scholarly journals Internal loading potential of phosphorus in reservoirs along a semiarid watershed

RBRH ◽  
2020 ◽  
Vol 25 ◽  
Author(s):  
Diana Souza Moura ◽  
Antonia Samylla Oliveira De Almeida ◽  
Carlos João Pestana ◽  
Laura Gomes Girão ◽  
José Capelo-Neto
Keyword(s):  
Water Quality ◽  
Total Phosphorus ◽  
Nutrient Dynamics ◽  
Internal Loading ◽  
Phosphorus Loading ◽  
Chemical Fractionation ◽  
Phosphorus Concentration ◽  
Ph Values ◽  
Upstream Reservoir ◽  
Artificial Reservoirs

ABSTRACT Sediments are important to nutrient dynamics, especially due to phosphorus internal loading. Several studies have observed that internal loading could prevent water quality from improving in lakes, even when external phosphorus loading is significantly decreased. Therefore, there is an urgent need to assess the potential release of phosphorus contained in the sediment, and thus, its potential to impact water quality. In this study, the vertical and horizontal distributions of distinct phosphorus forms in the bottom sediments of artificial reservoirs, located at Forquilha watershed (Ceará, Brazil), were investigated through sequential chemical fractionation. The reservoirs Lagoa Cercada (R#1), Riacho do Algodão (R#2), Riacho Verde (R#3), Cachoeira (R#4), Chagas Manu (R#5), Quandu (R#6) and Balanças (R#7) were investigated. Reservoirs R#1 (most downstream reservoir of the watershed) and R#7 (most upstream reservoir of the watershed) had higher concentrations of total phosphorus (PT) and lower pH values, potentially exerting greater influence in phosphorus concentration in the water column. Reservoirs R#3 and R#4 presented a predominance of residual phosphorus (PRe), the least available fractions of phosphorus and thus, presented a lower potential for internal loading. Reservoirs R#5, R#1 and R#2 showed a tendency of decreasing total phosphorus (PT) as the sediment depth increased, probably indicating an increase of allochthonous phosphorus loading along time. Reservoir R#6 showed the predominance of PFeAl and PCa fractions on points A and B, respectively, showing that the characteristics of the sediments may vary in the same reservoir. Mobile (PM) and iron and aluminum-bound phosphorus (PFeAl) were the least and the most abundant fractions in most of the samples analyzed, respectively.

Long-Term (15 Years) Results of NPS Controls in an Agricultural Watershed upon a Receiving Lake's Water Quality

1993 ◽  
Vol 28 (3-5) ◽  
pp. 441-449 ◽  
Author(s):  
Paul J. Garrison ◽  
Timothy R. Asplund
Keyword(s):  
Water Quality ◽  
Structural Changes ◽  
Soil Phosphorus ◽  
Water Clarity ◽  
Management Control ◽  
Agricultural Watershed ◽  
Control Measures ◽  
Phosphorus Loading ◽  
Phosphorus Concentration ◽  
White Clay

Nonpoint source controls were installed in a 1215 ha agricultural watershed in northeastern Wisconsin in the late 1970. Changes were made in handling of animal wastes and cropping practices to reduce runoff of sediment and nutrients. Modelling results predicted a reduction in phosphorus runoff of 30 percent. The water quality of White Clay Lake has worsened since the installation of NPS controls. The lake's phosphorus concentration has increased from a mean of 29 µg L−1 in the late 1970s to 44 µg L−1 in recent years. Water clarity has declined from 2.7 to 2.1 m and the mean summer chlorophyll levels have increased from 9 to 13 µg L−1 with peak values exceeding 40 µg L−1. Increased phosphorus loading is not the result of elevated precipitation but instead the failure of the control measures to sufficiently reduce P loading. Most of the effort was placed on structural changes while most of the P loading comes from cropland runoff. Further, soil phosphorus concentrations have increased because of artificial fertilizers and manure spreading. The White Clay Lake experience is discouraging since the majority of the polluters in this watershed utilized some NPS control practices, including 76 percent of the farms which installed waste management control facilities.

Water Quality, Phosphorus Budgets and Management of Dune Lakes Used for Recreation in Queensland (Australia)

1989 ◽  
Vol 21 (2) ◽  
pp. 111-118 ◽  
Author(s):  
A. H. Arthington ◽  
G. J. Miller ◽  
P. M. Outridge
Keyword(s):  
Water Quality ◽  
Total Phosphorus ◽  
Trophic Status ◽  
Compartment Model ◽  
Phosphorus Concentration ◽  
Lake Depth ◽  
Total Phosphorus Concentration ◽  
Dune Lakes ◽  
Phosphorus Budgets ◽  
Recreational Use

The water quality and trophic status of two Queensland dune lakes are compared in the context of assessing the impacts of recreational use and other human activities. Lake Freshwater, Cooloola, has a mean total phosphorus concentration of 12.1 ± 3.3 µg l−1 and is approaching mesotrophic status, whereas Blue Lagoon, Moreton Island, is oligotrophic. Natural loadings of total phosphorus, ranging from 0.2 to 0.35 g m−2 yr−1, are consistent with the progression of Lake Freshwater from oligotrophic to mesotrophic status. The phosphorus loadings predicted by Vollenweider's (1976) one-compartment model, for two values of mean lake depth, also indicate that Lake Freshwater is tending towards eutrophic conditions. The management implications of phosphorus loadings and budgets are discussed.

