Introduction to Geomedia:

Transcription

1 GIS Project in Geomedia Map digitization, Attribute data entry, Generating thematic maps, Connecting to external databases in MS Access. Map overlays and Map layouts Introduction to Geomedia: Geomedia is a vector based GIS operating on Windows 95/98/2000 platforms. A GIS consists of both data and maps (spatial representations of data). Data can be both spatial (geographic) and attribute data. But maps are not stored within the computer, only data are stored. During vector digitization spatial databases that identify digitized features, their properties and the topology are created. These are used to create the map on screen when required. The distinguishing feature of Geomedia is that it separates the map and data spaces into distinct folders. Maps are created, edited and viewed in the Geoworkspaces folder. The related spatial data tables are created during the digitization in one MS Access file (*.mdb) stored in the Warehouses folder. Different types of data are carried in the many Tables created within this.mdb file. Attribute data can be a Table in the same file or in other access files. A map is to be viewed in the Geoworkspace folder after connecting to the data files in the warehouse folder. The attribute data can be in external data bases created in MS Access and can be connected to the geoworkspace. This facilitates direct interfacing with MS Access databases and querying facilities. It also allows the attribute data to be managed independently of the GIS. Project : To develop a GIS for Rice in Andhra Pradesh Districts Required Downloads for proceeding the project development. (i) scanned image of Andhra Pradesh Districts Map (AP1.tif) (ii) External MS Acess Database (APRICEDATA.mdb) (iii) Shape file for the agroeco sub region map of AP(agroeco_ap) Activities: (i) (ii) (iii) (iv) (v) Digitize the given map of AP DISTRICTS with 3 feature classes- State boundary, Raingauge stations and Districts Enter district attribute data and create thematic maps using Geomedia Professional GIS software. Connect to the MS Access database APRICE.MDB created earlier, query data of rice production and area, and generate thematic maps for rice yield Overlay the raingauge station and districts feature classes, and Prepare a standard map layout for the thematic map in (iii) with legend, labels, scale, etc. Given: (i) (ii) Map of Andhra Pradesh Districts in 1:4 million scale, with data of longitude and latitude of several locations, including raingauge station locations. The scanned image of the map.(download)

2 (iii) MS Access database APRICE.MDB containing data of rice area and production in districts (developed as a practical exercise in MS Access) (Download) Summary of Steps for Developing the GIS Project in Geomedia Creating the GIS project in Geomedia proceeds in the following main steps: Step1. Step2. Step3. Step4. Creating a New Geo Workspace Creating a New Warehouse Setting the Coordinate System for Warehouse (coordinates, projection, geodetic datum) Setting the Coordinate system for Geo Workspace Step5. Defining Feature Classes (points, lines, areas) Step6. Displaying Feature Classes Step7. Map registration comprising: Inserting 4 reference points (or Tics) of known Lat, Long Scanning the map and inserting the Scanned Image (.TIFF file) Registering the scanned image in the reference coordinate (tic) system Step8. Vector digitization of registered image (raster image) on screen Step9. Adding attribute data Step10. Creating thematic maps for the data added in I Step11. Connecting to an external database in MS Access and creating thematic maps for attribute data in the database. Step12. Map Overlays Step13. Plotting maps - Map layouts Step 14. Converting maps into shape files Step 15 Additional Exercises using Geomedia PROCEDURE Creating a New Geo Workspace Start GeoMedia Professional Click on Start Button Click on Program Folder Click on GEO Media Professional Folder Click on GEO Media Professional In the Welcome to GeoMedia Professional Dialogue box select Create New Geo Workspace Option. In the NEW Dialogue Box, Keep the default template Name, i.e NORMAL.GWT and Click on NEW. A new geoworkspace with default name GeoWorkspace1 is created. 2

3 Select SAVE GEO WORKSPACE option from the FILE menu and enter the File Name as APDATA. Keep the Default File Type i.e Geo Workspace and Click on SAVE button. The Geo Workspace contains the empty legend and the map window. The map window, which is titled MapWindow1 by default, is the window in which feature geometries and images are viewed. Creating a New Ware House The warehouse is the source of geographic data for Geo Media Professional. Access and Oracle warehouses are the only types of data warehouses that can be created through Geo Media Professional. (But it allows connecting to other types of data warehouses (MGE, FRAMME, MGE Segment Manager, ARC/INFO, Arc View, MapInfo, MGDM, or CAD to view and query data. However, each warehouse can contain only one type of geographic data). In this project an ACCESS warehouse will be created: Click on WARE HOUSE on the Menu Bar Click on NEW WAREHOUSE Keep the default template NORMAL.MDT Keep the File of Type as ACCESS TEMPLATE Click on NEW Type the File Name as APDATA Keep the Save as Type is ACCESS Click on SAVE. This file is saved in the \Warehouses folder as APATA.MDB. Setting the Warehouse Coordinate System During digitization, Geo Media Professional creates a default coordinate system for screen display purposes. Specifying a new coordinate system provides a way to project the default coordinate system to the original geographic coordinate system of the map being digitized. This will involve specifying the map s projection system, its coordinates and the geodetic datum. To create a new warehouse coordinate system: Click on WAREHOUSE option on the Menu Bar Click on WAREHOUSE COORDINATE SYSTEM Click on APDATA Warehouse Connection Click on OK Set the Projection System (Projection is a geographic measurement of an area or distance on the 3-D curved surface of the earth projected onto a flat (2-D) surface). Select PROJECTION as the Base Storage Type for the Warehouse Coordinate system 3

