View In:   ArcGIS Online Map Viewer

Name: FTN_Inundation_Areas

Display Field: stateid

Type: Feature Layer

Geometry Type: esriGeometryPolygon

Description: The Mississippi Department of Environmental Quality Dam Safety Division (DSD) contracted with FTN Associates, Ltd. (FTN) to help update the hazard classifications of dams currently not in the State’s Inventory of Dams. Using a rule of thumb method (i.e., not a rigorous engineering dam break analysis) to produce approximate inundations maps from a dam failure, FTN provided suggested classifications for 1,223 dams based on hazards identified within the approximate inundation areas. Although FTN provided suggested hazard classifications, final verification of hazards and potential flooding extents for every dam and its subsequent classification is the responsibility of DSD.  FTN developed an ArcGIS (version 10.1) model that only requires a water height (or height of water behind a dam) and elevation data and applies this to a rule of thumb method to produce approximate inundation maps from a dam failure. The rule of thumb1 assumes the peak height of the breach floodwave at the dam is roughly half of the height of the water behind the dam and that the wave height is halved every 10 miles downstream (Table 1). This rule of thumb method does not take into consideration the volume of the impoundment, inflows or outflows from the dam, type of dam, condition of the dam, or the storage capacity of the floodplain downstream of the dam. FTN produced two sets of inundation areas, the first was based on a water height equal to the dam height (referred to as full inundation) and a secondary set of approximate inundation areas based on a water height that was 1/3 the height of the dam (referred to as partial inundation). The full inundation scenario was intended to be a conservative approximation for a barely overtopping dam breach and suggested dam classifications were based on hazards found in inundation areas generated from this scenario. The second scenario (partial inundation) was performed so that DSD staff could discriminate between dams which may potentially be high hazard under worst case conditions (overtopping breach) and dams which will easily be high hazard under more realistic conditions (water level of 1/3 height of the dam). To assist in the classification process FTN assigned each dam a unique ID, NOIXXXX, where NOI stands for Not On Inventory and XXXX was sequential from 0001 through 1223, e.g. NOI0123.

Service Item Id: a9578aeacb35446ba47b344df9d3262f

Copyright Text:

Default Visibility: true

MaxRecordCount: 2000

MaxSelectionCount: 0

Supported Query Formats: JSON, geoJSON, PBF

Min Scale: 0.0

Max Scale: 0.0

Supports Advanced Queries: true

Supports Statistics: true

Can Scale Symbols: false

Use Standardized Queries: true

Supports ValidateSQL: true

Supports Calculate: true

Extent:

XMin: -91.49729952799999
YMin: 30.306519387000037
XMax: -88.13102211499995
YMax: 35.00018505600008
Spatial Reference: 4326  (4326)  LatestVCSWkid(0)

Drawing Info:

Renderer:
Simple Renderer:
Symbol:
Style: esriSFSSolid
Color: [130, 130, 130, 0]
Outline:
Style: esriSLSSolid
Color: [255, 0, 197, 255]
Width: 1
Label: N/A
Description: N/A
Transparency: 0
Labeling Info:

Feature Draw Order:

N/A

Advanced Query Capabilities:

Supports Statistics: true
Supports OrderBy: true
Supports Distinct: true
Supports Pagination: true
Supports TrueCurve: false
Supports Returning Query Extent: true
Supports Query With Distance: true
Supports Sql Expression: true
Supports Query With ResultType: true
Supports Returning Geometry Centroid: true
Supports Binning LOD: true
Supports Query With LOD Spatial Reference: true
Supports Percentile Statistics: true
Supports Having Clause: true
Supports Count Distinct: true
Supports Time Relation: false
Supports Sql Format: false
Supports Query Analytic: true
Supports Query With Current User: true

HasZ: false

HasM: false

Has Attachments: false

HTML Popup Type: esriServerHTMLPopupTypeAsHTMLText

Type ID Field:

Fields:

• objectid ( nullable: false, defaultValue: null, editable: false, length: 4, type: esriFieldTypeOID, modelName: OBJECTID, alias: OBJECTID )
• stateid ( modelName: StateID, nullable: true, editable: true, defaultValue: null, length: 10, alias: StateID, type: esriFieldTypeString )
• SHAPE__Length ( virtual: true, nullable: true, editable: false, defaultValue: null, alias: SHAPE__Length, type: esriFieldTypeDouble )
• SHAPE__Area ( virtual: true, nullable: true, editable: false, defaultValue: null, alias: SHAPE__Area, type: esriFieldTypeDouble )

Templates:

• Name: FTN_Inundation_Areas
  Description:
  Prototype:
  stateid: null
  
  Drawing Tool: esriFeatureEditToolPolygon

Capabilities: Query

Sync Can Return Changes: true

Is Data Versioned: false

Supports Rollback On Failure: true

Supports ApplyEdits With Global Ids: false

Supports ApplyEdits By Upload Id: true

Supports Query With Historic Moment: false

Supports Coordinates Quantization: true

Child Resources:

Supported Operations:   Query   Query Attachments   Query Analytic   Query Top Features   Query Bins   Append   Validate SQL   Generate Renderer   Return Updates   Metadata   Update Metadata