scholarly journals To substantiate measures aimed at prevention of siltation of supply and transport channels in the Danube lakes (study of hydraulic and alluvial regimes)

2017 ◽  
pp. 99-104
Author(s):  
O. H. Kulibabin
Keyword(s):  
Water Supply ◽  
Stream Water ◽  
Water Area ◽  
Main Stream ◽  
Channel Dynamics ◽  
Analytical Studies ◽  
Hydraulic Regime ◽  
Constant Change ◽  
Supply Channel ◽  
Transport Channels

Underwater bucket channels connecting the Danube with sluices were built perpendicular to river’s main stream. Water supply tract consists of an supply bucket channel, connecting the Danube with a sluice facility, a transporting channel – from a sluice to the mouth, i.e. to an output of a channel into a lake, and a mouth section of a channel. Throughout the whole period of operation of these facilities silt accumulation has been observed within supply bucket channels, in a lesser degree – within transport channels, and emergence in a mouth section of transport channels of sandbars having considerable dimensions. Throughout the whole period of operation of facilities and channels plenty of money has been spent for cleaning facilities and channels off sediments, so there is a need for deeper examination of the nature of silting phenomenon and minimization of water supply tract siltation through its simple reconstruction. The aim of this research consists in substantiation of proposals to eliminate or to reduce effects of silting of supply and transport channels under existing conditions and substantiation of proposed necessary structural measures on the basis of proposed mathematical modelling and methods of analytical studies. Therefore methods of analytical studies including probable and statistical approaches used when analyzing processes with constant change of environment were proposed. These studies found that boundaries of supply of inlet channels in an open river’s channel depend on distribution of flow velocities throughout a river’s stream and conditions of stream distribution and flow pattern in the middle of the supply channel depends on shape of an inlet, particularly on shape of its lower side. These suggestions and studies give us an opportunity to recommend means of controlling a hydraulic regime in the middle of a supply channel. Fighting against deposition of bottom sediments at supply channels may be won after choosing a place for water intake and a type of bucket, as well as after specification of appropriate structural forms and sizes of their inlet components. Therefore the article provides suggestions on research of regime of interaction between the river and a supply channel, dynamics of water exchange in supply channels, forces of stream masses developing during mixing, hydraulic regime and regime of deposition of supply and transport channels in order to determine the major requirements regarding size of water area of a supply channel.

The effect of livestock on the concentration of nitrogen in stream water

1994 ◽  
Vol 30 (7) ◽  
pp. 167-170 ◽  
Author(s):  
Motoko Shimura ◽  
Toshio Tabuchi
Keyword(s):  
Land Use ◽  
Water Supply ◽  
Stream Water ◽  
Nitrogen Concentration ◽  
Stocking Density ◽  
Specific Load

Recently NO3-N concentrations of the rivers that flow into the Kasumigaura lake have increased. The lake is much eutrophicated and is used as a source of water supply for Tsuchiura-city. Stocking density and NO3-N specific load have a high correlation (r=0.93). NO3-N concentrations increase corresponding to the increase of stocking density. In this area the livestock has a larger influence to the nitrogen concentration of the rivers than the land use.

scholarly journals Are there signs of acidification reversal in freshwaters of the low mountain ranges in Germany?

2001 ◽  
Vol 5 (3) ◽  
pp. 367-378 ◽  
Author(s):  
C. Alewell ◽  
M. Armbruster ◽  
J. Bittersohl ◽  
C. D. Evans ◽  
H. Meesenburg ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
Extreme Values ◽  
Stream Water ◽  
Base Cation ◽  
Drinking Water Supply ◽  
Mountain Ranges ◽  
Acid Neutralising Capacity ◽  
Freshwater Acidification ◽  
Low Mountain Ranges

