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 I n t e gr a t e d W a t e r sh e d M ode lin g Usin g N u m e r ica l M e t h ods GI S & Usin g N u m e r ica l M e t h ods, GI S & 2 5 2 5
Integrated Watershed Modeling Using L25– L25 Numerical Methods, GIS & Remote Sensing l h d G S & S
Topics Cove r e d Topics Cove r e d
Integrated watershed modeling; Numerical Integrated watershed modeling; Numerical methods; Finite element method; Computer methods; Finite element method; Computer methods; Finite element method; Computer methods; Finite element method; Computer modeling; Geographical Information System; modeling; Geographical Information System; R R Remote sensing; Applications in Watershed Remote sensing; Applications in Watershed i i A A li li i i i W i W h d h d Management. Management.
Integrated watershed modeling, numerical Integrated watershed modeling, numerical
Keywords: Keywords: modeling; GIS; Remote sensing modeling; GIS; Remote sensing modeling; GIS; Remote sensing modeling; GIS; Remote sensing .. ..
Necessity of Integrated Catchment/ Necessity of Integrated Catchment/ Watershed Based Modeling Watershed Based Modeling Watershed Based Modeling Watershed Based Modeling
Water resources management- catchment/ watershed based
Watershed / catchment based- Watershed modeling-
Planning & management Catchment/ Rainfall Catchment/ Rainfall – runoff runoff Modeling based on physical laws – Importance, necessity An integrated catchment/ watershed model. An integrated catchment/ watershed model Hydrological Processes- Infiltration, Runoff, evaporation etc. Digital revolution Recent advances in watershed modeling -Use of numerical modeling, remote sensing and GIS.
g, g
I n t e gr a t e d W a t e r sh e d M ode lin g Appr oa ch I de n t ifica t ion of spe cific h ydr ologic pr oble m D e sign s of GI S ( da t a la ye r s & a t t r ibu t e s) & RS D e sign s of GI S ( da t a la ye r s & a t t r ibu t e s) & RS D a t a ba se bu ildin g D a t a Pr oce ssin g g g Se le ct ion of h ydr ologic m ode l a n d for m u la t ion u sin g n u m e r ica l m e t h ods M ode l com pu t a t ion s Com pa r ison of r e su lt s
Hydrologic/ Hydraulic Modeling
Ra in fa ll Ru n off - > w a t e r sh e d A
Fie ld da t a Con st r u ct ion M ode l Con ce pt u a liz a t ion M ode l Con ce pt u a liz a t ion Pe r for m a n ce Pe r for m a n ce cr it e r ia - M ode l M a t h e m a t ica l
Ca libr a t ion M ode l M ode l Fie ld da t a Fie ld da t a & com pa r ison N u m e r ica l M ode l
V a lida t ion Com pu t e r M ode l M ode l ve r ifica t ion M ode l ve r ifica t ion Se n sit ivit y An a lysis Re su lt s & D iscu ssion M ode l Ade qu a cy
Fi ld d t Fie ld da t a Post a u dit P t dit B An a lysis
Ph ysica lly Ba se d D ist r ibu t e d M ode ls
Rainfall Channel phase flowPh ysica lly Ba se d D ist r ibu t e d M ode ls
Infiltration Infiltration Overland flow Rainfall
Fig. Flow in a watershed – Typical flow pattern Flow at the Outlet Channel flow of watershed Overland flow Infiltration Infiltration
Fig. General concept of flow modeling Remote Sensing, GIS & Numerical Methods
Re m ot e se n sin g
The remote sensing data are capable of solving the problem of scarcity of data.
Spatial variation Temporal variation
Re m ot e se n sin g pr oce ss
1. Data acquisition
2. Data analysis
Remote sensing - Capability of observing several
hydrological variables - Over large areas on repetitive basis titi b i
Geographic Information Systems (GIS)
Com pon e n t s of GI S
1. Data input data
2. Storage and management
3. Data manipulation and analysis
4 D t t t System data storage and management and management Data Input for p system and analysis system Data Manipulation p
Data Output for p
User Interface - GUI User Interface - GUI4. Data output Numerical Methods – Computer Models
Conceptual modeling
Mathematical modeling
Mathematical problems - solved by M h i l bl l d b arithmetical operations.