Impacts of agriculture on aquatic systems: lessons learnt and new unknowns in Northern Ireland

2001 ◽  
Vol 52 (1) ◽  
pp. 151 ◽  
Author(s):  
S. I. Heaney ◽  
R. H. Foy ◽  
G. J. A. Kennedy ◽  
W. W. Crozier ◽  
W. C. K. O' Connor
Keyword(s):  
Water Quality ◽  
Northern Ireland ◽  
Soluble Reactive Phosphorus ◽  
Phosphorus Loading ◽  
Phosphorus Concentration ◽  
The European Union ◽  
Blue Green Algae ◽  
Lough Neagh ◽  
The Impact

Agriculture in Northern Ireland depends on grass-based production, but since 1980, expansion of output has been effectively constrained by production limits set by the European Union agricultural policy. Despite this, long-term monitoring over several decades has shown significant degradation of water quality in Lough Neagh, with persistent high biomass of blue-green algae. Similar long-term studies have revealed a marked decline in the freshwater survival of salmon in the nearby River Bush. These changes may be related and reflect the impact of farming on water quality and salmonid production. Regular sampling of the inflowing rivers to Lough Neagh has shown that continued increase in lake phosphorus concentration has been primarily due to an increase in the soluble reactive phosphorus loading from agricultural diffuse sources. Similar diffuse inputs of agriculturally derived nutrients to the River Bush, leading to increased plant growth together with the accumulation of fine sediment in salmon spawning redds, are considered to be important in the decline of freshwater survival of salmon from egg to smolt. The impact of farming practices on lakes and rivers is considered in relation to understanding of the complex and interacting factors that link land use to water quality.

scholarly journals Effects of changes in nutrient loading and composition on hypoxia dynamics and internal nutrient cycling of a stratified coastal lagoon

2017 ◽  
Vol 14 (19) ◽  
pp. 4423-4433 ◽  
Author(s):  
Yafei Zhu ◽  
Andrew McCowan ◽  
Perran L. M. Cook
Keyword(s):  
Water Quality ◽  
Primary Production ◽  
Total Phosphorus ◽  
Coastal Lagoon ◽  
Nutrient Dynamics ◽  
Nutrient Loading ◽  
Nitrogen Loading ◽  
Quality Model ◽  
Nitrogen Loads ◽  
Sediment Carbon

Abstract. The effects of changes in catchment nutrient loading and composition on the phytoplankton dynamics, development of hypoxia and internal nutrient dynamics in a stratified coastal lagoon system (the Gippsland Lakes) were investigated using a 3-D coupled hydrodynamic biogeochemical water quality model. The study showed that primary production was equally sensitive to changed dissolved inorganic and particulate organic nitrogen loads, highlighting the need for a better understanding of particulate organic matter bioavailability. Stratification and sediment carbon enrichment were the main drivers for the hypoxia and subsequent sediment phosphorus release in Lake King. High primary production stimulated by large nitrogen loading brought on by a winter flood contributed almost all the sediment carbon deposition (as opposed to catchment loads), which was ultimately responsible for summer bottom-water hypoxia. Interestingly, internal recycling of phosphorus was more sensitive to changed nitrogen loads than total phosphorus loads, highlighting the potential importance of nitrogen loads exerting a control over systems that become phosphorus limited (such as during summer nitrogen-fixing blooms of cyanobacteria). Therefore, the current study highlighted the need to reduce both total nitrogen and total phosphorus for water quality improvement in estuarine systems.

scholarly journals Effectiveness of Best Management Practices to Reduce Phosphorus Loading to a Highly Eutrophic Lake

2018 ◽  
Vol 15 (10) ◽  
pp. 2111 ◽  
Author(s):  
Alan D. Steinman ◽  
Michael Hassett ◽  
Maggie Oudsema
Keyword(s):  
Water Quality ◽  
Total Phosphorus ◽  
Best Management Practices ◽  
Management Practices ◽  
Soluble Reactive Phosphorus ◽  
Base Flow ◽  
Phosphorus Loading ◽  
Storm Events ◽  
Best Management ◽  
Significant Difference

