简介：ThepolicyoftheChinesegovernmentconcerningthehorizontalexpansionofthecultivatedlandthroughthereclamationofdesertsoilsresultinatotalincreaseof665.985km2duringtheperiod1987-1999inNorthShaanxi.Thisincreaseislessthanthelossinarablelandbyurbanization.Theacceleratedrateofchangeinagriculturalareascallsformorerapidsurveysofurbanizationandlossofarableland.Remotesensinghasanumberofadvantagesoverground-basedmethodsforsuchsurveys.Themulti-scaleconceptofremotesensingdatahelpusstudytheprobleminfourtowns.Severalmapswereproducedtoanalyzethesituationofurbancoverageindifferenttimes.Theevaluationofthestatus,rateandriskofurbanizationarebasedonanacceptedaverageofurbanincreaseas2%ofpopulationgrowthperyear.