scholarly journals Study on groundwater recharge assessment by rainfall in coastal district Thai Thuy, Thai Binh province

2021 ◽  
Vol 21 (2) ◽  
pp. 121-132
Author(s):  
Hoang Nguyen Van ◽  
Hoa Pham Lan ◽  
Van Dong Thu ◽  
Dao Le Quang
Keyword(s):  
Groundwater Recharge ◽  
Unsaturated Soils ◽  
Moisture Transfer ◽  
Vital Role ◽  
Soil Types ◽  
Silty Clay ◽  
Hourly Rainfall ◽  
Unsaturated Permeability ◽  
Rainfall Recharge ◽  
Coastal District

Groundwater always plays a vital role in socio-economic development. One of the components of groundwater resource potential is the recharge from rainfall and surface water. The paper presents finite element modeling in the moisture transfer simulation in unsaturated soils through the relationship between soil moisture, soil suction, unsaturated permeability, and moisture dispersion coefficient. Parameters required for moisture transfer in four subsurface soil types have been collected and analyzed: Saturated permeability, porosity and field moisture content. Hourly rainfall data of 2015 have been studied and grouped into different rainfall duration (1-hour, 2-hour,... 36-hour continuous rainfall). The different duration rainfall and temporal infiltration determined by the moisture transfer modeling allow calculating the groundwater recharge from the downpour. We had applied the methodology to coastal district Thai Thuy, Thai Binh province. The results show that during the rainy months from June to October 2015, the groundwater recharge from the rainfall is: Through silty clay 0.233 m, through silt 0.338 m, through sandy silt 0.374 and through silty sands 0.561 m. The rainfall recharge to groundwater through those four soil types in terms of percentage of total 2015 rainfall respectively is 12.85%, 18.65%, 20.63% and 30.95%. The methodology may be applied to other areas with an advantage in the minimal expense of budget and time and relatively high reliable results.

scholarly journals Antioxidant and phytochemical activities of Amaranthus caudatus L. harvested from different soils at various growth stages

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Muhali Olaide Jimoh ◽  
Anthony Jide Afolayan ◽  
Francis Bayo Lewu
Keyword(s):  
Biological Activity ◽  
Biological Activities ◽  
Antioxidant Properties ◽  
Clayey Loam ◽  
Soil Types ◽  
Growth Stages ◽  
Silty Clay ◽  
Clay Loam ◽  
Amaranthus Caudatus ◽  
Different Soils

Abstract This study aimed at profiling the biological activities of Amaranthus caudatus cultivated on different soils in a glasshouse experiment. Five soil types namely; sandy clay loam, silty clay loam, clayey loam, loam and control (unfractionated soil) were experimentally formulated from primary particles of clay, sand and silt following the United State Department of Agriculture’s (USDA) soil triangle technique. After harvesting at pre-flowering (61 days after planting), flowering (71 days after planting) and post-flowering (91 days after planting) stages, crude extracts were obtained with water and ethanol. Total flavonoids, phenolic and proanthocyanidin contents of the extracts, as well as their biological activities, were determined using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), 2,2 diphenyl-1-picrylhydrazyl ethanol (DPPH), nitric oxide and phosphomolybdate assays. It was observed that biological activity of A. caudatus varied with soil types, stages of maturity and solvents of extraction. The highest phytochemical yield was recorded in ethanolic extracts of clayey loam harvested prior to flowering and the same trend was replicated in the antioxidant properties of the plant. For optimal biological activity, it is recommended that clayey loam soil should be used for cultivation of A. caudatus and harvest should be made near flowering to capture high phytochemical yield from the species.

scholarly journals Examination of the estimation of relative permeability for unsaturated soils

