简介：土壤侵蚀是在整个世界的最严肃的陆地降级问题之一，引起不可逆的土地质量减小。在这份报纸，我们修改修订通用土壤损失方程(RUSLE)由用沉积运输索引(STI)代替斜坡长度和坡度的因素的模型。数字举起模型，地面参数，规范的差别植被索引(NDVI)，和降雨数据被用作输入到模型。与遥感技术和地面调查大小的申请一起，侵蚀危险性地图被生产。修订模型然后被用来在南部的意大利的Alianello获得土壤侵蚀危险性的最佳的估计，它是容易的玷污侵蚀。土壤损失从修改RUSLE估计模型显示出一个大空间变化，从10到差不多7000吨ha1yr1。高侵蚀易受影响的区域组成大约46.8%全部的侵蚀区域，并且什么时候由陆路分类盖子类型，33%被混合与灌木和草赤裸，由灌木和树的5.29%混合列在后面，与有0.06%的最低百分比的灌木。以斜坡类型，很陡峭的斜坡说明40.90%的一个总数并且而扁平的斜坡说明，属于高危险性仅仅0.12%，显示那扁平的地形学在侵蚀危险上有小效果。根据geomorphologic类型被担心，中等陡峭陡峭的斜坡与的类型对严重侵蚀中等是很有利的高玷污侵蚀，它包括大约9.34%。最后，我们对视觉解释地图从改编RUSLE模型验证土壤侵蚀地图，并且发现71.9%的类似度，反映在印射在这个学习区域的土壤侵蚀的改编RUSLE模型的效率。

简介：TheaimofthisworkisanimprovementoftheparameterizationofthesoilmoistureintheschemeoftheLandSurfaceProcessModel(LSPM)forapplicationsoverdesertareas.Infact,inverydryconditions,thewatervapourfluxplaysanimportantroleintheevaporationprocessesandinfluencestheundergroundprofilesofhumidityandtemperature.TheimprovedversionofsoilmoistureparametcrizationintheLSPMschemehasbeencheckedbyusingthedatatakenfromthedatabaseofthefieldexperimentHAPEX-Sahel(Hydrology-AtmospherePilotExperimentintheSahel,1990-1992).ModelsimulationsrefertothreedifferentstationslocatedinNiger(Fallow,MilletandTigersites)whereinputdataforLSPMandobservationsweresimultaneouslyavailable.TheresultsofsimulationstakingintoaccountthewatervapourfluxinthesoilmodelLSPM,seemtocomparebetterwiththeobservedbehaviourofsoilmoistureandturbulentheatfluxesthanthoseoverlookingthewatervapourflux,confirmingthegreatimportanceofthewatervapourinsuchdryconditions.

简介：在最近的年里，全球航行卫星系统反射计(GNSS-R)被开发作为一个新遥感工具估计土壤潮湿内容(SMC)。全球放的系统(GPS)bistatic雷达的信号错误是影响SMC评价的精确性的一个重要因素。在这份报纸，直接、反映的信号被介绍的包含两个的GPS信号刻度的二个方法，和如此的方法的理论基础的详细解释被给。利用校准的GPSL乐队信号的一个改进SMC评价模型被建议，并且评价精确性在2002从土壤潮湿实验用在空中的GPS数据被验证(SMEX02)。我们为确认在US的核桃溪区域与大豆和玉米选择21个地点。这些地点根据他们的植被盖子被划分成三个范畴：赤裸的土壤，中间植被的盖子(中间蔬菜)，并且高植被的盖子(高蔬菜)。SMC评价的精确性为赤裸的土壤是11.17%并且8.12%为中间蔬菜的地点，比传统的模型的好一些。为高蔬菜的地点，信号变细的效果preliminarily由于植被盖子被考虑，与规范的差别植被索引(NDVI)有关的一个线性模特儿被收养为修正在刻度上，和错误获得一个因素因为高蔬菜的地点最后被归结为3.81%。