4 Click on the PROJECTION SPACE tab of the Warehouse Coordinate system Dialogue Box. This allows selection of a projection algorithm and definition of projection parameters that are unique to the selected algorithm. Click on the PROJECTION ALGORITHMS. Select POLYCONIC from the displayed list as the projection algorithm for the current project as this is the standard for maps prepared by Survey of India. Click on the PROJECTION PARAMETERS option to specify the parameters for the selected projection algorithm: Type the coordinates (long, lat) of chosen origin (say Nalgonda) (longitude=79:16:00 and Latitude = 17:03:00 for the AP Districts map to be digitized. These represent a location roughly the mid region of the map). Let correction factors False X and False Y remain at default value of 0. Click on the GEOGRAPHIC SPACE tab in the Warehouse Coordinating System dialogue box to select the map s associated datum and reference ellipsoid. Click on the Geodetic datum option to get drop-down list of available datum. (geodetic datum is a precise location of the ellipsoid relative to the earth's surface and a network of control points. This definition usually includes the origin point of the ellipsoid, its orientation, and the radius and eccentricity of the ellipsoid ) Select the INDIAN 1975 as geodetic datum for the current warehouse coordinate system as this is the standard for Indian maps.. Click on OK Setting the Coordinate system for Geo Workspace Click on View Menu Click on Geo workspace Coordinate System Select PROJECTION as the Base Storage Type for the Warehouse Coordinate system Click on the Projection Space tab of the Geoworkspace Coordinate system Dialogue Box. Click on the Projection Algorithms Select POLYCONIC from the displayed list as the projection project. algorithm for the current Click on the PROJECTION PARAMETERS option to specifies the parameters for the selected projection algorithm Type 79:16:00 as the Longitude of Origin in the Projection Parameter Dialogue Box Type 17:03:00:00 as Latitude of Origin in the Projection Parameter Dialogue Box 4

5 Click on the Geographic Space tab in the Geoworkspace Coordinating System dialogue box Click on the Geodetic datum option to get drop-down list of available datum Select the INDIAN 1975 as geodetic datum for the current Geoworkspace coordinate system Click on OK Defining Feature Classes Feature : A geographic entity that is represented on a map by geometry and defined by non graphic attributes in the database. Three geographic features are identified: points, lines, areas Feature class : The classification to which each instance of a feature is assigned. For example, a data set generally consists of several feature classes, such as roads, bridges, schools, and churches. Each feature class will have associated with it a data table created in Access. The names of fields of this table (feature id, etc.) will need to be entered and primary key will also need to be identified Four feature classes will be defined in this project: (i) (ii) (iii) (iv) Tics (points feature class)for the four reference points with known longitude and latitude. (This will be used later to register the scanned image of the district map in its coordinate system for subsequent digitization). Boundary (area feature class) for the State boundary Stations (points feature class) for locations of raingauge stations Districts (area feature class) for the district boundaries. (i) Create a feature class for tics Click on WAREHOUSE Menu Click on FEATURE CLASS DEFINITION Click on NEW for Feature class for APDATA Warehouse. Type TICS as the NAME for the Feature Class Keep the GEOMETRY TYPE as the POINT Click on the ATTRIBUTE Tab Click in the KEY Column to identify the first field as primary Key Type TICID in the Name Column Select AUTONUMBER as the DATA TYPE (the id numbers are automatically identified as each successive feature is digitized) Type NRIS_ID in the name column Select NUMBER as the DATA TYPE Type TICSTATION in the Name Column Select CHARACTER as the DATA TYPE 5

