RESERVOIR SEDIMENTATION: RESEARCH NEEDS AND REFOCUSING PERSPECTIVES

IINTRODUCTIONReservoirsedimentationisannuallydecreasingconstT[lctedworldwidewaterstoragebyanestimatedonepercent(Mahmood,1987).Lossesinaridregionsaredoubled,reducingtheaverageusefulreservoirlifeto20-30years(Bruk,1996).Atthisrateofstorageloss,hydroelectricityasanenergysourcecanhardlybecalledrenewable(Nordin,1993).Reservoirsaregenerallyfillingwithsedimentmorerapidlythananticipated.Forexample,datafromindiaindicatethataCtllalsedimentdeliveryishigherthanpredictedin24of27reservoirs,rangingfro…     

BOULDERS ON THE MOVE: GEOMORPHIC HAZARDS FROM FLOODS AND DEBRIS FLOWS ALONG MOUNTAIN RIVERS

IMOUNTAINE~ON-MENTSANDSEDIMENTGeologistsandgeomorphologistsareabletomakeatleasttWoimportantcontributionstomitigatinghazardsassociatedwithsedimentprocessessuchasfloodsordebrisflows.First,geomorphologistscaninterpretgeologicrecordsofthehiStoryofseddrientprocesses.Theserecordsmayprovideinsightintothemagnitude,frequency,andlocationofsedimentsourcesandtransport,aswellashillslopeandchannelresponsestosedimentprocesses.Informationonpastsedimentproductionandmovement,andchannelresponse,mayb'…     

LAND USE CHANGE AND ITS DRIVING FORCES IN MINORITIES AREA

１　ＢａｃｋｇｒｏｕｎｄＹｕｎｎａｎｉｓａｂｏｒｄｅｒｐｒｏｖｉｎｃｅｗｉｔｈ２５ｍｉｎｏｒｉｔｉｅｓｉｎｓｏｕｔｈｗｅｓｔＣｈｉｎａ,ａｎｄｍｏｒｅｔｈａｎ９４％ｔｅｒｒｉｔｏｒｙｉｓｍｏｕｎｔａｉｎａｒｅａ．Ｗｉｔｈｄｉｆｆｅｒｅｎｔｌｉｖｉｎｇｅｎｖｉｒｏｎｍｅｎｔａｎｄｈｉｓｔｏｒｉｅｓｏｆｍｏｖｉｎｇａｎｄｄｅｖｅｌｏｐｍｅｎｔ,ｅａｃｈｍｉｎｏｒｉｔｙｈａｄｆｏｒｍｅｄｉｔｓｏｗｎｌｉｖｉｎｇａｎｄｐｒｏｄｕｃｔｉｏｎｐａｔｔｅｒｎｓ,ａｎｄｔｈｅｓｅｃｈａｒａｃｔｅｒｓａｒｅａｌｓ…     

地学棱镜实施计划：裂谷与俯冲带边缘的地球动力学过程（中）

2俯冲循环与彤变实施计划 2．4新西兰——主要研究区 2．4．1背景和动机：与俯冲循环和形变问题的关系 新西兰作为主要地点为地学棱镜实施计划（GeoPRISMS）俯冲带的研究提供了一个很好的机会。     

地学棱镜实施计划：裂谷和俯冲带边缘的地球动力学过程（下）

被动的裂谷系统在裂谷过程中扮演了重要角色,因为它们包括了整个地质学历史的记录,从裂谷开端、大陆裂解、海底扩张以及最后的成熟边缘。RIE 起始的目标如同地学棱镜科学计划草案（DSP）所描述,是了解裂谷初始如何进行,驱动裂谷的过程如何相互作用和演化,这些过程如何导致特别的裂谷架构,什么是裂谷期和后裂谷期边缘演化过程中大陆、海洋、大气之间的基本变动。     

