ARC GIS IN THE SANTA RIVER BASIN IN PERU GIS in Water Resources Fall 2006 Professor: Dr. David Maidment Presented by Presented by Eusebio Ingol

OUTLINE  Objectives  Study Area  Data Sources  Information Process  Arc Hydro for the river Basin  Precipitation and runoff  Conclusions

Objectives  Apply GIS for generating information in the Santa River Basin.  Delineate watershed and streams.  Calculate of Precipitation in the watershed.  Analysis of runoff in the Condocerro Station.  Determine some parameters of the basin of study.

Study Area  Santa River basin. Department of Ancash in the North Peru.  Parallels 10 15’ and 07 55’ Latitude South and Meridians 78 45’ and 77 05’Longitude West

Data Sources   Coordinates of 17 stations with average values of rainfall ( ).  Average discharges in the Condocerro Station ( ).  The exercises 3, 4, and 6 were the base for developing this term project. The exercises 3, 4, and 6 were the base for developing this term project.

DEM Processing  Terrain Processing DEM for the Area of Study 3 arc seconds of resolution 90 m. Extract by mask

Flow Direction Grid Flow Accumulation Grid

Catchments Drainage Lines Stream Definition Threshold drainage area: x90 Area = 8.1 km Catchments

Contours

Watershed Watershed Watershed processing Anta km2 Slope = 3.8 % Tablacacha km2 Slope = 3.2 % Santa –Outlet km2 Slope = 1.07 % Sub watersheds Sub watersheds At = 12, km2 Mean slope = 3 %

Stations of Precipitation Precipitation Stations Goodatabase for the Santa River Basin

Arc Hydro for the Santa River Basin  With the information generated is possible to apply the Arc hydro for the Santa Basin. Time Series for the Condocerro Station

Maps generated with the Application of Arc Hydro L = km Hydro junctions and Hydro Edges Direction of Flow Longest Flow Path

Estimation of the Precipitation Use Thiessen Polygon Annual precipitation for 17 stations.

Monthly Mean Precipitation for the Watersheds

Mean Precipitation for the Watersheds At = 12,166 km2. Vr = 6, 210,330,430 m3

Analysis of Discharge  Stream gage Condocerro

Conclusions  Arc Hydro in ArcMap is a powerful tool for delineating and organizing information data in river basins where databases are not available.  The drainage area calculated for the Santa River Basin was km2 with a length of streams of km. Likewise, the density of drainage is 0.26 / km.  The delineated watersheds were Santa-Outlet, Tablacacha, and Anta;  The sub watersheds Tablacacha and Anta are the main source of water resources in the basin, whose annual precipitation estimated were 568 mm and 593 mm respectively.  Based on the analysis of discharge, we conclude that for a 75 % of persistence, the annual mean flow will be 110 m3/s