Digital revolution- the role of numerical Digital revolution- the role of numerical methods
Computer models – various models p
Numerical methods
(a) finite difference method (b) finite element method
(c) finite volume method (d) boundary element method
Watershed Selection of Data collection for watershed model formulation of Mathematical Sensed data & Remotely GIS GIS Thematic maps Preparation of Numerical Formulation development development Model Model Evaluation of Testing and Finalization of model Integrated Use of Numerical Method, GIS & Integrated Use of Numerical Method GIS & Watershed Based Runoff modeling I nfiltration – fil i Various models i d l Overland flow - One dimensional/ 2D
Channel flow - - Channel flow One dimensional One dimensional Component models coupled to get the runoff
Rainfall Channel flow Infiltration Overland flow O l d fl
I n filt r a t ion I n filt r a t ion Eg.
Philip Infiltration Model: To calculate infiltration rate and subsequent excess rainfall The rate of infiltration is given by
1 1 / 2
1
2
i f s t K f potential infiltration rate i s infiltration sorptivity K 1/ 2 hydraulic conductivity
5 ( , ) 2(1 )
3
s ini i iniK d s s s
Infiltration sorptivity
K
3
K saturated hydraulic conductivity s ini s initial (uniform) soil saturation degree pore size distribution index d diffusivity index ( ) (1 2 ) / d
saturated matrix potential of the soil
Physically based Model Physically based Model
Governing equations for surface runoff
(1)
S i r S g x h g y u v x u u t u fx ox
h u
) (
u h u u u
b. Momentum equation
i r y x t
b M i
i r h v h u h
a. Continuity equation
C ti it ti
Governing equations for surface runoff
(2) Physically based Model.. Physically based Model..
) (
S v u u fx
A x Q
q t
2.Channel flow (One dimensional)
( ) ( )
2 Channel flow (One dimensional) 3 4 h fy 3 h
(4) (5)
3 4 2 1 2 2 2 h n
2 n S v u v fy
2
2
4 2 1
(3)
S i r S g y h g y v v x v u t v fy oy
h v
(6) Physically based Model… Physically based Model…
(7) (7)
2
Q Q Q Q y y
gA A S S S S gA A f
t x A x
Governing equation for ground water flow g q g
(Two dimensional) (8)
h h h
K h K h I x y t S ( , , ) x y
x x y y t
Gove r n in g e qu a t ion s for ove r la n d flow ( D iffu sion Gove r n in g e qu a t ion s for ove r la n d flow ( D iffu sion W a ve / Kin e m a t ic W a ve M ode ls) 1 . Con t in u it y e qu a t ion q q flo flow per unit width per nit idth
q h depth of flow h r
e r e excess rainfall intensity
x t 2 . M om e n t u m e qu a t ion
S h
o slope of overland flow plane
S S o f S = S (kinematic) o f x
S f friction slope of flow plane
Fin it e e le m e n t for m u la t ion - Ga le r k in ’s cr it e r ion is u se d t t t t t t t t t t t t t t t t t t
C h C h t B (1 ) q q t f (1 )( ) r ( ) r e e
is the factor that determines the type of finite difference scheme involved (0.5)
For diffusion wave modeling F diff i d li
h h
k i
S S f o i i
L
L k length of element i and represent successive nodes in flow direction Gove r n in g e qu a t ion s for ch a n n e l flow
1 c f Q R S A n
L
( ) c i k i f i h h S S
) ) 1 ( 1 ( g g
Q q q f t Q B t A C A C
t t t t t t t t t
Fin it e e le m e n t for m u la t ion
R P is hydraulic radius ( / A P ), is wetted perimeter n is channel flow Manning’s roughness coefficient
Fin it e e le m e n t fo m la t ion (2 / 3) (1/ 2)
The equation of continuity A Q Q
R is hydraulic radius ( / A P )
S S is friction slope of channel is bed slope of channel c f
(kinematic)
Manning’s equation S S c f h x = S f
Momentum equation S o
A x Q A is area of flow in the channel,
q t
A is discharge in the channel, is area of flow in the channel, Momentum equation
For diffusion wave modeling L
Start I t E i f ll f i filt ti d l d d ti N b d i f l t Input: Excess rainfall from infiltration model and duration, Number and size of elements, Roughness coefficients, Slopes, Bed width, Time step, Duration of simulation etc.