简介：ByemployingtheimprovedT42L9spectralmodelintroducedbyNMC(Beijing)fromECMWFandutilizingtheFGGE-IIIbdatacoveringtheperiodof14—19June1979,theatmosphericresponsestotheabnormalsoilmoistureduringthemedium-rangeperiodhavebeenstudiednumerically.Accordingtotheinitialfieldat12GMT14June,afive-daynumericalexperimentunderdifferentconditionsofthesoilmoisturehasbeencarriedoutrespectively.ThemonthlymeanclimatologicalsoilmoistureforJunehasbeenusedinthecontrolexperimentintheinitialtimeanditchangeswithtimeaccordingtothemoisturebudgetequationatthelandsurface.Comparingwiththeexperimentswithdryorwetsoil.onecanconcludethat:1)Sourceofprecipitationovercontinentsinsummerconsistsoftheland-surfaceevaporationandthemoisturetransferfromoceans.Theirintensitiesarecomparableduringthemedium-rangetimescalewhenthesoilevaporatesitsmoisturesufficiently.Therefore,thesoilmoisturecaninfluencetheglobalprecipitationandthegeneralcirculationsignificantly;2)Byinfluencingthethermodynamicdifferencebetweenlandandsea,thesoilmoisturecanchangetheintensityofmonsoonandprecipitationdistribution;3)Theresponseoftheatmospheretotheabnormalsoilmoisturehasthecharacteristicsofgeographicaldistributionandnonlinearinteractions;4)Humanactivi-tiesontheworldcaninfluencetheenvironmentgreatly.

简介：Avariationaldataassimilationmethodisproposedtoestimatethenear-surfacesoilmoistureandsurfacesensibleandlatentheatfluxes.Themethodmergesthefivepartsintoacostfunction,i.e.,thedifferencesofwind,potentialtemperature,antispecifichumiditygradientbetweenobservationsandthosecomputedbytheprofilemethod,thedifferenceoflatentheatfluxescalculatedusingtheECMWFlandsurfaceevaporationschemeandtheprofilemethod,andaweakconstraintforsurfaceenergybalance.Byusinganoptimalalgorithm,thebestsolutionsarefound.ThemethodistestedwiththedatacollectedatFeixiStation(31.41°N,117.08°E)supportedbytheChinaHeavyRainExperimentandStudy(HeRES)during7-30June2001.Theresultsshowthatestimatednear-surfacesoilmoisturescanquicklyrespondtorainfall,andtheirtemporalvariationisconsistentwiththatofmeasurementsofaveragesoilmoistureover15-cmtopdepthwithamaximumerrorlessthan0.03m~3m~(-3).ThesurfaceheatfluxescalculatedbythismethodareconsistentwiththosebytheBowenratiomethod,butatthesametimeitcanovercometheinstabilityproblemoccurringintheBowenratiomethodwhenthelatterisabout-1.Meanwhile,thevariationalmethodismoreaccuratethantheprofilemethodintermsofsatisfyingthesurfaceenergybalance.Thesensitivitytestsalsoshowthatthevariationalmethodisthemoststableoneamongthethreemethods.

简介：季节的干旱是在潮湿的气候的普通出现。一年2003在时期期间是最干燥的年19852011在东南的中国。这研究的目的是阐明在2003的非凡的干旱的影响，与旋涡流动大小相比在200411期间在土壤水分蒸发蒸腾损失总量(et)和相关因素的动力学上，以及他们的内在的机制，在在东南的中国的副热带的具球果的种植园。在集中的干旱时期期间从5.34～1.84公里减少了并且在恢复干旱时期的subsquent期间恢复了到4.80公里，被发现那每日的et。路径分析显示那et被华盖传导力和深土壤水内容(50厘米)主要分别地在集中的干旱和恢复干旱时期期间决定。华盖传导力当承受干旱应力时，在et上抵消空气蒸汽压力赤字的积极效果，当华盖传导力在迟了的成长季节期间在et上提高了空气温度的积极效果时。因为这种植园的好根主要在浅土壤，和土壤被散布，流水在上面40厘米没满足需求因为et，有气孔的闭合和落叶作为对干旱应力的生理的回答明显。

简介：关联分析被用来在中国和东方亚洲夏天季风(EASM)上学习在春天土壤潮湿之间的关系。EASM在西南中国和黄河的大拐弯区域上与春天土壤潮湿有强壮的积极关联，这被显示出。一个标准土壤潮湿索引(SMI)用二个区域的观察土壤潮湿被定义。结果证明SMI与EASM有强壮的关联。年强壮(弱)SMI与被联系更强壮(更弱)夏天季风循环。在强壮的SMI的年里，向西和平的副热带的高度在位置向北方多并且在紧张更弱；westerlies地区也是到北方的更多。所有这些让EASM循环向北方移动并且引起降雨带重定位到诺思中国和东北中国。SMI能在东方中国上反映夏天降雨异例的变化。在强壮的SMI的年里，降雨带主要在China.However的northem部分上被定位，在弱年期间，夏天降雨带大部分被定位在上中间--并且更低--长江的活动范围。另外，SMI有伪4-6年和伪的明显的摆动2年。而且，否定SMI比积极SMI更好预言EASM。

