Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam WFM 6202: Remote Sensing and GIS in Water Management Geographic Information System (GIS) Lecture 4 Geo-Spatial Database and GeoDatabase of ArcGIS Dr. A.K.M. Saiful Islam Institute of Water and Flood Management (IWFM) Bangladesh University of Engineering and Technology (BUET) December, 2015 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam What is a geographical Database? • Spatial databases provide structures for storage and analysis of spatial data • Spatial data is composed of objects in multi-dimensional space • Storing spatial data in a standard database would require excessive amounts of space • Queries to retrieve and analyze spatial data from a standard database would be long. • Spatial databases provide much more efficient storage, retrieval, and analysis of spatial data WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Needs • Need better ways to represent, understand, manage, and communicate our natural world WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam What is a geographical Database? –cont. • A spatial database is an ORDBMS that has the ability to store, query, manipulate and analyze spatial data as well as traditional data formats • It offers spatial data types/data models/ query language – Structure in space: e.g., POINT, LINE, REGION – Relationships among them: (ex:intersects) • It provides spatial indexing (retrieving objects in particular area without scanning the whole space). • It provides efficient algorithms for spatial joins . • SDBMS is mainly used for vector format. • It defines data types for points, lines, polygons, multipoint, multiline, and multipoloygon WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Concept of Spatial Database • A spatial database is defined as a collection of interrelated geospatial data, that can handle and maintain a large amount of data which is shareable between different GIS applications. • Required functions of a spatial database are as follows. - consistency with little or no redundancy. - maintenance of data quality including updating - self descriptive with metadata. - high performance by database management system with database language. - security including access control. WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Design of Spatial Database The design of spatial database will be made by the database manager who is responsible for the following issues: definition of database contents selection of database structure data distribution to users maintenance and updating control day-to-day operation WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Properties of geographic data • Has location – Location is a special kind of key (i.e. list of values) how is it handled? • Multidimensional – Directional, topological relationships, how is it formalized • Scale-dependent – Spatial versus Geographic • Its occurrence is spatially autocorrelated – Tobler’s first law of geography • Not well captured by precise description – Uncertainty should be formalized • Some geographic phenomena are continuous – Object-view wouldn’t fit well • Some geographic phenomenon is closely associated with temporal changes – event, process, moving object Geographic data need special treatment indeed! WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Database Design Parameters The following parameters should be well designed. • storage media Volume, access speed and on line service should be considered. • partition of data Choice of administrative boundaries, map sheets, watersheds etc. will be made in consideration of GIS applications • standards Format, accuracy and quality should be standardized. • change and updating Add, delete, edit and update should be well controlled by the database manager. • scheduling Data availability, priorities, data acquisition etc. should be well scheduled. • security Copyright, back up system and responsibilities should be well managed. WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Partition of Spatial Data WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Evolution of Database model • • • • • • File systems Network DBMS Hierarchical DBMS Relational DBMS Object-oriented DBMS Object-relational DBMS WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Relational Model • Based on two important concepts: – Key of relation - one to one, one to many, many to many – Primary attribute – which can’t be duplicate Student Table * * Course Table Many to Many relationship Student Table Student ID Name CourseID 1 Mr. X 001 2 Mr. X 002 3 Mr. Y 003 Course table Cour seID Title Cre dit 001 RS & GIS in WM 3 002 Watershed Hydrology 3 003 Risk Management 3 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Relational Database • • • • • • Relational database is the most popular model for GIS. For example, the following relational database softwares are widely used. - INFO in ARC/INFO - DBASE III for several PC-based GIS - ORACLE for several GIS uses In a relational model, the following two important concepts should be defined. Key of relation ; a subset of attributes Unique identification ; e.g. the key attributes is a phone directory in a set of last name, first name and address. non redundancy ; any key attribute selected and tabulated should keep the key's uniqueness. e.g. address can not be dropped from telephone address, because there may be many with the same names. Prime attribute : an attribute listed in at least one key. The most important point of the relational database design is to build a set of key attributes with a prime attribute, so as to allow dependence between attributes as well as to avoid loss of general information when records are inserted or deleted. WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Structural Query Language (SQL) • SQL is used to perform query in relations databases. • For example, find the name of the student who took more than or equal to 6 credit hour in this term SELECT Student.Name, Course.Credit FROM Student, Course WHERE Student.CourseID = Course.CourseID AND Credit >= 6 • The answer is : Mr. X 6 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Find the relationship between this two tables in the BUET Library Book Table ISBN Title Author 050 Applied David Hydrology Maidmen 060 Irrigation Cheng One to one Many to Many One to Many Borrow Table ID Name ISBN 1 2 3 Mr. P Mr. Q Mr. R 050 060 070 ? WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Normalization of an Un-normalized Table to relational database WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Advantage of Relational Database Advantages there is no redundancy. type of building of an owner can be changed without destroying the relation between type and rate. a new type of building for example "Clay" can be inserted. (row insert is easy). Disadvantages Require a number of tables and relationship Its difficult to add a new column in the table. WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam 4. Object Oriented Model BUET Part of Part of Departments Is a Is a CE Institutes Is a URP DCE IWFM AIT WRE Is a = Inheritance Part of = association Attributes: Faculty, Staff, Students WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Object Oriented Database • An Object Oriented model uses functions to model spatial and non-spatial relationships of geographic objects and the attributes. • An object is an encapsulated unit which is characterized by attributes, a set of orientations and rules. An object oriented model has the following characteristics. • generic properties : there should be an inheritance relationship. • abstraction : objects, classes and super classes are to be generated by classification, generalization, association and aggregation. • adhoc queries : users can order spatial operations to obtain spatial relationships of geographic objects using a special language. WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Example of Object Oriented Model WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Object based vector data model • It treats spatial data as object. An object can represent a spatial feature such as a road or a hydrologic unit. • Object based database differ from relational database in two important aspects: – 1. It stores both spatial and attribute data in a single system rather than an split system. – 2. it allows spatial feature (object) to be associated with a set of properties and methods. A property describes an attribute or characteristics of an object. A method performs a specific action. WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam What is object-Relational DBMS? • Add OO-ness to tables • All persistent (database) information is still in tables, but some of the tabular entries can have richer data structure, that is ADTs • ORDBMS supports an extended form of SQL • Potential for mapping spatial concepts • For example, Oracle 8i implements spatial data types and spatial operators WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Data types and models point line region Spatial Data types: • Point : object represented only by its location in space • Line : representation of moving through or connections in space • Region : representation of an extent in 2d-space WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Introduction to ArcGIS • Spatial Visualization & G.I.S. • What is ArcGIS? • Easy Mapping Techniques Using ArcGIS CSSCR Back-to-School Seminar, Fall 2009 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Spatial Visualization & G.I.S. |Spatial Visualization ‘How to say what to whom, and is it effective?’ Source: Kraak and Brown, 2001 CSSCR Back-to-School Seminar, Fall 2009 |G.I.S. • Geographic Information System (G.I.S.) if taken as a system, involves the hardware, software, peoples and the procedure in spatial data visualization, management, representation and analysis (NCGIA Core Curriculum in GIS, 2009) CSSCR Back-to-School Seminar, Fall 2009 Source: ESRI WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Spatial Visualization & G.I.S. WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Spatial Visualization & G.I.S. |Geospatial Database MAP DATABASE column vector raster t.i.n.