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<br />ELSEVIER
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<br />fl.J. H<JrJ,Y~' aI. I )",m,,,1 of H.,-JroIog,Y 2J6 (/999) lU-fl6
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<br />Journal
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<br />Hydrology
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<br />Juumal"fHyoJrolon11l'>11'l99) 114-136
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<br />The importance of spatial resolution in hydraulic models for
<br />floodplain environments
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<br />R.I. Hardy., P.O. Bates. M.G. Anderson
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<br />Ra'-f"d, C~II(,... fur (",'",,,,mm,,,J ",,,J G~"pi,.\,.k,,1 F/o"-'. S~houl of &".~r"phk"J Sd'lrcn. Un"-,,.;,,!, "f Bri>loJ. U"i,'~,,;(l.' RuuJ.
<br />Brim>lBSSJSS. UK
<br />~c;,-.41' ~by 1998, accopied 18 o"cemb"r 1998
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<br />A). MESH [, THE LOWEST RESOLUTION MESH.
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<br />Ab!itract
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<br />For many numerical modellin,applic3lions the problem of specifying an optimum mesh resolution remains unboundold;md
<br />I'or mesh con~lr\Il;lion objective a priori ruIn do IlOl exist. By contra,,,. W problem of spc:cifyina model parameter swbces is
<br />largely bound.:d within known physical ctror diwibulions. In this paper we thus iaveslisa~ the impact of Vllr)'iDJ mesh
<br />l'eilOlution on a lypico1\ lion-linear ftnilC numcric.1l sol\"er. S~citically. a two-dimensionallinite element code which $0]"':$
<br />tM Shallow Water equations wMltsed to simuhuc un!ileadl' nows ill a meanlierins compound channel. A range of different
<br />m.:sh reiOOlutions and paramcter surfaces were simul3ted to determine rel3tive dominance and. unlike previous studies.lhc
<br />cffo!l:l on both bull.; now and distributed outpUtS were analysed. The results showed a wide \'arlatiOll in performance for mesh
<br />discretizatiom which fulfilled.l(aditiona) ]enflh sca]e-based cORmuction. Mesh resolution effects were alleaSl u import/llll Ma
<br />l)'pical ca]ibrallon parameter and model response WM >hown to be highly complex. 101999 Elsevier Science B.V. AI] rights
<br />resto'cd.
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<br />K~,1'l'(Irds: HydrauUc modellinl: Finite delmlll: Aoodplains: SpOlia! resolutioo
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<br />J. Introduction
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<br />As a resuil of extensive reselllCh into numerical
<br />methods (the Solulion of non-linear partial differential
<br />equations lkrived from the laws of physics) there are
<br />now many readily available codes for simulating the
<br />behaviour of environmental systems. These schemes
<br />originaled largely in the mathematics and engineering
<br />fields but have been rapidly taken up by eanh scien-
<br />tislS a.nd can now be found in a wide mnie of fields
<br />from hydrology (Abboll et aI., 1986) and hydraulics
<br />(Falconer and Chen, I 996;Fl1lconer and Owens, 1990;
<br />King and NORon. 1978)10 geomorphology ILane et
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<br />'C<ll'n.pondin,;u>lhor.Tel.: +44..(OlI17-928.I)OO;fu.; +4+
<br />10l117.9~8.781H: e-mail: RJ.Hardyllbriuc.uk IRJ. HardYI
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<br />B). MESH 4, THE MEDIAN RESOLUTION MESH.
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<br />al..199-1-: l\otiller.I994)andgroundwaternowIGe and
<br />Garven. 199-1-; Gvirtman el al.. 1997.). For example.
<br />hydraulics models have been constructed which are
<br />capable of being applied to rivers in the scale of 1-
<br />60km (e.g. Gee et aI., 1990; Baird el al., 1992; Feld-
<br />hausetal..I992; Bll.tesetal.. 1992. 1995, 1996)whilsl
<br />maintaining a high spalial and temporal resolulion.
<br />In lhe de,'elopment of such models, there has been a
<br />trend among many modellers 10 increase the spatial
<br />resolution(thenumberofcellsrepresenlinglhesp81ial
<br />area of interesl) in the ell~clatioo of improved
<br />insights inlo temporal 3nd spatial processes. However,
<br />the spatial resolulion al which a model is applied
<br />affecls the solulion of the equations and thus the simu-
<br />lalion resullS. The relalionship between model space!
<br />time resolution and simulation outputs is therefore
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<br />C). MESH 7, THE IDGHEST RESOLUTION MESH.
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<br />Fill. I. ~ hypolhcli~l.ldomain used in the malyoi.. n.. eUlllpJes liven an: Ibc lowe'l K><lluliun me.h (mc:sIll). the median K>OlulioolllC..h
<br />CllICsIl 4) <>n<.I the hi,hc'l re"",lulj"" mull (me.h 7). Dimension. of <loomain. an: liven in melre..
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<br />f.(l~!.1694199JS_...,e fronl IlWlerClI999 Eloc.'ierScicncc B.V. All nl!hl'K>Cl""d.
<br />PIl: S0022-1694C99l0000~.S
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