Initialization of variables (Initialize nonzero depth at time t=0) Calculation of element matrix for channel and overland flow Generation of global matrix by assembling element matrices and applying boundary conditions for channel and overland flow Solving the system for overland flow If t t k t t k h h
1 t t t h h No Yes
t t k t t k h h 1
[ ] [ ] t t t h h A A t t t Solving the system for channel flow if No
t t k t t k A A 1 t t k t t k A A
1 Yes Yes No If k k A A 1 max t t t
Stop No
M ode lin g Pr oce du r e
Data collection for the selected watershed.
Mathematical modeling Mathematical modeling.
Numerical formulation for the mathematical model.
Preparation of thematic maps of the watershed by using Remote sensing imageries and GIS.
Development of software for the formulated model
Development of software for the formulated model.
Testing and evaluation of the model for different rainfall events
Finalization of model.
Modeling Procedure…
Discretization as rectangular strips Channel network in
1 Overland flow the watershed Channel meeting point 4 3 2 1 2 3 Overland flow strip 4 element node Single discretized channel with overland flow adding at channel
W nodes 4 L Overland flow element W L Channel flow element Overland flow element
( Aral ( Aral et et al al..
Example of Example of Channel Channel flow flow model model:: Diffusion Diffusion wave wave model model 1998)) .. 1998
Example Length of each branch = 5,000 m; channel g , ; width is 50 m for two upstream channels & 100 m for d/s channel. Bed slope is 0.0002. Roughness coefficient is 0.025.
15 elements with element length 1000 m & time step 200 sec is used. Results for
Khadakhol Watershed
Ca se St u dy:
(Venkata Reddy, 2007) (V k R dd 2007) Location- Nashik district, Maharashtra, India o o
E East Longitudes of 73 t L it d f 73 17' d 17' and 73 73 20' 20' o o North Latitudes of 20 07' and 20 09'.
Major soil class – Silty loam
Remotely sensed data- IRS 1D LISS III image Jan.13,1998
Thematic maps - Drainage, Slope and LU/LC, DEMCase Study: Rainfall –Runoff Modeling
D a t a ba se pr e pa r a t ion
Initially scanned topographical maps of the Initially scanned topographical maps of the Drainage m ap: Drainage m ap:
area in 1:25000 scale are registered in ERDAS IMAGINE
software. Watershed boundary and the drainage maps are
digitized in ArcMap. digitized in ArcMap
Slope m ap: Contours with 10 m interval of the watershed
are digitized in ArcMap from topographical maps and Digital Elevation Model (DEM) with 100 m cell size has been Elevation Model (DEM) with 100 m cell size has been generated using TOPOGRID option of ArcInfo software. LU/ LC m ap: Remotely sensed data of IRS 1D LISS III path 105 and row 55 of January 13, 1998 has been used to 105 and row 55 of January 13 1998 has been used to extract LU/ LC of the watershed. LU/LC map is derived from remotely sensed data of watershed by supervised classification using ERDAS IMAGINE software classification using ERDAS IMAGINE software
Land Use/Land Cover map False Colour Composite p False Colour Composite
Kh a da k oh ol W a t e r sh e d Digital Elevation Model map g p
8 10 m 3 /s) 10 R i f ll 20 n sity
2 4 6 Discharge ( m 20 30 40 50 Rainfall 60 Rainfall Inte n (mm/hr) Observed Simulated 100 200 300 400 500 600 700 Time (min) 60 August 23 1997
5 6 10 i f ll August 23, 1997
1 2 3 4 5 D ischarge (m 3 /s) 10 20 30 40 Rainfall 50 R ainfall Intensity (mm/hr) Observed Simulated D 1 60 120 180 240 300 360 Time (min) 60 70 R A t 22 1997
Finite element grid map Observed and Simulated hydrographs
August 22, 1997 Integrated Modeling – Concluding Remarks The digital revolution.