2015 ◽  
Vol 52 (12) ◽  
pp. 2077-2087 ◽  
Author(s):  
Feixia Zhang ◽  
D.G. Fredlund
Keyword(s):  
Lower Limit ◽  
Unsaturated Soils ◽  
Integral Formula ◽  
Characteristic Curve ◽  
Soil Conditions ◽  
Mathematical Algorithm ◽  
Soil Systems ◽  
Permeability Function ◽  
Unsaturated Permeability ◽  
Flexible Integration

The unsaturated permeability function is an important soil property function used in the numerical modeling of saturated–unsaturated soil systems. The permeability function is generally predicted by integrating along the soil-water characteristic curve (SWCC) starting at saturated soil conditions. The integration is based on a particular integral formula. The Fredlund–Xing–Huang permeability function is a flexible integration technique used for calculating the unsaturated permeability function. The original permeability theory published by Fredlund, Xing, and Huang in 1994 specified that the air-entry value (AEV), ψaev, be used as the lower limit of the integration when calculating the permeability function. However, as there was no analytical procedure available for the calculation of the AEV on the SWCC, it became common practice to start the integration procedure from a value near zero. The assumption was made that the error associated with starting the integration from an arbitrary low value was minimal. While this might be the case in some situations, the error can be quite substantial in other situations. This paper undertakes a study of the effect of the lower limit of integration on the calculation of the permeability function. Comparisons are made between starting the integration from various values below the AEV and starting the integration from the calculated AEV, ψaev. A mathematical algorithm is also proposed for the calculation of the AEV for integration purposes. The results show that the relative coefficient of permeability can be significantly underestimated when the lower limit of integration is smaller than the AEV. The recommendation is that the AEV always be used as the lower limit of integration in the Fredlund–Xing–Huang permeability equation.

In situ measurements of moisture and salt movement in freezing soils

1986 ◽  
Vol 23 (5) ◽  
pp. 696-704 ◽  
Author(s):  
D. M. Gray ◽  
R. J. Granger
Keyword(s):  
Soil Moisture ◽  
Moisture Transfer ◽  
Freezing Point ◽  
Frozen Soil ◽  
Vapor Flow ◽  
Silty Clay ◽  
Upward Movement ◽  
Silt Loam ◽  
Freezing Front ◽  
Ice Content

The paper presents the results of field studies on the movement of moisture and salts during freezing of Prairie soils. It is shown that large fluxes of water can migrate to the freezing front and move upward into the frozen soil above. The fluxes are largest in light-textured soils (e.g., silt loam) having a water table at shallow depth. However, substantial amounts of soil moisture may also move in silty clay, silty clay loam, and clay soils under dryland farming provided there is sufficient water present to support capillary flow.The dynamics of soil moisture transfer under natural conditions as a result of freezing involves movement of water in both vapor and liquid phases. In the shallow surface layer of soil, to a depth of 300–400 mm, vapor flow predominates; in the depth below, water usually moves primarily as a liquid. It is demonstrated that the accumulation of ice with time increases because of the downward movement of the freezing front and the upward movement of water into the frozen soil above. In a silt loam with large fluxes, the ice content of the frozen zone rapidly reaches a level (80–85% pore saturation) where measurable migration ceases. Conversely, in a silty clay the movement of moisture into the frozen soil is observed to continue throughout most of the freezing period, and the ice content reaches 93% pore saturation. The greater movement in the finer grained soil is attributed to a higher freezing-point depression, a larger number of capillary pores, and a higher concentration of soluble salts in the liquid films.A close association is observed between changes in the ice content and electrical conductivity of a silt loam after freezing. In a silty clay the agreement is less clear, probably the result of the exchange of ions between the migrating liquid water and the clay particles. Maximum amounts of exchangeable ions moving into a 1 m depth of soil by the freezing action are estimated to be 11.9 t/ha in a silt loam and 15.7 t/ha in a silty clay loam.Data showing the redistribution of water and salts during thawing are also presented and discussed.

scholarly journals Estimation of groundwater recharge using multiple climate models in Bayesian frameworks