* Point Cell Triangle row Line Polygon *T.I.N. (Triangulated Irregular Network) WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam What is ArcGIS? |Software Background • ArcGIS is the ‘hegemonic’ G.I.S. software program; developed & distributed by ESRI ArcGIS editions ArcView ArcEditor ArcInfo Standard Professional Enterprise Increasing product price CSSCR Back-to-School Seminar, Fall 2009 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam What is ArcGIS? |Software Background ArcGIS Interfaces ArcCatalog •Organization of GIS files •Creation, Preview, Open GIS data files CSSCR Back-to-School Seminar, Fall 2009 ArcMap •Create, Edit, Manipulate, Analyze & Query GIS data ArcToolbox •Contains a set of handy tools •Analysis, Conversion & Data Mgt Tools WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam What is ArcGIS? |Exploring ArcMap • Loading, Arranging & Exploring Attributes of Layers • Zoom & Pan • Selection Features: Selecting, Identifying and Finding Features WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Loading, Arranging and Exploring Layer Attributes • Add Data toolbar • • • • Layer = map + attribute Sorting Layers Open Attribute table Change Layer Properties CSSCR Back-to-School Seminar, Fall 2009 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Zoom & Pan • Tool toolbar • Zoom, Pan and Change Map Scale Zoom & Pan WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Selection Features: Selecting, Identifying and Finding Features • Select Feature Tool – Zoom to Selected Features – Statistics – Clear Selected Features • Identify Feature Tool WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Finding Features • Find Toolbar WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Easy Mapping Techniques Using ArcGIS|Loading A Map With ArcMap Open, click the Add Data toolbar Search for the shapefiles (.shp) in the folders you created earlier and click Add CSSCR Back-to-School Seminar, Fall 2009 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Easy Mapping Techniques Using ArcGIS|Querying With the layer, dtl_cnty checked, go to: Selection >Select By Attributes Query the attributes (see illustration) CSSCR Back-to-School Seminar, Fall 2009 Introduction to ArcGIS WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Easy Mapping Techniques Using ArcGIS|Selecting & Creating Layers Out of Selection Selected features (counties of Washington State) are highlighted Create a new layer out of the selected features (see illustration) WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Easy Mapping Techniques Using ArcGIS|Creating Shapefiles Create a new shapefile out of the layer (see illustration) & make sure to create your desired .shp filename in your folder (for easy access) Add the new shapefile using Add Data toolbar WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Easy Mapping Techniques Using ArcGIS|Creating A Choropleth Map Choropleth maps are thematic maps in which areal units are shaded in proportion to measurement of variable (e.g. population density) Right Click Layer of interest and Select Properties WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Easy Mapping Techniques Using ArcGIS|Creating A Choropleth Map With Layer Properties opened, go to Symbology and then select: Quantities > Field (POP05_SQMI) > OK A choropleth map showing population density (2005) per county within Washington State is shown CSSCR Back-to-School Seminar, Fall 2009 Introduction to ArcGIS WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Easy Mapping Techniques Using ArcGIS|Adding Fields and Calculating new variables Examine Table Attributes of your created shapefile Let us say we are interested to see the spatial distribution of proportion of blacks per county in Washington State We can create a new attribute(variable) (say, variable name, pblack) for this by using the formula: pblack=black/pop2000 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Easy Mapping Techniques Using ArcGIS|Adding Fields and Calculating new variables We first add a new field Open attribute table Right Click and Select ‘Add Field’ WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Easy Mapping Techniques Using ArcGIS|Adding Fields and Calculating new variables With the Add Field window open, fill-out variable specifics (name = pblack, type = double) Right click the new variable, pblack, and click Field Calculator With the Field Calculator window open, calculate the values (see illustration) WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Easy Mapping Techniques Using ArcGIS|Map Layout WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam History of ArcGIS Arc/INFO (Unix) 1969 1982 1989 PC Arc/INFO (DOS + Windows) Jack Dangermond founds ESRI 1992 ArcView + Arc/INFO 1999 ArcGIS v.8.0 (to v8.3) 2002 ArcView 3.3 “retired product” 2004 2008 ArcGIS v.9.0 ArcGIS v.9. 48 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Overview of Applications ArcGIS Server ArcSDE ArcIMS ArcGIS Engine ArcObjects ArcGIS Desktop ArcReader ArcGIS Explorer ArcGIS Mobile ArcPad 49 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Overview of ArcGIS Desktop • ArcGIS Desktop has three levels of licensing: • ArcView – Mapping + geoprocessing + data management • ArcEditor – ArcView + additional editing + additional geoprocessing • ArcInfo – ArcEditor + advanced geoprocessing + extensive database management + high-end cartography 50 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Overview of ArcGIS Desktop • ArcGIS Desktop has three levels of licensing: • ArcView – Mapping + geoprocessing + data management • ArcEditor – ArcView + additional editing + additional geoprocessing • ArcInfo – ArcEditor + advanced geoprocessing + extensive database management + high-end cartography 51 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam ArcGIS Desktop Components • ArcCatalog • ArcMap • ArcToolbox • Extensions • 3D Analyst, Spatial Analyst, Network Analyst, Geostatistical Analyst, Crime Analyst, ArcGIS Schematics, Business Analyst, PLTS, Data Interoperability, Tracking Analyst, ArcGIS Publisher, Survey