Availability and Distribution of Base Flow in Lower Honokohau Stream, Island of Maui

2003 ◽  
Keyword(s):  
Base Flow

Altering turbulence in compressible base flow using axisymmetric sub-boundary-layer disturbances

AIAA Journal ◽  
2002 ◽  
Vol 40 ◽  
pp. 2217-2224
Author(s):  
C. J. Bourdon ◽  
J. C. Dutton
Keyword(s):  
Boundary Layer ◽  
Base Flow

Managing urban wastewater for maximising water resource utilization

1999 ◽  
Vol 39 (10-11) ◽  
pp. 353-356 ◽  
Author(s):  
Gideon Tredoux ◽  
Peter King ◽  
Lisa Cavé
Keyword(s):  
Water Resource ◽  
Industrial Wastewater ◽  
Water Resource Management ◽  
Quality Parameters ◽  
Base Flow ◽  
Treated Wastewater ◽  
Groundwater Exploitation ◽  
Trade Area ◽  
Management Scheme ◽  
Domestic Effluent

The Atlantis Water Resource Management Scheme uses artificial recharge of urban stormwater and treated wastewater to augment the natural groundwater resource. The key to the success of the scheme is the fractionation of the stormwater into components of distinctly different quality, and the separate treatment of domestic and industrial wastewater for different end-uses. The groundwater exploitation strategy is largely controlled by water quality requirements. Reuse of domestic and industrial wastewater depends on quality parameters. Tertiary treated domestic effluent is destined for indirect reuse via the aquifer, while treated industrial wastewater is used together with spent regenerant brine and stormwater from the noxious trade area for preventing seawater intrusion. Both residential and industrial stormwater is separated into the base flow and storm flow components and utilised for various purposes. The sustainable operation of the water resource scheme serves as a prototype for the optimal use of water and protection of the environment.

scholarly journals Estimation of recharge in mountain hard-rock aquifers based on discrete spring discharge monitoring during base-flow recession

2021 ◽  
Author(s):  
Stefano Segadelli ◽  
Maria Filippini ◽  
Anna Monti ◽  
Fulvio Celico ◽  
Alessandro Gargini
Keyword(s):  
Hard Rock ◽  
Monitoring Program ◽  
Base Flow ◽  
Low Flow ◽  
Reliable Estimate ◽  
Spring Discharge ◽  
Aquifer Recharge ◽  
Clear Cut ◽  
Groundwater Circulation ◽  
Hard Rock Aquifers

AbstractEstimation of aquifer recharge is key to effective groundwater management and protection. In mountain hard-rock aquifers, the average annual discharge of a spring generally reflects the vertical aquifer recharge over the spring catchment. However, the determination of average annual spring discharge requires expensive and challenging field monitoring. A power-law correlation was previously reported in the literature that would allow quantification of the average annual spring discharge starting from only a few discharge measurements in the low-flow season, in a dry summer climate. The correlation is based upon the Maillet model and was previously derived by a 10-year monitoring program of discharge from springs and streams in hard-rock aquifers composed of siliciclastic and calcareous turbidites that did not have well defined hydrogeologic boundaries. In this research, the same correlation was applied to two ophiolitic (peridotitic) hard-rock aquifers in the Northern Apennines (Northern Italy) with well-defined hydrogeologic boundaries and base-outflow springs. The correlation provided a reliable estimate of the average annual spring discharge thus confirming its effectiveness regardless of bedrock lithology. In the two aquifers studied, the measurable annual outputs (i.e. sum of average annual spring discharges) could be assumed equal to the annual inputs (i.e. vertical recharge) based on the clear-cut aquifer boundaries and a quick groundwater circulation inferable from spring water parameters. Thus, in such setting, the aforementioned correlation also provided an estimate of the annual aquifer recharge allowing the assessment of coefficients of infiltration (i.e. ratio between aquifer recharge and total precipitation) ranging between 10 and 20%.

scholarly journals Relationships of Hydrological Seasons in Rivers and Groundwaters in Selected Catchments in Poland

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 250
Author(s):  
Przemysław Tomalski ◽  
Edmund Tomaszewski ◽  
Dariusz Wrzesiński ◽  
Leszek Sobkowiak
Keyword(s):  
River Flow ◽  
Geographical Location ◽  
Base Flow ◽  
Water Shortages ◽  
Groundwater Levels ◽  
Average Value ◽  
Geographical Regions ◽  
New Variables ◽  
Mixed Types

The study applied the method of hydrological season identification in a time series of river total and base flows and in groundwater levels. The analysis covered a series of daily measurements from the period 2008–2017 in nine catchments located in different geographical regions of Poland. The basis of the classification of hydrological seasons, previously applied for river discharges only, was the transformation of the original variables into a series reflecting three statistical features estimated for single-name days of a year from a multiyear: average value, variation coefficient, and autocorrelation coefficient. New variables were standardized and after hierarchical clustering, every day of a year had a defined type, valorizing three features which refer to quantity, variability, and the stochastic nature of total and base river flow as well as groundwater stage. Finally, sequences of days were grouped into basic (homogenous) seasons of different types and transitional seasons including mixed types of days. Analysis indicated determinants of types, length, and frequency of identified hydrological seasons especially related to river regime, hydrogeological and hydrometeorological conditions as well as physiographical background were directly influenced by geographical location. Analysis of the co-occurrence of the same types of hydrological seasons allowed, in some catchments, periods of synchronic alimentation (groundwater and base flow, mainly in the cold half-year) and water shortages (all three components, mainly in the warm half-year) to be identified.

