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Layer: Topographic Wetness Index (ID: 6)

Name: Topographic Wetness Index

Display Field: Shape_Leng

Type: Feature Layer

Geometry Type: esriGeometryPolygon

Description: The TWI is a physically based index or indicator of the effect of local topography on runoff flow direction and accumulation. The index is a function of both the slope and the upstream contributing area.The computation of TWI is performed using both geographic information systems (GIS) and Python, a programing software used to enhance computing capabilities. The indices help identify rainfall runoff patterns, areas of potential increased soil moisture, and ponding areas. Illinois State Water Survey generated the index to the Illinois counties of DuPage and Will (see report at http://hdl.handle.net/2142/98495), but has subsequently generated the index for all Illinois counties. The DEM used for this county was derived from LiDAR acquired in 2017. While TWI is usually viewed in raster format, ISWS is distributing a version in polygon format for easier access and use.

Copyright Text: Illinois State Water Survey

Default Visibility: false

MaxRecordCount: 1000

Supported Query Formats: JSON, geoJSON, PBF

Min Scale: 24000

Max Scale: 0

Supports Advanced Queries: true

Supports Statistics: true

Has Labels: false

Can Modify Layer: false

Can Scale Symbols: false

Use Standardized Queries: true

Supports Datum Transformation: true

Extent:
Drawing Info: Advanced Query Capabilities:
HasZ: false

HasM: false

Has Attachments: false

HTML Popup Type: esriServerHTMLPopupTypeAsHTMLText

Type ID Field: null

Fields:
Supported Operations:   Query   Query Attachments   Query Analytic   Generate Renderer   Return Updates

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