Simulation of base-flow and tile-flow for storm events in a subsurface drained watershed

2009 ◽  
Vol 102 (2) ◽  
pp. 227-235 ◽  
Author(s):  
Debashish Goswami ◽  
Prasanta K. Kalita
Keyword(s):  
Base Flow ◽  
Storm Events ◽  
Tile Flow

Ptaquiloside from bracken in stream water at base flow and during storm events

2016 ◽  
Vol 106 ◽  
pp. 155-162 ◽  
Author(s):  
Frederik Clauson-Kaas ◽  
Carmel Ramwell ◽  
Hans Chr. B. Hansen ◽  
Bjarne W. Strobel
Keyword(s):  
Stream Water ◽  
Base Flow ◽  
Storm Events

scholarly journals A multi-functional and multi-compartment constructed wetland to support urban waterway restoration

2018 ◽  
Vol 13 (4) ◽  
pp. 764-770 ◽  
Author(s):  
T. M. Adyel ◽  
M. R. Hipsey ◽  
C. Oldham
Keyword(s):  
Constructed Wetland ◽  
Flow System ◽  
Surface Flow ◽  
Base Flow ◽  
Low Flow ◽  
Nutrient Loads ◽  
Storm Events ◽  
Flow Conditions ◽  
Storm Flow ◽  
Diverse Area

Abstract This study assessed the significance of a multi-functional and multi-compartment constructed wetland (CW) implemented to restore a degraded urban waterway in Western Australia. The wetland was initially constructed as a surface flow system, then modified through the incorporation of the additional laterite-based subsurface flow system, with the potential for operation of a recirculation scheme and groundwater top-up during low water flows in summer. The CW performance was assessed by comparing nitrogen (N) and phosphorus (P) attenuation during base flow, high flow and episodic storm flow conditions. The performance varied from approximately 41% total nitrogen (TN) and 66% total phosphorus (TP) loads reduction during storm events, increasing up to 62% TN and 99% TP during low flow and summer recirculation periods. In overall, the CW attenuated about 45% TN and 65% TP loads from being delivered to the downstream sensitive river between 2009 and 2015. The CW design proved to be not only highly effective at reducing nutrient loads, but also improved the ecological services of the urban waterway by providing a diverse area for habitat and recreational activities.

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.

scholarly journals Differential behaviour of Escherichia coli and Campylobacter spp. in a stream draining dairy pasture

2011 ◽  
Vol 9 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Rebecca Stott ◽  
Robert Davies-Colley ◽  
John Nagels ◽  
Andrea Donnison ◽  
Colleen Ross ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Base Flow ◽  
Storm Events ◽  
Flood Wave ◽  
E Coli ◽  
Transport Dynamics ◽  
Bacterial Indicator ◽  
Routine Monitoring ◽  
Differential Behaviour ◽  
Campylobacter Spp

The faecal indicator bacterium Escherichia coli and thermotolerant Campylobacter spp., which are potentially pathogenic, were investigated in the Toenepi Stream draining a pastoral catchment dominated by dairying. Bacteria concentrations were monitored routinely at fortnightly intervals over 12 months and intensively during storm events to compare the transport dynamics of bacterial indicator and pathogen under varying hydro-meteorological conditions. Routine monitoring indicated median concentrations of 345 E. coli MPN 100 ml−1 and relatively low concentrations of 2.3 Campylobacter MPN 100 ml−1. The bacterial flux was three orders of magnitude greater under elevated stream flow compared with base-flow. E. coli peak concentrations occurred very close to the turbidity peak and consistently ahead of the Campylobacter spp. peak (which was close to the hydrograph peak). We postulate that, under flood conditions, the E. coli peak reflects the entrainment and mobilisation of in-stream stores on the flood wave front. In contrast, Campylobacter spp. are derived from wash-in from land stores upstream and have travelled at the mean water velocity which is slower than the speed of the flood wave. Our findings of different dynamics for E. coli and Campylobacter spp. suggest that mitigation to reduce faecal microbial impacts from farms will need to take account of these differences.

Analysis of parameter variations in L–Q equations for river runoff processes from the viewpoint of spatial and temporal conditions

2006 ◽  
Vol 53 (10) ◽  
pp. 141-152 ◽  
Author(s):  
S. Fujii ◽  
B.R. Shivakoti ◽  
K. Shichi ◽  
P. Songprasert ◽  
H. Ihara ◽  
...  
Keyword(s):  
Continuous Monitoring ◽  
Base Flow ◽  
Storm Event ◽  
Storm Events ◽  
Flow Conditions ◽  
Regional Effect ◽  
Run Off ◽  
Parameter Variations ◽  
Variation Characteristics ◽  
Temporal Flow

