General Introduction

Developed by USGS Freely available via Internet

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

Purpose: simplify the creation of spatial information in modeling by providing tools to delineate parameterize relevant spatial features.

delineate: make a map of a type of spatial feature -for example, a map of hillslopes

delineate: make a map of a type of spatial feature -for example, a map of hillslopes  NOTE: each hillslope is called a “zone”

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

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”

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

parameterize: Surface values vary cell-by-cell Zone values vary zone-by-zone

parameterize: = f(, )

Elevation data Any resolution Any coordinate system

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!

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

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

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

Also produces MMS format output

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

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

ArcInfo GRID Cells Continuously varying surfaces -For example, elevation or vegetation density Categorical Surfaces - For example, vegetation type or land cover

GIS Weasel uses both vector and raster formats Mostly raster based

3x3 matrix of cells Used in many raster analysis functions

Every cell has an elevation value and a position

Determine direction of steepest slope out of cell using ELEVATION

Use FLOW DIRECTION surface to calculate upslope area

Define minimum flow accumulation (upslope area) needed to support streamflow

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

Alternate HRU conceptualizations Different models sensitive to different physical attributes Variety of MRU delineation tools in GIS Weasel No fixed methods in GIS Weasel

Automation Speed Well defined methods Transfer methods to new areas easily Ability to reproduce results

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

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…