6 At the end of this one empty MS Access table is created in the warehouse with one field, called TICS in the warehouse APDATA. This Table will have only one field TICID, which is filled automatically as each tic is digitized. ii) Create a feature class for State Boundary Click on NEW for Feature class for APDATA Warehouse. Type BOUNDARY as the NAME for the Feature Class Select the GEOMETRY TYPE as the LINE Click on the ATTRIBUTE Tab Click in the KEY Column to identify the field as primary Key Type ID in the Name for the Column Select AUTONUMBER as the DATA TYPE Click on the 2 ND row of the Name Column Type NAME as the Name for the Column Select the CHARACTER as the Data Type Click on OK and Click on Close (iii) Create a feature class for raingauge stations Click on WAREHOUSE Menu Click on FEATURE CLASS DEFINITION Click on NEW for Feature class for APDATA Warehouse. Type RAINGAUGESTATIONS as the NAME for the Feature Class Keep the GEOMETRY TYPE as the POINT Click on the ATTRIBUTE Tab Click in the KEY Column to identify the first field as primary Key Type STNID in the Name Column Select AUTONUMBER as the DATA TYPE (the id numbers are automatically identified as each successive feature is digitized) Type NRIS_ID in the Name Column Select NUMBER as the DATA TYPE Type STATION in the Name Column Select CHARACTER as the DATA TYPE (iv) Create a feature class for District Boundaries Click on NEW for Feature class for APDATA Warehouse. Type DISTRICTS as the NAME for the Feature Class Select the GEOMETRY TYPE as the Area Click on the ATTRIBUTE Tab Click in the KEY Column to identify the field as primary Key Type ID in the Name for the Column Select AUTONUMBER as the DATA TYPE Click on the 2 ND row of the Name Column Type NRIS_ID as the Name for the Column Select the NUMBER as the Data Type Click on the 3 rd row of the Name Column Type DIST_NAME as the Name for the Column 6

7 Select the CHARACTER as the Data Type Click on OK Click on CLOSE At the end of this one MS Access table is created in the Warehouse folder APDATA called DIST_BOUND, with 3 fields, ID, DISTID, DISTNAME. DISTID is the primary key (DISTID will be filled automatically as each district is digitized successively. The other two fields represent attribute data of districts to be provided by the user. More fields can be added for attribute data if required.) Display Feature Classes This specifies the feature classes to be added to the legend. Click on LEGEND Menu Click on ADD FEATURE CLASS Select all the four Feature Classes for current APDATA warehouse Connection Map Registration Digitize Reference points (Tics) based on Lat, Lon Digitizing tics (reference points) is done by directly entering the coordinates of 4 reference points. The reference points are selected to be broadly at the 4 corners of the map of AP Districts. The reference points chosen for this project are listed in the table below: Reference Longitude Latitude Location Srikakulam 83:54:00 18:18:00 Chittore 79:07:00 13:13:00 Adilabad 78:30:00 19:42:00 Hyderabad 78:28:00 17:27:00 Click on INSERT Menu Click on FEATURE Click on APDATA Connection Select the Feature Class TICS Enter the 4 pairs of Longitude and Latitude data (given in Table below) successively in the (long,lat) window. By Clicking FIT ALL Icon or ZOOM IN or ZOOM OUT Icons make sure that all the four points are visible on the screen. 7

8 Insert Scanned Image (of Given District map of AP, Fig.1) Click on INSERT Menu Click on IMAGE to display Insert Image Dialogue Box Click on BROWSE on the Dialogue Box Select the File of Type as TIFF Select the AP1.TIF on the DESKTOP folder Click OPEN The image will not appear on the screen yet. Create a box for the image on the screen, that lies within the four reference points by DRAGGING with mouse. Select a point close to the lower left tic point as the starting point of the box. Make sure that the box is within the displayed four points (tics) only. The scanned image of the AP Map is inserted within the box. Press <Esc> Key Image Registration This registers the image (scanned map) with respect to the digitized reference (tic) points. (This will ensure that when the registered map is digitized later, it will be with reference to the coordinates of the tics so that any point in the digitized map will be automatically georeferenced.) An image can also be re-registered by editing the registration originally used to register the image. A saved registration can also be edited to improve the accuracy of registration. To Register an Image by Creating New Registration Select the image to be registered by Clicking on the Image (obtained at end of stage H) Click on Tools Menu Click on Image Registration. Click on New option On the Registrations dialog box,. Click Add Points on the New Image Registration dialog box. The dialog box disappears, and you are prompted to enter source control-point 1. (see text on the task bar): Note in the following source = scanned image and target = visible tic points. Clearly note the 4 points on the image (source) that correspond to the 4 tics (target points) Click in the map window at the first source control point i.e Srikakulam (on the raster image). Next, Click in the map window at the corresponding target control point (Tic point representing location of Srikakulam). Similarly match the Source control-point and Target Control Points for the remaining 3 places i.e Chittore, Adilabad and Hyderabad) Care needs to be exercised not to click any where on the screen except at the source and target points, as each such click will be registered as a reference point. Finally, double click to end. 8

