An ecohydrologic model for a shallow groundwater urban environment

2014 ◽  
Vol 70 (11) ◽  
pp. 1789-1797 ◽  
Author(s):  
Sam Arden ◽  
Xin (Cissy) Ma ◽  
Mark Brown

The urban environment is a patchwork of natural and artificial surfaces that results in complex interactions with and impacts to natural hydrologic cycles. Evapotranspiration is a major hydrologic flow that is often altered through urbanization, although the mechanisms of change are sometimes difficult to tease out due to difficulty in effectively simulating soil–plant–atmosphere interactions. This paper introduces a simplified yet realistic model that is a combination of existing surface runoff and ecohydrology models designed to increase the quantitative understanding of complex urban hydrologic processes. Results demonstrate that the model is capable of simulating the long-term variability of major hydrologic fluxes as a function of impervious surface, temperature, water table elevation, canopy interception, soil characteristics, precipitation and complex mechanisms of plant water uptake. These understandings have potential implications for holistic urban water system management.

2012 ◽  
Vol 7 (2) ◽  
Author(s):  
S. R. Weijers ◽  
J. de Jonge ◽  
O. van Zanten ◽  
L. Benedetti ◽  
J. Langeveld ◽  
...  

The Kallisto project aims at finding cost effective sets of measures to meet the WFD derived goals for the river De Dommel. The project reasons from the both acute and long term impacts of the urban wastewater system on the quality and ecology of the river that are studied with an integral monitoring campaign in the wastewater system (WWTP and sewers) and river. By applying impact based RTC, the project aims at minimizing additional investments in infrastructure while meeting the requirements. Moreover, uncertainty is explicitly considered in the optimization and decision making process. The paper describes the overall project strategy, some preliminary results of modelling and monitoring of the components of the urban water system and the demonstration research for treatment techniques and the planned integration into optimization and decision making.


2015 ◽  
Author(s):  
◽  
Ramsey Elliott Kellner

A study was implemented in fall 2010, in the Hinkson Creek Watershed, Missouri, USA to improve quantitative understanding of the long-term impact of forest removal on floodplain hydrology. Automated volumetric water content (VWC) probes and piezometers equipped with pressure transducers to monitor shallow groundwater (SGW) temperature and level were installed in a gridded study design within a historic agricultural field (Ag) and a remnant bottomland hardwood forest (BHF). Groundwater was analyzed for 49 physiochemical metrics. Results showed VWC to be significantly different between sites (p less than 0.01) during the study, with site averages of 33.1 and 32.8% at the Ag and BHF sites, respectively. Semi-variogram analyses results suggest historic forest removal and cultivation of the Ag site facilitated the development of strong VWC spatial dependency. SGW temperature range at the Ag site was 72% greater than at the BHF site. BHF groundwater contained significantly (p less than 0.05) higher concentrations of nutrients, while Ag groundwater was characterized by significantly (p less than 0.05) higher concentrations of trace elements. Collective results highlight the greater extent to which BHF vegetation impacts subsurface hydrology, relative to grassland/agricultural systems, and point to the value of reestablishing floodplain forests for freshwater routing, water quality, aquatic ecosystem conservation, and flood mitigation in mixed-land-use watersheds.


1989 ◽  
Vol 154 (6) ◽  
pp. 775-782 ◽  
Author(s):  
Liz Kuipers ◽  
Brigid MacCarthy ◽  
Jane Hurry ◽  
Rod Harper ◽  
Alain LeSage

A psychosocial intervention is described geared to the needs of carers of the long-term mentally ill, which is feasible for a busy clinical team to implement: relatives were not selected for the group by patient diagnosis or motivation and little extra staff input was required. An interactive education session at home was followed by a monthly relatives group which aimed to reduce components of expressed emotion (EE) and to alleviate burden. The group facilitators adopted a directive but non-judgemental style, and constructive coping efforts were encouraged. The intervention was effective at reducing EE and improving family relationships. The study offers a realistic model of how to offer support to people providing long-term care for the severely mentally ill.


