Techniq es in Wate shed Management”
M odu le 6 – ( L2 2 – L2 6 ) : “ Use of M ode r n Te ch n iqu e s in W a t e r sh e d M a n a ge m e n t ” Te ch n iq e s in W a t e sh e d M a n a ge m e n t ” Applica t ion s of Ge ogr a ph ica l I n for m a t ion Syst e m a n d Re m ot e Se n sin g in W a t e r sh e d M a n a ge m e n t , Role of g g , D e cision Su ppor t Syst e m in W a t e r sh e d M a n a ge m e n t GI S & Applica t ion s in 2 2 2 2 W a t e r sh e d M a n a ge m e n t W a t e r sh e d M a n a ge m e n t
L22 L22– GI S & Applicat ions in Wat ershed
Managem ent M t
Topics Cove r e d Topics Cove r e d
Geographical I nform at ion Syst em , GI S Geographical I nform at ion Syst em , GI S
im plem ent at ion, GI S Spat ial dat a m odel, im plem ent at ion GI S Spat ial dat a m odel im plem ent at ion, GI S Spat ial dat a m odel, im plem ent at ion GI S Spat ial dat a m odelAdvant ages of GI S, GI S dim ensionalit y, Advant ages of GI S, GI S dim ensionalit y,
A Applicat ions in Wat ershed Managem ent . Applicat ions in Wat ershed Managem ent . A li li i i i i W W h d M h d M
Geographical I nform at ion Syst em , Spat ial Geographical I nform at ion Syst em , Spat ial g g p p y y p p Keywords: Keywords: y y dat a m odel, Dim ensionalit y, ArcGI S. dat a m odel, Dim ensionalit y, ArcGI S. Geographic I nform at ion Syst em ( GI S )
Ge ogr a ph ic I n for m a t ion Syst e m ( GI S) is a
Com put er based decision m aking t ool t o plan, im plem ent and govern t he obj ect s in space. im plem ent and govern t he obj ect s in space
GI S accept large volum es of spat ial dat a derived from
different sources, ret rieve, m anipulat e, analyze & display according t o user- defined specificat ions.
Com ponent s of GI S: Dat a input ; Dat a out put ; St orage
and m anagem ent ; Manipulat ion and analysis and m anagem ent ; Manipulat ion and analysis
D a t a H a n dlin g
Rast er or grid- based dat a
uses point s & coordinat es ( point s, lines & areas )
Vect or dat a –
Digit al Elevat ion Models ( DEM)
Triangular I rregular Net works ( TI N) Triangular I rregular Net works ( TI N) Geographic I nform at ion Syst em ( GI S ) ..
GI S t ransform s dat a int o inform at ion on spat ial locat ions of ent it ies t hat occupy space in nat ural & built Environm ent .
-
Spa t ia l D a t a S t i l D t
80% of all inform at ion held in dat abases anywhere in t he world
cont ains som e kind of geographic elem ent . I nform at ion t hat has:
Addit ional inform at ion includes – 1) Connect ivit y; 2) Cont iguit y.
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Any ent it y t hat has locat ion and can be show n on m ap. E.g. Maps Any ent it y t hat has locat ion and can be show n on m ap. E.g. Maps of st at e of I ndia.
Convent ional Dat a: At t ribut es of t he Spat ial ent it y. E.g. St at e
wise per capit a incom e. wise per capit a incom e. Re su lt s I n t e r pr e t a t ion www..lumina-media.com
Analysis present ed in form of m ap
Visualizat ion- supplem ent ed by spat ial & aspat ial queries of Vi li i l d b i l & i l i f Geographic I nform at ion Syst em ( GI S ) ..
Applicat ion of GI S : - GI S is capable t o capt ure, st ore,
- m anipulat e, analyze & visualize diverse set of spat ial dat a.
S Spat ial perspect ive t i l t i is very useful in t he est ablishm ent of i f l i t h t bli h t f
linkage bet w een various t ypes of process i.e. hydrological process, soil erosion, veget at ion cover , hum an act ivit ies et c., and also int eract ion bet ween t hem .
