Topic
Vadose zone
About: Vadose zone is a research topic. Over the lifetime, 5781 publications have been published within this topic receiving 130825 citations. The topic is also known as: unsaturated zone.
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11 May 2007
TL;DR: In this paper, the authors used a vadose zone model, such as SESOIL, to predict contamination potential beneath infiltration devices with both engineered and non-engineered methods.
Abstract: Stormwater managers use infiltration to promote groundwater recharge in urban areas and to reduce the volume and flow rate of stormwater runoff created by post development conditions. However, the potential for groundwater contamination exists. Studies have shown that some areas are more prone to groundwater contamination than others. As a result, methods for easily predicting contamination potential beneath infiltration devices are being developed. One such method involves the use of computer programs, such as SESOIL – a one-dimensional vadose zone model. SESOIL was selected because of the multitude of processes available in the program for predicting pollutant removal. SESOIL was first evaluated using a full factorial design, considering six potential factors that were thought to influence the predictions (rainfall, concentration, vadose zone thickness, intrinsic permeability, soil pH, and soil organic matter. The results showed that, at the concentrations typical of urban stormwater runoff, only rainfall, concentration and intrinsic permeability were important. Difficulties of application were encountered due to a lack of available input values and data sets. Therefore, laboratory research on partitioning factors between the water and the soil were undertaken. The results showed that the partitioning coefficients calculated from the removal of pollutants from a multicomponent mix at typical stormwater concentrations were similar to the low range found in the literature. However, the literature did not have values for sparingly-sorbable compounds such as the nutrients. This research is using a vadose zone model, such as SESOIL which incorporates these numerous chemical reactions in the calculations, as a design tool for infiltration devices with both engineered and
01 Sep 2016
TL;DR: An integrated approach to natural vulnerability analysis of groundwater has been presented in this article, where the authors suggest a combination of three most common methods, i.e., water table, head and water table levels, absorption capacity of soils and clay rocks.
Abstract: Groundwater quality is possible to provide under the condition of aquifers effective protection from surface contamination and bottom pollution prevention in the areas of intense oil-gas production operations. Qualitative and quantitative assessment of groundwater vulnerability is based on regional characteristics of lithological composition and thickness of impermeable deposits in unsaturated zone and overlying deposits. The correlation of head and water table levels, absorption capacity of soils and clay rocks are also considered. An integrated approach to natural vulnerability analysis of groundwater has been presented. It suggests a combination of three most common methods. Based on performed calculations, the map has been made to plot fresh groundwater vulnerability of Atlym-Novomikhailovsk aquifer system (Nizhnevaryovsk Region, Khanty-Mansiysk Autonomus Okrug).
Journal Article•
TL;DR: In this article, the authors used the Ensemble Kalman Filter (EKF) data assimilation framework to improve the performance of the Netherlands Hydrological Model LHM and developed an accurate system for real-time groundwater simulations and forecasts.
Abstract: To support robust water management, water managers should have access to up-to-date information about their water system. For example, Dutch regional water authorities are interested in temporally and spatially distributed groundwater level information. The Netherlands Hydrological Model LHM is often used for retrieving such information on several spatial scales in the Netherlands (De Lange et al., 2014). LHM is a physically-based distributed integrated hydrological model for simulating surface water, unsaturated zone and saturated zone dynamics. However, a validation of saturated zone simulations shows that, on a local to regional scale, deviations occur between observations and simulations of groundwater levels. The availability of high-resolution remotely sensed hydrological information has led to new possibilities for hydrological model improvements. Assimilating soil moisture information can improve both unsaturated and saturated zone simulations (Camporese et al., 2009; Zhang et al., 2016). Recently, a fine-resolution surface soil moisture product based on the freely available Sentinel-1 imagery has been developed. We use this new soil moisture information in combination with an Ensemble Kalman Filter to improve groundwater simulations of the LHM and to develop an accurate system for real-time groundwater simulations and forecasts. The open-source data assimilation framework OpenDA is used to implement the filter technique. The Twente region in the Netherlands serves as a case study. The availability of in-situ soil moisture and groundwater level measurement networks enables validation of the results. The results of this study show the potential of using high-resolution Sentinel-1 satellite imagery for water management. Water managers can use this knowledge to improve forecasts of groundwater levels and to estimate effects of control measures. Furthermore, water managers can use the results to explore the use of soil moisture information for water management. References Camporese, M., Paniconi, C., Putti, M., & Salandin, P. (2009). Ensemble Kalman filter data assimilation for a process-based catchment scale model of surface and subsurface flow. Water Resources Research, 45(10). doi:10.1029/2008wr007031. De Lange, W. J., Prinsen, G. F., Hoogewoud, J. C., Veldhuizen, A. A., Verkaik, J., Oude Essink, G. H. P., van Walsum,P.E.V.,Delsman,J.R.,Hunink,J.C.,Massop,H.T.L.,&Kroon,T.(2014).Anoperational,multi-scale, multi-model system for consensus-based, integrated water management and policy analysis: The Netherlands Hydrological Instrument. Environmental Modelling & Software, 59, 98-108. doi:10.1016/j.envsoft.2014.05.009. Zhang, D., Madsen, H., Ridler, M. E., Kidmose, J., Jensen, K. H., & Refsgaard, J. C. (2016). Multivariate hydrological data assimilation of soil moisture and groundwater head. Hydrology and Earth System Sciences,
TL;DR: In this article, the authors investigated the impact of proposed repository thermalloading on mountain-scale flow and heat transfer in the unsaturated fractured rock of Yucca Mountain, Nevada, and developed a coupled thermal-hydrological (TH) processes at the scale of the entire Yucca mountain.
Abstract: This paper investigates the impact of proposed repository thermal-loading on mountain-scale flow and heat transfer in the unsaturated fractured rock of Yucca Mountain, Nevada. In this context, a model has been developed to study the coupled thermal-hydrological (TH) processes at the scale of the entire Yucca Mountain. This mountain-scale TH model implements the current geological framework and hydrogeological conceptual models, and incorporates the latest rock thermal and hydrological properties. The TH model consists of a two-dimensional north-south vertical cross section across the entire unsaturated zone model domain and uses refined meshes near and around the proposed repository block, based on the current repository design, drift layout, thermal loading scenario, and estimated current and future climatic conditions. The model simulations provide insights into thermally affected liquid saturation, gas- and liquid-phase fluxes, and elevated water and rock temperature, which in turn allow modelers to predict the changes in water flux driven by evaporation/condensation processes, and drainage between drifts.
01 Jan 2021
TL;DR: In this article, a technique is proposed for evaluating the protective capacity of unconfined aquifers by using a geoelectrical parameter viz. total longitudinal conductance of the unsaturated vadose zone overlying the aquifer.
Abstract: In this work, a technique is proposed for evaluating the protective capacity of unconfined aquifers by using a geoelectrical parameter viz. total longitudinal conductance of the unsaturated vadose zone overlying the aquifer. The approach has been tested in Saharanpur town of Uttar Pradesh, India, from available data of electrical resistivity soundings. Interpretation of the resistivity soundings yielded data of total longitudinal conductance of the unsaturated sedimentary overburden (vadose zone) which ranged between 0.03 and 0.74 mho. The perusal of the total longitudinal conductance map of the area and its comparison with a potentially hazardous activities map of the area was found to match quite well indicating the effectiveness of the technique in finding degree of protection of the unconfined aquifer vis a vis the hazardous chemicals percolating downwards with the infiltrating runoff in the area. This approach when used in combination with groundwater vulnerability estimates can prove to be of considerable help in planning groundwater protection and governance issues in alluvial and coastal areas of the country.