Abstract. The reversal of freshwater acidification in the low mountain ranges of Germany is of public, political and scientific concern, because these regions are near natural ecosystems and function as an important drinking water supply. The aim of this study was to evaluate the status and trends of acidification reversal after two decades of reduced anthropogenic deposition in selected freshwaters of the low mountain ranges in the Harz, the Fichtelgebirge, the Bavarian Forest, the Spessart and the Black Forest. In response to decreased sulphate deposition, seven out of nine streams investigated had significantly decreasing sulphate concentrations (all trends were calculated with the Seasonal Kendall Test). The decrease in sulphate concentration was only minor, however, due to the release of previously stored soil sulphur. No increase was found in pH and acid neutralising capacity (defined by Reuss and Johnson, 1986). Aluminum concentrations in the streams did not decrease. Thus, no major acidification reversal can currently be noted in spite of two decades of decreased acid deposition. Nevertheless, the first signs of improvement in water quality were detected as there was a decrease in the level and frequency of extreme values of pH, acid neutralising capacity and aluminium concentrations in streams. With respect to nitrogen, no change was determined for either nitrate or ammonium concentrations in precipitation or stream water. Base cation fluxes indicate increasing net loss of base cations from all ecosystems investigated, which could be interpreted as an increase in soil acidification. The latter was due to a combination of continued high anion leaching and significant reduction of base cation deposition. No major improvement was noted in biological recovery, however, initial signs of recovery were detectable as there was re-occurrence of some single macroinvertebrate species which were formerly extinct. The results of this study have important implications for water authorities, forest managers and policy makers: the delay in acidification reversal suggests a need for ongoing intensive amelioration of waters, a careful selection of management tools to guarantee sustainable management of forests and the reduction of nitrogen deposition to prevent further acidification of soils and waters. Keywords: freshwater, acidification reversal, drinking water supply, forested catchments, Germany

scholarly journals About constructions for the protection of water supply channels from sediment load and driftwood

2019 ◽  
pp. 69-75
Author(s):  
Dilshod Raimovich Bazarov ◽  
Bekhzod Eshmirzaevich Norkulov ◽  
Irina Mikhailovna Markova ◽  
Mikhail Ermilov ◽  
Durdona Oblakulovna Tadjieva
Keyword(s):  
Adverse Effect ◽  
Water Supply ◽  
Sediment Load ◽  
Suspended Sediments ◽  
Structural Elements ◽  
Hydraulic Unit ◽  
Floating Structures ◽  
Supply Channel ◽  
Analytical Review ◽  
Functional Reliability

The article shows the results of the analytical review of the main floating structures used in the water supply channels. It is noted that there are two classes of floating constructions: active - affecting the flow regime and changing its structure in the selected direction (floating regulators, jetting devices for changing the flow structure); passive - eliminating the adverse effect of flow ingredients on the elements of the hydraulic unit of the pumping station, without changing its structure and parameters (debris deflector, aero curtain). The basic requirements for the design of floating devices are formulated: reduction of hydraulic losses (streamlining of pontoons and fenders) increase of stability, durability, maneuverability of conditions for installation on water ensuring the water tightness of hermetic compartments, the possibility of balancing and repair, increasing functional reliability and efficiency. A fundamentally new design of the structural elements of the water supply channel has been proposed to help reduce the flow of both bottom and suspended sediments to the mainstream of the water supply channel.    

scholarly journals Assessment of Hydrologic Transient Storage of Three Streams

2003 ◽  
Vol 27 ◽  
pp. 79-80
Author(s):  
Michael Gooseff
Keyword(s):  
Porous Media ◽  
Hyporheic Zone ◽  
Stream Water ◽  
Stream Sediments ◽  
Hyporheic Exchange ◽  
Ecosystem Functions ◽  
Main Stream ◽  
Stream Channel ◽  
Ample Opportunity ◽  
Biogeochemical Transformations

Stream sediments are important locations of biogeochemical transformations upon which many stream ecosystem functions depend. Stream water is often exchanged between the stream channel and surrounding subsurface locations - this process is known as hyporheic exchange. While stream water is moving through the hyporheic zone, solutes and nutrients may undergo important chemical reactions that are not possible in the main stream channel. Further, because the hyporheic zone is composed of porous media (sand, sediment, alluvium, etc.), flow inherently slows down and the exchanging water has ample opportunity to interact with mineral grain surfaces and biofilms.

A Simulation Modeling of Forest Water Supply Under Community-Managed PES Schemes

2019 ◽  
Vol 05 (04) ◽  
pp. 1950005
Author(s):  
Ram Ranjan
Keyword(s):  
Water Supply ◽  
Simulation Modeling ◽  
Stream Flow ◽  
Forest Conservation ◽  
Stream Water ◽  
Monetary Incentives ◽  
Ecological Constraints ◽  
Municipal Water Supply ◽  
Long Run ◽  
Downstream Communities

This paper explores the design of a forestry-based payment for ecosystem services (PES) scheme, which improves stream water supply while simultaneously helping conserve forests and supporting livelihoods in communities of Uttarakhand, India. Under a PES arrangement, upstream communities reduce fuelwood harvesting to restore forest quality and improve stream flow in the downstream communities. Results suggest that such PES projects can play a crucial role in supporting forest conservation efforts and mitigating water scarcity in the region. For instance, PES-based payments required to meet the water needs of downstream communities can be three times lower than the costs of municipal water supply. Whereas, if communities do not receive any monetary incentives for reducing fuelwood harvesting, it results in a significant degradation of the forests in the long run. However, hydrological and ecological constraints can reduce the effectiveness of PES programs in the region. A high displacement of oak forests by the pine forests would lower the benefits from PES participation for the local communities. When the shifting species composition of forests also increases the failure risk of PES projects, optimal response requires further restricting fuelwood harvesting.