Analyst, ArcScan (included with ArcEditor license), Maplex (included with Arcinfo license) http://www.esri.com/software/arcgis/about/desktop _extensions.html 52 http://support.esri.com/index.cfm?fa=software.exte ntions WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Data Models - 1 • How we represent real world spatial phenomena • Two main models: • Vector – Points (single x,y coordinate) – Lines (strings of x,y coordinates) – Polygons (closed string of x,y coordinates) • Raster – A grid of (often) square-shaped cells – Individual cells together are used to create a layer of points, lines and areas 53 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Data Models - 2 – Other models: • Surfaces for 3D visualisation • Networks (geometric, transportation) 54 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam ESRI Data Formats • Coverages (vector) and GRIDs (raster) – Consists of two folders: • name of coverage or grid • INFO directory • Shapefiles • Geodatabases Examples of coverages in Windows File Explorer 55 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Shapefiles <filename>.shp stores the spatial or feature information <filename>.dbf dBASE file contains attribute information about the spatial features <filename>.shx stores the index of the features <filename>.sbn stores the spatial index of features <filename>.sbx also stores information pertaining to the spatial index of features <filename>.prj contains projection information WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Geodatabases • Core ArcGIS data model • A comprehensive model for representing and managing geographic data • Personal Geodatabase • Single user editing / multiple readers • Stored in MS Access ArcGIS • Size limit of 2 GB • File Geodatabase • Single user editing / multiple readers • 1 TB per table • Reduced storage requirements • ArcSDE Geodatabase ArcSDE Personal • Stored in an Enterprise DBMS Geodatabase • Supports multiuser editing via versioning • Requires ArcEditor or ArcInfo to edit File Geodatabase ArcSDE Geodatabase Oracle SQL Server DB2 Informix PostgreSQL WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam ArcCatalog • these formats are comprised of many files so you need a GIS data management system WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam The ArcCatalog Interface 1 Title bar 4 Standard toolbar 2 Location toolbar 5 Dockable toolbars 3 Metadata toolbar 6 Catalog Tree (navigation) 7 Geography Preview Mode 59 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Catalog Tree • Icons identify data types • Right-click of a context menus • Supports drag, drop, copy, paste • Displays folder connections • Displays other connections • ArcSDE databases • Web servers (internal, ESRI) Context menu 60 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Different Views – Contents Tab 61 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Preview - Geography 62 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Preview - Table View 63 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Metadata View 64 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Management tasks • Copy, paste, delete, rename data • Move to other locations • Create new objects • Connect to folders 65 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Searching for Data • Edit Search • can search for geography or metadata • can search using different parameters • Name + physical location • Geography • Date 66 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam ArcCatalog Options • Tools Options • Manage ArcCatalog’s content and behaviour • Add new file types (e.g. ppt) • Set font characteristics for tables • Set geoprocessing environment • Set metadata defaults 67 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Metadata • Descriptive information about data • Content • Quality • Condition • Origin • Other characteristics – But do you really need it? • All GIS resources need metadata – Spatial data – Non-spatial data 68 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Metadata in ArcCatalog • one-stop shop for all your metadata needs • can create metadata for anything visible in the catalog • ArcCatalog has the tools for working with it • ToolsOptions Metadata tab • Metadata toolbar for working with metadata 69 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Metadata Components • Documentation: metadata elements the user can edit • • • • Abstract Purpose Use constraints Etc. • Properties: elements that update automatically • Names and types of attributes • Coordinate system information • Bounding coordinates 70 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Metadata Standards • GEMINI v.2.1 is the UK metadata standard (Oct 2007) • based on ISO19115 • to meet the requirements for metadata of the EU INSPIRE Directive http://www.gigateway.org.uk/metadata/standards.html 71 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Create and update metadata • Automatically • Created first time an item’s metadata is viewed • Updated whenever metadata is viewed in metadata tab • Edit metadata button • Manually • Tools Options Metadata tab • Create / Update metadata button • Choose your stylesheet here 72 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Metadata Editor 73 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam More Information on Metadata • Sample code or custom applications to automate metadata production from the ESRI