2020 ◽  
Vol 287 (1928) ◽  
pp. 20200538
Author(s):  
Warren S. D. Tennant ◽  
Mike J. Tildesley ◽  
Simon E. F. Spencer ◽  
Matt J. Keeling

Plague, caused by Yersinia pestis infection, continues to threaten low- and middle-income countries throughout the world. The complex interactions between rodents and fleas with their respective environments challenge our understanding of human plague epidemiology. Historical long-term datasets of reported plague cases offer a unique opportunity to elucidate the effects of climate on plague outbreaks in detail. Here, we analyse monthly plague deaths and climate data from 25 provinces in British India from 1898 to 1949 to generate insights into the influence of temperature, rainfall and humidity on the occurrence, severity and timing of plague outbreaks. We find that moderate relative humidity levels of between 60% and 80% were strongly associated with outbreaks. Using wavelet analysis, we determine that the nationwide spread of plague was driven by changes in humidity, where, on average, a one-month delay in the onset of rising humidity translated into a one-month delay in the timing of plague outbreaks. This work can inform modern spatio-temporal predictive models for the disease and aid in the development of early-warning strategies for the deployment of prophylactic treatments and other control measures.


2019 ◽  
Vol 76 (5) ◽  
pp. 831-846 ◽  
Author(s):  
C.J. Watras ◽  
D. Grande ◽  
A.W. Latzka ◽  
L.S. Tate

Atmospheric deposition is the principal source of mercury (Hg) to remote northern landscapes, but its fate depends on multiple factors and internal feedbacks. Here we document long-term trends and cycles of Hg in the air, precipitation, surface water, and fish of northern Wisconsin that span the past three decades, and we investigate relationships to atmospheric processes and other variables, especially the regional water cycle. Consistent with declining emission inventories, there was evidence of declining trends in these time series, but the time series for Hg in some lakes and most fish were dominated by a near-decadal oscillation that tracked the regional oscillation of water levels. Concentrations of important solutes (SO4, dissolved organic carbon) and the acid–base status of lake water also tracked water levels in ways that cannot be attributed to simple dilution or concentration. The explanatory mechanism is analogous to the “reservoir effect” wherein littoral sediments are periodically exposed and reflooded, altering the internal cycles of sulfur, carbon, and mercury. These climatically driven, near-decadal oscillations confound short or sparse time series and complicate relationships among Hg emissions, deposition, and bioaccumulation.


1976 ◽  
Vol 16 (74) ◽  
pp. 205-218 ◽  
Author(s):  
Steven M. Hodge

AbstractBore-hole drilling techniques have been used to connect with the subglacial water system of the temperate South Cascade Glacier. The water level in a connecting bore hole probably represents a direct measurement of the basal water pressure over an area at least to m in extent. Fluctuations of up to 40 m in bore-hole water levels occur typically over periods of several days and often peak about 2 d after large changes in water input at the glacier surface. The long-term trend in bore-hole water levels supports the idea of seasonal storage and release of liquid water.


2013 ◽  
Vol 17 (4) ◽  
pp. 1379-1391 ◽  
Author(s):  
A. H. Aubert ◽  
C. Gascuel-Odoux ◽  
G. Gruau ◽  
N. Akkal ◽  
M. Faucheux ◽  
...  

Abstract. High-frequency, long-term and multisolute measurements are required to assess the impact of human pressures on water quality due to (i) the high temporal and spatial variability of climate and human activity and (ii) the fact that chemical solutes combine short- and long-term dynamics. Such data series are scarce. This study, based on an original and unpublished time series from the Kervidy-Naizin headwater catchment (Brittany, France), aims to determine solute transfer processes and dynamics that characterise this strongly human-impacted catchment. The Kervidy-Naizin catchment is a temperate, intensive agricultural catchment, hydrologically controlled by shallow groundwater. Over 10 yr, five solutes (nitrate, sulphate, chloride, and dissolved organic and inorganic carbon) were monitored daily at the catchment outlet and roughly every four months in the shallow groundwater. The concentrations of all five solutes showed seasonal variations but the patterns of the variations differed from one solute to another. Nitrate and chloride exhibit rather smooth variations. In contrast, sulphate as well as organic and inorganic carbon is dominated by flood flushes. The observed nitrate and chloride patterns are typical of an intensive agricultural catchment hydrologically controlled by shallow groundwater. Nitrate and chloride originating mainly from organic fertilisers accumulated over several years in the shallow groundwater. They are seasonally exported when upland groundwater connects with the stream during the wet season. Conversely, sulphate as well as organic and inorganic carbon patterns are not specific to agricultural catchments. These solutes do not come from fertilisers and do not accumulate in soil or shallow groundwater; instead, they are biogeochemically produced in the catchment. The results allowed development of a generic classification system based on the specific temporal patterns and source locations of each solute. It also considers the stocking period and the dominant process that limits transport to the stream, i.e. the connectivity of the stocking compartment. This mechanistic classification can be applied to any chemical solute to help assess its origin, storage or production location and transfer mechanism in similar catchments.


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