pollutants, including phosphorus, nitrogen, arsenic, and sulfates, from 1967 to 2018 in Chile. We construct buffers of several distances around water monitoring stations and consider those that intersect with at least one protected area

upriver as treated. To estimate these effects, we employ a variety of estimation meth- ods. Overall, the results show consistent suggestive evidence of a negative short-term

effect on nitrogen concentrations, localized within a maximum distance of 10 km, rang- ing from -18.4% to -32.6% at different buffer sizes, equivalent to an average reduction

of -.14 to -.26 mg/L. For phosphorus, arsenic and sulfates concentrations we found no significant effect. Additionally, there are potential differences in baseline concentration levels between treated and control water monitoring stations (WMS). This research aims to comprehend the potential influence of PAs on water quality by using novel estimation techniques and comparing different methodologies, filling the literature gap on this topic in the Chilean context.