Developer Network • http://edn.esri.com – find resources for ArcGIS 9.2 and prior and in Code Exchange, enter “metadata”) • • • • • Metadata SpellChecker Edit Metadata in ArcMap Create Metadata for All in Folder Metadata Quick Editor (executable file) Template Exporter 74 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam In Summary •ArcCatalog allows you to: • Browse, manage and find spatial data • Record, view and manage metadata • Search for GIS data on local drives, networks and the Web • Define, import and export geodatabases and other datasets • Create and manage the schemas of geodatabases • Administer ArcSDE geodatabases • Administer an ArcGIS server 75 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam An Introduction to ArcCatalog •Hands-on Exercise #1 76 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam The ArcMap Interface 4 Standard Toolbar 6 Drawing Toolbar 3 Main Menu Toolbar 5 Tools Toolbar 1 Table of Contents 2 Map Display 77 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam • • Adding Layers Use the Add Data button Search for data in ArcCatalog and slide the data into ArcMap 78 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Right-click: Context Menu 79 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Tools Toolbar Zoom in Zoom in to a fixed extent Pan Go to previous extent Select features Select elements Find Measure Zoom out Zoom out to a fixed extent Go to full extent Go to next extent Clear selected features Identify Go to X-Y coordinate Hyperlink 80 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam First Generation Storage/Linking AS400 Database Access Database Tabular Data Spatial Data •Tabular/Spatial data is linked outside the database •Links occur using unique IDs….Parcel Numbers •Storage is still in separate locations WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Second Generation Storage/Linking Geodatabases Tabular Data Spatial Data •Tabular/Spatial data is stored/linked in a single location!! WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Benefits of a GeoDatabase o Spatial & attribute data integrity o Intelligent Behavior o Centralized Data Storage o Increased Performance o Advanced Analysis Capabilities o Multi-user editing (SDE format) WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Benefits of Migrating to a Geodatabase Data Integrity • Maintain tabular data more efficiently – Reduce typological data errors • Maintain spatial data more efficiently – Reduce spatial errors Pro-West & Associates WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam What is a Geodatabase? • A spatial and attribute data container – Relational database management system (RDBMS) – Maintains data integrity – Apply Rules and Behavior • Native data format for ArcGIS Relational Database - A method of structuring data as collections of tables that are logically associated to each other by shared attributes. Any data element can be found in a relation by knowing the name of the table, the attribute (column) name, and the value of the primary key. WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam 2 Types of Geodatabase • Personal Geodatabase – Stand alone PC, MS Access database – Supports individual and small groups on moderate size datasets • Enterprise Geodatabase – Exists on underlying RDBMS through Spatial Database Engine (SDE) e.g. SQL Server – Usually runs on a dedicated server – Supports many users and massive datasets – Supports raster datasets WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Two types of GeoDatabases • Personal – Access • Multi-user – SDE GIS SDE SQL View/Anal yze Interpret er Data Stora ge WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam The Personal Geodatabase It’s not Scary! • Stores spatial and tabular data in an Access database format • Sets the stage for future SDE geodatbase migration • Edit in ArcView, ArcEditor or ArcInfo WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Geodatabase Features Feature Dataset • Contains Topology tables, feature classes, feature Feature Classes datasets, topology rules, etc. Tables WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Geodatabase Elements Geodatabase Feature data set Geometric network Feature class Relationship class Table Annotation class WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam GeoDatabase (GDB) structure • Stores – Feature datasets – Feature classes – Tables – Raster – More • A unique structure within the GDB WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Feature Dataset • Contains Feature Classes – Must have same coordinate system • Required for Topology – Behavior relationships between feature classes. WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam GDB Objects: Feature Dataset • A collection of feature classes – Environment for spatial reference – Environment for topology – Environment for coincident geometry and linked annotation – Feature classes inherit spatial reference • Data loaded are projected on the fly, if necessary WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Feature Class • Stores a single feature type – Point, Line, Polygon • Can be standalone or member of a Feature dataset Feature Dataset Feature Class Stand Alone WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam GDB Objects: Feature Class (FC) • A collection of features – Each feature class has one geometry type (point, multi-point, line, polygon) • Can