简介：Low-molecular-weight(LMW)organicacidsexistwidelyinsoilsandhavebeenimplicatedinmanysoilprocesses.TheobjectiveofthepresentpaperwastoevaluateeffectoftwoLMWorganicacids,citricacidandoxalicacid,onCl-adsorptionbythreevariablechargesoils,alatosol,alateriticredsoilandaredsoil,usingabatchmethod.TheresultsshowedthatthepresenceofcitricacidandoxalicacidledtoadecreaseinCl-adsorptionwithlargerdecreasesforcitricacid.AmongthedifferentsoilsGl-adsorptioninthelateriticredsoilandtheredsoilwasmoreaffectedbyboththeLMWorganicacidsthanthatinthelatosol.

简介：Informationaboutthespatialdistributionofsoilattributesisindispensableformanylandresourcemanagementapplications;however,theabilityofsoilmapstosupplysuchinformationformodernmodelingtoolsisquestionable.Theobjectivesofthisstudyweretoinvestigatethepossibilityofpredictingsoildepthusingsometerrainattributesderivedfromdigitalelevationmodels(DEMs)withgeographicinformationsystems(GIS)andtosuggestanapproachtopredictothersoilattributes.Soildepthwasdeterminedat652fieldobservationsovertheAl-MuwaqqarWatershed(70km2)inJordan.Terrainattributesderivedfrom30-mresolutionDEMswereutilizedtopredictsoildepth.Theresultsindicatedthattheuseofmultiplelinearregressionmodelswithinsmallwatershedsubdivisionsenabledthepredictionofsoildepthwithadifferenceof50cmfor77%ofthefieldobservations.Thespatialdistributionofthepredictedsoildepthwasvisuallycoincidedandhadgoodcorrelationswiththespatialdistributionoftheclassesamalgamatingthreeterrainattributes,slopesteepness,slopeshape,andcompoundtopographicindex.Thesesuggestedthatthemodelingofsoil-landscaperelationshipswithinsmallwatershedsubdivisionsusingthethreeterrainattributeswasapromisingapproachtopredictothersoilattributes.

简介：PhysiographyandsoilinMaeRimwatershed,ChiangMaiProvince,Thailandwereinvestigatedbyusingaerialphotographsandsatelliteimageinconjunctionwithfieldwork,andsoilinfiltrationrateandsoilshearresistanceweremeasuredinfield.ManyfactorsaffectingrunoffwereanalyzedusigtheIntegratedLandandWaterInformaitonSystem(ILWIS).Asaresult,amodeldeterminingfloodhazarwassetup.Threempsincludingrunoffcurvenumbermap,runoffcoefficentmap,andfloodinumdationmapwerecreated,Inaddition,thetimeofconcentrationwaspredicted.