scholarly journals Modelling the Effect of Efficiency Measures and Increased Irrigation Development on Groundwater Recharge through a Deep Vadose Zone

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 936 ◽  
Author(s):  
Glen R. Walker ◽  
Dougal Currie ◽  
Tony Smith
Keyword(s):  
Numerical Model ◽  
Vadose Zone ◽  
Time Delays ◽  
Total Change ◽  
Initial Development ◽  
Irrigation Development ◽  
Soil Layers ◽  
Efficiency Measures ◽  
Water Tables ◽  
Individual Actions

Water use measures are being implemented in irrigation areas to make better use of limited water resources and reduce adverse environmental impacts. A semi-analytical model is developed and tested with a numerical model to estimate changes in timing and magnitude of recharge from such measures in irrigation areas to support management of impacts, especially for areas with deep vadose zones and perched water tables. Low hydraulic conductivity of soil layers will lengthen time delays between actions and changes to recharge in addition to limiting the maximum recharge. Despite variations in detailed processes, the recharge outputs from models are surprisingly similar, irrespective of whether lateral effects are major. Superposition may be used to simplify the modelling of the total change in recharge from successive actions, including the initial development. Further simplification is possible, using an exponential conceptual model to approximate recharge responses to individual actions.

Impact of Sustainable Urban Drainage Systems (SUDS) on Vadose Zone Water

2020 ◽  
Author(s):  
Arne Reck ◽  
Eva Paton ◽  
Björn Kluge
Keyword(s):  
Trace Metal ◽  
Vadose Zone ◽  
Natural Water ◽  
Water Cycle ◽  
Stormwater Runoff ◽  
Urban Drainage ◽  
Soil Layers ◽  
Term Operation ◽  
Metal Contents

<p>Sustainable Urban Drainage System (SUDS), like bioretention for stormwater runoff infiltration, offer several advantages compared to the traditional centralised sewage drainage. Such approaches maintain the natural water cycle in the urban critical zone and help to mitigate climatic extremes impact on urban areas by retarding, storing and evaporating stormwater runoff. Although SUDS are established since longer time (>25 years for example in Germany) we lack systematic investigations on the hydrological functionality and pollutant retention performance of these systems after long-term operation. We employed laboratory and field experiments coupled with numerical simulations to investigate three long-term operated bioretention systems in Germany with following objectives: (i) a detailed mapping of spatial contamination patterns; (ii) a soil hydrological and -chemical substrate characterisation; (iii) an event-based influent and effluent trace metal concentrations monitoring covering 36 months in total; and (iv) a soil water balance simulation using HYDRUS-1D. Regarding the pollution patterns, we found significantly enhanced trace metal contents in the soil substrate mainly as a function of the drainage area type and kind of inflow regime. Nonetheless, average free metal ion concentrations in the soil seepage water extracted below the upper soil layers (30-45 cm) fall below German trigger values considering the soil-groundwater pathway at all three investigated sites. Compared to influent concentrations, average load reduction of the major pollutants Cu and Zn was 55-95 % within the upper soil layers. With regard to infiltrated runoff volumes, simulated water balances revealed hydraulic load reductions of 10-40 % by evapotranspiration. Our current findings demonstrate no risk of groundwater degradation suggesting bioretention as a powerful tool in terms of maintaining the natural water cycle in the urban vadose zone even after long-term operation. Debatable might be the handling of soil substrates modified by stormwater infiltration showing enhanced trace metal contents and a certain amount of technogenic sediments like tyre wear. On the one hand, a big metal pool is specifically bound meaning it can easily turn into free ions during changing conditions like the application of de-icing agents. On the other hand, these substrates perfectly fulfil pollutant retention and water conductivity requirements as mandatory for an effective stormwater treatment using SUDS approaches.</p>

scholarly journals Changes of soil salinity and ground waters at the rice systems in Sivash lowland after irrigation cease

2020 ◽  
pp. 70-102
Author(s):  
N. B. Khitrov ◽  
L. V. Rogovneva ◽  
V. S. Pashtetskiy
Keyword(s):  
Ground Water ◽  
Water Table ◽  
Vadose Zone ◽  
Soil Salinity ◽  
Soil Cover ◽  
Chloride Ion ◽  
Ground Water Table ◽  
Water Tables ◽  
Ion Activity ◽  
Increasing Trend