2021 ◽  
Author(s):  
Kevin O. Achieng ◽  
Jianting Zhu
Keyword(s):  
Groundwater Recharge ◽  
River Basin ◽  
Empirical Bayes ◽  
Climate Models ◽  
Regional Climate ◽  
Regional Climate Models ◽  
Bayesian Framework ◽  
Vital Role ◽  
Bias Error ◽  
Bayesian Priors

Abstract Groundwater recharge plays a vital role in replenishing aquifers, sustaining demand, and reducing adverse effects (e.g. land subsidence). In order to manage climate change-induced effects on groundwater dynamics, climate models are increasingly being used to predict current and future recharges. Even though there has been a number of hydrological studies that have averaged climate models’ predictions in a Bayesian framework, few studies have been related to the groundwater recharge. In this study, groundwater recharge estimates from 10 regional climate models (RCMs) are averaged in 12 different Bayesian frameworks with variations of priors. A recession-curve-displacement method was used to compute recharge from measured streamflow data. Two basins of different sizes located in the same water resource region in the USA, the Cedar River Basin and the Rainy River Basin, are selected to illustrate the approach and conduct quantitative analysis. It has been shown that groundwater recharge prediction is affected by the Bayesian priors. The non-Empirical Bayes g-Local-based Bayesian priors result in posterior inclusion probability values that are consistent with the performance of the climate models outside the Bayesian framework. With the proper choice of priors, the Bayesian frameworks can produce good results of groundwater recharge with R2, percent bias error, and Willmott's index of agreement of >0.97, <2%, and >0.97, respectively, in the two basins. The Bayesian framework with an appropriate prior provides opportunity to estimate recharge from multiple climate models.

Model analysis of observed and predicted climate changes of groundwater recharge in the basin of a small river

2019 ◽  
pp. 78-86
Author(s):  
S. P. Pozdniakov ◽  
S. O. Grinevsky ◽  
E. A. Dediulina ◽  
V. N. Samartsev
Keyword(s):  
Groundwater Recharge ◽  
General Circulation ◽  
Moisture Transfer ◽  
Global Climate ◽  
Weather Conditions ◽  
Small River ◽  
Catchment Basin ◽  
Dryness Index ◽  
Kaluga Region ◽  
The Difference

The analysis of the connection of groundwater recharge in the basin of a small river with the current and expected climatic changes in the European territory of Russia is carried out using the catchment basin of Zhizdra river Kaluga region as an example. The analysis was based on the modeling of the processes of transformation of moisture on the earth surface and moisture transfer in the aeration zone. The results of global climate predictions for five models of the general circulation of the atmosphere and ocean (GCM) from the CMI5 family were applied for the forecast in the second half of the 21st century using the LARSWG5 forecast weather conditions generator. The simulation results show that despite the fact that all the GCM used predict a warming in the region at 2–6 ᵒC, the difference in the predicted recharge is still significantly large, which is associated with the difference in the predicted dryness index.

Effects of Incorporating or Burning Straw, and of Different Cultivation Systems, on Winter Wheat Grown on Two Soil Types, 1985–91

1995 ◽  
Vol 124 (2) ◽  
pp. 173-194 ◽  
Author(s):  
R. D. Prew ◽  
J. E. Ashby ◽  
E. T. G. Bacon ◽  
D. G. Christian ◽  
R. J. Gutteridge ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Sandy Loam ◽  
Disease Incidence ◽  
Soil Types ◽  
Silty Clay ◽  
Clay Loam ◽  
Silty Clay Loam ◽  
Cultivation Systems ◽  
Sharp Eyespot ◽  
Take All

