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? Comparison to other tools Comparison to other tools Capabilities of tool Capabilities of tool Future work Future work Acknowledgement Acknowledgement OVERVIEW
WHY WE NEED IT? * HEC – HMS (Hydrologic Modeling System) : Simulates precipitation –runoff processes for dendritic watershed systems HEC – HMS (Hydrologic Modeling System) : Simulates precipitation –runoff processes for dendritic watershed systems 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, e.g. subbasin, streams, longest flow path, slopes, etc. BASIN FILE : Physical data describing the watershed, e.g. subbasin, streams, longest flow path, slopes, etc. METEOROLOGICAL FILE : Precipitation and evapotranspiration data METEOROLOGICAL FILE : Precipitation and evapotranspiration dataPREPRO2004
WHY WE NEED IT? (Contd...) Extracting hydrologic information from digital spatial data - create formatted text files – Readable by HMS Extracting hydrologic information from digital spatial data - create formatted text files – Readable by HMS Automating saves Time and Money Automating saves Time and Money Useful for future predictions – Change in Landuse, Impervious cover percentage. Useful for future predictions – Change in Landuse, Impervious cover percentage.PREPRO2004
PREPRO2004INPUT/OUTPUT THRESHOLD FOR STREAM DEFINITION (In number of cells) DEM NHD STREAMS PREPRO2004PREPRO2004 IDM (Interface Data Model) HEC-HMS Mask
PREPRO2004 PrePro (ArcView 3.x) PrePro (ArcView 3.x) Written in Avenue ( Scripting Language) Written in Avenue ( Scripting Language) Linear Procedure Linear Procedure HEC-GeoHMS ( ArcView 3.x) HEC-GeoHMS ( ArcView 3.x) Written in Avenue Written in Avenue Linear Procedure Linear Procedure PrePro2002 (ArcView 8.x) PrePro2002 (ArcView 8.x) Written in Visual Basic Written in Visual Basic Linear Procedure Linear Procedure PrePro2004 (ArcView 8.x) PrePro2004 (ArcView 8.x) Exploiting GeoDatabase concept Exploiting GeoDatabase concept Improvements over PrePro2002 Improvements over PrePro2002 COMPARISION
PREPRO2004 DEM PATH SETUP
PREPRO2004 DEM/Mask/BurnIn Projection: DEM should be projected Could change Z-unit
PREPRO2004 DEM/Mask/BurnIn RawDEM Mask Streams for BurnIn
PREPRO2004 FIL/FDIR/FACC TargetDEM BurnedDEM
PREPRO2004 FDIR
PREPRO2004 FACC Flow Accumulation Grid : Flow Accumulation Function counts the number of cells upstream of a particular cell
PREPRO2004 STREAMS/OUTLET
PREPRO2004 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)
outletPREPRO2004 STREAMS/OUTLET
PREPRO2004 ADD STREAMS RAIN DROP TOOL : Helps in adding stream by creating graphics New streams
PREPRO2004 ADD Inlet/Outlet/Reservoirs Break stream linksINLETS Get rid of every- thing upstreamRESERVOIRS Pose restrictions when merging Reservoir Outlet Inlet/Source
PREPRO2004 Delineate Watershed
PREPRO2004 HMS Elements HMSSubbasin HMSReach HMSJunction HMSSource HMSReservoir Outlets Junction
PREPRO2004 Merging Subbasins
PREPRO
PREPRO2004 Calculate Parameters SUBBASIN PARAMETERS Longest Flow Path Length Slope of LFP Full length 10 – 85 % length U/S Elevation D/S Elevation Centroid of Subbasins Elevation at Centroid Centroidal Flow Length REACH PARAMETERS Length of Reach Slope of Reach U/S Elevation D/S Elevation
PREPRO2004 Curve Number Curve Number: SCS Curve Number method uses CN to determine amount 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
PREPRO2004 Tool/IDM
PREPRO2004 IDM to HMS
PREPRO2004 HMS Files Subbasin: R00 Canvas X: Canvas Y: Label X: Label Y: Area: 0.05 DownStream: J0 End: Junction: J0 Canvas X: Canvas Y: Label X: Label Y: DownStream: R460 End:
PREPRO2004 HMS Basin Model GIS HEC-HMS
PREPRO2004 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
PREPRO2004 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
PREPRO2004 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 hechms-hechms.html
PREPRO2004 Questions ?