The aim of the article is to submit data about ground water table and soil salinity of the rice irrigated systems at the Sivash seashore in Nyzhnegorsky district of Crimea in 2017–2018 which is 4–5 years from irrigation cease. It was found that many soil cover patterns with salt-affected solonetz at the rice system were leached from salts to the depth about 3–3.5 m by flooding irrigation during half a century. In 2017–2018 ground water tables were deeper than the critical depth. Ground water mineralization is characterized by mosaic spatial distribution, varying from 1.9 to 7.4 g/l with a tendency to growth as ground water depth increases. Depression funnel of ground water table was formed at the seashore. The bottom water drive is up to 0.8–1.6 m relatively sea level. The first symptoms of the salinity returning in grounds of vadose zone were found: (1) appearance of calcium and magnesium chlorides in pore solutions of formally no saline or weakly saline horizons; (2) increasing trend of sodium and chloride ion activity measured in pastes with moisture 50% (w) at the dynamic plots in 2018 as compared with 2017; (3) frequency of grounds with clustered gypsum crystals is increased.

scholarly journals Remediation of Artificially Hydrocarbon Polluted Vadose Zone Soil in Glass Column through Percolation with Solution of Nutrient, Nutrient-Surfactant or Surfactant

2020 ◽  
Vol 24 (6) ◽  
pp. 997-1008
Author(s):  
P.L. Peekate ◽  
J.L. Konne ◽  
T.K.S. Abam
Keyword(s):  
Vadose Zone ◽  
Petroleum Hydrocarbons ◽  
Anaerobic Bacteria ◽  
Surfactant Solution ◽  
Soil Layers ◽  
Start Up ◽  
Glass Column ◽  
Glass Columns ◽  
Microbial Groups ◽  
Hydrocarbon Utilizing Bacteria

Remediation of hydrocarbon polluted vadose zone (HPVZ) through percolation with solution of nutrient, nutrient-surfactant, or surfactant in glass columns was investigated in this study using standard methods. Percolated liquids from the columns and soils retrieved at the end of the  experiment were analyzed for nitrate, phosphate, sulphate, total-petroleum hydrocarbon, and selected microbial groups. Results obtained showed that there were nitrate, phosphate, and sulphate in the percolated liquids. Cumulative hydrocarbon in the percolated liquids was 5.35 – 7.59 % of cumulative hydrocarbon start-up concentration in the columns. Cumulative hydrocarbon attenuation across soil layers in column flooded with solution of nutrients (column NT), nutrient-surfactant (column NTS), and surfactant (column SF) were 89.29, 95.27, and 66.92 % respectively. There was more phosphate reduction in column NTS, and more sulphate reduction in column NT. Hydrocarbon-utilizing fungi in columns NT and NTSincreased from 3.5 Log10 CFU.g-1 to between 4.0 – 5.0 Log10 CFU.g-1, whereas a decrease was observed for column SF. Hydrocarbon-utilizing bacteria in all the columns increased from between 1.0 – 2.5 Log10 CFU.g-1 to between 2.0 - 3.5 Log10 CFU.g-1. Emergence of hydrocarbon utilization among anaerobic bacteria population was also observed in all the columns. It is concludedthat percolation with nutrient-surfactant  solution will be more effective in remediation of HPVZ, and that consequential migration of nutrients alongside hydrocarbons into groundwater canaid in enhancing biodegradation of the infiltrated hydrocarbons. Keywords: Biodegradation; petroleum hydrocarbons; vadose zone; inorganic nutrients; surfactant

scholarly journals Modelling Recharge from Irrigation Developments with a Perched Water Table and Deep Unsaturated Zone

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 944 ◽  
Author(s):  
Glen R. Walker ◽  
Dougal Currie ◽  
Tony Smith
Keyword(s):  
Vadose Zone ◽  
Numerical Models ◽  
Environmental Risks ◽  
Time Lags ◽  
New Developments ◽  
Perched Water ◽  
Perched Water Table ◽  
Water Tables ◽  
Temporal And Spatial ◽  
Parameter Ranges

