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  • B CC 1.Tnh cp thit ca ti 2. Mc tiu ngin cu 3. Phm vi nghin cu 4. Phng php nghin cu PHN M U

    PHN NI DUNG

    KT LUN V KIN NGH

    Chng I: Khi qut v m hnh s cao Chng II : Khi qut v khu vc nghin cu Chng III: Thu thp d liu DEM Chng IV: Phn tch d liu DEM

    Kt lunKin ngh Ti liu tham kho

    B cc ti gm 3 phn:

  • A.PHN M U

    1.Tnh cp thit ca ti:

    M hnh s cao l mt trong nhng d liu u vo quan trng trong cc nghin cu lin quan n a hnh, cc tai bin a cht, thin tai, st l t, ngp ltV vy chng ti thc hin nghin cu vi ti Nghin cu phng php thnh lp v mt s ng dng ca m hnh s cao DEM2.Mc tiu nghin cu:

    p dng cng ngh GIS thnh lp bn m hnh s cao. Nghin cu mt s ng dng ca m hnh s cao.3.Phm vi nghin cu: Khu vc tnh Thi Nguyn4.Phng php nghin cu: S dng phn mm ArcGIS v cc s liu thu thp c to m hnh s cao.

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  • KHI QUT M HNH S CAO

    1. Khi nim DEM (Digital Elevation Model )M hnh s ho cao (DEM) l s th hin bng s cao ca b mt t, cao ca tng t, ca mc nc ngm so vi cao ca b mt t.2.Cc kiu th hin m hnh s cao-DEM c lu tr khc nhau tu thuc vo kiu s liu l Raster hayVector.

  • Trong m hnh Raster DEM : ma trn cc vung gm cc hng v ct. Mi mt (cell) cha gi tr cao ca im trung tm ca

  • Trong cu trc Vector DEM : c th c coi nh l mt li tam gic khng u _TIN. TIN l tp cc nh ni vi nhau thnh cc tam gic, mi mt tam gic c gii hn bi 3 im xc nh v gi tr x,y v z ( cao).

  • CC PHNG PHP THNH LP DEMPhng php chp nh lp th :- Dng cc dng c chuyn dng chp nh thu thp d liu ca mt vng vi cc gi tr x, y z ca cc im trn b mt qu t .- Phng php ny i hi k thut cao trong vic chp v x l nh, i hi s im kim sot nhiu v i hi k thut cao trong chp v x l nh.- Cc dng DEM ph bin : + DEM xy dng t v tinh ASTER; + DEM xy dng t v tinh SPOTvd: nh hng khng ; nh vin thm .Phng php ng ng mc :M hnh TIN l mt dng d liu Raster c th hin di dng li tam gic khng u. Grid: l mt dng d liu Raster m t mt b mt mang gi tr lin tc. Gi tr mi li (cell) l gi tr ca b mt ti .Phng php giao thoa Radar

  • Mt s ng dng ca DEM

  • 2.2 c im a hnh

    Thi Nguyn c nhiu dy ni cao chy theo hng Bc Nam v thp dn xung pha Nam. Cu trc vng ni pha Bc ch yu l a phong ha mnh, to thnh nhiu hang ng v thung lng nh.

  • Tnh hnh kinh t - x hiTnh hnh kinh t-x hi trn a bn tnh nhng nm gn y, mc d cn gp nhiu kh khn song kinh t-x hi ca tnh vntip tc pht trin theo hng tch cc. Mt s lnh vc x hi cng c s ci thin ng k.

    c im kh hu Kh hu Thi Nguyn vo ma ng c chia thnh 3 vng r rt: - Vng lnh. - Vng lnh va - Vng m

  • THU THP D LIU

    1. D liu DEMTrung tm phn tch d liu t xa Tri t (ERSDAS)Nht Bn c ng link:

    http://gdem.ersdas.jspacesystems.or.jp/search.jsp V trang web ca Cc kho st a cht Hoa K (USGS):

    http://gdex.cr.usgs.gov/gdex/

  • Mt s ng dng ca GIS

  • Gii thiu v phn mm ArcGIS

    Thnhphn ca ArcGIS

    Phn mm ArcGIS:Phn mm ng dng cng ngh h thng tin a l ca Vin nghin cu h thng mi trng (ESRI) ca M. Phn mm ArcGIS cung cp nhng cng c rt mnh qun l v cp nht, phn tch thng tin to nn mt h thng thng tin a l hon chnh.

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  • Cu trc t chc d liu trong ArcGIS

    im (point) ng (polyline) Vng (polygon)

    M hnh d liu TIN(Triangular Irregular Networks)

    ArcGIS cho php kt ni trc tip vi cc d liu dng bng v kt ni d liu khng gian vi d liu bng biu M t i tng b mt di dng mt mng li tam gic khng u(xy dng t mt tp hp cc im (vertices/points) c ni vi nhau bi cc cnh (edges)) M hnh d liu VectorM hnh d liu Raster D liu trong ArcGIS

    M hnh d liu Raster

    Biu din i tng khng gian bi mt tp hp cc cell hay pixel (picture element), bao gm : image vgrid

    D liu dng bng

  • Giao din phn mm ArcGIS Desktop

  • PHN TCH D LIU

    ng ng mc:

  • Hin th DEM

    Phng php biu th mt cong a hnh1. Phng php ton hcTon vngDy Fouriera thc bc bn biChi titChia vng ng uChia vng khng ng u2. Phng php vt th bn ng ng mc (ng bnh ngang)ng mt ct dcim (ma trn cao) hay mng li u (Regular rectangular grid, GRID)Vector: Mng khng u tam gic (Triangualr irregualar network, TIN)

  • ng dng ca DEM

  • ng dng ca DEM (tip)Phn chia lu vcPhn chia lu vc l mt trong nhng cng vic quan trng v l d liu u vo khng th thiu trong cc m hnh thy vn.

    Thnh lp bn bng a hnhs n gin ha bi s lng hn ch s im d liu v khng th th hin ht tt c cc chi tit ca a hnh thc t

    Bn ng ng mc c to ra bng cch ct giao tip m hnh DEM a hnh vi cc mt phng ngang theo phn loi cao a hnh.

  • KT QU NGHIN CU

    DEM

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  • C.KT LUN V KIN NGH

    2.Kin nghDo thi gian nghin cu v kin thc cn hn ch nn chng ti ch a ra c mt s ng dng, trong thi gian ti chng ti s tip tc nghin cu su hn v cc ng dng ca DEM nhm gii quyt cc bi ton lin quan n DEM.

    1.Kt lun ti hon thnh c ng cc mc ch yu cu ra, l thnh lp c cc bn DEM cho khu vc Thi Nguyn vi phn gii 30m v 90m. ng dng cc cng ngh GIS thnh lp c bn m hnh s cao cho khu vc Thi Nguyn. Sn phm ca ti khoa hc ny c chnh xc cao v hon ton c th mang ng dng trong thc th khng ch cho tnh Thi Nguyn m cn p dng c cho tt c cc vng khc.

  • Cm n Thy C v cc bn ch lng nghe !

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