Anthropogenic nutrients and eutrophication in multiple land use watersheds: Best management practices and policies for the protection of water resources

Álvarez, Xana; Valero, Enrique; Santos, R.M.B.; Varandas, Simone; Fernandes, Luís Filipe Sanches; Pacheco, Fernando António Leal

doi:10.1016/j.landusepol.2017.08.028

Cited by 108 publications

(57 citation statements)

References 74 publications

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“…Predictor variables were chosen to reflect categorical and continuous factors known to affect N and P losses to water, such as land use and land use intensity 26,74 , and catchment and climate characteristics 75 . Continuous variables (e.g., percentage cropland) were expressed as a mean across a catchment.…”

Section: Methodsmentioning

confidence: 99%

Global mapping of freshwater nutrient enrichment and periphyton growth potential

McDowell

Noble

Pletnyakov

et al. 2020

Sci Rep

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periphyton (viz. algal) growth in many freshwater systems is associated with severe eutrophication that can impair productive and recreational use of water by billions of people. However, there has been limited analysis of periphyton growth at a global level. to predict where nutrient over-enrichment and undesirable periphyton growth occurs, we combined several databases to model and map global dissolved and total nitrogen (N) and phosphorus (P) concentrations, climatic and catchment characteristics for up to 1406 larger rivers that were analysed between 1990 and 2016. We predict that 31% of the global landmass contained catchments may exhibit undesirable levels of periphyton growth. Almost three-quarters (76%) of undesirable periphyton growth was caused by P-enrichment and mapped to catchments dominated by agricultural land in North and South America and Europe containing 1.7B people. In contrast, undesirable periphyton growth due to N-enrichment was mapped to parts of North Africa and parts of the Middle East and India affecting 280 M people. The findings of this global modelling approach can be used by landowners and policy makers to better target investment and actions at finer spatial scales to remediate poor water quality owing to periphyton growth. Periphyton contains a broad range of algae, cyanobacteria, heterotrophic microbes, and detritus that grows on the beds of streams and rivers. Some species of cyanobacterial algae can be toxic, while the excessive growth and subsequent death and decay of toxic and non-toxic species can deplete oxygen, clog the hyporheic zone and alter pH 1. These changes can impair the reproductive capacity or even kill fish and bottom-dwelling animals, taint potable water supply and reduce the aesthetic and recreational quality of streams and rivers 2. These effects, commonly termed eutrophication, put aquatic biodiversity and ecosystem function at risk and globally, cost billions of dollars annually to remediate 3,4. To target efforts to remediate periphyton growth, information is required on where periphyton grows, how much grows, is the level of growth acceptable and what controls growth. This information is commonly available at a site or catchment-scale, but seldom available at a regional or national scale. To our knowledge, no global analysis exists. The controlling factors important in periphyton growth include light, temperature, flow rates and nutrient concentrations and bioavailability 5-8. In most streams and rivers, little can be done about altering light, temperature or flow rates to minimise periphyton growth, therefore most attention focuses the relative concentrations and bioavailability of nitrogen (N) and phosphorus (P), although in some system carbon may also be important 9,10. The ratio of N to P has been found to limit growth, not only in periphyton but also in microbes and terrestrial fauna and freshwater algae 11,12. Originally described as a molar ratio of carbon (C), N and P of 106:16:1 13 , in marine phytoplankton, the ratio reduces to N and P in freshw...

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Section: Methodsmentioning

confidence: 99%

Global mapping of freshwater nutrient enrichment and periphyton growth potential

McDowell

Noble

Pletnyakov

et al. 2020

Sci Rep

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“…The thematic maps (e.g., Figures 1-3) were prepared in ArcMap software of ESRI [47], a common tool in spatial analysis of hydrologic and environmental data widely used in many studies [42,44,[48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66]. The base information was compiled from various spatial databases, namely the maps published by the Brazilian Institute for Geography and Statistics (https://ww2.ibge.gov.br) on the 1: 100,000 scale, and the digital terrain model obtained from the ASTER GDEN V2 satellite image with a spatial resolution of 30 m.…”