scholarly journals Hydrological, Environmental and Taxonomical Heterogeneity during the Transition from Drying to Flowing Conditions in a Mediterranean Intermittent River

Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 316
Author(s):  
Andy Banegas-Medina ◽  
Isis-Yelena Montes ◽  
Ourania Tzoraki ◽  
Luc Brendonck ◽  
Tom Pinceel ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Base Flow ◽  
Ephemeral Streams ◽  
Biogeochemical Processes ◽  
Flow Conditions ◽  
Intermittent Rivers ◽  
Terrestrial Biodiversity ◽  
Turn Over ◽  
Zero Flow ◽  
Intermittent River

Intermittent rivers and ephemeral streams (IRES) are increasingly studied because of their often-unique aquatic and terrestrial biodiversity, biogeochemical processes and associated ecosystem services. This study is the first to examine the hydrological, physicochemical and taxonomic variability during the dry-wet transition of an intermittent river in the Chilean Mediterranean Zone. Based on 30-years of river monitoring data and the TREHS tool, the hydrology of the river was characterised. Overall, the river shows a significant reduction in streamflow (−0.031 m3/s per year) and a substantial increase of zero flow days (+3.5 days per year). During the transition of hydrological states, variations were observed in the environmental conditions and invertebrate communities. During the drying phase, abundance, richness, and diversity were highest, while species turn-over was highest during base flow conditions. The disconnected pools and the flow resumption phases were characterised by high proportions of lentic taxa and non-insects, such as the endemic species of bivalves, gastropods, and crustaceans, highlighting the relevance of disconnected pools as refuges. Future climatic change scenarios are expected to impact further the hydrology of IRES, which could result in the loss of biodiversity. Biomonitoring and conservation programmes should acknowledge these important ecosystems.

Aspects of Shear Layer Unsteadiness in a Three-Dimensional Supersonic Wake

2005 ◽  
Vol 127 (6) ◽  
pp. 1085-1094 ◽  
Author(s):  
Alan L. Kastengren ◽  
J. Craig Dutton
Keyword(s):  
Shear Layer ◽  
Stream Flow ◽  
Free Stream ◽  
Angle Of Attack ◽  
Three Dimensional ◽  
Base Flow ◽  
Recirculation Region ◽  
Side View ◽  
Near Wake ◽  
Supersonic Wake

The near wake of a blunt-base cylinder at 10° angle-of-attack to a Mach 2.46 free-stream flow is visualized at several locations to study unsteady aspects of its structure. In both side-view and end-view images, the shear layer flapping grows monotonically as the shear layer develops, similar to the trends seen in a corresponding axisymmetric supersonic base flow. The interface convolution, a measure of the tortuousness of the shear layer, peaks for side-view and end-view images during recompression. The high convolution for a septum of fluid seen in the middle of the wake indicates that the septum actively entrains fluid from the recirculation region, which helps to explain the low base pressure for this wake compared to that for a corresponding axisymmetric wake.

scholarly journals Towards a hydrological classification of European soils: preliminary test of its predictive power for the base flow index using river discharge data

2007 ◽  
Vol 11 (4) ◽  
pp. 1501-1513 ◽  
Author(s):  
M. K. Schneider ◽  
F. Brunner ◽  
J. M. Hollis ◽  
C. Stamm
Keyword(s):  
Water Movement ◽  
Base Flow ◽  
Regression Coefficients ◽  
Northern Europe ◽  
Flow Index ◽  
Discharge Data ◽  
Base Flow Index ◽  
The Uk

Abstract. Predicting discharge in ungauged catchments or contaminant movement through soil requires knowledge of the distribution and spatial heterogeneity of hydrological soil properties. Because hydrological soil information is not available at a European scale, we reclassified the Soil Geographical Database of Europe (SGDBE) at 1:1 million in a hydrological manner by adopting the Hydrology Of Soil Types (HOST) system developed in the UK. The HOST classification describes dominant pathways of water movement through soil and was related to the base flow index (BFI) of a catchment (the long-term proportion of base flow on total stream flow). In the original UK study, a linear regression of the coverage of HOST classes in a catchment explained 79% of BFI variability. We found that a hydrological soil classification can be built based on the information present in the SGDBE. The reclassified SGDBE and the regression coefficients from the original UK study were used to predict BFIs for 103 catchments spread throughout Europe. The predicted BFI explained around 65% of the variability in measured BFI in catchments in Northern Europe, but the explained variance decreased from North to South. We therefore estimated new regression coefficients from the European discharge data and found that these were qualitatively similar to the original estimates from the UK. This suggests little variation across Europe in the hydrological effect of particular HOST classes, but decreasing influence of soil on BFI towards Southern Europe. Our preliminary study showed that pedological information is useful for characterising soil hydrology within Europe and the long-term discharge regime of catchments in Northern Europe. Based on these results, we draft a roadmap for a refined hydrological classification of European soils.

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