V a r iou s GI S pa ck a ge s V a r iou s GI S pa ck a ge s ArcI nfo, ArcView ( ESRI ) ; Aut oCAD Map ( Aut odesk I nc.) ; GRASS ( Baylor Uni., Texas) ;
I DRI SI ( Clark Labs) ;
I LWI S ( I nt . I nst . For Aero. Survey & Eart h Sciences, Net herlands) ; Aero Survey & Eart h Sciences Net herlands) ; MapI nfo ( MapI nfo ( Mapinfo Mapinfo Cor.) ; MFw orks ( Think Space I nc.) ; GeoMedia ( I nt ergraph Cor.) ; Microst at ion ( Bent ley Syst em s I nc) ; PAMAP ( PCI Geom at ics) ; SPANS SPANS ( Tydac I nc.) ; ( Tydac I nc ) ; GRAM+ + GRAM+ + ( I I T Bom bay) ( I I T Bom bay) et c. et c Represent ing Surfaces and sub- surfaces
DEMs, TI Ns and cont ours available for surface represent at ion
Cross sect ion shown by fencing, st acked surfaces and t rue Cross sect ion shown by fencing st acked surfaces and t rue
3D volum es beyond t he scope
Wire- fram e m odels capable of displaying geologic cross sect ions and borehole geophysical dat a sect ions and borehole geophysical dat a
Select ion of part icular spat ial dat a source
Dat a st ruct ure, file form at , quant izat ion and error propagat ion t i
GI S offers efficient algorit hm s for dealing w it h m ost of dat a
Surface Generat ion
Spat ial Resolut ion and I nform at ion cont ent
Drainage net works and resolut ion www..lumina-media.com
Spat ially variable precipit at ion Spat ially variable precipit at ion
GI S I m ple m e n t a t ion St a ge s
Maj or st ages of GI S I m plem ent at ion:
1 GI S awareness w hat is possible wit h GI S?; Proj ect s t o be used?.
1. GI S awareness – w hat is possible wit h GI S?; Proj ect s
- – Defining needs Feasibilit y st udies, Funct ional requirem ent st udy; Budget ; Proposal
2.
3. GI S select ion – suit able – specific needs; m arket survey survey - purchase purchase
4. GI S im plem ent at ion – I nst allat ion; Training, dat abase design/ developm ent , case st udy/ I m plem ent at ion
5. Man pow er developm ent
6. Field applicat ions – for specific st udies
7 Operat ion & Maint enance
7. Operat ion & Maint enance.
Adva n t a ge s of GI S a pplica t ion s
I nt eract ive visualizat ion/ analysis
Planning and m anagem ent Pl i d t
Spat ial dat a m anagem ent and access
Environm ent al risk assessm ent
Mult i- dim ensional planning
Cust om s applicat ions developm ent for decision support
Web accessible spat ial inform at ion W b ibl i l i f i
GI S for W a t e r sh e d M a n a ge m e n t
Vit al com ponent s of wat ershed m anagem ent :
Soil and land resource dat a for planning at m icro
level. Creat ion of a Mult i- t em poral dat abase for nat ural
resources
People’s part icipat ion People s part icipat ion Awareness for farm ers, policy m akers , users, soil
conservat ionist & scient ist s.
People’s part icipat ion at m icro- level P l ’ t i i t i t i l l
Technological int egrat ion: GI S along wit h convent ional dat abase g
Hydrological and socio econom ic analysis
Technological adopt ion and convent ional pract ices
GI S for W a t e r sh e d M a n a ge m e n t Ba sic St e ps in Typica l GI S a pplica t ion
for w a t e r sh e d
Acquisit ion of DEM dat a from sat ellit e
im age/ t oposheet .
Conduct DEM processing t o derive st ream , cat chm ent Conduct DEM processing t o derive st ream cat chm ent and drainage point feat ures.
Populat e dat a wit h required at t ribut es.
Use net work analysis and archydro t ools t o derive
desired m at rices.
