Experiments and Modeling of Infiltration and Recharge in Sand Dunes With Application to Ash Sharqiya High Sands, Sultanate of Oman

Project: Other project

Project Details

Description

SUMMARY Hydrology of soil and vadose zone of Ash Sharqiya Sands, Oman, will be investigated as a conduit of precipitated water to the subjacent system of two aquifers (aeolinite and alluvial) as a natural recharge on the water table whose depth is ranging from meters to tens of meters. Topographically, the area consists of dune lines that causes no-ponding post-rain infiltration on the crests of the dunes and their slopes having coarser sand and temporary shallow ponding in the interdunal indentations of finer beds. The vertical stratification of the topsoil and vadose zone as well as horizontal heterogeneity of hydraulic properties (permeability and porosity) and capillarity will be described and experimentally studied for understanding the topology of water fluxes and heat transfer. The biocrust in the topographic depressions will be examined both in situ and in microscopic studies of pore space and microstructure. Capillary barriers caused by macro-, and micro-layering impede propagation of infiltration pulses and reduce or delay groundwater recharge as compared with allegedly homogeneous sand massifs of the vadose zone. Evaporation and redistribution of moisture in layered porous media will be investigated both analytically (using the Green-Ampt, Gardner and J.R.Philip models) and numerically (by HYDRUS). Field experiments (in particular, infiltration tests) and laboratory permeametry and infiltration-evaporation laboratory experiments in heterogeneous soil columns repacked with soil-sediments collected in the field will be used for calibration of the models. The obtained vadose zone inputs for recharge will be used in groundwater flow models (MODFLOW) with calibration of the recharge parameters against available piezometric data from the existing boreholes? hydrographs. Upscaling to water resources management of the area adjacent to Wadi Batha and applications to management of soil water in tilled, mulched or crusted crop fields will be done.

Layman's description

SUMMARY Hydrology of soil and vadose zone of Ash Sharqiya Sands, Oman, will be investigated as a conduit of precipitated water to the subjacent system of two aquifers (aeolinite and alluvial) as a natural recharge on the water table whose depth is ranging from meters to tens of meters. Topographically, the area consists of dune lines that causes no-ponding post-rain infiltration on the crests of the dunes and their slopes having coarser sand and temporary shallow ponding in the interdunal indentations of finer beds. The vertical stratification of the topsoil and vadose zone as well as horizontal heterogeneity of hydraulic properties (permeability and porosity) and capillarity will be described and experimentally studied for understanding the topology of water fluxes and heat transfer. The biocrust in the topographic depressions will be examined both in situ and in microscopic studies of pore space and microstructure. Capillary barriers caused by macro-, and micro-layering impede propagation of infiltration pulses and reduce or delay groundwater recharge as compared with allegedly homogeneous sand massifs of the vadose zone. Evaporation and redistribution of moisture in layered porous media will be investigated both analytically (using the Green-Ampt, Gardner and J.R.Philip models) and numerically (by HYDRUS). Field experiments (in particular, infiltration tests) and laboratory permeametry and infiltration-evaporation laboratory experiments in heterogeneous soil columns repacked with soil-sediments collected in the field will be used for calibration of the models. The obtained vadose zone inputs for recharge will be used in groundwater flow models (MODFLOW) with calibration of the recharge parameters against available piezometric data from the existing boreholes? hydrographs. Upscaling to water resources management of the area adjacent to Wadi Batha and applications to management of soil water in tilled, mulched or crusted crop fields will be done.
AcronymTTotP
StatusNot started

Keywords

  • infiltration
  • evaporation
  • recharge
  • water table
  • stratified vadose zone

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