9 (Note that all four reference points may not be simultaneously visible on the screen. Then it becomes necessary to zoom in to match successive pairs of source and control points. Each time you zoom in press ESC key to return to registration mode. Even when all points are visible, it is preferable to use the zoom feature to register accurately) The New Image Registration dialog box appears with the control-point grid populated for each control point pair that was created. Enter a name for the registration. Enter a description for the registration. Click Register to register the image. Minimizing the Residual Error While Registration After three or more control points are added, the calculated error for the pairs is given on the New Image Registration dialog box as RMS error. If the error is unacceptable, each pair of points can be selected from the table and edited. Click on Image Click on Tools Menu Click on Image Registration Select Point 1 Click on EDIT SOURCE Zoom to maximum extent and press ESC key Then click Exactly on Target point Similarly edit other source points to match accurately with the target points till acceptable RMS is reached. Click on REGISTER Save Geo workspace Vector digitization of registered scanned image ( raster image) on screen for each feature class The registered raster image (AP Districts Map) will be digitized by tracing over the boundaries on the screen to turn into vector data Digitization of State Boundary Click on INSERT Menu Click on FEATURE. Then it will add feature tool bar Click on APDATA on the feature tool bar Click on BOUNDARY Now, the map on screen is ready for digitization Click on ZOOM IN 9

10 Click at a point to Start digitization of the State Boundary By using ZOOM In and Pan Icons make sure that boundary is clearly visible on the screen then, with the help of mouse start tracing from any point along with State Boundary. Click the mouse pointer on vertex as and when needed (Each click will be registered as a point /node. Two adjacent nodes will be joined by straight line. Nodes will need to be placed more frequently along sharp curves. Use your judgment in deciding on which points along the boundary to click) After completing the digitization of the state boundary (that is, when you return to the point from which digitization of the state boundary started.) DOUBLE CLICK. The attribute table will appear Similarly digitize the scale in the scanned image. Type the Name as ANDHRA PRADESH To view the digitized Map of State Boundary Click on the AP1.TIFF in the Legend frame Click Right mouse button Click on DISPLAY OFF The digitized state boundary alone is displayed (Fig.2) Digitization of Raingauge Stations (Point Feature) Click on the AP1.TIFF in the Legend frame Click Right mouse button Click on DISPLAY ON Click on INSERT Menu Click on FEATURE to display the feature tool bar Click on APDATA on the feature tool bar Click on STATION Now, the map on screen is ready for digitized Click on ZOOM IN Click on one point location, say Adilabad By using ZOOM In and Pan Icons make sure that required station, that is DOT, is clearly visible on the screen then, with the help of mouse Click on the required Station point (DOT). Digitize the raingauge station points by clicking on them successively (Alternately the longitude and latitude of the stations can be entered from the following table. It is suggested that the digitization be done onscreen and the longitude and latitude of digitized stations compared with those in the table 10

11 Latitude and Longitude of the stations in districts State District Station Latitude Longitude A.P. Adilabad Adilabad 19.42: :00 A.P. Anantpur Anantapur 14.41: :00 A.P. chittoor Chittor 13.13: :00 A.P. Cuddapah Cuddapah 14.29: :00 A.P. East Godavari Kakinada 16.57: :00 A.P. Guntur Guntur 16.18: :00 A.P. Hyderabad Hyderabad 17.27: :00 A.P. Karimnagar Karimnagar 18.25: :00 A.P. Khammam Khammam 17.18: :00 A.P. Krishna Machilipatnam 16.10: :00 A.P. Kurnool Kurnool 15.50: :00 A.P. Mahbubnagar Mahbubnagar 16.44: :00 A.P. Medak Sangareddi 17.38: :00 A.P. Nalgonda Nalgonda 17.03: :00 A.P. Nellore Nellore 14.27: :00 A.P. Nizamabad Nizamabad 18.40: :00 A.P. Prakasam Ongole 15.34: :00 A.P. Srikakulam Srikakulam 18.18: :00 A.P. Visakhapatnam Visakhapatnam 17.43: :00 A.P. Vizianagaram Vizianagaram 18.07: :00 A.P. Warangal Warangal 18.01: :00 A.P. West Godavari Eluru 16.42: :00 To view the digitized Map of Stations Click on the AP1.TIFF in the Legend frame Click Right mouse button Click on DISPLAY OFF The digitized Map for Stations will be displayed (Fig.3) Digitization of District Boundaries Click on the AP1.TIFF in the Legend frame Click Right mouse button Click on DISPLAY ON Click on INSERT Menu Click on FEATURE. The feature tool bar is displayed Click on APDATA on the feature tool bar Click on DISTRICT Now, the map on screen is ready for digitized Click on ZOOM IN Click on one districts, say Adilabad 11