scholarly journals Potensi dan Tantangan Pengembangan Sektor Unggulan di Kalimantan Barat

2016 ◽  
Vol 5 (2) ◽  
pp. 94
Author(s):  
Dinarjad Achmad
Keyword(s):  
Time Series ◽  
Water Supply ◽  
Time Series Data ◽  
Water Area ◽  
Primary Objective ◽  
Series Data ◽  
West Kalimantan ◽  
The Earth ◽  
Descriptive Method ◽  
Land Water

The primary objective of this study was to analyze the potential and challenges of superior sectordevelopment in West Kalimantan. Superior sectors here interpreted as a sector that producesgoods that can be exported. Descriptive method and time series data for 7 years (2007- 2013) wasused as the tools and materials to perform the analysis.The results showed that the based on ofnatural resources (land, water area and the river, fill the earth) and geography, West Kalimantanhave a greater potential for superior sector development, but there are several challenges to thedevelopment potential of the superior sector, including: (1) resource human (HR) is still weak.(2) Infrastructure (electricity, gas and water supply, road and port export) are limited. (3)Marketing and networking is still weak 

Variations of disinfection by-product precursors of stream systems in north Missouri watersheds of drinking water supply reservoirs

2017 ◽  
Author(s):  
◽  
Latitia Ramolino
Keyword(s):  
Drinking Water ◽  
Chemical Composition ◽  
Water Supply ◽  
Organic Compounds ◽  
Water Samples ◽  
Aromatic Compounds ◽  
Organic Nitrogen ◽  
Stream Water ◽  
Land Uses ◽  
Water Supply Reservoirs

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Dissolved organic matter (DOM) and its potential to form disinfection by-products (DBPs) during water treatment are of great public health concern. The link between temporal patterns of terrestrial DOM quantity and quality of stream systems in north Missouri watershed of drinking water supply reservoirs was explored to assess catchment controls on stream water DOM chemical composition and reactivity in DBP formation. TCM (trichloromethane) was the dominant of trihalomethane (THM) species and trichloroacetic acid (TCAA) and DCAA (dichloroacetic acid) were the dominant of haloacetic acid (HAA) species formed in chlorinated stream water samples. N-nitrosodimethylamine (NDMA) formed in chloraminated stream water samples. Catchment land uses and soil characteristics of northern Missouri and their impact on watershed hydrology were the most controlling factors of terrestrial DOM transport and transformation in Northern Missouri sub-watersheds. DOM chemical interactions with clay mineral soil surfaces along water flow paths and residence time within catchments were in large responsible for variations of stream water DOM chemical composition. The chemical and structural reactivity of TCMFP, TCAAFP, DCAAFP and NDMAFP precursors in North Missouri stream water DOM were intrinsically coupled together and both seasonally varied in function of mixed effects of anthropogenic land uses and hydrogeochemical sorption processes within catchments that controlled aromaticity and organic nitrogen contents of North Missouri stream water DOM. Organic nitrogen and aromaticity contents of precursor organic moieties in north Missouri stream water DOM controlled DBP formation potentials. Hydrophobic nitrogen-rich aromatic compounds gave the lowest TCM, TCAA, DCAA and NDMA formation potentials, respectively. Hydrophobic carbon-rich aromatic TCMFP precursors were the most reactive with respect to chloroform formation potential. Hydrophilic nitrogenous aliphatic organic micronutrients were more potent TCMFP precursors than hydrophobic and hydrophilic nitrogen containing aromatic organic compounds. Nitrogenous aliphatic micronutrients and nitrogen-rich aliphatic compounds had the largest NDMAFP and DCAAFP yields, respectively. Hydrophilic nitrogenous aromatic organic micronutrients and hydrophilic nitrogen containing aromatic organic compounds facilitated TCAA formation potential compared to more hydrophobic nitrogen containing aromatic compounds. Understanding of how north Missouri catchment anthropogenic land uses affect the mobilization of precursor material can help in establishment of effective monitoring programs. Evaluating DBP chemical and structural transformations during their transport to drinking water sources can help to implement effective watershed management policy to reduce DBPs transfer from watershed to drinking water sources.

scholarly journals The water quality of streams draining a plantation forest on gley soils: the Nant Tanllwyth, Plynlimon mid-Wales

