1 / 32

The GIS Weasel!!

The GIS Weasel!!. General Introduction. The GIS Weasel!!. Developed by USGS Freely available via Internet http://wwwbrr.cr.usgs.gov/weasel. Platform Requirements. Any platform (Unix/Windows) Workstation ArcInfo - with GRID raster processing software C compiler (if running under Unix).

cole
Download Presentation

The GIS Weasel!!

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The GIS Weasel!! General Introduction

  2. The GIS Weasel!! • Developed by USGS • Freely available via Internet • http://wwwbrr.cr.usgs.gov/weasel

  3. Platform Requirements • Any platform (Unix/Windows) • Workstation ArcInfo • - with GRID raster processing software • C compiler (if running under Unix)

  4. The GIS Weasel!! • Purpose: simplify the creation of spatial information in modeling by providing tools to • delineate • parameterize • relevant spatial features.

  5. The GIS Weasel!! delineate: make a map of a type of spatial feature -for example, a map of hillslopes

  6. The GIS Weasel!! delineate: make a map of a type of spatial feature -for example, a map of hillslopes  NOTE: each hillslope is called a “zone”

  7. The GIS Weasel!! delineate: make a map of a type of spatial feature -for example, a map of hillslopes  NOTE: each hillslope is called a “zone” -for example, a map of stream channels

  8. The GIS Weasel!! delineate: make a map of a type of spatial feature -for example, a map of hillslopes  NOTE: each hillslope is called a “zone” -for example, a map of stream channels  NOTE: each stream channel is called a “zone”

  9. The GIS Weasel!! • parameterize:calculate a measure of central tendency (e.g. mean, mode) • - of a value surface • - for each zone of a map • parameter [] = function ( zone_map, value_surface) •  produces one parameter value for each zone

  10. The GIS Weasel!! • parameterize: • Surface values vary cell-by-cell • Zone values vary zone-by-zone

  11. The GIS Weasel!! parameterize: = f( , )

  12. Required Input Data • Elevation data • Any resolution • Any coordinate system

  13. Optional Input Data • Many GIS Weasel functions use elevation • Many GIS Weasel functions do not use elevation • - may use any raster data • user must provide this data • (more on rasters later) • These data may be necessary to parameterize for your model!

  14. Optional Input Data • For example, you may need raster maps of • Soils characteristics • Porosity, texture, depth • Vegetation type • Bare ground, grass, shrub, deciduous tree, coniferous tree • Vegetation density • Land Cover • Impervious surfaces, surface geology • Other

  15. Sample Optional Data Layers for United States Vegetation Type (USFS) Vegetation Density (USFS) Land Use-Land Cover (USGS)

  16. Supported Models • The GIS Weasel is a generic, stand-alone application • Produces simple, ASCII formatted output • -easy to reformat for non-MMS models

  17. Supported Models • Also produces MMS format output

  18. Supported Models • Routines for PRMS • - Daily & storm modes • Routines for TOP_PRMS • - soil moisture based on topographic wetness index • Routines for Xroute • - Muskingum routing model • Routines for Flood Frequency Analyses • Generic Routines • - user specified sets of parameters

  19. Vector vs. Raster • ArcInfo Coverage & ArcView Shapefile • Points • Lines • Polygons • Good for representing things with clear, discrete positions and boundaries.

  20. Vector vs. Raster • ArcInfo GRID • Cells • Continuously varying surfaces • -For example, elevation or vegetation density • Categorical Surfaces • - For example, vegetation type or land cover

  21. Internal Data Formats • GIS Weasel uses both vector and raster formats • Mostly raster based

  22. Raster Processing Kernel • 3x3 matrix of cells • Used in many raster analysis functions

  23. Elevation Data Every cell has an elevation value and a position

  24. Flow Direction Determine direction of steepest slope out of cell using ELEVATION

  25. Flow Accumulation Use FLOW DIRECTION surface to calculate upslope area

  26. Extract Drainage Network Define minimum flow accumulation (upslope area) needed to support streamflow

  27. Modeling Response Units (MRUs) • A concept for sub-dividing an Area-Of-Interest • - for example, a watershed • Different landscape behavior at different locations • An HRU is represented to model as a single, homogenous feature • delineation activity

  28. Modeling Response Units (MRUs) • Alternate HRU conceptualizations • Different models sensitive to different physical attributes • Variety of MRU delineation tools in GIS Weasel • No fixed methods in GIS Weasel

  29. Benefits of Parameter Estimation • Automation • Speed • Well defined methods • Transfer methods to new areas easily • Ability to reproduce results

  30. Benefits of Parameter Estimation • Automation • - reduce labor • Speed • - reduce time costs • Well defined methods • - objective parameter estimation • Transfer methods to new areas easily • - increase value through reusability • Ability to reproduce results • - increase reliability

  31. 9 topographic slope, aspect, area, x,y,z, … 3 soils texture, water holding capacity) type, density, seasonal interception, radiation transmission) 8 vegetation 2 evapotranspiration 5 topological indices Connect HRUs, groundwater reservoirs, subsurface reservoirs, channel reaches, and point measurement stations Always adding more… PRMS Parameters Estimated

  32. The GIS Weasel!! http://wwwbrr.cr.usgs.gov/weasel

More Related