Reducing nonpoint source pollution is an ongoing challenge in watersheds throughout the world. Implementation of best management practices, both structural and nonstructural, is the usual response to this challenge, with the presumption that they are effective. However, monitoring of their efficacy is not a standard practice. In this study, we evaluate the effectiveness of two wetland restoration projects, designed to handle runoff during high flow events and serve as flow-through retention basins before returning flow further downstream. The Macatawa Watershed is located in west Michigan, is heavily agricultural, and drains into Lake Macatawa, a hypereutrophic lake with total phosphorus concentrations usually exceeding 100 µg/L. We measured turbidity, total phosphorus, and soluble reactive phosphorus both upstream and downstream of these wetland complexes during base flow and storm events. While both turbidity and phosphorus increased significantly during storm events compared to baseflow, we found no significant difference in upstream vs. downstream water quality two years following BMP construction. We also measured water quality in Lake Macatawa, and found the lake remained highly impaired. Possible reasons for the lack of improved water quality: (1) The restored wetlands are too young to function optimally in sediment and phosphorus retention; (2) the scale of these BMPs is too small given the overall loads; (3) the locations of these BMPs are not optimal in terms of pollutant reduction; and (4) the years following postconstruction were relatively dry so the wetlands had limited opportunity to retain pollutants. These possibilities are evaluated.

A Simple Method for Predicting the Capacity of a Lake for Development Based on Lake Trophic Status

1975 ◽  
Vol 32 (9) ◽  
pp. 1519-1531 ◽  
Author(s):  
P. J. Dillon ◽  
F. H. Rigler
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Total Phosphorus ◽  
Water Budget ◽  
Trophic Status ◽  
Phosphorus Concentration ◽  
Phosphorus Load ◽  
Secchi Disc ◽  
Total Phosphorus Concentration ◽  
Lake Trophic Status

A general technique is presented for calculating the capacity of a lake for development based on quantifiable relationships between nutrient inputs and water quality parameters reflecting lake trophic status. Use of the technique for southern Ontario lakes is described. From the land use and geological formations prevalent in a lake’s drainage basin, the phosphorus exported to the lake in runoff water can be calculated, which, when combined with the input directly to the lake’s surface in precipitation and dry fallout, gives a measure of the natural total phosphorus load. From the population around the lake, the maximum artificial phosphorus load to the lake can be calculated and, if necessary, modified according to sewage disposal facilities used. The sum of the natural and artificial loads can be combined with a measure of the lake’s morphometry expressed as the mean depth, the lake’s water budget expressed as the lake’s flushing rate, and the phosphorus retention coefficient of the lake, a parameter dependent on both the lake’s morphometry and water budget, to predict springtime total phosphorus concentration in the lake. Long-term average runoff per unit of land area, precipitation, and lake evaporation data for Ontario provide a means of calculating the necessary water budget parameters without expensive and time-consuming field measurements. The predicted spring total phosphorus concentration can be used to predict the average chlorophyll a concentration in the lake in the summer, and this, in turn, can be used to estimate the Secchi disc transparency. Thus, the effects of an increase in development on a lake’s water quality can be predicted. Conversely, by setting limits for the "permissible" summer average chlorophyll a concentration or Secchi disc transparency, the "permissible" total phosphorus concentration at spring overturn can be calculated. This can be translated into "permissible" artificial load, which can then be expressed as total allowable development. This figure can be compared to the current quantity of development and recommendations made concerning the desirability of further development on the lake.

A Test of a Simple Nutrient Budget Model Predicting the Phosphorus Concentration in Lake Water

1974 ◽  
Vol 31 (11) ◽  
pp. 1771-1778 ◽  
Author(s):  
P. J. Dillon ◽  
F. H. Rigler
Keyword(s):  
Total Phosphorus ◽  
Additional Data ◽  
Nutrient Budget ◽  
Phosphorus Loading ◽  
Phosphorus Concentration ◽  
Total Phosphorus Concentration ◽  
Southern Ontario ◽  
Budget Model ◽  
Phosphorus Budgets ◽  
Quantitative Changes

The total phosphorus budgets for a number of lakes in the Haliburton–Kawartha region of southern Ontario were measured over a 20-mo period. These data, combined with the lakes' morphometry and water budgets, were used to test a simple nutrient budget model similar to that proposed by Vollenweider (1969) purporting to predict the total phosphorus concentration in lakes. Except in the case of two very shallow lakes [Formula: see text], the concentrations predicted by the model were very close to those measured in the lakes at spring overturn. Additional data from the literature supported the belief that this model could be used effectively for oligotrophic and mesotrophic lakes. Its value lies in the fact that quantitative changes in phosphorus loading can be interpreted in terms of changes in phosphorus concentration, which in turn, can be related to changes in parameters that reflect the lake's trophic state such as summer chlorophyll a concentration.

