Abstract
River pollutant loads encompass a combination of natural and anthropogenic factors related to land use and land cover (LULC). Progressive changes in LULC can significantly alter pollutant behaviors of changing flows and pollutant concentrations, reducing biodiversity, and emerging uncertainties regarded to poor gauged basins. To assess the factors involved in the generation of pollutant loads, this paper examined empirical uncertainties from observed pollutant loads in river basins through nested catchment experiments (NCE). Monitored river flows, concentration and drainage areas of each NCE were associated with LULC in order to determine specific pollution generation coefficients per unit of drainage area (Ys) of BOD, a- chlorophyll, NTK, TSS, and Total Coliforms. Three Brazilian watersheds were tested with drainage areas ranging from 0.93 km² to 242 km², and under different conditions of: (1) LULC (urban, forest and agricultural), (2) numbers of NCEs (2 to 11), (3) sampling seasons (1 to 4), (4) antecedent precipitation index (dry or wet conditions) and (5) biomes (Atlantic Forest and Cerrado-savanna). LULC appraisal showed complex upstream-downstream uncertainties of BOD, a-chlorophyll, and TSS from both urban and rural areas. Therefore, limitations of addressing representative values of specific pollution loads were preliminarily regarded due to the lack of continuous spatiotemporal schemes of experimental data at NCEs linked to existing point-sources and progressive LULC. Conclusions of this paper would benefit decision-makers on adapting resilient-driven land use plans to cope with regional pollution disaster risk management in Brazilian river basins.
Highlights
Changes in land use and land cover (LULC) have been recognized as stressors of aquatic ecosystems and drainage areas [1,2]
Catchments under LULC are more vulnerable to conditions of increased pollutant loads and biodiversity loss due to the geomorphological changes that take place when the occupation site undergoes adaptation
The generation of higher flow and pollutant loads in urban areas is due to the intense changes in these areas, reduced quality was observed in the rural areas
Summary
Changes in land use and land cover (LULC) have been recognized as stressors of aquatic ecosystems and drainage areas [1,2]. Some of the most relevant effects are reduced biodiversity and impacts on the quality and quantity of water [3,4,5,6]. These effects can be observed even in areas where the degree of urbanization is low [7], and which already have increased impermeable surfaces and structures implemented to increase the velocity and power of water runoff [8]. According to Richardson et al [13], the removal of riparian vegetation, which occurs in urban and rural areas, significantly impacts the water quality and biodiversity of the watercourses
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
