Weibeiupland,locatedinsouthernpartoftheLoessPlateau,isacommercialappleproductionbaseinChina.Theenlargementofapple-plantingareahasagreatimpactontheregionalwatercycle.Theeffectsofdifferentlanduseonhydrologicalparametersarecomparedandstudiedinthispaper.Themainresultsareasfollows:(1)Theinitialandsteadyinfiltrationratesinappleorchardarehigherthanthoseinotherlandusetypessuchasgrassland,idlelandandfarmland.Theirinitialratesofinfiltrationare0.823cm/min,0.215cm/min,0.534cm/minand0.586cm/mininappleorchard,grassland,idlelandandfarmlandrespectively.Theirsteadyinfiltrationratesare0.45cm/min,0.038cm/min,0.191cm/minand0.155cm/minrespectively.(2)Thereisnorunoffgeneratedinplotofappleorchardinall8stormeventsinobservednaturalrainfalls,whilerunoffisgeneratedinwinterwheatplot,complotandalfalfaplotwithrunoffcoefficientsof2.39%,1.58%and0.31%respectively.(3)Thetranspirationofappletreesisstrongandthussoilmoistureisgraduallydepleted.Theaveragesoilwatercontentsin3-9msoilprofileinChangwuplotswithappletreesof14and32yearsinageare11.77%and11.59%andinLuochuanplotswiththoseof15and28yearsinageare11.7%and11.59%respectively,whicharenearly9.0%ofwiltingmoistureofChangwusoiland8.6%ofwiltingmoistureofLuochuansoil.Thepathwayofrainfallpercolatingtogroundwaterishinderedbydrysoilprofile.