12 By using ZOOM In and Pan Icons make sure that district boundary is clearly visible on the screen then, with the help of mouse start tracing from any point along with District Boundary.( Preferable a common point between two districts) Click the mouse pointer on vertex as and when needed. While digitizing you need not once again digitized the district boundaries for which districts having the common boundaries of the state. In such case, hold the common pointer between state boundary and district boundary, and show the common boundary without clicking the mouse. At last point of the common boundary click the Mouse. (Each click will be registered as a point /node. Two adjacent nodes will be joined by straight line. Nodes will need to be placed more frequently along sharp curves,. Use your judgment in deciding on which points along the boundary to click) After completing the digitization of the District boundary (that is, when you return nto the point from which digitization of the state boundary started.) DOUBLE CLICK. The attribute table will appear Type the Name as ANDHRA PRADESH Type the respective NRIS_ID Similarly, digitize the other districts in A.P. Press <ESC> key to come out from the digitization mode when needed.. To view the digitized Map of districts Click on the AP1.TIFF in the Legend frame Click Right mouse button Click on DISPLAY OFF The digitized districts only are displayed (Fig.4) Editing the slivers Slivers are digitizing errors Click on the AP1.TIFF in the legend frame Click on the right mouse button Click on DISPLAY OFF. The digitized districts are only displayed Click on EDIT Menu Click on GEOMETRY Click on EDIT option The digitized nodes and liners of the selected district are displayed. Edit the respective and lines of the selected district are displayed. Edit the respective nodes and lines using mouse. After completion of editing press <ESC> key to come out from Edit Geometry Mode 12

13 Viewing Area, Perimeter of the District in the database First select area and perimeter display Area and Perimeter of each polygon (district) are automatically calculated while digitizing,. To view these parameters Click on ANALYSIS Click on ANALYZE GEOMETRY Select DISTRICT as the FEATURE TO ANALYZE Click on AREA an PERIMETER as option for FIND (Select appropriate units for area and perimeter) Next View the Database Click on WINDOW Click on NEW DATA WINDOW Click on APDATA in the SLEECT FEATURE CLASS dialogue box Click on DISTRICT The database window with area and perimeter fields are displayed Close the data window Adding Attribute data. The attribute data of Rice Total Irrigated area in 1994 will be added to the district feature class Click on WAREHOUSE menu Click on FEATURE CLASS DEFINITION Select DISTRICT as the feature class Click on EDIT in the Feature Class Definition Dialogue Box Click on ATTRIBUTE Icon in the EDIT - DISTRICT Dialogue BOX Type RICETAI in NAME COLUMN Select Number as the Data Type Enter NRIS-ID as indicated Enter the data Click on WINDOW Click on NEW DATA WINDOW Click on APDATA in the SELECT FEATURE CLASS dialogue box Click on DISTRICT 13

14 DISTNAME NRIS_ID YEAR RICETAI Srikakulam Vizianagaram Visakhapatnam East Godavari West Godavari Krishna Guntur Prakasam Nellore Kurnool Anantapur Cuddapah Chittoor Rangareddy Hyderabad Nizamabad Medak Mahabubnagar Nalgonda Warangal Khammam Karimnagar Adilabad Create Thematic Map of RICETAI A thematic display symbolizes geographic features according to non-graphic attribute data through the use of color and other user-defined display properties. A thematic display is created from a feature class in any open warehouse connection, or from a query in the active Geo Workspace. Thematic Map for Rice Kharif Area Click on LEGEND Menu Click on ADD THEMATIC Select the DISTRICT as the Feature class From the available attributes for the selected feature class in the Available attributes list. Select RICETAI Click on Range in the ADD THEMATIC ENTRY Dialogue Box Click on DEFINE Select EQUAL RANGE as the option for Map Range Technique in the Map By Range Dialogue Box Select 4 for the Number of Range (if you digitize more than two districts) Click on Color Selection Icon to pickup required color Click on OK in the Map By Range Dialogue Box Click on OK in the Add Thematic Entry Dialogue box 14

15 Then the selected RICE TAI attribute is displayed in the Map Inserting Lables on the Map Labels are text strings that are inserted as features in a feature class of a warehouse, or output as a query in a Geo Workspace. To create labels, the map window must be active and a open warehouse connection open. The content of the label may be composed of keyed in text and one or more attribute values derived from values stored in the warehouse. Labels can be output as a query or a feature class. Outputting as a query allows the labels to be automatically associated with the feature being labeled. Thus, labels automatically update if attribute values on which they are based change and are moved, deleted, and so forth, when their corresponding features are edited. However, labels cannot be edited until they are output to a read / write feature class. Conversely, outputting as a feature class does not provide the active link for attribute values, but allows the labels to be edited independently of their corresponding features. Click on Insert Click on Label Click on the Label features in drop-down list Select the APDATA Select DISTRICT feature class Click on DISTNAME attributes in the Attributes list box to place them in the Layout text box In the Layout text box, type any text to appear in the label. Press CTRL+ENTER to create a new line Keep the default alignment for label placement, Click on Style to change the default text style using the Style Definition dialog box. Connecting to an external database in MS Access and creating thematic maps for attribute data in the database. Connect to an Existing Access Warehouse APRICEDATA.MDB It is possible to connect to and display multiple attribute data contained in Access databases simultaneously and map them as required. Select NEW CONNECTION.option from the WAREHOUSE MENU The WAREHOUSE CONNECTION WIZARD displays the different types of warehouses to which you can connect. Select ACCESS, and click NEXT. In the CONNECTION NAME field, delete the current text, and type APRICEDATA Click BROWSE. (select he file APRICE.MDB from the gistrg folder) Select APRICE.MDB, and click OPEN. Click NEXT. With the option ACCESS ALL FEATURES IN THE WAREHOUSE selected, click NEXT. 15

