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Layer: dauph_ntwi.tif (ID: 8)

Parent Layer: Dauphin

Name: dauph_ntwi.tif

Display Field:

Type: Raster Layer

Geometry Type: null

Description: GIS raster dataset displaying Topographic Wetness Index (TWI) for north Dauphin County, PA. This TWI raster was derived from the 2016 USGS QL2 LiDAR DEM data for Dauphin County. The TauDEM extension (D-Infinity tools) for ArcMap was used to create flow direction, slope, and contributing area rasters. TWI was then calculated using the following equation: Ln (Contributing Area/Slope). The methodology was described by Cody Fink in his 2013 thesis entitled Dynamic Soil Property Change in Response to Natural Gas Development in Pennsylvania. TWI results in a dimesionless raster and should be displayed using a red (low values representing no flow) to blue (high, representing high probability flowpaths) color gradient. TWI results vary depending on raster size and analysis options so value thresholds for probability-based overland flowpaths for water should be field verified.

Definition Expression: N/A

Copyright Text: Jamie Shallenberger, SRBC, and Cody M. Fink.

Default Visibility: true

MaxRecordCount: 0

Supported Query Formats: JSON, AMF

Min Scale: 0

Max Scale: 0

Supports Advanced Queries: false

Supports Statistics: false

Has Labels: false

Can Modify Layer: false

Can Scale Symbols: false

Use Standardized Queries: true

Drawing Info: Advanced Query Capabilities:
HasZ: false

HasM: false

Has Attachments: false

HTML Popup Type: esriServerHTMLPopupTypeNone

Type ID Field: null

Fields: None

Supported Operations:   Query   Generate Renderer   Return Updates