GIS for integrated 2D H&H modeling support. Dean Djokic and Lori Armstrong, Esri Inc.

Transcription

1 GIS for integrated 2D H&H modeling support Dean Djokic and Lori Armstrong, Esri Inc.

2 Overview GIS for H&H modeling support 1D vs. 2D modeling with GIS GIS techniques for data simplification Schematization Lumping /characterization Weeding /VIP identification 2D (terrain) 1D

3 GIS for H&H modeling support

4 Model and Data Integration!? Integration of data, data models, and analyses in a functional system used to support decision process (spatial decision support system) USGS EPA Local Other GIS ICPR RAS HMS Other Data Providers Models

5 Types of Model Integration - Modeling Support Standard GIS tools are used to derive data and information used in water resources modeling (e.g. watershed boundaries, watershed characteristics, etc.) Data exploration and processing (e.g. develop layer of curve numbers based on land use and soil type layers)

6 Types of Model Integration - Linked GIS is linked to external models GIS internal tools preprocess and post-process model data for costefficient and visually effective results GIS and models maintain their distinctive user interfaces

7 Types of Model Integration - Integrated GIS is integrated with external models GIS internal tools preprocess and post-process model data for costefficient and visually effective results GIS and models share the same user interface

8 Types of Model Integration - Embedded Model functionality is implemented as a core GIS tool (e.g. Porous Puff dispersion model has been implemented as a GRID function)

9 Model/Application Integration Components Data exchange How will the applications/models share the data UI How will the applications manage use interaction Model/application control How will the applications control (each other s) execution SW/HW infrastructure What infrastructure is available to support the integration process

10 Integration Issues Data providers Data consumers (often both) Unspecified at the beginning of the integration exercise Proprietary Data Control Independence from integration platform Development out of control Maintenance curse Long term cost of ownership Complexity increase (multiplicative)

11 Integration Issues (direct interfacing) N RAS MIKE 11 MIKE 21 GIS SWMM FLDWAV HMS Other N * (N - 1) Bi-directional

12 Integration Issues (intermediary interfacing) N RAS MIKE 11 MIKE 21 GIS XML SWMM FLDWAV HMS Other 2 * N Bi-directional

13 Integration Issues (number of interfaces) Number of models Direct integration Intermediary integration N N * (N-1) 2 * N

14 Model Integration Approach Whatever works for particular situation different conditions even for the same integration problem can result in a different integration method Tight or loose coupling Technical issues Legal issues Access to the underlying model structure or not (NSS vs. Excel) Check out the existence of 3 rd party solutions Almost always cheaper to buy a solution than to develop one except for simple tasks.

15 Data Exchange Methods GIS is a database any application that can read and write into one of supported databases has already an interface to GIS data (feature attributes). No direct access to geometry, projection parameters, Use RDBMS native development tools (VBA, ORACLE Forms, ) Custom ArcObjects code full access to every element of ArcGIS in COM environment Allows tight coupling of GIS and numerical models Using other software that can read/write to the same structures as the meeting ground (e.g. Excel, shape files) Data exchange tools/extension

16 1D vs. 2D modeling with GIS

17 Data representation within GIS GIS is by nature a 2D/3D system GIS data structures driven by the data content (where the data are not how they will be modeled) GIS data structures driven by the source of data/data collection techniques (vector/raster) Easy manipulation of spatial data (ETL) structures

18 Data representation within models Type of model defines its data structure (1D/2D/3D) Model data structures driven by the solvers (how the data are modeled e.g. FE/FD/FV) Not always easy (or often any) manipulation of spatial data structures

19 Typical GIS role in modeling support Loose coupling (GIS for model pre/post processing) Space discretization Space characterization Data formatting Visualization/results presentation

20 Typical GIS role in modeling support Model type/function 1D 2D Discretization Characterization Formatting Development of node-link or wireframe representation Spatial averaging/lumping over discretized spatial elements Simpler data structures, smaller volumes Development of modeling schema (triangulation, fishnet) Spatial averaging/lumping over discretized spatial elements and/or push-pin data extraction More complex data structures, larger volumes

21 GIS techniques for data simplification

22 Schematization 1D Node link representation Wireframe representation

23 Schematization 2D Thiessen polygon TIN Fish net Can get tricky need to understand solvers for optimal tessellation!

24 Schematization 2D Topology to ensure spatial consistency within and across layers

25 Lumping /characterization Push-pin (not much to do unless it needs vertical aggregation) Lumping /characterization Zonal stats operations Can do interpolation first, then stats

26 Weeding /VIP identification 2D (terrain/surface) Terrain dataset (terrain pyramids) Window size Z-tolerance

27 Weeding /VIP identification 1D

28 Summary Understanding modeling techniques and their requirements on data preparation (model schematization in particular) Techniques for ensuring data consistency Techniques for geometry simplification before going into 2D models

29 Questions