Modelling of recharge under irrigation zones for input to groundwater modelling is important for assessment and management of environmental risks. Deep vadose zones, when coupled with perched water tables, affect the timing and magnitude of recharge. Despite the temporal and spatial complexities of irrigation areas; recharge in response to new developments can be modelled semi-analytically, with most outputs comparing well with numerical models. For parameter ranges relevant to the western Murray Basin in southern Australia, perching can reduce the magnitude of recharge relative to irrigation accessions and will cause significant time lags for changes to move through vadose zone. Recharge in the vicinity of existing developments was found to be similar to that far from existing developments. This allows superposition to be implemented spatially for new developments, thus simplifying estimation of recharge. Simplification is further aided by the use of exponential approximants for recharge responses from individual developments.

scholarly journals In-Situ Monitoring and Characteristic Analysis of Freezing-Thawing Cycles in a Deep Vadose Zone

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1261
Author(s):  
Ce Zheng ◽  
Yudong Lu ◽  
Xiuhua Liu ◽  
Jiří Šimůnek ◽  
Yijian Zeng ◽  
...  
Keyword(s):  
Soil Temperature ◽  
Water Content ◽  
Vadose Zone ◽  
In Situ Monitoring ◽  
Characteristic Analysis ◽  
Soil Layers ◽  
Vapor Flux ◽  
Freeze Thaw ◽  
Soil Temperature And Moisture

Freeze-thaw cycles play a critical role in affecting ecosystem services in arid regions. Monitoring studies of soil temperature and moisture during a freeze-thaw process can generate data for research on the coupled movement of water, vapor, and heat during the freezing-thawing period which can, in turn, provide theoretical guidance for rational irrigation practices and ecological protection. In this study, the soil temperature and moisture changes in the deep vadose zone were observed by in-situ monitoring from November 2017 to March 2018 in the Mu Us Desert. The results showed that changes in soil temperatures and temperature gradients were largest in soil layers above the 100-cm depth, and variations decreased with soil depth. The relationship between soil temperature and unfrozen water content can be depicted well by both theoretical and empirical models. Due to gradients of the matric potential and temperature, soil water flowed from deeper soil layers towards the frozen soil, increasing the total water content at the freezing front. The vapor flux, which was affected mainly by temperature, showed diurnal variations in the shallow 20-cm soil layer, and its rate and variations decreased gradually with increasing soil depths. The freeze-thaw process can be divided into three stages: the initial freezing stage, the downward freezing stage, and the thawing stage. The upward vapor flux contributed to the formation of the frozen layer during the freezing process.

scholarly journals Modelling Groundwater Returns to Streams From Irrigation Areas with Perched Water Tables

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 956 ◽  
Author(s):  
Dougal Currie ◽  
Tariq Laattoe ◽  
Glen Walker ◽  
Juliette Woods ◽  
Tony Smith ◽  
...  
Keyword(s):  
Surface Water ◽  
Vadose Zone ◽  
Transfer Functions ◽  
Root Zone ◽  
Integrated Modelling ◽  
Perched Water ◽  
Modelling Method ◽  
Murray River ◽  
Water Tables

Quantifying the magnitude and timing of groundwater returns to streams from irrigation is important for the management of natural resources in irrigation districts where the quantity or quality of surface water can be affected. Deep vadose zones and perched water tables can complicate the modelling of these fluxes, and model outputs may be biased if these factors are misrepresented or ignored. This study was undertaken in the Murray Basin in southern Australia to develop and test an integrated modelling method that links irrigation activity to surface water impacts by accounting for all key hydrological processes, including perching and vadose zone transmission. The method incorporates an agronomic water balance to simulate root zone processes, semi-analytical transfer functions to simulate the deeper vadose zone, and an existing numerical groundwater model to simulate irrigation returns to the Murray River and inform the management of river salinity. The integrated modelling can be calibrated by various means, depending on context, and has been shown to be beneficial for management purposes without introducing an unnecessary level of complexity to traditional modelling workflows. Its applicability to other irrigation settings is discussed.

