GIS Applications in Meteorology and Hydrology John S. Quinlan NWS Albany, NY

GIS Applications in GIS Applications in Meteorology and HydrologyMeteorology and Hydrology

John S. QuinlanJohn S. Quinlan

NWS Albany, NYNWS Albany, NY

What is GIS?What is GIS?Geographic Information SystemsGeographic Information Systems

• Systems of hardware and software which store, retrieve, map and analyze geographic data in relational databases.

• GIS uses spatial and attribute data with vector and raster data structures, and topology to create geographic data models.

• GIS also allows for the representation of a third dimension which is usually elevation (i.e. Digital Elevation Model (DEM) produced by the USGS).

A view is an interactive map that allows you to display, query and analyze data.

ArcView supports tabular data in dBASE, delimited text and INFO format.

Charts are linked to maps and tables and allow for the display of additional info.

Layouts let you assemble all the components you want to appear in a map.

Scripts are project components that can be associated with either a control, such as a menu item or a button, or with an event.

DEM is a file format created by the USGS for DEM is a file format created by the USGS for storing elevation data. Converting DEM elevation storing elevation data. Converting DEM elevation data to grid format allows the user to determine data to grid format allows the user to determine

slope, aspect, hillshade and contour.slope, aspect, hillshade and contour.

Elevations and Towns at 500 FT Elevations and Towns at 500 FT Increments in ALY Forecast AreaIncrements in ALY Forecast Area

What is Spatial AnalystWhat is Spatial Analyst

• It is a GIS extension which allows the user to study the locations and shapes of geographic features and the relationships between them.

• It is very useful for analyzing meteorological or hydrologic data in terms of geographic distribution, and for verification analyses of forecasts and warnings.

Spatial Analyst Surface InterpolatorsSpatial Analyst Surface Interpolators(These Create a Continuous Surface from Sampled Input Points)(These Create a Continuous Surface from Sampled Input Points)

• Inverse Distance Weighted (IDW) - assumes each input point has an influence which diminishes with distance.

• Spline - is an interpolation method that fits a minimum-curvature surface through the input points.

• Kriging - is a specialized interpolation method that assumes the spatial distance or direction between points shows spatial correlation.

• Trend - is an interpolator that fits a mathematical function to all input ponts.

Growing SeasonGrowing SeasonALY Forecast AreaALY Forecast Area

Growing SeasonGrowing Season ALY Forecast Area & Verification ALY Forecast Area & Verification

Blizzard 1/22-23/05Blizzard 1/22-23/05

Even with the correct QPF, your Even with the correct QPF, your snow forecast can be off target.snow forecast can be off target.

Notice the Snow to Liquid Ratio Notice the Snow to Liquid Ratio varied from 10-20:1 to 40-50:1varied from 10-20:1 to 40-50:1

Elevation Snow Event (Wilma) Elevation Snow Event (Wilma) 10/25-26/0510/25-26/05

Snowfall amounts and Analysis for Snowfall amounts and Analysis for Elevations > 1500 FTElevations > 1500 FT

Snow Event 12/9/05Snow Event 12/9/05

GFE Snow Forecast for 12/9/05GFE Snow Forecast for 12/9/05

Snowfall Verification 12/9/05Snowfall Verification 12/9/05(Forecast vs. Observed from GIS)(Forecast vs. Observed from GIS)

Snow Survey Data and AnalysisSnow Survey Data and Analysis

April 2-4, 2005 Flood April 2-4, 2005 Flood EventEvent

Use of GIS to Improve Flood Use of GIS to Improve Flood WarningsWarnings

Antecedent ConditionsAntecedent Conditions

http://www.wrcc.dri.edu/spi/spi.html

Major East Coast Storm with Major East Coast Storm with Tremendous Upslope Flow into the Tremendous Upslope Flow into the

Catskills April 2-3, 2005Catskills April 2-3, 2005

Precipitation and SnowmeltPrecipitation and SnowmeltApril 2-4, 2005April 2-4, 2005

• GIS Basin Average Rainfall 4.01” in the Esopus Basin and 4.28” in the Rondout Basin.

• GIS Basin Average Water Content released from Snow 3.76” in the Esopus Basin and 3.00” in the Rondout Basin.

• Little if any use of water by vegetation.

Site Specific Model Output MRNN6Site Specific Model Output MRNN6

MRNN6 3/28/05–4/25/05MRNN6 3/28/05–4/25/05

Ashokan Reservoir SpillwayAshokan Reservoir Spillway

Kingston Traffic CircleKingston Traffic Circle

April 2-4, 2005 Flood EventApril 2-4, 2005 Flood Event

• Combination of Heavy Rain and Snowmelt

• 35 Million in Federal Disaster Assistance

• Gage/Flood Stage/Crest/Date/Rank MTRN6 FS = 11.0, 20.58 4/3/05 (3rd) MRNN6 FS = 20.0, 26.46 4/4/05 (1st) ROSN6 FS = 18.0, 24.96 4/3/05 (2ND)

High Wind Event 1/21/06High Wind Event 1/21/06

High Wind Event 2/17/06High Wind Event 2/17/06

WSEta 30AGL Winds 16Z 2/17/06WSEta 30AGL Winds 16Z 2/17/06

High Wind Event 2/17/06High Wind Event 2/17/06

• National Grid reported that 120,000 out of their 520,000 customers across eastern New York were without power. 328,000 customers were without power across the state.

• Wind Gusts of 60 to 80 MPH were common.• Hundreds of power poles were snapped.• Largest amount of wind damage since remnants

of Floyd in 1999 and the Labor Day Derecho in 1998.

Summary and Future WorkSummary and Future Work

• GIS has many applications in Meteorology and Hydrology. It can help with the analysis of data as well as the issuance of warnings and verification.

• Future work includes automating the analysis of the snow survey data and creation of snow grids from past storms which can be imported into GFE for storms with similar characteristics.