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Integrating GIS and environmental models

Integrating GIS and environmental models. object-oriented integration. Integrating GIS . Environmental problems are spatial problems, environmental data can almost always be georeferenced. GIS is therefor an appropriate tool for environmental analysis. Integrating GIS .

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Integrating GIS and environmental models

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  1. Integrating GIS and environmental models object-oriented integration K.Fedra ‘97

  2. Integrating GIS ... Environmental problems are spatial problems, environmental data can almost always be georeferenced. GIS is therefor an appropriate tool for environmental analysis. K.Fedra ‘97

  3. Integrating GIS ... Basic concepts in GIS are: • location • spatial distribution • spatial relationship Basic elements: • spatial objects K.Fedra ‘97

  4. Integrating GIS ... spatial (geometric) objects: • point • node (topological) • arc, chain, graph • polygon • pixel, grid cell, cell grid, raster • TIN, FE mesh, nested grids • 3D elements K.Fedra ‘97

  5. Integrating GIS ... spatial (topical) objects: • landmark, reference point • river reach, road segment • administrative units: block, district, city, county, province, country, region, ..... • river basin, landform • island, continent K.Fedra ‘97

  6. Integrating GIS ... Basic concepts in environmental modeling are: • systems state • systems dynamics • interaction Basic elements: • functional objects and processes K.Fedra ‘97

  7. Object-oriented integration links the basic elements: of GIS: spatial objects and models: functional objects and processes through object-oriented design. K.Fedra ‘97

  8. Object-oriented integration Some concrete examples: • ECOSIM, an urban environmental information and decision support system • WaterWare, a river basin management information system • GAIA, a global multi-media EIS K.Fedra ‘97

  9. ECOSIM EN1006: is a model-based decisionsupportsystem for urban environmental management. It integrates on-line data acquisition and monitoring systems, GIS and dynamic simulation models in a flexible client-server architecture based on standard protocols: TCP/IP and http. K.Fedra ‘97

  10. Systems architecture supports three main function groups: • data acquisition and storage • analysis and forecasting of management scenarios • communication of information contents and results to the user (user dialogue, visualization). K.Fedra ‘97

  11. Systems architecture data acquisition layer DBMS GIS data management models expert system models expert system analyticalmodels graphical user interface K.Fedra ‘97

  12. Systems architecture client-server architecture based on TCP/IP and http. Main ECOSIM SERVER coordinates: • user interface and dialogue • information display, GIS • external information resources: - data bases, monitoring data - simulation models. K.Fedra ‘97

  13. Systems architecture these functions are supported by a set of conceptual servers: • Data Resources Servers • Model/Compute Servers • User Interface Servers that integrate the information resources and tools of ECOSIM K.Fedra ‘97

  14. Systems architecture MODEL 1 MONITORING ECOSIM SERVER MODEL 2 DATA BASES X Windows http browser K.Fedra ‘97

  15. Systems architecture MODEL 1 MONITORING ECOSIM SERVER MODEL 2 DATA BASES X Windows http browser K.Fedra ‘97

  16. Systems architecture Object-oriented paradigm: the systems OBJECTS encapsulate methods that utilize the information resources and tools provided by the conceptual servers. K.Fedra ‘97

  17. Development methodology Object-oriented design: models based on real-world concepts. OBJECTS combine: datastructure and function in a single construct. K.Fedra ‘97

  18. Development methodology Objects in ECOSIM include: • decision scenarios • model scenarios • emission sources • observation data (stations) K.Fedra ‘97

  19. Development methodology Object-oriented design: Abstraction: denotes essential characteristics that distinguish different object (classes) K.Fedra ‘97

  20. Development methodology Abstraction is implemented through the ECOSIM Object TEMPLATE definition files K.Fedra ‘97

  21. Development methodology Object-oriented design: Encapsulation: hides all the details of an object that do not contribute to it's specific characteristics. K.Fedra ‘97

  22. Development methodology Encapsulation for ECOSIM Objects includes their respective set of methods used for • instantiation (obtaining data) • update of state (context dependent) • display and dialogue • communication with other objects K.Fedra ‘97

  23. Development methodology Object-oriented design: Modularity: is the property of a system that can be decomposed into a set of strongly cohesive and loosely coupled modules. K.Fedra ‘97

  24. Development methodology Modules in ECOSIM include: • individual simulation models • model and decision scenarios • emission inventories • observation (monitoring) systems • geographic information system represented as object classes and implemented on conceptual servers. K.Fedra ‘97

  25. Development methodology Object-oriented design: Hierarchy: is the ranking order of abstraction: • Aggregation: is part of ... • Inheritance: is a kind of ... K.Fedra ‘97

  26. Development methodology Hierarchy in ECOSIM: Air-quality monitoring stations (AQ) are part of observation stations (OS). A specific station (kind of AQ) inherits the generic properties of the AQ (parent) class. K.Fedra ‘97

  27. Development methodology Object-oriented design: Concurrency: is the property that distinguishes objects in terms their respective threads of control and state of activity (interactive, active (batch), passive). K.Fedra ‘97