This study aims to find out variation characteristics of the parameters of ‘a’ and ‘b’ in L=a ·Qb, an empirical equation for run-off loading (L) and flow rate (Q), by evaluating the effects of flow conditions and regional properties of the watersheds on the values. We selected the Kamo River basin (155 km2) as a study field, and conducted various kinds of investigations, such as 80 day high frequency observations, continuous monitoring for more than 2 years, storm event surveys, and simultaneous surveys of 39 stations. Then, we obtained 7–170 data in each of 39 sampling stations. The main results obtained are as follows: 1) L–Q equation with a range of ‘a’ can express L–Q relation in most of the WQIs (water quality indices); 2) ‘a’ receives temporal (flow condition) effects more in SS, VSS and Al, while it receives regional effect more in inorganic carbon, TN, Ca and Fe; 3) both of flow change in storm events, and base flow levels affect the L–Q relation, and their effects can classify the WQIs into several groups; 4) the effects of regional properties were obviously observed in ‘a’, and quantitatively evaluated, especially for density of population.

scholarly journals Hydrology and riparian forests drive carbon and nitrogen supply and DOC:NO<sub>3<sup>−</sup></sub> stoichiometry along a headwater Mediterranean stream

2021 ◽  
Author(s):  
José L. J. Ledesma ◽  
Anna Lupon ◽  
Eugènia Martí ◽  
Susana Bernal
Keyword(s):  
Riparian Forest ◽  
Base Flow ◽  
Riparian Forests ◽  
Storm Events ◽  
Flow Conditions ◽  
Heterotrophic Activity ◽  
Molar Ratios ◽  
Mediterranean Stream ◽  
Storm Flow ◽  
Forest Coverage

Abstract. In forest headwater streams, metabolic processes are predominately heterotrophic and depend on both the availability of carbon (C) and nitrogen (N) and a favourable C:N stoichiometry. In this context, hydrological conditions and the presence of riparian forests adjacent to streams can play an important, yet understudied role determining dissolved organic carbon (DOC) and nitrate (NO3−) concentrations and DOC:NO3− molar ratios. Here, we aimed to investigate how the interplay between hydrological conditions and riparian forest coverage drives DOC and NO3− supply and DOC:NO3− stoichiometry in an oligotrophic headwater Mediterranean stream. We analysed DOC and NO3− concentrations, and DOC:NO3− molar ratios during both base flow and storm flow conditions at three stream locations along a longitudinal gradient of increased riparian forest coverage. Further, we performed an event analysis to examine the hydroclimatic conditions that favour the transfer of DOC and NO3− from riparian soils to the stream during large storms. Stream DOC and NO3− concentrations were generally low (overall average ± SD was 1.0 ± 0.6 mg C L−1 and 0.20 ± 0.09 mg N L−1), although significantly higher during storm flow compared to base flow conditions in all three stream sites. Optimal DOC:NO3− stoichiometry for stream heterotrophic microorganisms (corresponding to DOC:NO3− molar ratios between 4.8 and 11.7) was prevalent at the midstream and downstream sites under both flow conditions, whereas C-limited conditions were prevalent at the upstream site, which had no surrounding riparian forest. The hydroclimatic analysis of large storm events highlighted different patterns of DOC and NO3− mobilization depending on antecedent soil moisture conditions: drier antecedent conditions promoted rapid elevations of riparian groundwater tables, hydrologically activating a wider and shallower soil layer, and leading to relatively higher increases in stream DOC and NO3− concentrations compared to events preceded by wet conditions. These results suggest that (i) increased supply of limited resources during storms can promote in-stream heterotrophic activity during high flows, especially during large storm events preceded by dry conditions, and (ii) C-limited conditions upstream were gradually overcome downstream, likely due to higher C inputs from riparian forests present at lower elevations. The contrasting spatiotemporal patterns in DOC and NO3− availability and DOC:NO3− stoichiometry observed at the study stream suggests that groundwater inputs from riparian forests are essential for maintaining in-stream heterotrophic activity in oligotrophic, forest headwater catchments.

Effects of Urbanization on Stream Ecosystems

2005 ◽  
Keyword(s):  
Water Quality ◽  
Suspended Sediment ◽  
Brown Trout ◽  
Dose Response ◽  
Quality Criteria ◽  
Base Flow ◽  
Response Model ◽  
Storm Events ◽  
Flow Conditions ◽  
Blood Samples

<em>Abstract.</em>—Urban streams typically have increased flows, high suspended sediment concentrations, and reduced water quality during rainstorms as a result of changes within the watershed related to human activity. In the 6-month periods from May through October of 2001 and 2002, water quality was monitored continuously at five sites along Rapid Creek within Rapid City, South Dakota. Water quality samples were collected for eight base flows (nonevents) and eight storm events. Blood samples were collected from wild adult brown trout <em>Salmo trutta </em>during base flow conditions and six of eight storm events to determine if storm events could elicit physiological stress responses. Blood samples were also collected 24, 48, and 96 h after each storm event had started. Water monitoring results showed significant increases in runoff volume and peak flows during storm events. Water quality parameters exceeding South Dakota’s water quality criteria for a coldwater fishery were total suspended solids and temperature. Plasma concentrations of cortisol and lactate, during and after storm events, were not significantly different than those measured during base flow conditions. Plasma glucose values were lower during storm events than during nonevent periods. These observations were compared to those predicted by a suspended sediment dose–response model developed for adult salmonids. The dose–response model overpredicted the severity of the effects of increased total suspended sediment on the brown trout during stormwater runoff events.