scholarly journals Simulating Nutrients and Phytoplankton Dynamics in Lakes: Model Development and Applications

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2088
Author(s):  
Bushra Tasnim ◽  
Xing Fang ◽  
Joel S. Hayworth ◽  
Di Tian
Keyword(s):  
Chlorophyll A ◽  
Nutrient Dynamics ◽  
Nutrient Loading ◽  
Phosphorus Release ◽  
Phosphorus Loading ◽  
Phosphorus Concentration ◽  
Model Parameters ◽  
Quality Model ◽  
Demand Models ◽  
Mean Square Errors

Due to eutrophication, many lakes require periodic management and restoration, which becomes unpredictable due to internal nutrient loading. To provide better lake management and restoration strategies, a deterministic, one-dimensional water quality model MINLAKE2020 was modified from daily MINLAKE2012 by incorporating chlorophyll-a, nutrients, and biochemical oxygen demand models into the regional year-around temperature and dissolved oxygen (DO) model. MINLAKE2020 was applied to six lakes (varying depth and trophic status) in Minnesota focusing on studying the internal nutrient dynamics. The average root-mean-square errors (RMSEs) of simulated water temperature and DO in six lakes are 1.51 °C and 2.33 mg/L, respectively, when compared with profile data over 2–4 years. The average RMSE of DO simulation decreased by 24.2% when compared to the MINLAKE2012 model. The internal nutrient dynamics was studied by analyzing time series of phosphorus, chlorophyll-a, and DO over several years and by performing a sensitivity analysis of model parameters. A long-term simulation (20 years) of Lake Elmo shows that the simulated phosphorus release from sediment under the anoxic condition results in surface phosphorus increase, which matches with the observed trends. An average internal phosphorus loading increase of 92.3 kg/year increased the average daily phosphorus concentration by 0.0087 mg/L.

scholarly journals Remote Sensing Estimation of Lake Total Phosphorus Concentration Based on MODIS: A Case Study of Lake Hongze

2019 ◽  
Vol 11 (17) ◽  
pp. 2068 ◽  
Author(s):  
Junfeng Xiong ◽  
Chen Lin ◽  
Ronghua Ma ◽  
Zhigang Cao
Keyword(s):  
Remote Sensing ◽  
Water Quality ◽  
Total Phosphorus ◽  
Training Dataset ◽  
Phosphorus Concentration ◽  
Optical Remote Sensing ◽  
Lake Chaohu ◽  
Total Phosphorus Concentration ◽  
Direct Derivation ◽  
Inorganic Matter

Phosphorus (P) is an important substance for the growth of phytoplankton and an efficient index to assess the water quality. However, estimation of the TP concentration in waters by remote sensing must be associated with optical substances such as the chlorophyll-a (Chla) and the suspended particulate matter (SPM). Based on the good correlation between the suspended inorganic matter (SPIM) and P in Lake Hongze, we used the direct and indirect derivation methods to develop algorithms for the total phosphorus (TP) estimation with the MODIS/Aqua data. Results demonstrate that the direct derivation algorithm based on 645 nm and 1240 nm of the MODIS/Aqua performs a satisfied accuracy (R2 = 0.75, RMSE = 0.029mg/L, MRE = 39% for the training dataset, R2 = 0.68, RMSE = 0.033mg/L, MRE = 47% for the validate dataset), which is better than that of the indirect derivation algorithm. The 645 nm and 1240 nm of MODIS are the main characteristic band of the SPM, so that algorithm can effectively reflect the P variations in Lake Hongze. Additionally, the ratio of the TP to the SPM is positively correlated with the accuracy of the algorithm as well. The proportion of the SPIM in the SPM has a complex effect on the accuracy of the algorithm. When the SPIM accounts for 78%, the algorithm achieves the highest accuracy. Furthermore, the performance of this direct derivation algorithm was examined in two inland lakes in China (Lake Nanyi and Lake Chaohu), it derived the expected P distribution in Lake Nanyi whereas the algorithm failed in Lake Chaohu. Different water properties influence significantly the accuracy of this direct derivation algorithm, while the TP, Chla, and suspended particular inorganic matter (SPOM) of Lake Chaohu are much higher than those of the other two lakes, thus it is difficult to estimate the TP concentration by a simple band combination in Lake Chaohu. Although the algorithm depends on the dataset used in the development, it usually presents a good estimation for those waters where the SPIM dominated, especially when the SPIM accounts for 60% to 80% of the SPM. This research proposed a direct derivation algorithm for the TP estimation for the turbid lake and will provide a theoretical and practical reference for extending the optical remote sensing application and the TP empirical algorithm of Lake Hongze’s help for the local government management water quality.

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