PREPRO2004 BY ASHISH AGRAWAL. PREPRO2004 Why we need this tool? Why we need this tool? Inputs, Outputs and How it works? Inputs, Outputs and How it works?

PREPRO2004PREPRO2004

BY ASHISH AGRAWALBY ASHISH AGRAWAL


Why we need this tool?Why we need this tool?

Inputs, Outputs and How it works?Inputs, Outputs and How it works?

Comparison to other toolsComparison to other tools

Capabilities of toolCapabilities of tool

Future workFuture work

AcknowledgementAcknowledgement

OVERVIEWOVERVIEW

WHY WE NEED IT?WHY WE NEED IT? *

HEC – HMS (Hydrologic Modeling System) : Simulates HEC – HMS (Hydrologic Modeling System) : Simulates

precipitation –runoff processes for dendritic watershed precipitation –runoff processes for dendritic watershed

systemssystems INPUT - TEXT FILES (BASIN, METEOROLOGICAL , CONTROL, etc.)INPUT - TEXT FILES (BASIN, METEOROLOGICAL , CONTROL, etc.)

OUTPUT – HYDROGRAPH (TABLES, GRAPHS)OUTPUT – HYDROGRAPH (TABLES, GRAPHS)

BASIN FILE : Physical data describing the watershed, BASIN FILE : Physical data describing the watershed,

e.g. subbasin, streams, longest flow path, slopes, etc.e.g. subbasin, streams, longest flow path, slopes, etc.

METEOROLOGICAL FILE : Precipitation and METEOROLOGICAL FILE : Precipitation and

evapotranspiration dataevapotranspiration data


WHY WE NEED IT? (Contd...)WHY WE NEED IT? (Contd...)Extracting hydrologic information from Extracting hydrologic information from

digital spatial data - create formatted text digital spatial data - create formatted text

files – Readable by HMSfiles – Readable by HMS

Automating saves Time and MoneyAutomating saves Time and Money

Useful for future predictions – Change in Useful for future predictions – Change in

Landuse, Impervious cover percentage.Landuse, Impervious cover percentage.



INPUT/OUTPUTINPUT/OUTPUT

THRESHOLD THRESHOLD FOR STREAM FOR STREAM DEFINITIONDEFINITION(In number of (In number of cells)cells)

DEM

NHD STREAMS

PREPRO2004

IDM (Interface Data Model)

HEC-HMSMask


PrePro (ArcView 3.x)PrePro (ArcView 3.x)

Written in Avenue ( Scripting Language)Written in Avenue ( Scripting Language)

Linear ProcedureLinear Procedure

HEC-GeoHMS ( ArcView 3.x)HEC-GeoHMS ( ArcView 3.x)

Written in AvenueWritten in Avenue


PrePro2002 (ArcView 8.x)PrePro2002 (ArcView 8.x)

Written in Visual BasicWritten in Visual Basic


PrePro2004 (ArcView 8.x)PrePro2004 (ArcView 8.x)

Exploiting GeoDatabase conceptExploiting GeoDatabase concept

Improvements over PrePro2002Improvements over PrePro2002

COMPARISIONCOMPARISION


DEM

PATH SETUP


DEM/Mask/BurnIn

Projection: DEM should be projectedCould change Z-unit


DEM/Mask/BurnInRawDEM

Mask

Streams for BurnIn


FIL/FDIR/FACCTargetDEM

BurnedDEM


FDIR

3232 6464 128128

1616 11

88 44 22


FACC

Flow Accumulation Grid :Flow Accumulation Function counts the number of cells upstream of a particular cell


STREAMS/OUTLET


STREAMS/OUTLET

Extracted Flow Accumulation Grid : (extflowacc)Flow Accumulation values which are greater than threshold

Stream Link Grid : (strgrid)Streams are divided into links with unique identification number

Outlet Grid : (out)Outlet points of the stream links, which is most downstream point of every link

Vectorized : Out(grid) -------> outlet (shapefile)Strgrid (grid) ------> Reach (shapefile)

outlet


STREAMS/OUTLET


ADD STREAMS

RAIN DROP TOOL :Helps in adding stream by creating graphics

New streams


ADD Inlet/Outlet/Reservoirs

• Break stream links

INLETSINLETS• Get rid of every-thing upstream

RESERVOIRSRESERVOIRS•Pose restrictionswhen merging

Reservoir

OutletInlet/Source


Delineate Watershed


HMS Elements

HMSSubbasinHMSReachHMSJunctionHMSSourceHMSReservoir

OutletsJunction


Merging Subbasins


Merging Subbasins

91

92

91


Calculate Parameters

SUBBASIN PARAMETERSSUBBASIN PARAMETERSLongest Flow Path

LengthSlope of LFP

Full length10 – 85 % length

U/S Elevation D/S Elevation

Centroid of SubbasinsElevation at Centroid

Centroidal Flow Length

REACH PARAMETERSREACH PARAMETERSLength of ReachSlope of ReachU/S Elevation D/S Elevation


Curve Number

Curve Number: SCS Curve Number method uses CN to determineamount of runoff for given amount of rainfall.

How?Intersection of Landuse (Shapefile), Soiltype (Shapefile) and watershed (Shapefile)Lookup Table

•Change Impervious Cover percentage – Modify Curve Number

• Edit Landuse • Edit Soiltype


Tool/IDM


IDM to HMS


HMS Files

Subbasin: R00 Canvas X: 614903.792 Canvas Y: 3364445.138 Label X: Label Y: Area: 0.05 DownStream: J0End:

Junction: J0 Canvas X: 615194 Canvas Y: 3364208 Label X: Label Y: DownStream: R460End:


HMS Basin Model

GIS GIS HEC-HMS HEC-HMS


Future Work

• Calculate some more parameters - required by HMS • Modify Curve Number – Antecedent Moisture Condition (AMC)• Create Meteorological files (in progress)

Preliminary Milestones

Final Destination

• Delineate Flood Plain Map


Conclusion

• Automating – Less Time & Money

• Predicting future changes will be easy

• IDM can maintain different scenarios for

comparison

• Better data, advance algorithms – may

attain greater accuracy over traditional

method


Acknowledgment

• Dr. Francisco Olivera

• For his guidance and support

• Janghwoan Choi

• Used some modules from his code

• Srikanth Koka

• Used some of the snapshots from exercise

created by him

• http://www.hec.usace.army.mil/software/hec-hms/

hechms-hechms.html


Questions

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Documents

PREPRO2004 BY ASHISH AGRAWAL. PREPRO2004 Why we need this tool? Why we need this tool? Inputs, Outputs and How it works? Inputs, Outputs and How it works?