Numerical Study of Distribution Characteristics and Influencing Factors on Geo-Temperature Field of Groundwater Heat Pump

2011 ◽  
Vol 320 ◽  
pp. 536-541 ◽  
Author(s):  
Su Fen Li ◽  
Shi Yao Liu ◽  
Yan Shang ◽  
Guo Fu Du
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Numerical Model ◽  
Influencing Factors ◽  
Heat Pump ◽  
Numerical Study ◽  
Distribution Characteristics ◽  
Soil Layers ◽  
Groundwater Heat Pump

A 3-D numerical model was developed to simulate the distribution characteristics and influencing factors on geo-temperature field of groundwater heat pump. Analyzing from different soil layers, different permeability, different porosity, different inter-well distances, and different aquifer thickness, temperature distribution characteristics and variations of pumping temperature were gotten. Base on those, permeability and different porosity produce little effect to the temperature of pumping, different inter-well distances and different aquifer thickness produce great effect to the temperature of pumping.

Measurement and estimation of capillary upflow from water tables under maize on irrigated soils

Soil Research ◽  
1993 ◽  
Vol 31 (2) ◽  
pp. 119 ◽  
Author(s):  
SA Prathapar ◽  
WS Meyer
Keyword(s):  
Environmental Factors ◽  
Root Length ◽  
Root Length Density ◽  
Stepwise Multiple Regression ◽  
Clay Loam ◽  
Soil Layers ◽  
Water Tables ◽  
L1 And L2 ◽  
Combined Data ◽  
Irrigated Soils

An experiment with maize on two soils in lysimeters L1 and L2 (Hanwood clay loam and Mundiwa clay loam respectively) was conducted to measure daily capillary upflow and to establish a relationship between capillary upflow and significant soil, watertable, crop and environmental factors. Total evapotranspiration from L1 and L2 during the season was 748 and 631 mm respectively. Capillary upflow contribution to evapotranspiration in L1 and L2 was 215 (29%) and 101 (16%) mm respectively. Daily capillary upflow ranged from 0 to 5 mm day-1 in the Hanwood clay loam and 0 to 2 mm day-1 in the Mundiwa clay loam during the experiment. Measured daily capillary upflow was significantly (P < 0.001) different between the two soils studied. A stepwise multiple regression, by using the combined data from L1 and L2, showed that the depth to the watertable, water content of the soil layers at 0.1 and 0.4 m and root length density Lv at 0.65 m significantly influenced capillary upflow (n = 68, R2 = 0.79, P < 0.05) in both soils.

Combining subsurface drainage and windbreaks to control dryland salinity

2006 ◽  
Vol 86 (3) ◽  
pp. 555-563
Author(s):  
H. Steppuhn
Keyword(s):  
Vadose Zone ◽  
Land Surface ◽  
Root Zone ◽  
Subsurface Drainage ◽  
Water Levels ◽  
Blowing Snow ◽  
Dryland Salinity ◽  
Water Tables ◽  
The Mean ◽  
A Site

The reclamation of salinized soil involves lowering ground water levels, draining the vadose zone, and leaching the salts from the root zone. Plastic drain tubing placed 1.5 to 1.8 m below the land surface can lower water tables and drain phreatic water, but irrigation is usually required to leach the offending salts. The leaching process in non-irrigated drylands depends on natural precipitation. Rows of tall wheatgrass, Thinopyrum ponticum (Podp.) Lui & Wang, (1.2 m mean height) spaced on 15.2-m centres across saline fields can retain blowing snow, augment water for leaching salts, and moderate evapotranspiration, especially when grown in conjunction with subsurface drainage. The mean salinity of saturated soil paste extracts from sets of soil samples taken every fall from such a site in southwestern Saskatchewan averaged 14.1 dS m-1 during 1985–1990 before the drainage was installed, 13.0 dS m-1 for 1991–1992 after drainage but before the grass windbreaks became established, and 9.6 dS m-1 for 1993–1998 with both drainage and windbreaks in place. Key words: Saline soil, engineered drainage, snow management, grass barriers

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