16 Select the option LET THE WIZARD OPEN THE CONNECTION AS READ-ONLY. This option ensures that the original source database is not changed in Geomedia. Click on FINISH. The connection between the geoworkspace/warehouse in geomedia and the Access database is now made. To verify this: Click on window in main menu Select New data window Click on connection name APRICEDATA to display the tables in the Access database Calculation of rice yield Select Warehouse from main menu Click on Feature class definition Edit Ricedata Click on Attribute Add two new fields RICEKY and RICERY; select their data type as number (2 decimals) Click on Close Select Edit > Attribute Under Attribute select Update Attribute Select APDATA > RICEDATA Double click on RICEKY; the Expression box is highlighted Click on Expression Box, the Expression Dialog box is highlighted In the description box type [ RICEKP/RICEKA] Click Apply Similarly, Double Click on RICERY and repeat above steps up to clicking the Expression box In the description box type [RICERP/RICERA] Click Apply The kahrif and rabi rice yields are calculated for all the years. Using JOIN to establish a relationship between the feature classes A join is a type of query that extracts selected data from two tables that have at least one common field and combines it into a new table CREATING A JOIN Use Analysis > Join to perform multi-field joins on feature classes and queries. Which feature classes or queries to join, which attributes within those feature classes or queries to join on, and what type of join operation to perform need to be specified. 16

17 Note Join uses the geometry from the left feature class or query when attempting to display the join in a map window. Therefore, when joining two feature classes or queries that are not nongraphic, select as the left side of the join, the feature class or query whose geometry should be displayed. 1 Select JOIN option from Analysis Menu. 2 Select the left feature class APDATA from THE LEFT SIDE OF JOIN drop-down list 3 Select the right feature class Use the RIGHT SIDE OF JOIN drop-down list to or query. 4 From the left Available attributes list box, select the AREA feature class on which to create a join. 5 From the right Available attributes list box, select the APRICE feature class on which to create a join. 6 Select the Common Filed Name that is NRIS_ID in both sides 7 Click on ARROW button to add the attribute pair to the SELECTED ATTRIBUTE PAIRS LIST BOX. 8 Select the type of join to perform. The available join types are inner join, left outer join, right outer join, and full outer join. Keep the join type ass INNER 9 Type the RICEYIELD as query name in the QUERY NAME text box, 10 Assign an optional description for the query. 11 To display the new join in a map window, click the Display join in map window check box to enable the option. 12 Accept the default map window name or enter another name. 13 Click Style to change the default display style. 14 To display the new join in a data window, click the Display join in data window check box. 15 Accept the default data window name or enter another name. 16 to generate, and, if specified, display the new join. Querying Rice data for the year 1997 for thematic mapping A QUERY requests information from a database. Queries can be on feature classes and on other queries. It is possible to define both attribute filter and spatial queries. Labels and joins can also be stored as queries. Defining an Attribute Filter, Three kinds of queries with the New Query command can be defined: attribute filter, spatial, and linear network query. An attribute filter query allows request of information from the database about one feature class or query. A spatial query requesting information from the database about two feature classes or queries and their spatial relationships to each other. A query can be defined on a feature class or on another query in the active GeoWorkspace. Spatial queries can be run across different warehouses and warehouse types. Defining an Attribute Filter Query 1 Select NEW QUERY option from ANALYSIS Menu 17

18 2 From the Select features in drop-down list, select the warehouse connection that contains the feature class That is, APDATA 3 Select the APRICE feature class from the list. 4 Click on FILTER to select attributes of the feature class to be queried, 5 Click on YEAR from the ATTRIBUTES 6 Select = sign as the operators 7 Click on SHOW VALUES and click on OK 8 Select 1997 from the displayed years 9 Click on OK 10 Type a new name for the query say RICEYIELD97 11 On the New Query dialog box, click OK. Creating Thematic Map on Joined Data Thematic Map for Rice Kharif Area for the year 1997 Click on LEGEND Menu Click on ADD THEMATIC Click on FEATURE DROP DOWN List Click on QUERIES Select RICEYIELD97 query Then it will display the available attributes in the RICE query. From the available attributes Select RICEKY Click on RANGE in the ADD THEMATIC ENTRY Dialogue Box Click on DEFINE Select EQUAL RANGE as the option for Map Range Technique in the Map By Range Dialogue Box Select 4 for the NUMBER OF RANGE (if you digitize more than two districts) Click on Color Selection Icon to pickup required color Click on OK in the Map By Range Dialogue Box Click on OK in the Add Thematic Entry Dialogue box Then the selected RICEKY attribute is displayed in the Map (Fig.5) Map Overlays: The overlay (Intersection or Difference) is a linear - network query that is used to query distributed attributes. Overlay option is used to overlay different thematic maps, queries and different map features, which are with in the Geo workspace. Union as well as differences between two specified map features can be done and the data related to them is seen in the Data window. Click on Analysis Click on Spatial Intersection A Spatial Intersection Dialog Box is seen Select Station as input feature class Select Districts as output feature class In spatial operators Click on OVERLAP 18