GI S have becom e an GI S have becom e an in t e gr a l pa r t of H ydr ology in t e gr a l pa r t of H ydr ology
GI S M a ps: t opography, land use and cover, soils, rainfall and m et eorological variables
GI S – D a t a Sou r ce s & St r u ct u r e s
V a r ie t y of da t a sou r ce s a n d st r u ct u r e for a sin gle h ydr ologica l pa r a m e t e r y g p
For exam ple t opogr a ph y can be represent ed by a series of point elevat ions, cont our lines, Triangular I rregular Net work ( TI N) , elevat ions in a gridded or rect angular coordinat ed ( ) , g g syst em s
Ra in fa ll – Tim e series at a point , array of rainfall rat es de derived from radar, gridded array of rainfall rat es, isohyet al ed o ada , g dded a ay o a a at es, so yet a cont ours
I n filt r a t ion r a t e s – Soil m aps
Eva pot r a n spir a t ion r a t e s or h ydr a u lic r ou gh n e ss: Eva pot r a n spir a t ion r a t e s or h ydr a u lic r ou gh n e ss: Rast er array of rem ot ely sensed surrogat e m easures
http://www.microimages.com
GI S Spa t ia l D a t a M ode l
Spat ial dat a are referred t o as la ye r s, cove r a ge s, or
la ye r s la ye r s
V e ct or dat a represent feat ures as discret e point s,
lines, and polygons
Ex a m ple s: l
ArcI nfo Coverages
ArcGI S Shape Files ( Point , Line, Polygon) ArcGI S Shape Files ( Point Line Polygon)
CAD ( Aut oCAD DXF & DWG, or MicroSt at ion DGN files)
ASCI I coordinat e dat a
http://www.microimages.com
GI S Spa t ia l D a t a M ode l
m at rix of square cells m at rix of square cells
Ra st e r dat a represent t he landscape as a rect angular
Ex a m ple s:
- ArcI nfo Grids
- I m ages
- Digit al Elevat ion Models ( DEMs)
- Generic rast er dat aset s
- Generic rast er dat aset s
GI S - D im e n sion a lit y
Does not follow precise Euclidean not ions of 1,2 and 3- Dim ensional dat a
Ex: Generally st ream net work com posed of vect ors in
2D but here nodes and various point s along t he st ream m ay be represent ed by 1- D point dat a y p y p
Com plexit y of dat a represent at ions offers m any possibilit ies for analyzing hydrological dat a
Dist ance along t he st ream is different from sim ply Di t l t h t i diff t f i l specifying x,y- point
Point dat a: m easured quant it ies are oft en represent ed q p at a single point in 2D space
Ex: Rain gauge St at ion
M a p Sca le a n d Spa t ia l D e t a ils
Map of t opography can be show n at any scale in GI S
Resolut ion of DEM m ay be alt ered by resam pling t o a coarser or finer resolut ion or finer resolut ion
Hydrologist m ust be decide w hat scale w ill best represent t he im pact of t opography on t he hydrological processes
Select ion of Dat um Select ion of Dat um
Geographic Coordinat ion Syst em
Map Proj ect ion Syst em
DEM: An ordered array of num bers represent ing t he DEM: An ordered array of num bers represent ing t he spat ial dist ribut ion of elevat ions above som e arbit rary dat um in a landscape
Consist of elevat ions sam pled at discret e point s p p
DEM – Subset of DTM
DTM: Spat ial dist ribut ion of t errain at t ribut es like slope, soil dept h, soil drainabilit y, soil fert ilit y p , y, y
Choice of part icular m et hod of represent at ion of surface
Applica t ion of GI S for W a t e r sh e d M a n a ge m e n t M a n a ge m e n t
GI S has been exploit ed by t he hydrology and
wat ershed m anagem ent com m unit y in t h d t it i different ways: Wat ershed delineat ion Wat ershed delineat ion
Wat ershed Charact erizat ion and Assessm ent
Managem ent Planning g g
Wat ershed Rest orat ion ( Analysis of Alt ernat ive
Managem ent St rat egies) W t Wat ershed Policy Analysis and Decision Support h d P li A l i d D i i S t
Wat ershed Delineat ion Using GI S
The m aj or st eps involved in delineat ing a wat ershed
are: are:- – Geo- regist ering t he scanned t opo sheet s
- – Creat ing shape files
- – Cont our digit izat ion
- – Preparat ion of DEM
- – Filling of DEM Filling of DEM