2004 ◽  
Vol 8 (3) ◽  
pp. 485-502 ◽  
Author(s):  
C. Neal ◽  
B. Reynolds ◽  
M. Neal ◽  
H. Wickham ◽  
L. Hill ◽  
...  
Keyword(s):  
Water Quality ◽  
Management Practices ◽  
Stream Water ◽  
Chemical Reactivity ◽  
Ammonium Phosphate ◽  
Small Scale ◽  
Main Stream ◽  
Stream Water Quality ◽  
Atmospheric Inputs

Abstract. The water quality of the Nant Tanllwyth stream in the Plynlimon region of mid-Wales is related to the key hydrobiogeological controls and the effects of conifer harvesting based on an analysis of rain, cloud, stream and groundwater measurements. The results show the normal patterns of stream water quality response to hydrology. Thus, there is a high damping of atmospheric inputs due to storage in a highly heterogeneous soil and groundwater system. Correspondingly, there is a highly dynamic response for components such as calcium, bicarbonate and aluminium. This response links to the relative inputs of acidic and aluminium-bearing soil waters under high flow conditions and base enriched bicarbonate bearing waters from the groundwater areas under baseflow conditions. The introduction of a deep borehole near the main stem of the river opened up a groundwater flow route to the stream and other parts of the catchment. There were two aspects to this. Firstly, it caused a change to the stream water quality, particularly under baseflow conditions, by increasing the concentrations of calcium and magnesium and by reducing the acidity. The monitoring shows that this change has persisted for over eight years and that there is no sign of reversion to pre-borehole times. Secondly, it caused a change in the groundwater level and chemistry at a borehole on the other side of the river. This feature shows that the fracture system is of hydrogeochemical and hydrogeological complexity. The effects of conifer harvesting are remarkable. At the local scale, felling leads to the expected short term increase in nitrate, ammonium and phosphate from the disturbance of the soil and the reduction in uptake into the vegetation. Correspondingly, there is a reduction in sodium and chloride linked to reduced scavenging of atmospheric inputs from cloud water by the vegetation and also due to increased dilution potential due to reductions in transpiration by the trees. However, within the main stream, virtually no change is observed in stream water quality with felling, except for a decrease rather than an expected increase in nitrate concentration. It seems that the increase in phosphate, for a system that is essentially phosphate limiting, has stimulated biological activity in the stream leading to increased uptake of nitrate and ammonium. However, there is little change in the sodium and chloride in the stream and there are important issues of the representative nature of studying small scale drainage areas. Boreholes, introduced to assess the impacts of the felling programme, show unexpected variations in groundwater chemistry. These variations are associated with the complexity of both flow routing and the chemical reactivity within the groundwater and lower soil zones, rather than changes that can be linked specifically to felling. The implications of the study are discussed in relation to both process understanding and forestry management practices. Keywords: water quality, acidification, conifer, harvesting, pH, nitrate, ammonium, phosphate, nutrients, alkalinity, Plynlimon, Wales, Tanllwyth, streams, groundwater

scholarly journals The Potential of Small Dams for Conjunctive Water Management in Rural Municipalities

2019 ◽  
Vol 16 (7) ◽  
pp. 1239 ◽  
Author(s):  
Sara Soares ◽  
Daniela Terêncio ◽  
Luís Fernandes ◽  
João Machado ◽  
Fernando Pacheco
Keyword(s):  
Water Management ◽  
Drinking Water ◽  
Surface Water ◽  
Water Supply ◽  
Stream Water ◽  
Groundwater Resources ◽  
Drinking Water Supply ◽  
Annual Rainfall ◽  
Small Dams ◽  
Conjunctive Water Management

The drinking water supply to Vila Pouca de Aguiar municipality in North Portugal is based on high quality groundwater, namely on nearly one hundred artesian springs and fifty boreholes. The groundwater resources are plentiful on a municipal level, but evidence some deficits at the sub-municipal (village) level, especially during the dry period (July- August) that coincides with the return of many emigrants for holiday time. The deficits affect mostly the municipal capital (Vila Pouca de Aguiar) and a neighboring village (Pedras Salgadas), which populations nearly double or even triple during that period. The estimated annual deficits approach 55,000 m3/yr in those villages. If the anticipated increase in consumption/habitant and decrease in annual rainfall become reality in the next two decades, then the deficits may raise to approximately 90,000 m3/yr. To balance the water supply system, this study proposes its transition towards a conjunctive water management based on surface water stored in small dams and groundwater. A hydrologic modeling involving small forested catchments (< 15 km2) elected the Cabouço watershed as most suited basin to store stream water, because surface water availability is large (2.4 Mm3/yr) and forest cover is dominant (84.8%). Estimated nutrient loads are also compatible with drinking water supply.

Sign in / Sign up

Export Citation Format

Share Document