19 Name the query Station_districts Type Station_district as map window and Type Station_district as data window The result of the overlay map is seen in the Data window station_district (see fig 6) Plotting maps Map layouts Placing the North arrow & Scale Bar: Select View > North arrow Right click on north arrow and select properties to display the North arrow properties dialog box. Click Browse Select the north arrow of your choice, such as arrow10.wmf Or arrow2.wmf. Click Ok Drag the north arrow to top right corner. Select View > Scale bar Right click on scale bar and select properties to display the Scale bar properties dialog box. Change the units to Km for Kilometer Change the text/line color to dark blue, and on the color dialog box. Change the Minor fill color to black and click OK on the color dialog box. Change the Major fill color to white, and click OK Check set interval values. Specify 5 for Number of Intervals. Set the Length of interval field to 50. Click Apply to preview your changes., drag the scale bar to lower-right corner. Save the Geoworkspace. Naming the Legend Select Legend > Name Legend In the Name Field, type APLegend.. Rename the Map window Select Window > Map window properties. In the Map window name field, type APMap.. Open a New Map Window Select Window > New Map Window In the New Map Window dialog box, in the Window name field, type Location.( the name of the new map window) Select APLegend..( the new map window, Location, is displayed in front of the APMap window.) Select View > Fit All Save the Geo Workspace. 19

20 Layout of Map / Geo workspace: The layout of Geoworkspace : You will import an existing layout from a Geo Media Layout Template(.glt file). The Template automatically defines the page setup parameters and contains four Smart Frames (for a map, north arrow, legend and scale bar). You will use the template and delete the default sheets that are not used. Select Window > Layout Window Plot the layout window is displayed Maximize the layout window Select Sheets > Import Layout The import Layout dialog box is displayed Select A wide layout, Click Open Select View > Fit You will work in the sheet called A Wide. The layout window provides a "working" sheet and a "background" sheets. The default working sheet is called Sheet 1and the default background sheet called background 1, both the default sheets are to be deleted. Select Sheet1 by Clicking on the Sheet1 on the lower- left corner of the layout window. Select Sheets > Delete Sheet, Sheet1 is deleted only A Wide remains as the working sheet, which is defines as foreground of the layout and it usually contains the graphics that are unique to a particular layout. Select View > Background Sheets. Select Background1 by clicking on the Background1 tab. Delete it by selecting Select > Delete Sheet, the background1 is deleted and A Wide Background remains. (The background sheets typically contain the graphics that are the same for multiple layouts, whereas foreground sheets are usually unique.) Select View > Working Sheets. Page setup: Since you are using the template, the page setup of the sheet has already been defined. By using the Page setup command you can review the paper size, orientation, and other settings of the page. Select File > Page setup On the General tab, notice that the Name is set to A Wide, the Back Ground is set to A Wide- Background, the Paper Size is set to A Size sheet and the Orientation is set to Landscape. Detach the background sheet by selecting the blank field in the Background drop-down list., on the Layout Window page setup dialog box. Select View > Background sheets (toview the graphics on the background sheet) Select View > Working Sheets ( to View the graphics on the view working sheet) 20