北京石景山工业区附近一个污染土壤剖面的磁学研究

对北京西郊石景山工业区附近的土壤剖面进行环境磁学研究,结合粒度、金属元素分析、磁学指标测试和多元统计分析,发现磁参数(χ,ARM,SIRM)与重金属元素(Mn,Cu,Fe,Pb,Zn,Al,Sr)含量呈同步垂向变化趋势.来源于工业区附近工业生产排放(钢铁厂、发电厂、水泥厂)的污染物是土壤剖面上部(0～3 cm)磁性和金属含量增强的主要原因,由富集在细粉砂和中粉砂的多畴磁铁矿主导了样品的磁性特征.3～10 cm重金属含量逐渐下降,土壤的磁性特征与上层相似,但磁性矿物含量降低,属于剖面中的迁移过渡阶段.10 cm以下,土壤基本未受到污染,磁性矿物和重金属含量都低,磁性颗粒大小变化稳定,基本代表了该地区土壤的自然背景.指标聚类和相关分析表明,土壤磁参数与重金属元素含量显著相关.结合模糊聚类分析,磁参数可用于追踪、识别工业污染物质在土壤剖面中的富集、迁移状态,揭示不同深度土壤的污染程度.     

MODELING DEPOSITION PROCESSES IN VEGETATIVE FILTER STRIPS

lINTRoDUCTIONVegetativefilterstrips(VFS)havelongbeenacceptedasaneffectivesoilerosioncontrolpractice(Hudson,l97l).TheefficiencyofsedimenttraPpingisofmainconcernininvestigationsofVFS.However,moststudieshavebeenconcemedwiththeeffectofVFSwidthonsedimenttraPpingefficiency.Dillahaetal.(l989)foundthattrappingefficiencydecreasedwiththeaccumulationofsedimentinthefilterstrip.Orchardgrassfilterstripsof4.6mand9.lmwidthsremoved53%to86%and7o%to98%oftheincomingsediment,respectively.Line(l99l)showed…     

STABLE CHANNEL OBJECTIVE FUNCTION

1 INTRODUCTIONA stable channel is a stream in equilibrium that is neither silting nor scouring over a period of time.Obviously, such a stream has developed a cross sectional area of flow through natural processes ofdeposition and scour. Gilbert (Chang 1988) in 1880 was perhaps the first to recognize the role ofndnilnization processes in arriving at an equilibrium cross-section of such a stream. Langbein (1964)gave an arbitrarily formed function of various knit powers obtained by dividing …     

A PETROLOGICAL OVERVIEW OF THE KOHISTAN MAGMATIC ARC, NW HIMALAYA, N. PAKISTAN

A PETROLOGICAL OVERVIEW OF THE KOHISTAN MAGMATIC ARC, NW HIMALAYA, N. PAKISTAN1　TahirkheliRAK ,MattauerM .ProustF ,etal.1979.In :GeodynamicsofPakistan[C].FarahA ,DeJongKA ,eds.GeolSurvPakistan ,Quetta ,1979.12 5～ 130 . 2　CowardMP ,WindleyBF ,BroughtonRD ,etal.In :CollisionTectonics[C]..CowardMP ,RiesAC ,eds.GeolSoc,London ,SpecPub ,1986 ,19:2 0 3～ 2 19. 3　BardJP ,MaluskiH ,MattePh ,etal.GeolBull ,PeshawarUniversity ,1980 ,13:87～ 93. …     

BLOCK ROTATIONS AT THE NORTHERN EDGE OF INDIA (SPITI,N-INDIA) AND THEIR CONTINUATION TO THE EAST (MALARI, N-INDIA)-REGIONAL SIGNIFICANCE FOR THE TECTONIC DEVELOPMENT OF THE TETHYAN HIMALAYAS

BLOCK ROTATIONS AT THE NORTHERN EDGE OF INDIA (SPITI,N-INDIA) AND THEIR CONTINUATION TO THE EAST (MALARI, N-INDIA)-REGIONAL SIGNIFICANCE FOR THE TECTONIC DEVELOPMENT OF THE TETHYAN HIMALAYAS1　AppelE ,MuellerR ,WidderRW .GeophysJInt ,1991,10 4:2 5 5～ 2 6 6 . 2　AppelE ,PatzeltA ,ChoukerC .GeophysJInt ,1995 ,12 2 :2 2 7～ 2 42 . 3　BagatiTN .J .Himal.Geol,1990 ,(1) :35～ 47. 4　BesseJ ,CourtillotV .JGeop…