be stored in a feature dataset or ‘stand-alone’ • Attributes are stored with coordinate data in one table WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Spatial Reference A WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Coordinate domain • Extent of available coordinates – Min and max X,Y coordinates – Precision = storage units per map unit • Example, 1000 mm per meter • Make sure it covers study area – Allow for growth • ArcCatalog default – Import: data plus room for growth • Set your own – Import from existing data – Type in extent for study area 2.14 billion storage units WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Domain • A property of a feature dataset or feature class (cannot change once set) WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Domains • Spatial • Attribute – Range of values (e.g., 0-100) – Coded values (e.g., 1 = potatoes 2 = wheat) WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam The Spatial Domain • The Geodatabase stores all geometry coordinates as positive integers – Faster Display, Processing, and Analysis – Better Compression (DBMS only) – Efficient for managing topologic relationships • Limited to 2,147,423,647 storage units. – 2.14x109 meters, or miles, or inches, or ... WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Accuracy and Precision • Accuracy in the Data – Scale of source map scale will determine accuracy* • 1:600 (1”=50’) ± 1.7 feet • 1:1,200 (1”=100’) ± 3.33 feet • 1:2,400 (1”=200’) ± 6.67 feet • 1:4,800 (1”=400’) ± 13.33 feet • 1:24,000 ± 40.00 feet – Precision • Ability to store the accuracy – Significant digits » Single precision 6-7 precise digits » Double precision 13-14 precise digits » Geodatabase 0-10 precise digits WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Example: Spatial Domain • All GIS Features Must Fit Within this Positive, 32-bit Integer Space. 2,147,423,647 2,147,423,647 0 0 OFF LIMITS The Database’s Spatial Domain WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Standard Fields • Feature classes have default fields – ObjectID – unique identifier – Shape – contains coordinates of feature – Area – automatically calculated and maintained for polygons • Shape_Area (Personal GDB) – Length – automatically calculated and maintained for lines and polygons • Shape_Length (Personal GDB) WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Spatial Reference • Property of a feature class or feature dataset • Components – Coordinate system – Coordinate domain • Permanent after definition is saved – Warning: it may look like you changed the coordinate system, but you can’t and don’t try. It messes things up! • See next slide for more information WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Storing Feature Coordinates Two important considerations when storing feature coordinates in a Geodatabase: 1. All data is stored as positive, 32-bit integers (Spatial Domain) 2. All data must maintain a Coordinate Precision. WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Coordinate Precision • The geodatabase converts all coordinates into 32-bit Storage Units. • Storage Units are the smallest measurable unit that can be stored in a Geodatabase. • Precision is used to convert coordinate system units into storage units. WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Example: Coordinate Precision • Precision is a Scale Factor – Used to preserve decimal places before rounding – Larger precision preserves more digits X = 123.456789 Precision =1000 Floating Point Coordinate in ArcGIS (123.456000) Multiply by Precision 123.456789 × 1000 Integer Storage Unit in a Geodatabase (123456) Divide by Precision 123456 ÷ 1000 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Example: Precision Preservation Coordinate System Units Storage Units = Precision Coordinate system units ÷ Precision = Storage units Meters 100 1 cm Meters 1000 1 mm Meters 50 2 cm Feet 12 1 inch WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Topology Objects • Maintain data integrity – Within feature class – Between feature class • Feature Dataset required • • Functionality – Display Topology Errors – Select and Correct Errors – Validation Regarding map features, topology is relationship between features connectivity and adjacency. • Geodatabase topology provides tools to ensure integrity of spatial data. WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Selected Topology Rules • 25 available topology rules • 2 Rules currently applied – Must Not Overlap – Must Not Have Gaps WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam File Management • Compacting the Personal Geodatabase – Reduces file size • Procedure – In ArcCatalog, right click on the .mdb file – Select the Compact Database option in the context menu WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Reference Data Locations • Proscribed by the Standard for Geospatial Dataset File Naming – http://dlnt20.fsa.usda.gov/scdm/DP/Parent3.htm • Standard folder structure on shared f: drive • Geodata – top level geospatial data folder • Local Geodata Administrators have authority to create, delete, and change folders, but only as outlined in the standards document. WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Data Management File Naming Standards • The current standard has 23 common geospatial dataset categories such as soils that consist of 1 or more geospatial datasets. <disk drive>: geodata plants <geospatial dataset category (directory / folder)> soils <geospatial dataset category (directory / folder)> soil_a_ks057 <geospatial dataset> soil_p_ks057 <geospatial dataset> soil_l_ks057 <geospatial dataset> topographic_images <geospatial dataset category (directory / folder)> WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Data Management File Naming Standards cont. • Elements of a file name soil_a_ks057 Feature category Location: Alpha or numeric FIPS code Feature type: a-polygon, l-line, p-point, t-table, i-image, etc. A geospatial dataset file name should: • be less than 30 characters long • consist of lower case a-z and numerals 0-9 • first character always a-z WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Data Storage and Backup • Shared data in a service center must be on the f: drive. • Personal data can be stored on the c: drive or h: drive. – c: drive is not routinely backed up. – h: drive should contain important working files that can be routinely backed up. • Local Geodata Administrators are responsible for ensuring backups are routinely being made of specific directories. – Large, easily replaced datasets should not be routinely backed up because they can be obtained again. – Files and directories that change regularly should be routinely backed up. WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam GDB Design • A critical step • UML modeling for ArcGIS – IBM Rational Rose – MS Visio • Class diagrams WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Managing Your GDB • ArcCatalog is your main tool to manage the schema – Construction of component parts – Organization of those parts – Properties for the parts • Many capabilities are available – Some are not on the default GUI WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Reading Schemas Most data access technologies provide a way for you to query the schema of a database, and obtain information about the tables, stored procedures, data types, users, and other content of a database. Logical Structural WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam A Creating a GDB • Personal – Use ArcCatalog • Multi-user – Must be done at the system level WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Creating a new personal geodatabase 1. Open ArcCatalog 2. Choose a folder location 3. Right click: Choose New < Personal Geodatabase WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Creating Feature Datasets Right click your geodatabase Choose: New < Feature Dataset WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam A Creating an empty feature class • Two locations available: stand-alone and within a feature dataset WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam A Creating a feature dataset WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Creating Feature Datasets Right click your geodatabase Choose: New < Feature Dataset WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Feature Datasets: Setting the spatial reference 1. Set the Projection 2. Set the Domain • Precision • Extent http://arcscripts.esri.com/ : Search on Spatial Domain WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Import existing data •Navigate to the feature dataset or geodatabase icon in ArcCatalog •Right Click •Choose Import Use this to import any existing format! WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Subtypes & Domains Subtype: •Distinguish features within a single layer •Maintain different domains within the same field •Need ArcEditor or ArcInfo Domain: •Identify & constrain attribute values •Can utilize in ArcView WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Subtypes & Domains Parcels Example Subtype: Boundary Line Domains: ROW Type WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Subtypes • Must be long or short integer fields • Created in ArcEditor or ArcInfo • Increases the efficiency of the editing process • Use when – Standardizing a legend – distinguishing different default values/domains within the same field WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Creating Subtypes • In ArcCatalog • Double click on a feature class • Select the Subtype tab WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Creating Domains Created in ArcCatalog 1. Double Click on the Personal Geodatabase Icon 2. Choose the Domains tab WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Creating Domains—Assigning to Feature Classes In ArcCatalog 1. Double click a feature class 2. Choose the Fields tab 3. Highlight a field 4. Click Domain under the Field properties section WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Creating Domains—Assigning default values Set in the Field Properties section WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Using Domains during the Editing Process WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Geodatabase Topology Putting the power into your hands – Topology Rules • Preset rules to define topological relationships to ensure connectivity, adjacency and coincidence – Can be changed at any time – Topology Tools • Maintain spatial relationships • Toolbar and Tasks Pro-West & Associates WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Creating Topology 1. Rules – Land use boundaries overlap parcel boundaries – Manholes overlap sanitary line endpoints 2. Cluster Tolerance – Min distance where vertices within tolerance are snapped 3. Ranks – Control what features