scholarly journals The Relationship of Lake Morphometry and Phosphorus Dynamics of a Tropical Highland Lake: Lake Tana, Ethiopia

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2243 ◽  
Author(s):  
Mebrahtom G. Kebedew ◽  
Aron A. Kibret ◽  
Seifu A. Tilahun ◽  
Mulugeta A. Belete ◽  
Fasikaw A. Zimale ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Resources ◽  
Water Column ◽  
Available Phosphorus ◽  
Lake Morphometry ◽  
Lake Tana ◽  
Dissolved Phosphorus ◽  
Phosphorus Dynamics ◽  
Water Hyacinths ◽  
The Relationship

Lakes hold most of the world’s fresh surface water resources. Safeguarding these resources from water quality degradation requires knowledge of the relationship between lake morphometry and water quality. The 3046-km2 Lake Tana in Ethiopia is one of the water resources in which the water quality is decreasing and water hyacinths have invaded. The objective of this study is to understand the interaction between the lake morphometry and water quality and specifically the phosphorus dynamics and their effect on the water hyacinths. A bathymetric survey was conducted in late 2017. Various morphometric parameters were derived, and both these parameters and sediment available phosphorus were regressed with the dissolved phosphorus. The results show that, with a wave base depth that is nearly equal to a maximum depth of 14.8 m, the bottom sediments were continuously suspended in the water column. As a result of the resuspension mixing, we found that the dissolved phosphorus in the water column decreased with lake depth and increased with sediment available phosphorus (R2 = 0.84) in the northern half of the lake. This relationship is not as strong in the south due to a large flow of Gilgel Abay to the outlets. Water hyacinths were found where the lake was shallow and the available phosphorus was elevated. The large reservoir of sediment phosphorus will hamper any remedial efforts in removing the water hyacinths.

scholarly journals Bottom Sediment Characteristics of a Tropical Lake: Lake Tana, Ethiopia

Hydrology ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 18
Author(s):  
Mebrahtom G. Kebedew ◽  
Seifu A. Tilahun ◽  
Fasikaw A. Zimale ◽  
Tammo S. Steenhuis
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Bottom Sediment ◽  
Total Nitrogen ◽  
Available Phosphorus ◽  
Northwestern Part ◽  
Sediment Characteristics ◽  
Lake Tana ◽  
Sediment Samples ◽  
Water Hyacinths

Sediment concentration of rivers in developing countries has been increasing greatly over the last 50 years due to the conversion of forest to continuously cultivated land with the increasing population. Few studies have addressed its effect on sedimentation and water quality of the lakes by analyzing bottom sediment characteristics. In this study, the objective was to investigate the spatial distribution (and their interrelationships) of the bottom sediment characteristics in the largest lake in Ethiopia, Lake Tana where water hyacinths have been spreading rapidly during the last decade. Sediment samples were collected from the lake bottom at 60 locations and analyzed for texture, organic matter, total nitrogen, and available phosphorus. Bottom sediment samples had a median of 75% clay, 13% silt, and 9% sand. Clay was greatest in the northwestern part and smallest in the areas near the major rivers entering or exiting the lake. Clay percentage and lake depth were strongly correlated. The mean organic matter content of bottom sediment was 16 g kg−1, total nitrogen 0.8 g kg−1, and Olsen available phosphorus 19 mg kg−1. Phosphorus concentrations peaked where water hyacinths were found in the northeastern part of the lake. This study will serve as a baseline for future water quality and sedimentation changes in Lake Tana. In particular, it might aid in explaining the spread of the water hyacinths.

scholarly journals Phosphorus dynamics in the water of tropical semiarid reservoirs in a prolonged drought period

2018 ◽  
Vol 30 (0) ◽  
Author(s):  
Herika Cavalcante ◽  
Fabiana Araújo ◽  
Vanessa Becker
Keyword(s):  
Water Column ◽  
Organic Phosphorus ◽  
Soluble Reactive Phosphorus ◽  
Particulate Phosphorus ◽  
Semiarid Region ◽  
Drought Period ◽  
Chl A ◽  
Dissolved Phosphorus ◽  
Phosphorus Dynamics ◽  
Prolonged Drought

