Schwartz,M.O.(2006): Numerical modelling
of groundwater vulnerability: the example Namibia. Environ.Geol.,
50, 237-249.
『地下水の脆弱性の数値モデル:ナミビアの例』
『Abstract
The UNSAT-H, HELP3 and MACRO4.3 computer codes, which have been
developed for simulating the water balance of the unsaturated
zone of soils and unconsolidated sediments, are also capable simulating
water flow in low-porosity media such as fractured rock. The codes
can be used to model the ability of rocks and overlying soils
in the vadose zone to protect the groundwater in the uppermost
aquifer. The net infiltration rates simulated by the different
codes are compared against recharge determined by the chloride-balance
method in Namibia. The dual-permeability code MACRO4.3 was found
to produce more realistic estimates of net infiltration than the
UNSAT-H and HELP3 codes, which are based on a single-permeability
or effective-continuum method. The net infiltration rate together
with the water storage in the unsaturated zone and the groundwater
depth are used to calculate the residence time of pore water in
the unsaturated zone. This parameter determines the intrinsic
vulnerability of the aquifer.
Keywords: Groundwater vulnerability; Physically based model; Numerical
model; Namibia』
Introduction
Code descriptions
UNSAT-H
HELP3
MACRO4.3
Data input for water-balance models
Climatological data
Vegetative data
Hydraulic properties of lithological units
Hydraulic properties of soils
Water balance simulation
Mapping
Recommendations and conclusions
Acknowledgements
References
- MACRO4.3 (dual-permeability model; Jarvis 2002; Merdun
and Quisenberry 2004)
- RZWQM98 (dual-permeability model; Ma et al. 2000)
- HYDRUS-1D (dual-porosity and dual-permeasbility model;
Simunek et al. 2003, 2005; Castiglione et al. 2003)
- LEACHM with the CALF subroutine (functional
model; Hutson 2003; Nolan et al. 2005)
- UNSATH-H (Version 3.01; Fayer 2000)
- HELP3 (Version 3.07; Schroeder et al. 1994)
- Castiglione,P., Mohanty,B.P., Shouse,P.J., Simunek,J., van
Genuchten,M.T. and Santini,A.(2003): Lateral water diffusion
in an artificial macroporous system. Vadose Zone J.,
2, 212-221.
- Civita,M. and De Maio,M.(2004): Assessing and mapping
groundwater vulnerability to contamination: the Italian “combined”
approach. Geofisica Int., 43, 513-532.
- Dash,Z.V.(2003): Software users manual (UM) for the
FEHM application, version 2.21. Los Alamos National Laboratory,
http://www.ees5-www.lanl.gov/EES5/fehm/fehm_mms.pdf (accesssed
on 2 November 2005).
⇒http://www.ees5.lanl.gov/fehm/fehm_um.pdf
- FAO(2003): Soil and terrain database for southern Africa
1:2,000,000 (CD-ROM).
- Fayer,M.J.(2000): UNSAT-H version 3.0: unsaturated
soil water and heat flow model - theory, user manual, and examples.
U.S. Department of Energy, Oak Brridge, USA, various paginations.
- Gogu,R.C. and Dassargues,A.(2000): Current trends and
future challenges in groundwater vulnerability assessment using
overlay and index methods. Environ. Geol., 39,
549-559.
- Gogu,R.C., Hallet,V. and Dassargues,A.(2003): Comparison
of aquifer vulnerability assessment techniques. Application to
the Neblon(eの頭に´) river basin (Belgium).
Environ. Geol., 44, 881-892.
- Hutson,J.L.(2003): LEACHM model description and user's
guide. School of Chemistry, Physics and Earth Sciences,
Flinders University of South Austraria, p.142.
- Jarvis,N.(2002): The MACRO model (version 4.3) technical
description. Swedish University of Agricultural Sciences
(SLU), Department of Soil Sciences, Uppsala, p.37.
- Ma,L., Ahuja,L.R., Ascough,J.C., Shaffer,M.J., Rojas,K.W.,
Malone,R.W. and Cameira,M.R.(2000): Integrating system modeling
with field research in agriculture: application of the root zone
water quality model (RZWQM). Adv. Agron., 71,
233-292.
- Margane,A.(2003): Guideline for groundwater vulnerability
mapping and risk assessment for the susceptibility of groundwater
resources to contamination. Bundesanstalt fur Geowissen
schaften und Rohstoffe (Hannover, Germany). Archive no. 0122917.
http://www.bgr.bund.de/cln_030/nn_454716/EN/Themen/Wasser (accessed
on 1 November 2005).
⇒http://www.bgr.bund.de/nn_670772/EN/Themen/Wasser/Projekte/TZ/TZ__Acsad/Vol__4__fb.html
- Merdun,H. and Quisenberry,V.L.(2004): Simulation of water
and solute transport with MACRO model in Cecil loamy sand soil.
Aust. J. Soil Res., 42, 939-951.
- Nolan,B.T., Bayless,E.R., Green,C.T., Garg,S., Voss,F.D.,
Lampe,D.C., arbasch,J.E., Capel,P.D. and Bekins,B.A.(2005): Evaluation
for unsaturated-zone solute-transport models for studies of agricultural
chemicals. U.S. Geological Survey open-file report 2005-1196,
p.16.
- Pruess(1991): TOUGH2 - a general purpose numerical
simulator for multiphase fluid and heat flow. Lawrence
Berkeley Laboratory, University of California, Earth Science
Division, p.120.
- Scanlon,B.R., Christman,M., Reedy,R.C., Porro,I., Simunek,J.
and Flerchinger,G.N.(2002): Intercode comparisons for simulating
water balance of surfacial sediments in semiarid regions.
Water Resour. Res., 38, 59-1 - 59-16.
- Schroeder,P.R., Dozier,T.S., Zappi,P.A., McEnroe,B.M., Sjostrom,J.W.
and Peyton,R.L.(1994): The hydrologic evaluation of landfill
performance (HELP) model - engineering documentation for version
3. Risk Reduction Engineering Laboratory Office of Research
and Development, U.S. Environmental Protection Agency, Cincinnati,
USA, P.116.
- Simunek,J., Jarvis,N.J., van Genuchten,M.T. and Gardenas(両方のaの頭に¨),A.(2003): Review and comparison
of models for describing non-equilibrium and preferential flow
and transport in the vadose zone. J. Hydrol., 272,
14-35.
- Simunek,J., Sejna,M. and van Genuchten,M.T.(2005): The
HYDRUS-1D software package for simulating the one-dimensional
movement of water, heat, and multiple solutes in variably-saturated
media, Version 3.0. Department of Environmental Sciences,
University of California Riverside, Riverside, USA, p.240.
- van Wyk,A.E., Strub,H. and Struckmeier,W.F.(2001): Hydrogeological
map of Namibia 1:1,000,000. Namibia Department of water
Affairs, Namibia Geological Survey, Windhoek.
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