Recent advances -remote sensing and GIS R t d t i d GIS technologies.
Use of remote sensing and GIS in watershed Use of remote sensing and GIS in watershed modeling.
Use of Distributed / Lumped models Use of Distributed / Lumped models
Hydrologic/ Hydraulic Modeling – By
Numerical methods Numerical methods
Integrated models – Remote Sensing, GIS & Hydrologic Models y g
Re fe r e n ce s Re fe r e n ce s
Raj Vir Singh (2000), Watershed Planning and Management, Yash • Publishing House J.V.S Murthy (1991), Watershed Management, New Age international y ( ), g , • g Publications
Venkata Reddy K., Eldho T. I., Rao E.P. and Hengade N. (2007) “A kinematic wave based distributed watershed model using FEM, GIS and remotely sensed data.” Journal of Hydrological Processes, 21, 2765- t l d d t ” J l f H d l i l P 21 2765 2777
Chow, V.T., Maidment, D.R., and Mays, L.W. (1988). Applied Hydrology, McGraw Hill, Inc., New York. Hydrology McGraw-Hill Inc New York
Bedient, P.B. and Huber W.C.(1988). Hydrology and flood plain analysis, Addison-Wesley Publishing Company., London.
Cunderlik, J. M. (2003). Hydrologic model selection for the CFCAS Cunderlik, J. M. (2003). “Hydrologic model selection for the CFCAS project: Assessment of Water Resources Risk and Vulnerability to
changing Climatic Conditions – Project Report 1”, Department of Civil
and Environmental engineering, University of Western OntarioTu t or ia ls - Qu e st ion !.?
Critically study the necessity of integrated
approach of watershed modeling using approach of watershed modeling using numerical methods, GIS and remote sensing. Study various case studies g y available in literature (details can be obtained from Internet).
Study the role of integrated watershed Study the role of integrated watershed modeling in Integrated Water Resources modeling in Integrated Water Resources Management. Management
Prof. T I Eldho, Department of Civil Engineering, IIT Bombay
Se lf Eva lu a t ion - Qu e st ion s!. Q
Describe the necessity of Integrated Watershed based modeling. b d d li
Explain the step by step methodology in use of numerical models, GIS and remote sensing for i l d l GIS d t i f watershed based modeling
Differentiate between dynamic wave/ diffusion Diff ti t b t d i / diff i wave/ kinematic wave based physical modeling for rainfall-runoff modeling of watersheds. for rainfall runoff modeling of watersheds
Assign m e n t - Qu e st ion s?. g Q
Illustrate how GIS & remote sensing can help in effective watershed modeling in p g combination with numerical modeling.
For physically event based rainfall runoff modeling, illustrate various hydrologic processes to be considered in the modeling.
In integrated approach of watershed f modeling, describe the modeling procedure.
Un solve d Pr oble m !. Un solve d Pr oble m !
For your watershed area, study the scope of integrated For your watershed area, study the scope of integrated modeling for rainfall--runoff using numerical models, GIS modeling for rainfall g g runoff using numerical models, GIS g g and remote sensing. Remote sensing for the watershed and remote sensing. Remote sensing for the watershed area may be obtained from ASTER area may be obtained from ASTER (( http://asterweb.jpl.nasa.gov/ http://asterweb.jpl.nasa.gov/ )/ SRTM )/ SRTM (( http://srtm.usgs.gov/index.php http://srtm.usgs.gov/index.php ) / BHUVAN/ IRS ) / BHUVAN/ IRS (( http://bhuvan.nrsc.gov.in/bhuvan_links.html http://bhuvan.nrsc.gov.in/bhuvan_links.html ) )
Hydrological model may be obtained from HEC--RAS, HEC Hydrological model may be obtained from HEC RAS, HEC-- h e c h e c
HMS software: HMS software: www. w w w .h e c .usace.arm y.m il/ soft ware/ h e c -- .usace.arm y.m il/ soft ware/ h m s h m s
For the average/ maximum/ minimum rainfall pattern in the watershed area, asses the runoff for the watershed.
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: eldho@iitb.ac.in eldho@iitb.ac.in eldho@iitb.ac.in eldho@iitb.ac.in