Adapting the ArcHydro Water Resource Data Model to NY State Canal Inspection Data

Design and Implementation of a Geodatabase for New York StateCanal Inspection DataRuth Ann TrudellNY State GIS Users ConferenceLake Placid, NYOctober, 2009TopicsProject ObjectiveCanal HistoryInspection Methods, Data Storage and Need for modernizationDatabase DevelopmentLessons LearnedProject ObjectiveProvide a single storage location for all spatial and tabular data pertinent to Canal Inspections.Canal History

Travelway for Commerce

Current Canal System

Canal ManagementOperated and maintained by the Canal Corporation, New York State Thruway AuthorityInventory performed by NYS DOT through MOUCanals managed primarily for recreational purposes and historic valuesCanal ConstructionParts of canal are embedded in the landscape; parts raised above.

Portions are raised above the surrounding landscape with the use of levees or embankments.

Typical High Embankment

Embankment Failure

Inspection ProcessInspect every 5 years.Inspection segments delineated on paper maps.Embankment conditions documented in field.Pictures taken at points of interest.Segments are ranked and rated. Miles of segments summarized by rating.Report written summarizing findings.

Inspection Segment Map

Back side with Risk assessment calculationsCurrent Data StoragePaper maps, inspection forms and reports.Disparate spatial files stored on CC and DOT servers.

Solution? A Database!Database Development Database Development StepsDetermine Business Needs/Database StructureDecide upon Database ElementsPopulate DatabaseTest by Querying Database

Key steps I took in developing the database. 2009 Business Needs MeetingValidate data input and output needs (business functions)Discuss Database ConsiderationsSpatial representations- feature classes vs. linear referencing Appropriate routeAggregation/disaggregation of dataImage hyperlinks

Database StructurePersonnel GDBFile GDBAccess DBAccess based, user familiarity

Queries and data input done within ArcGIS environmentUser familiaritySpatial data storage,Limited storage capacitySpatial data storageLarge storage capacityNo spatial data storage; User develops relates in ArcMapGPS check-in/check-outGPS check-in/check-out Topology storedTopology stored Terrain storage capability File Geodatabase!

Database Elements Element 1- The Value of Terrains

Element 2- Linear Representation; Events or FeaturesTwo Critical Questions:Use linear events or line features to represent inspection segments?

If events are to be used, which route is appropriate? which measure?

Events vs. FeatureSegment vs. route reference. Line features are collected using GPS and represent geographic locations of the segments. Linear referenced data represents the segment locations along a reference route (canal prism).

Another ExampleAnother exampleSelection of Linear RouteCanals Corporation routed lines (measure in meters)

Canal Corporation lines calibrated to stationing in feet.

National Hydrography Dataset (NHD)- National Standard

EventFeatureElements 3-5 Features, Data Tables, Relationship ClassesThere are also hyperlinks to scanned inspection forms and photos.

Element 6- Domains

Element 7- MetadataAnd YES, of course a Data Dictionary!Database Maintenance Complexities of RoutesRequires for both Events and Feature Classes

1. Linear referencing requires event tables with measures, WHILE:

2. Field data collection using GPS and mapping query results both require features classesTabular Data Input-Existing Feature

Testing and Data Reporting Extracting Data-Making Query Table

Located in toolbox under Data Management Tools>Layer and Table ViewsExample: SQL Expression Segment2009.SegID = Inspection.SegID AND Inspection.AdjTerrain = DevRes

Segment2009.SegID = Inspection.SegID AND Inspection.InspectionID = OtbdChar.InspectionID AND OtbdChar.DrainStrID = DrainStruct.DrainStrID AND DrainStruct.StructCondition = Good

Lessons LearnedRelationship classes in GDB depend on exact match of field names in feature attribute and data tables.

Use descriptive codes for coded domains. Exported tables contain codes, not descriptions! Ensure topology of routes is uni-directional and calibration point measures increase sequentially in up route direction.

Take advantage of NY State GIS Help Desk; They are an excellent resource!

Final ResultSuccessful development of a database that addresses data storage, data retrieval and data display needs! CreditsDr. Patrick Kennelly, Graduate AdvisorAssist. Professor, Long Island University, and Penn State UniversityJamie DeLuca, NY State Canal CorporationSteve Heiser, Department of TransportationRicardo Lopez and Tim Daly, Department of Environmental ConservationENDHydraulic Modeling with NHD

Spatial Placement, Canal Prism vs NHD Route

Event Table, cont.

Directly put new data, measure and other info in event table. Then, create feature. recreate relationship class input data into other related tables. Example of Implementation Data Input- New SegmentsEnsure database contains empty (temporary) segment feature related to inspection table (required to GPS new features),Check out DB to GPS,Collect data - database tables will be updated through relates,Check in DB,Use Locate Features along Routes to obtain measures and RID,

Data Input- New Segments (cont)Rename Segment ID with measure info.,Append this attribute table to event table,Recreate permanent feature class, Empty contents of the temporary feature class for future use with GPS.