- – Flow Direct ion Rast er generat ion
- – Flow Accum ulat ion Rast er Flow Accum ulat ion Rast er
- – Det erm ining Pour Point s
- – Wat ershed Delineat ion
GI S has been w idely used in charact erizat ion and
assessm ent st udies w hich require a w at ershed- based
approach. Basic physical charact erist ics of a w at ershed such as t he
drainage net work and flow pat hs can be derived from
readily available Digit al Elevat ion Models ( DEMs) . readily available Digit al Elevat ion Models ( DEMs)
This, in conj unct ion w it h precipit at ion and ot her w at er
qualit y qualit y m onit oring m onit oring dat a, dat a enhances enhances developm ent developm ent of of a aw at ershed act ion plan and ident ificat ion of exist ing and
pot ent ial pollut ion problem s in t he w at ershed . Dat a gat hered from GPS surveys and from environm ent al rem ot e sensing syst em s can be fused w it hin a GI S for a
successful charact erizat ion and assessm ent of w at ershed
funct ions and condit ions.W M - M a n a ge m e n t Pla n n in g
I nform at ion obt ained from charact erizat ion and assessm ent
st udies - in t he form of chart s and m aps can be com bined
w it h ot her dat a set s t o im prove underst anding of t he com plex w it h ot her dat a set s t o im prove underst anding of t he com plex relat ionships bet ween nat ural and hum an syst em s.
GI S provides a com m on fram ework – spat ial locat ion – for
w at ershed m anagem ent dat a obt ained from various sources. w at ershed m anagem ent dat a obt ained from various sources. GI S can be a pow erful t ool for underst anding t hese processes and for m anaging pot ent ial im pact s of hum an act ivit ies.
Modelling & visualizat ion capabilit ies of m odern GI S, coupled Modelling & visualizat ion capabilit ies of m odern GI S coupled w it h I nt ernet & World Wide Web , offer new t ools t o underst and t he processes & dynam ics t hat shape t he physical, biological and chem ical environm ent of wat ersheds. biological and chem ical environm ent of wat ersheds
Linkage bet w een GI S, I nt ernet , & environm ent al dat abases is especially helpful in planning st udies where inform at ion exchange and feedback on a t im ely basis is very crucial. exchange and feedback on a t im ely basis is very crucial
W t W a t e r sh e d Re st or a t ion ( An a lysis of h d R t t i ( A l i f
Alt e r n a t ive M a n a ge m e n t St r a t e gie s)
Wat ershed rest orat ion st udies generally involve
evaluat ion of various alt ernat ives. GI S GI S has been used for rest orat ion st udies ranging from has been used for rest orat ion st udies ranging from
relat ively sm all rural wat ersheds t o heavily urbanized landscapes.
Coupled wit h hydrodynam ic and spat ially explicit Coupled wit h hydrodynam ic and spat ially explicit hydrologic/ wat er qualit y m odelling , GI S can assist in
unified source wat er assessm ent program s including t he t ot al m axim um daily load ( TMDL) program . t he t ot al m axim um daily load ( TMDL) program
GI S can also provide a plat form for collaborat ion
am ong researchers, wat ershed st akeholders, and policy m akers. m akers
I nt egrat ing capabilit ies of GI S provide an int erface t o t ranslat e & em ulat e com plexit ies of a real world syst em wit hin confines of digit al world accurat ely & efficient ly. wit hin confines of digit al world accurat ely & efficient ly
Ca se St u dy Ca se St u dy: Am ba W a t e r sh e d ba a t e s e d
St udy Area
Lies in t he Khalapur t aluka near Khopoli in West ern Ghat s es e a apu a u a ea opo es e G a s of Raigad dist rict in Maharasht ra
15' and 73º 25‘; North Latitudes East Longit udes 73 18º 40 and 18º 50 18º 40' and 18º 50'
Topographical m aps num ber 47F/ 5 and 47 F/ 6
Part of t he cat chm ent Num bered as 5B2A6 by Wat ershed y At las of I ndia
Ca se st u dy: D a t a
Survey of I ndia t oposheet num ber 47 F/ 5 and 47 F/ 6 of scale 1: 50000 w it h cont our int erval of 20m .