Stormwater pollution modelling: minor sources of pollutants in urban sewer networks

1987 ◽  
Vol 14 (1) ◽  
pp. 131-134 ◽  
Author(s):  
Boregowda Shivalingaiah ◽  
William James
Keyword(s):  
Water Pollution ◽  
Environmental Protection Agency ◽  
Stormwater Management ◽  
Base Flow ◽  
Storm Events ◽  
Management Options ◽  
Water Pollution Management ◽  
Local Deposition ◽  
Stormwater Pollution ◽  
Better Than

In addition to the well-known, major pollution processes of dry weather buildup and wet weather washoff and routing, some less obvious minor processes contribute background pollutants to urban stormwater. Since related pollutant loads during storm events are not significant, the processes are termed "minor." These processes, which appear to be seasonally persistent, include aerosol and gaseous scavenging from the atmosphere, leaf canopy washoff, dry weather base flow, and local deposition/erosion due to obstructions.Equations are presented for each process. Algorithms for these equations were incorporated in version 3 of the U.S. Environmental Protection Agency stormwater management model (SWMM3) and tested collectively. The modified version is known as CHGQUAL. The effect of variable time steps in the computational scheme is discussed.CHGQUAL evidently contains more process-oriented algorithms and may predict surface water pollution management options better than SWMM3. Until more definite data becomes available, however, CHGQUAL should of course be used with caution. Key words: precipitation scavenging, canopy washoff, base flow, water pollution, air pollution, stormwater management models, urban runoff.

scholarly journals Impact of Combined Sewer Systems on the Quality of Urban Streams: Frequency and Duration of Elevated Micropollutant Concentrations

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 850 ◽  
Author(s):  
Ulrich Dittmer ◽  
Anna Bachmann-Machnik ◽  
Marie A. Launay
Keyword(s):  
Aquatic Organisms ◽  
Urban Streams ◽  
Base Flow ◽  
Storm Events ◽  
Urban Catchment ◽  
Mixing Ratios ◽  
Sewer Systems ◽  
Wwtp Effluent ◽  
Wide Range ◽  
Combined Sewer

Water quality in urban streams is highly influenced by emissions from WWTP and from sewer systems particularly by overflows from combined systems. During storm events, this causes random fluctuations in discharge and pollutant concentrations over a wide range. The aim of this study is an appraisal of the environmental impact of micropollutant loads emitted from combined sewer systems. For this purpose, high-resolution time series of river concentrations were generated by combining a detailed calibrated model of a sewer system with measured discharge of a small natural river to a virtual urban catchment. This river base flow represents the remains of the natural hydrological system in the urban catchment. River concentrations downstream of the outlets are simulated based on mixing ratios of base flow, WWTP effluent, and CSO discharge. The results show that the standard method of time proportional sampling of rivers does not capture the risk of critical stress on aquatic organisms. The ratio between average and peak concentrations and the duration of elevated concentrations strongly depends on the source and the properties of the particular substance. The design of sampling campaigns and evaluation of data should consider these characteristics and account for their effects.

scholarly journals Runoff generation processes during the wet-up phase in a semi-arid basin in Iran

2014 ◽  
Vol 11 (4) ◽  
pp. 3787-3810 ◽  
Author(s):  
H. Zarei ◽  
A. M. Akhondali ◽  
H. Mohammadzadeh ◽  
F. Radmanesh ◽  
H. Laudon
Keyword(s):  
Isotope Composition ◽  
Base Flow ◽  
Hydrograph Separation ◽  
Storm Events ◽  
Rainfall Runoff ◽  
Runoff Generation ◽  
Isotopic Tracers ◽  
Southwestern Iran ◽  
Semi Arid

Abstract. Understanding the hydrological processes in catchments is important for water resources management, particularly in semi-arid regions of the world. To contribute to this field, dominant runoff generation processes in a semi-arid basin (283 km2) in Southwestern Iran were investigated using analysis of hydrometric data in combination with natural isotopic tracers through the wet-up phase of a rainy season. The analysis of seven rainfall–runoff events during the rainfall dominated period illustrated the role of antecedent base flow and cumulative rainfall for explaining the hydrological response. Three distinct storm events and the corresponding discharge were collected and analyzed for oxygen-18 and deuterium isotope composition. The results show that during the wetting-up cycle, the runoff ratio during storm events increased progressively from 1 to 10%. Higher event runoff ratios following catchment wet-up were shown to be directly linked to changes in soil moisture, which in turn controlled the runoff generation processes. In line with the hydrometric results, the two-component hydrograph separation using δ18O and δ2H demonstrated a clear connection to the antecedent wetness conditions. The results suggest that the runoff ratios during storms and the partitioning of event and pre-event water fractions are sensitive to the amount of catchment wet-up and could hence be strongly impacted by changes in the timing, duration and amount of precipitation in the future.

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