move during validating • Surveyed points will not move (snap) during the validation process Pro-West & Associates WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Validating Topology • Validate edited features using set topology rules • Evaluate rules/tolerance and generates error notifications • Snaps vertices using set cluster tolerance and ranks Pro-West & Associates WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Create a New Topology • Created in ArcCatalog • Created within a Feature Dataset • Topology Wizard – Allows user to set Rules, Ranks, Tolerance, and perform initial Validation Pro-West & Associates WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Final Topology When added to ArcMap, will show errors from the validation process WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Managing Topologies • Right click on the Topology in ArcCatalog WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Topology Tools Maintenance • Standard toolbar in ArcView-ArcInfo • Used in an editing environment in ArcMap • Use in conjunction with Topology Tasks in Editor Toolbar Pro-West & Associates WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Editor Toolbar Maintenance • Topology Tasks: Modify, Auto Complete Polygon and Reshape – Allows user to use basic editing tools to alter vertices, replace lines, add adjacent polygons or alter existing polygons – Use in conjunction with the Topology Edit Tool on the Topology Toolbar Remember: Set snapping and snapping tolerance WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Flexible Editing • Topology edit tool – Allows for editing shared boundaries – Builds a temporary topology cache within a given extent • Faster performance • Must use each time your extent changes • Show shared features tool – Move a boundary without effecting shared boundaries (temporary) • Parcels & land use • Parcels and easements Pro-West & Associates WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Validate & Fix • Validate after editing is complete – Errors are highlighted • Click the Fix Error button • Select a feature and right click – Fix – Mark as an Exception – Do Nothing WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Process in Review 1. Plan for success 2. Import data 3. Set Subtypes & Domains 4. Create Topology 5. Start editing! Pro-West & Associates WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Tips • Projecting data – Must create a new feature class • PGDB is 2 GB max • Read-only on a PGDB will restrict some analyses, such as Select by Location • Use compact to clean up temporary files • All table names need to be unique WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Ex 2 • • • • Create a Personal GDB Create an empty Feature Class Create a Feature Dataset Create a Feature Class within the Feature Dataset WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Importing Google Earth Data into a GIS WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Google Earth • Provides free access to a rich resource of satellite imagery and geographic data • Excellent for visualization • On-screen digitizing capabilities allow mapping of features – Features can be saved as kml files – kml files cannot be directly loaded into a GIS 149 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam The “Convert KML to SHP” tool • Converts kml features to shapefile features – Names and descriptions of kml features are retained in the shapefile • Easy to use - run as a tool in ArcToolbox • Runs on ArcView 9.2 – no extensions required. • Works with kml files created by Google 4.2 – May not work with older versions 150 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Creating features in Google Earth • Create a folder to contain the features Right-click Enter single line description 151 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Creating features in Google Earth • Create feature in the appropriate folder polygon name Select folder point line description 152 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Saving features to a KML file • Save the entire folder as a kml file (do not save as a kmz file) • Folder can contain more than one feature type. Right-click 153 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Running the “Convert KML to SHP” tool • Add toolbox to ArcToolbox Input kml file Feature type Output shapefile 154 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Google Polygons to Shapefile Shapefile is not projected 155 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Feature Attributes 156 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Using Google Earth Imagery in a GIS • Google Earth imagery cannot be downloaded. • Screen captures can be georeferenced and used in a GIS. • Reference points are needed to georeference a screen capture. • Features digitized in Google Earth can be used as references. 157 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Georeferencing Snapshots 158 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Saving the Georeferenced Image 159 160 WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam WFM 6202: Remote Sensing and GIS in Water Management © Dr. Akm Saiful Islam Downloads • The “Convert KML to SHP” tool, as well as other geospatial tools, can be downloaded through the Center for Land use Education and Research (CLEAR) website: • http://www.clear.uconn.edu/tools/geospatial/KML _to_SHP_ArcGIS.zip 161