  28. Development methodology Concurrent objects in ECOSIM are used for the HPC models • MEMO (3D atmospheric) • DYMOS (3D photochemistry) which require computing times that may make interactive use infeasible depending on available machines. K.Fedra ‘97

  29. Object-oriented design Rumbaugh et al. (1991) • informal and flexible, based on recommendations (legacy software) • stresses readability and expressive power in code and documentation • focus on adding detail incrementally • encourages iteration and prototyping K.Fedra ‘97

  30. Object-oriented design • well proven for commercial, event driven (OO/C++) software products • appropriate for interactive (event driven) GUI software • implementation through coding (prototyping) cycles • more informal, middle-out life cycle. K.Fedra ‘97

  31. Object-oriented design References: Rumbaugh,et al., (1991) Object Oriented Modelling and Design. Prentice Hall, NJ, USA, ISBN 0-13-629841-9. Oskarsson, Ö. and Glass, R.L. (1996) An ISO 9000 Approach to Building Quality Software. 274 pp., Prentice Hall, NJ, USA, ISBN 0-13-228925-3. K.Fedra ‘97

  32. Integration example: WaterWare, a river basin management information system combines: • hybrid GIS linked to object classes: • river basin elements • models and model scenarios • tasks or decision problems K.Fedra ‘97

  33. WaterWare River basin objects are spatially referenced; they can represent • measurement stations point • treatment plants point • river reaches line, arc • subcatchments polygon • etc., etc. K.Fedra ‘97

  34. WaterWare River basin objects are defined by: • context defined by other objects • methods they use to update their state using other objects, models, rules of an embedded expert system, any information resource available. K.Fedra ‘97

  35. WaterWare Tasks are specific problem oriented view of sets of river basin objects. They assess or forecast their state (over time) given a number of decision variables and scenario assumptions (the context) to provide decision support information. K.Fedra ‘97

  36. WaterWare Objects are interlinked, providing information to each other: Reservoir is linked to subcatchment that provides its inflow, linked to a monitoring station that records it, and an irrigation district it supplies. Reservoirs itself an element in the water allocation task. K.Fedra ‘97

  37. WaterWare Objects have their specific display, reporting and editing functions (user interface) as part of their encapsulated methods. All object attributes can be edited through a rule-based expert systems. K.Fedra ‘97

  38. WaterWare RiverBasinObject Classes climate stations flow stations water quality st. settlements water works treatment plants industries animal farms irrigation districts subcatchments dams, reservoirs weirs, falls, gates, sluices abstraction river reaches, cross sections aquifers, wells scenic sites K.Fedra ‘97

  39. WaterWare RiverBasinObject Classes spatially referenced by • location (reference point, shape, extent) • links to geographical objects: • community, province, state • subcatchment, river segment K.Fedra ‘97

  40. WaterWare RiverBasinObjects can be • displayed on the map • selected from the map • aggregated across spatial objects Base maps and display functionality are provided by the GIS K.Fedra ‘97

  41. WaterWare RiverBasinObjects main functions: • obtain or update their current state (load, compute, infer, ask ....) from information resources (objects) • report their current state to clients (other objects, display clients: X-Windows or http, hardcopy, etc.) K.Fedra ‘97

  42. WaterWare RiverBasinObjects each class has a set of specific attributes in a set of data structures and associated methods, defined in a object class TEMPLATE. Objects inherit this structures and the generic class properties upon instantiation. K.Fedra ‘97

  43. WaterWare RiverBasinObjects TEMPLATEs • header with name, ID, location, links to geographical objects, meta data • attributes defined as • DESCRIPTORS (variables of the expert system) • lists and tables • time series • links K.Fedra ‘97

  44. WaterWare • RiverBasinObjects attributes can be • data stored with the objects • methods that retrieve or generate these data: • DESCRIPTORS use the expert system • file references • embedded SQL • URLs for remote information sources. K.Fedra ‘97

  45. RiverBasinObjects subcatchments: methods include the display of the object in hypertext multi-media style. K.Fedra ‘97

  46. RiverBasinObjects subcatchments: object display includes a map with a DEM of the basin as part of an embedded hypertext display. K.Fedra ‘97

  47. RiverBasinObjects subcatchments: basin properties like landcover distribution and topography (elevation bands) are presented in a graphical format as well as a list of numerical values that can be edited through the embedded expert system: K.Fedra ‘97

  48. RiverBasinObjects subcatchments: basin properties like landcover distribution and topography (elevation bands) are presented in a graphical format as well as a list of numerical values that can be edited through the embedded expert system: K.Fedra ‘97

  49. RiverBasinObjects subcatchments: basin properties like landcover distribution and topography (elevation bands) are presented in a graphical format as well as a list of numerical values that can be edited through the embedded expert system: K.Fedra ‘97

  50. RiverBasinObjects subcatchments: the main functional attribute of the subcatchment object is its outflow, which feeds into a number of other models. This is computed, as a function of the basin attributes, with the dynamic (daily) rainfall-runoff model: K.Fedra ‘97

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