Hourly rainfall dat a m easured at Tukasai m et eorological Hourly rainfall dat a m easured at Tukasai m et eorological st at ion sit uat ed at Anand nagar adj acent t o Am ba River.
I RS- 1D LI SS- I I I MSS digit al dat a for t he wat ershed acquired on 13t h Novem ber 2001. h b
Pixel size as 23.50m ; Window size is kept as 360 lines by 405 pixels. pixels.
Drainage map Drainage map
Ca se st u dy: M e t h odology
Them at ic m aps are com piled from t he source dat a product s like Survey of I ndia t opo sheet s, I RS I D product s like Survey of I ndia t opo sheet s, I RS- I D LI SSI I I MSS digit al dat a.
The t hem at ic m aps were digit ized and rast erized in t he GI S environm ent and t hese rast er dat a is t he GI S environm ent and t hese rast er dat a is regist ered wit h t he ot her t hem at ic inform at ion.
SCS- CN m et hod is applied t o est im at e t he rainfall excess of each pixel at various t im e int ervals.
Tim e of concent rat ion of all t he pixels based on t he act ual flow lengt h is calculat ed t o est im at e t he act ual flow lengt h is calculat ed t o est im at e t he hydrograph at t he out let of t he wat ershed.
Ca se st u dy: Ca se st u dy: M e t h odology.
Algorit hm t o find rainfall excess per
25400
2
CN P S ( . 2 ) p pixel
254 254 S S Q Q
I nput : Rainfall ( m m ) ,CN based on
P S ( . 8 ) Soil Type, Landuse class and AMC-
I I I , I nit ial Abst ract ion. , Q= r u n off ( m m )
For every pixel, t he t hem es
P= r a in fa ll ( m m ) considered for t he runoff est im at ion a e a d use, are land use, HSG ( Hydrological Soil SG ( yd o og ca So
S= pot e n t ia l m a x im u m S= pot e n t ia l m a x im u m Group) and AMC- I I I . r e t e n t ion
Base flow of 2cu.m / sec ( CWC I = I n it ia l a bst r a ct ion s a
Report , 1992) Report , 1992) CN = Cu r ve N u m be r
Out put : Runoff volum e for each • pixel ( ASCI I file)
Algor it h m t o fin d a ct u a l flow le n gt h a n d t im e of con ce n t r a t ion le n gt h a n d t im e of con ce n t r a t ion
I n pu t : DEM ASCI I file ( Elevat ion of each pixel) Pr oce ss:
3X3 grid, Minim um am ong t he 8 adj acent cells.
Flow lengt h= 23.50m ( Hori. And Vert . direct ion) Flow lengt h= 1.414* 23.50m ( Diagonal Direct ion) Rem oval of pit s.
Minim um dist ance from t he pixel of lowest elevat ion. l i
Ou t pu t : Lag t im e based on hydraulic lengt h, slope and
surface ret ent ion, t im e of concent rat ion by Lag Met hod. surface ret ent ion t im e of concent rat ion by Lag Met hod
Ca se st u dy: Re su lt s H ydr ologic Soil Gr ou ps H ydr ologic Soil Gr ou ps St a n da r d FCC of Am ba S d d FCC f A b W a t e r sh e d of Am ba W a t e r sh e d
Case St udy: Result s Case St d Res lt s
Digit al analysis of t he I RS- I D LI SS- I I I band 2, band 3 and band 4. and band 4.
Classes ident ified are agricult ural land, built up land, grassland, open forest and dense forest .
La n d u se M a p of Am ba W a t e r sh e d
| 20 73 20
73 |
45
18 Elevat ion values in
t m et ers
D igit a l Ele va t ion M ode l ( D EM ) D igit a l Ele va t ion M ode l ( D EM )
|
73
20 |
18
45 3–5 1–3 % 0–1 % 0 1 % % 15-35% 10-15% 5–10 % 5 10 %
>35% Slope M a p of Am ba W a t e r sh e d Slope M a p of Am ba W a t e r sh e d
Sim u la t ion of St or m - w it h H SG ( D )
140 160 Observed values HSG (D) HSG (C) Infiltration rate
.sec) 140 100 120 of 0.35mm/ hr
60 80 D ischarge (cu.m .
