Precipitation, landscape properties and land use interactively affect water quality of tropical freshwaters

Regina Lúcia Guimarães Nobre; Adriano Caliman; Camila Rodrigues Cabral; Fernando de Carvalho Araújo; Joris Guérin; Fabíola da Costa Catombé Dantas; Letícia Barbosa Quesado; Eduardo Martins Venticinque; Rafael Dettogni Guariento; André Megali Amado; Patrick Kelly; Michael J Vanni; Luciana Silva Carneiro

doi:10.1016/j.scitotenv.2020.137044

Precipitation, landscape properties and land use interactively affect water quality of tropical freshwaters

Sci Total Environ. 2020 May 10:716:137044. doi: 10.1016/j.scitotenv.2020.137044. Epub 2020 Jan 31.

Authors

Affiliations

¹ Programa de Pós-Graduação em Ecologia, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil.
² Programa de Pós-Graduação em Ecologia, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil; Departamento de Ecologia, Universidade Federal do Rio Grande do Norte, Natal, RN 59078-900, Brazil. Electronic address: caliman21@gmail.com.
³ Departamento de Ciências do Mar, Universidade Federal de São Paulo, Santos, SP 11030-400, Brazil.
⁴ Departamento de Ecologia, Universidade Federal do Rio Grande do Norte, Natal, RN 59078-900, Brazil.
⁵ Instituto de Computação, Universidade Federal Fluminense, Rio de Janeiro, RJ, Brazil.
⁶ Programa de Pós-Graduação em Ecologia, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil; Departamento de Ecologia, Universidade Federal do Rio Grande do Norte, Natal, RN 59078-900, Brazil.
⁷ Laboratório de Ecologia, Instituto de Biociências, Universidade Federal de Mato Grosso do Sul, MS, Brazil.
⁸ Programa de Pós-Graduação em Ecologia, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil; Departamento de Biologia, Universidade Federal de Juiz de Fora, Juiz de Fora, MG 36036-900, Brazil.
⁹ Department of Biology, Rhodes College, Memphis, United States.
¹⁰ Department of Biology, Miami University, Oxford, OH, United States.

PMID: 32059302
DOI: 10.1016/j.scitotenv.2020.137044

Abstract

Globally, conversion of pristine areas to anthropogenic landscapes is one of the main causes of ecosystem service losses. Land uses associated with urbanization and farming can be major sources of pollution to freshwaters promoting artificial inputs of several elements, leading to impaired water quality. However, how the effects of land use on freshwater quality are contingent on properties of the local landscape and climate is still poorly understood. The aim of this study was to evaluate the effects of landscape properties (morphometric measurements of lakes and their catchments), precipitation patterns, and land use properties (extent and proximity of the land use to freshwaters) on water quality of 98 natural lakes and reservoirs in northeast Brazil. Water quality impairment (WQI) was expressed as a composite variable incorporating parameters correlated with eutrophication including nitrogen (N), phosphorus (P) and Chlorophyll-a concentration. Regression tree analysis showed that WQI is mainly related to highly impacted "buffer areas". However, the effects of land use in these adjacent lands were contingent on precipitation variability for 13% of waterbodies and on surface area of the buffer in relation to the volume of waterbody (BA:Vol) for 87% of waterbodies. Overall, effects on WQI originating from the land use in the adjacent portion of the lake were amplified by high precipitation variability for ecosystems with highly impacted buffer areas and by high BA:Vol for ecosystems with less impacted buffer areas, indicating that ecosystems subjected to intense episodic rainfall events (e.g. storms) and higher buffer areas relative to aquatic ecosystem size (i.e. small waterbodies) are more susceptible to impacts of land use. Land use at the catchment scale was important for the largest ecosystems. Thus, our findings point toward the need for considering a holistic approach to managing water quality, which includes watershed management within the context of climate change.

Keywords: Nitrogen; Nonpoint source pollution; Phosphorus; Shallow lakes; Subsidy.