Abstract Aim To verify the vertical distribution of phosphorus in the water and to identify the predominant forms of P in the water column for understand the phosphorus dynamics in tropical semiarid reservoirs during a prolonged drought period. Methods Two reservoirs from the semiarid region of Rio Grande do Norte were analysed during the period from May 2015 to June 2016. Were analysed: Suspended solids (SS), chlorophyll a (Chl-a), dissolved oxygen (OD) and temperature. Vertical profiles were plotted for total phosphorus (PT), total dissolved phosphorus (PTD), particulate phosphorus (PP), dissolved organic phosphorus (POD) and soluble reactive phosphorus (FRS). Results The phosphorus values distributed in the water column were high for both reservoirs, presenting the highest values during the periods with lower depth. Gargalheiras presented greater predominance of PT and PP, while Cruzeta had the highest values of FRS. Chl-a and SS values were also consistent with phosphorus values: Chl-a was higher in Gargalheiras, while SS, mainly inorganic, were higher in Cruzeta. Gargalheiras presented anoxic conditions close to the sediment from May 2015 to December 2015, which may induce the release of phosphorus from the sediment to the water column. Values that are too high during the shallower months, especially in Cruzeta, may have been influenced by the release of P from sediment through wind resuspension. Conclusions The amounts and predominant types of phosphorus in the water column are of great importance to understand the phosphorus dynamics and will support restoration plans for the studied environments. In this study it was possible to verify that the reservoirs are susceptible to the release of P from the sediment due to the environmental conditions, mainly low depths, resuspension of the wind and anoxia in the hypolimnion.

scholarly journals Correlação entre qualidade das águas e outorgas superficiais no trecho alto da bacia do médio rio das Velhas, Minas Gerais, Brasil / Water quality and granting of permits for water use in the middle course of Velhas river basin, Minas Gerais, Brazil

2018 ◽  
Vol 28 (55) ◽  
pp. 828-844
Author(s):  
Julia Piazi ◽  
Frederico Azevedo Lopes ◽  
Úrsula De Azevedo Ruchkys
Keyword(s):  
Water Quality ◽  
Water Resources ◽  
Water Use ◽  
Oxygen Demand ◽  
Minas Gerais ◽  
Quality Analysis ◽  
Belo Horizonte ◽  
The Right ◽  
The Relationship ◽  
Qualitative Characteristics

Dentre os instrumentos de gestão de recursos hídricos previstos pela Política Nacional de Recursos Hídricos, Lei 9433/97, a outorga de direito de uso de recursos hídricos objetiva assegurar o controle quantitativo e qualitativo dos usos da água. A outorga com objetivos de diluição de efluentes impacta diretamente nas características qualitativas do curso d'água, podendo afetar os múltiplos usos das águas e usuários. Além disso, trata-se de uma modalidade de outorga relativamente recente e pouco aplicada nas bacias hidrográficas do estado de Minas Gerais. Deste modo, esse trabalho tem por objetivo analisar a relação entre a qualidade das águas no trecho alto da bacia do médio Rio das Velhas e outorgas superficiais emitidas. A espacialização da variável da Demanda Bioquímica de Oxigênio (DBO), considerada para análise de qualidade das águas, foi feita por interpolação utilizando o método Ponderação do Inverso da Distância (IDW), sendo que, para os pontos de outorgas vigentes, utilizou-se a ferramenta densidade de Kernel. A relação da qualidade e quantidade das águas foi realizada por meio da elaboração de uma matriz de atribuição, visando a criação de diversos cenários a partir da suposição de pesos para as referidas variáveis. Os resultados demonstram que em locais com mais concessões de outorga (região metropolitana de Belo Horizonte e município de Sete Lagoas) apresentam piores níveis de qualidade das águas, demonstrando situações de exploração intensiva dos recursos hídricos e consequentemente, áreas potencias de conflitos entre usos e usuários na bacia.Palavras–chave: Gerenciamento de recursos hídricos, qualidade das águas, outorga, Rio das Velhas.Abstract Among the instruments for managing water resources provided for by the National Water Resources Policy, Law 9433/97, the granting of the right to use water resources aims at ensuring the quantitative and qualitative control of water uses. The granting of permits with effluent dilution objectives interferes more significantly in the qualitative characteristics of the watercourse, affecting water availability within sectors for various uses and users. In addition, it is a modality of granting that has not yet been applied in the hydrographic basins of the state of Minas Gerais. Thus, this work aims to analyze the relationship between water quality in the high section of the Rio das Velhas mid basin and surface allowances emitted. The spatialization of the Biochemical Oxygen Demand (BOD), considered for water quality analysis was made by interpolation, while the kernel density tool was used for the current grant points. The relation of the quality and quantity of the waters was accomplished by means of the elaboration of an attribution matrix, that helped in the creation of diverse scenarios from the supposition of weights for each one. The results show that in places with more concession concessions (metropolitan area of Belo Horizonte and municipality of Sete Lagoas) they present worse levels of water quality, demonstrating situations of intensive exploration of water resources and consequently, potential areas of conflicts between uses and users in the basin.Keywords: Management of water resources, water quality, granting of permits for water use, Rio das Velhas.