Runoff volume 42 85% 20 40 D 42.85%
10 20 30 40 50 60 70 Time (Hours)
R ff h d h f t Runoff hydrographs for storm
Re fe r e n ce s Re fe r e n ce s
J.V.S Murt hy ( 1991) , Wat ershed Managem ent , New Age • int ernat ional Publicat ions Kang Tsung Chang ( 2002) , I nt roduct ion t o Geographical • Kang- Tsung Chang ( 2002) I nt roduct ion t o Geographical • I nform at ion Syst em s, Tat a- McGrae- Hill, New Delhi.
Leipnik, Mark R., Karen K. Kem p, and Hugo A. Loaiciga, I m plem ent at ion Of GI S For Wat er Resources Planning And I m plem ent at ion Of GI S For Wat er Resources Planning And Managem ent , Journal of Wat er Resources Planning and Managem ent , Vol. 119, No.2, 1993.
Vieux, B.E. ( 2001) . Dist ribut ed Hydrologic Modeling Using GI S, Vieux B E ( 2001) Dist ribut ed Hydrologic Modeling Using GI S Kluw er Academ ic Publishers, Dordrecht , The Net herlands
Tu t or ia ls - Qu e st ion !.?
Crit ically st udy various GI S packages available for wat ershed based st udies. available for wat ershed based st udies
Evaluat e t he capabilit ies of each package. Evaluat e t he capabilit ies of each package.
Explore how effect ively t he GI S packages Explore how effect ively t he GI S packages Explore how effect ively t he GI S packages Explore how effect ively t he GI S packages
can be used for developm ent of wat ershed can be used for developm ent of wat ershed
m anagem ent plans. m anagem ent plans. m anagem ent plans. m anagem ent plans.Prof. T I Eldho, Department of Civil Engineering, IIT Bombay
Se lf Eva lu a t ion - Qu e st ion s!. Q
I llust rat e t he working of GI S wit h det ails of various com ponent s. various com ponent s
Discuss t he various st ages of GI S im plem ent at ions im plem ent at ions.
Describe basic st eps in t ypical GI S applicat ions for wat ershed m anagem ent . applicat ions for wat ershed m anagem ent .
I llust rat e GI S based spat ial dat a m odeling.
Prof. T I Eldho, Department of Civil Engineering, IIT Bombay P f T I Eldh D t t f Ci il E i i
IIT B b
Assign m e n t - Qu e st ion s?. g Q
How we represent surfaces & sub- surfaces
in GI S?. in GI S? What are t he advant ages of GI S applicat ions for various problem s?. for various problem s?
I llust rat e GI S dat a sources & dat a st ruct ures. st ruct ures.
Describe GI S dim ensionalit y issues.
Describe various applicat ions of GI S in Describe various applicat ions of GI S in wat er m anagem ent .
Un solve d Pr oble m !. Un solve d Pr oble m !
Using ArcGI S t ools, develop GI S dat abase Using ArcGI S t ools, develop GI S dat abase for your wat ershed area for your wat ershed area for your wat ershed area. for your wat ershed area.
Based on Topo sheet and ot her available Based on Topo sheet and ot her available dat a, generat e DEM, LU/ LC m ap, slope dat a generat e DEM LU/ LC m ap slope dat a generat e DEM LU/ LC m ap slope dat a, generat e DEM, LU/ LC m ap, slope m ap, soil m ap et c. m ap, soil m ap et c.
Explore how effect ively GI S can be used for Explore how effect ively GI S can be used for Explore how effect ively GI S can be used for Explore how effect ively GI S can be used for wat ershed m anagem ent plans. wat ershed m anagem ent plans.
Dr. T. I. Eldho Dr. T. I. Eldho Professor, Professor, Department of Civil Engineering, Department of Civil Engineering, p p g g g g Indian Institute of Technology Bombay, Indian Institute of Technology Bombay, Mumbai, India, 400 076. Mumbai, India, 400 076. Email: Email: Email: Email: [email protected] [email protected] [email protected] [email protected]