SUMMARYDisposal methods for straw from continuous winter wheat were tested on two soil types, a flinty silty clay loam and a sandy loam, over 7 years (1985–91). The methods tested were burnt or chopped straw in full factorial combination with four cultivation methods (tined to 10 cm, tined to 10 cm then to 20 cm; ploughed to 20 cm; tined to 10 cm then ploughed to 20 cm). Measurements were taken to determine the effects on crop establishment and growth, pest and disease incidence, and the consequent effects on yield. Another experiment (1985–91) on the flinty silty clay loam site, investigated the interactions between straw treatments (burnt, baled or chopped in plots that were all shallow cultivated to 10 cm) and five other factors; namely, time of cultivation, insecticides, molluscicides, fungicides and autumn nitrogen. All the straw x cultivation systems allowed satisfactory crops to be established but repeated incorporation of straw using shallow, non-inversion cultivations resulted in very severe grass-weed problems. Early crop growth, as measured by above-ground dry matter production, was frequently decreased by straw residues, but the effect rarely persisted beyond anthesis. Pests were not a problem and their numbers were not greatly affected either by straw or cultivation treatments, apart from yellow cereal fly which, especially on the heavier soil, was decreased by treatments which left much straw debris on the soil surface. Incorporating straw also caused no serious increases in the incidence of diseases. Indeed, averaged over all sites and years, eyespot and sharp eyespot were both slightly but significantly less severe where straw was incorporated than where it was burnt. Eyespot, and even more consistently sharp eyespot, were often more severe after ploughing than after shallow, non-inversion cultivations. Effects on take-all were complex but straw residues had much smaller effects than cultivations. Initially the disease increased most rapidly in the shallow cultivated plots but these also tended to go into the decline phase more quickly so that in the fourth year (fifth cereal crop) take-all was greater in the ploughed than in the shallow cultivated plots. On average, yields did not differ greatly with straw or cultivation systems, although there were clear effects of take-all in those years when the disease was most severe. In the last 2 years, yields were limited by the presence of grass weeds in the plots testing chopped straw incorporated by tining to 10 cm.

The effects of climate change on groundwater recharge for different soil types of the west shore of Lake Urmia—Iran

2019 ◽  
Vol 12 (8) ◽  
Author(s):  
Seyed Mehdi Esmat Saatloo ◽  
Maaroof Siosemarde ◽  
Seyed Abbas Hosseini ◽  
Hossein Rezaei
Keyword(s):  
Climate Change ◽  
Groundwater Recharge ◽  
Soil Types ◽  
Lake Urmia ◽  
The West

scholarly journals Simplicity versus complexity in modelling groundwater recharge in Chalk catchments

2002 ◽  
Vol 6 (5) ◽  
pp. 927-937 ◽  
Author(s):  
R. B. Bradford ◽  
R. Ragab ◽  
S. M. Crooks ◽  
F. Bouraoui ◽  
E. Peters
Keyword(s):  
Groundwater Recharge ◽  
Input Data ◽  
River Flow ◽  
Climatic Conditions ◽  
Soil Types ◽  
Flow Data ◽  
Catchment Scale ◽  
Distributed Models ◽  
Headwater Catchment ◽  
Simple Models

Abstract. Models of varying complexity are available to provide estimates of recharge in headwater Chalk catchments. Some measure of how estimates vary between different models can help guide the choice of model for a particular application. This paper compares recharge estimates derived from four models employing input data at varying spatial resolutions for a Chalk headwater catchment (River Pang, UK) over a four-year period (1992-1995) that includes a range of climatic conditions. One model was validated against river flow data to provide a measure of their relative performance. Each model gave similar total recharge for the crucial winter recharge period when evaporation is low. However, the simple models produced relatively lower estimates of the summer and early autumn recharge due to the way in which processes governing recharge especially evaporation and infiltration are represented. The relative uniformity of land use, soil types and rainfall across headwater, drift-free Chalk catchments suggests that complex, distributed models offer limited benefits for recharge estimates at the catchment scale compared to simple models. Nonetheless, distributed models would be justified for studies where the pattern and amount of recharge need to be known in greater detail and to provide more reliable estimates of recharge during years with low rainfall. Keywords: Chalk, modelling, groundwater recharge

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