scholarly journals Valuing Florida Water Resources: Prices of Waterfront Properties

EDIS ◽  
2019 ◽  
Vol 2019 (4) ◽  
pp. 9
Author(s):  
Tatiana Borisova ◽  
Xiang Bi ◽  
Tara Wade ◽  
Kurt Oehlbeck ◽  
Kelly Grogan
Keyword(s):  
Water Quality ◽  
Water Resources ◽  
Economic Value ◽  
Resource Economics ◽  
Residential Property ◽  
Property Value ◽  
Property Prices ◽  
Poor Water Quality ◽  
Economics Department ◽  
The Relationship

This 9-page fact sheet written by Tatiana Borisova, Xiang Bi, Tara Wade, and Kurt Oehlbeck and published by the UF/IFAS Food and Resource Economics Department explores the relationship between water quality and sale prices of waterfront properties, that is, the amenity value provided by water resources to waterfront communities. Being near to water to water generally increases the value of a residential property. However, poor water quality may decrease waterfront property prices. In other words, investments in restoring water quality can translate into increases in property value and tax collection. https://edis.ifas.ufl.edu/fe1062 This paper is a part of a series “Economic Value of Florida Water Resources”.

Composite Water Quality: Evaluation and Management Feedbacks

2007 ◽  
Vol 42 (1) ◽  
pp. 20-25 ◽  
Author(s):  
Arkadi Parparov ◽  
K. David Hambright
Keyword(s):  
Water Quality ◽  
Water Resources ◽  
Water Resources Management ◽  
Quality Evaluation ◽  
Quantitative Estimation ◽  
Water Quality Evaluation ◽  
Resources Management ◽  
Simplified Procedure ◽  
The Relationship ◽  
Equal Weighting

Abstract In this article we both outline and offer an approach to quantitative estimation of aggregated water quality, in the form of the Composite Water Quality Index (CWQI), calculated as a weighted sum of rating values for a set of preselected water quality indices. The weighting procedure uses variable weights that are inversely proportional to the separate rating values. We also suggest a simplified procedure for estimating the sensitivity of several common algorithms that may be used for CWQI calculations. Among the different methods of CWQI calculation, Smith's minimum operator had the highest sensitivity, while an equal weighting procedure based on the arithmetic mean had the lowest sensitivity. We discuss the relationship between the choice of method for a CWQI calculation and the strategy of water resources management, and show that besides its indicative function, the CWQI should serve as a target of, and tool for, water resources management.

Drinking water quality and protection of resources

2010 ◽  
Vol 1 (1-2) ◽  
pp. 51-54
Author(s):  
J. Fettig
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Resources ◽  
River Water ◽  
Spring Water ◽  
Public Water Supply ◽  
Legal Requirements ◽  
Reservoir Water ◽  
Water Lake ◽  
Treatment Step

Abstract The structure of public water supply in Germany and the water resources used are briefly described. An overview over the legal requirements for drinking water is given, and the sources for contaminants are outlined. Then the multiple-barrier approach is discussed with respect to the resources groundwater and spring water, lake and reservoir water, and river water. Examples for treatment schemes are given and the principle of subsurface transport of river water as a first treatment step is described.

Sign in / Sign up

Export Citation Format

Share Document