简介：Theimpactsofsoilmoisture(SM)onheavyrainfallandthedevelopmentofMesoscaleConvectionSystems(MCSs)areinvestigatedthrough24-hnumericalsimulationsoftwoheavyrainfalleventsthatoccurredrespectivelyon28March2009(Case1)and6May2010(Case2)oversouthernChina.ThenumericalsimulationswerecarriedoutwithWRFanditscoupledNoahLSM(LandSurfaceModel).First,comparativeexperimentsweredrivenbytwodifferentSMdatasourcesfromNCEP-FNLandNASA-GLDAS.Secondary,withtherundrivenbyNASA-GLDASdataasacontrolone,aseriesofsensitivitytestswithdifferentdegreeof(20%,60%)increaseordecreaseintheinitialSMwereperformedtoexaminetheimpactofSMonthesimulations.Comparativeexperimentresultsshowthatthe24-hsimulatedcumulativerainfalldistributionsarenotsubstantiallyaffectedbytheapplicationofthetwodifferentSMdata,whiletheprecipitationintensityischangedtosomeextent.ForecastskillscoresshowthatsimulationwithNASA-GLDASSMdatacanleadtosomeimprovement,especiallyintheheavyrain(芏50mm)forecast,wherethereisupto5%increaseintheTSscore.SensitivitytestanalysisfoundthatapredominantlypositivefeedbackofSMonprecipitationexistedinthesetwoheavyraineventsbutnotwithcompletelythesamefeatures.Organizationoftheheavyrainfall-producingMCSseemstohaveanimpactonthefeedbackprocessbetweenSMandprecipitation.ForCase1,theMCSwaspoorlyorganizedandoccurredlocallyinlateafternoon,andtheincreaseofSMonlycausedaslightenhancementofprecipitation.Driersoilwasfoundtoresultinanapparentdecreaseofrainfallintensity,indicatingthatprecipitationismoresensitivetoSMreduction.ForCase2,astheheavyrainwascausedbyawell-organizedMCSwithsustainedprecipitation,therainfallismoresensitivetoSMincrease,whichbringsmorerainfall.Additionally,distinctivefeedbackeffectswereidentifiedfromdifferentstagesanddifferentorganizationofMCS,withstr

简介：Thepaperinvestigatestheabilitytoretrievethetruesoilmoistureprofilebyassimilatingnear-surfacesoilmoistureintoasoilmoisturemodelwithanensembleKalmanfilter(EnKF)assimilationscheme,includingtheeffectofensemblesize,updateintervalandnonlinearitiesintheprofileretrieval,therequiredtimeforfullretrievalofthesoilmoistureprofiles,andthepossibleinfluenceofthedepthofthesoilmoistureobservation.Thesequestionsareaddressedbyadesktopstudyusingsyntheticdata.The'true'soilmoistureprofilesaregeneratedfromthesoilmoisturemodelundertheboundaryconditionof0.5cmd-1evaporation.Totesttheassimilationschemes,themodelisinitializedwithapoorinitialguessofthesoilmoistureprofile,anddifferentensemblesizesaretestedshowingthatanensembleof40membersisenoughtorepresentthecovarianceofthemodelforecasts.Alsocomparedaretheresultswiththosefromthedirectinsertionassimilationscheme,showingthattheEnKFissuperiortothedirectinsertionassimilationscheme,forhourlyobservations,withretrievalofthesoilmoistureprofilebeingachievedin16hascomparedto12daysormore.Fordailyobservations,thetruesoilmoistureprofileisachievedinabout15dayswiththeEnKF,butitisimpossibletoapproximatethetruemoisturewithin18daysbyusingdirectinsertion.ItisalsofoundthatobservationdepthdoesnothaveasignificanteffectonprofileretrievaltimefortheEnKF.Thenonlinearitieshavesomenegativeinfluenceontheoptimalestimatesofsoilmoistureprofilebutnotveryseriously.

简介：Theatmosphericgeneralcirculationmodelcoupledtothemixedlayeroceanmodelhasbeenusedtosimulatethechangesoftheglobalsoilmoisture.Comparingthesimulatedresultswithobservations,itisshownthatthemodelisca-pableofdoingsensitiveexperimentsaboutthecarbondioxidechange.The2×CO2/1×CO2comparisonshowsthattherearetheobviouschangesofthesoilmoistureintheglobalforfourseasons.Therearethewetsoilmoistureinthelowerlatitudesofbothhemispheresanddrysoilmoistureinthemid-dlelatitudesofbothhemispheresforfourseasons.Thedrysoilmoistureinsummerandwetinotherseasonsarefoundinthenorthernhigherlatitudes.TheanalysesofthephysicalfeedbacksresponsiblefortheCO2-inducedchangesofsoilmoistureshowthatthebud-getsofthesurfacewaterandheataretheimportantfactors.