21 To re-attach the A Wide-Background sheet to the A Wide working sheet, you must view the working sheet. Select File > page Setup Select A Wide-Background for the background using the Background dropdown sheet..( the background sheet is displayed along the foreground) Delete a Smart Frame: Place the cursor over the smartframe for the legend, and pause the mouse. The Pick-Quick dialog box appears.( the pick-quick contain two entries- the first, number1 is for all the smart frames in the group, the second, number2, is for just the legend smart frame. Click number2,which corresponds to legend smart frame. Select Edit > Delete Select View > Background Sheets Select legend text, and press the Delete key ( legend text is deleted) Select View > Working Sheets to return the working sheet. Placing the smart Frame for a Map: Select Layout > Design map layout Design map layout box is appears, In the frames to be place, notice that map(required) is disabled. Make sure that Legend, North arrow, and Scale bar options are not checked. Click Apply Place the cursor at the top of the largest smart frame and click the left mouse button. Click it to a second point that is diagonal to the first, making a rectangular frame. Click Close Save Geo workspace Insert Map Graphics in the Smart Frames: Select Layout > Insert Map Graphics. The Insert map Graphics dialog box is displayed. In the Map Window drop-down list, select APMAP and make sure that Map Window is selected for the Method for the Geographical extent. Make sure that the User-define is selected as the plot scale option and Crop/Flood map to fit Frame option. Make sure that all three Associated marginalia options are checked : Legend, North Arrow, and Scale Bar Make sure Dynamic(enables updates) is selected.. By the above exercise all the features of the Graphics like map, Legend, North arrow and Scale bar and one empty smartframe are viewed on layout window. Select the empty smart frame. Select Layout > Insert Map Graphics In the Map Window drop - down list, select Location. Make sure that Map Window is selected for the method for the Geographic extent. 21

22 Select Fit to frame. Make sure that no Associated marginalia options are checked. Select Static(disables updates). (Selecting this option means that if a change is made to the country map window, the change will not be reflected in this smart frame on the layout sheet..( The map called Location is placed into its corresponding smart Frame.) Select View > Background sheets. Select the Scale Bar text, and press the DELETE key. Select the North Arrow text, and press the DELETE key. Select the Map text, and press the DELETE key. Return to the working sheet by selecting View > Working Sheets. Double click the text plot Title. Delete the text string, and type A.P MAP Print the Layout Window: (Fig 7) Select File > print. Select Selected sheet under Print Range. Set the Number of copies to 1. Converting Maps into Shape files: A shape file is map which contain spatial data along with a attribute data. A shape file generally has three types of files they are of format : <filename.exl>, < filename.shx>, <filename.shp>. 1. Click on Wear house Menu, Click on Export To 2. Click on Shape file.. 3. Export to Shape file window will appear. 4. Select Districts as Feature to Export. 5. Click on Browse, Give the path as d://training/district. 6. Click on Apply, Then Click Ok. 7. Similarly repeat steps 1 to 6 for all other maps. Additional Exercise using Geomedia Importing the shapefile in to Geomedia (The shapfile folder should be download) 1. Click on Ware house in Main menu 2. Click on New connection 3. A ware house new connection wizard window will appear 4. Click Next 5. Click on Browse, to the folder in which shape files are kept 6. Click Next 7. Click Next 22

23 8. Click on Finish (see Fig.8) To view the shape files in the map window 1. Click on Warehouse 2. Click on Import from Warehouse 3. A Import Warehouse wizard window will appear 4. Click Next 5. Select the connection ( the folder which you want to import into mapwindow) 6. Click Next 7. Click Next 8. Select all the shapefiles 9. Click Next 10. Again Click Next 11. Click Finish 12. Click Close Overlaying the Maps: 1. Activate District map, Right click on it and Click Display on( which is Digitised in the beginning) 2. Click on Select tool (arrow). Click on the District map to read the data. 3. Right Click on District Click on Display off. 4. Now highlight the imported shapefilemap agroeco_ap 5. Once two maps are brought onto map window 6. Click on Analysis menu, Select Spatial Intersection. 7. A Spatial Intersection dialog box is open, Select Districts as first input future. 8. Select agroeco_ap as Second input future 9. Select overlap command from Spatial operators. 10. Type overlay_ap as a Query name. 11. Click on Display Intersection in data window, Type overlay_ap as a Data window name. 12. Click Ok 13. overlay_ap map and overlay_ap data window are seen on window. 14. close overlay_ap data window.(see Fig:9) Editing of Maps to remove very small polygons: The overlay_ap map is a Read-only map. It is not editable. In order to make it editable, Create a new coverage. 1. Click on Wear House menu. 2. Click on Feature Class Definition. 3. Click on New ( a New Feature Class dialog box is open) 4. Name the Feature Class as ap_result. 5. Select Geometry type as Area. 6. Click on attribute, Double Click on first row of the Key column to highlight the primary key and Type ID as Attribute name, Type autonumber as Data type. 23

24 7. Similarly in Second row, Type Dist_name as Attribute and character as Data type. 8. In third row Type agro_no as Attribute name and number as Data type. 9. In forth row Type agro _region as Attribute name and number as Data type. 10. Type Dist_id as Attribute name and number as Data type. 11. Click Ok. 12. Click Close. 13. Click on Insert menu and Select Feature ( a Feature box is attached to the mail menu). 14. Select the Coverage ap_result from the Feature box. Now your cursor will change in to editable mode. 15. Edit the coverage by re-digitizing keeping the district boundary unchanged; Remove the arcs of agroeco_ap map which forms very small polygons with the Dist_ap map boundary. 16. After editing the whole coverage a map ap_result is prepared.( Fig.10) 24