Section: Thematic Mapsmentioning

confidence: 99%

A Regression Model of Stream Water Quality Based on Interactions between Landscape Composition and Riparian Buffer Width in Small Catchments

Pissarra

Valera

Costa

et al. 2019

Water

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Riparian vegetation represents a protective barrier between human activities installed in catchments and capable of generating and exporting large amounts of contaminants, and stream water that is expected to keep quality overtime. This study explored the combined effect of landscape composition and buffer strip width (L) on stream water quality. The landscape composition was assessed by the forest (F) to agriculture (A) ratio (F/A), and the water quality by an index (IWQ) expressed as a function of physico-chemical parameters. The combined effect (F/A × L) was quantified by a multiple regression model with an interaction term. The study was carried out in eight catchments of Uberaba River Basin Environmental Protection Area, located in the state of Minas Gerais, Brazil, and characterized by very different F/A and L values. The results related to improved water quality (larger IWQ values) with increasing values of F/A and L, which were not surprising given the abundant similar reports widespread in the scientific literature. But the effect of F/A × L on IWQ was enlightening. The interaction between F/A and L reduced the range of L values required to sustain IWQ at a fair level by some 40%, which is remarkable. The interaction was related to the spatial distribution of infiltration capacity within the studied catchments. The high F/A catchments should comprise a larger number of infiltration patches, allowing a dominance of subsurface flow widespread within the soil layer, a condition that improves the probability of soil water to cross and interact with a buffer strip before reaching the stream. Conversely, the low F/A catchments are prone to the generation of an overland flow network, because the absence of permanent vegetation substantially reduces the number of infiltration patches. The overland flow network channelizes runoff and conveys the surface water into specific confluence points within the stream, reducing or even hampering an interaction with a buffer strip. Notwithstanding the interaction, the calculated L ranges (45–175 m) are much larger than the maximum width imposed by the Brazilian Forest Code (30 m), a result that deserves reflection.

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“…In addition, the intense exploitation of water resources in urban areas can generate water scarcity and even depletion [44][45][46]. At catchment scale, the inadequate managing of water sources and recharge areas can reduce water availability and increase the vulnerability of surface and groundwater to contamination [46][47][48][49][50][51][52][53][54][55][56][57]. It is therefore time for policy makers and water planners to start a robust assessment of groundwater recharge potential.…”

Section: Introductionmentioning

confidence: 99%

Groundwater Recharge Potential for Sustainable Water Use in Urban Areas of the Jequitiba River Basin, Brazil

et al. 2019

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The zoning of groundwater recharge potential would be attractive for water managers, but is lacking in many regions around the planet, including in the Jequitiba River basin, Minas Gerais, Brazil. In this study, a physically based spatially distributed method to evaluate groundwater recharge potential at catchment scale was developed and tested in the aforementioned Jequitiba River basin. The data for the test was compiled from institutional sources and implemented in a Geographic Information System. It comprised meteorological, hydrometric, relief, land use, and soil data. The average results resembled the annual recharge calculated by a hydrograph method, which worked as validation method. The spatial variation of recharge highlighted the predominant contribution of flat areas, porous aquifers, and forested regions to groundwater recharge. They also exposed the negative effect of urbanization. In combination, these factors elected the following sectors of the Jequitiba River basin as regions of high recharge potential: the south-southeast part of the headwaters in Prudente de Morais; Sete Lagoas towards the central part of the basin; and the region between Funilândia and Jequitiba, near the Jequitiba river mouth. Some management practices were suggested to improve groundwater recharge. The map of groundwater recharge potential produced in this study is valuable and is therefore proposed as tool for planners in the sustainable use of groundwater and protection of recharge areas.

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Anthropogenic nutrients and eutrophication in multiple land use watersheds: Best management practices and policies for the protection of water resources

Cited by 108 publications

References 74 publications

Global mapping of freshwater nutrient enrichment and periphyton growth potential

Global mapping of freshwater nutrient enrichment and periphyton growth potential

A Regression Model of Stream Water Quality Based on Interactions between Landscape Composition and Riparian Buffer Width in Small Catchments

Groundwater Recharge Potential for Sustainable Water Use in Urban Areas of the Jequitiba River Basin, Brazil

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