GEOGRAPHIC MODELLING AND ANALYSIS

Transcription

1 GEOGRAPHIC MODELLING AND ANALYSIS I. INTRODUCTION A. Background Geographic Information System is organized within a GIS so as to optimize the convenience and efficiency with they can be used. To distinguish a GIS from other types of information system are its spatial analysis (Arronof, 1994). The GIS database is a model of the real world that can be used to mimic certain aspect of reality. An important GIS application is predicting the consequences of purpose activities. The spatial analysis will identify area suitable for the proposed lab site and the tabular analysis will provide an estimated cost acquisition. Geographic analysis allows studying real-world processes by developing and applying models (ESRI, 1994). Introduction and Advanced courses in Geographic Information Systems about Geographic Modeling and Analysis data sources techniques used in the planning process, with an emphasis placed on appropriate applications. We receive considerable experience in using geographic information systems technology to solve real-world problems. Modeling use GIS has the advantage, because of its capability of dynamic simulation, and repeat analysis under changing conditions. This assignment introduce to the spatial analysis capabilities of ArcView GIS that we focus on the modeling and analysis and analysis capabilities of a GIS and working with data provide that to perform a geographic analysis application which we choice. My project is determining ideal location to build Tobacco Processing Manufacture in Lombok Island. There are several constrains for an application of interest, those are: 1. The site in agriculture area 2. Site must be within 1 km of existing road 3. Site must be beyond 500 m of existing river 4. Site must contains an area at least 50,000 meters square The coverages should be available to support this project are lanzon, river, linriver, and road of Lombok island. The data provided in the shared directory on \\Biosvrrex01\Courses\ITM524\Assn2\Data. B. Objective The objectives this assignment are to introduce concepts of geographic analysis and describes some of methods involved in this assignment, to establish a set criteria and constrains for GIS application that interest to build project, to define our problem and then identify a sequence of operations to produce meaning results, to try to finding suitable area for a new project (Tobacco Processing Manufacture).

2 II. GENERAL PROCEDURE Step 1. Determining agriculture area First requirement of the project (analysis suitable area for Tobacco Processing Manufacture), that s site is agriculture area. To determine this land use type, we use landzon data, which has agriculture type. The steps for determining this land use are: Start ArcView. Click Add themes to open a data. In the Add themes dialog, chose landzon as feature data source, then click OK (Figure 1a and 1b) Checks the attributes of the landzon coverage. To do this, make the landzon theme active in the TOC, and click on the ShowTable button. (Figure 2) Open theme table (1a) (1b) Figure 1. Add theme dialog box (1a); Displaying of lanzon feature data source Join item attribute table of landzon with landzone.dbf The attribute table of landzon doesn t has description or characteristic of land use (i.e. agriculture, urban, indutry, forest, etc), so to get it we have to make join item with lanzone.dbf o Open the attribute table of landzon coverage and landzone.dbf o Combine both of attribute tables by click zone field in lanzone.dbf first, then zone field in lanzon, and click button from toolbar menu. Figure 2. Join item procedure using zone field 1

3 Convert the file changing to shape file as Landuse.shp (shown as Figure 3). This file is selected to get agriculture area by using query. Figure 3. Displaying of landuse.shp Query to get agriculture site Open the Theme menu and choose Query. In the query dialog, determine agriculture site, then click New Set button. The query dialog and agriculture site is shown as Figure 4. Figure 4. Query dialog; and Displaying of agriculture.shp Step 2. Determining site within 1 km of existing road To determine site within 1 km of existing road, could be done by create buffer from jalan coverage. Open the jalan coverage by click button from toolbar menu. Figure 5. Displaying jalan as feature data source 2

4 Create buffer in jalan coverage with distance 1 km Before perform buffer, sets up properties jalan to units meters by click menu View\ properties from toolbar menu. Click Theme\Create buffer from menu toolbar, then perform buffer jalan. Perform the buffer distance to 1000 meters. Figure 6 is shown buffer road dialog; and displaying of the result Buffer_road.shp Figure 6. Buffer road dialog; and Displaying of the result Buffer_road.shp Step 3. Determining site beyond 500 m of existing river There are two coverages used to determine site beyond 500 m of existing river. They are river and linriver coverage. First, we have to create buffer to these coverage with distance 500 meters. A. Buffer of river o Create buffer river with distance 500 m, by click Theme menu\create buffer from toolbar menu Figure 7. Buffer river dialog box; and Displaying of Buffer_riv.shp o Convert to Shapefile the result of river buffering as Buffer_riv.shp as Figure 7. B. Buffer linriver o Create buffer linriver with distance 500 m, by click Theme menu\create buffer from menu toolbar 3

5 Figure 8. Buffer linriver dialog box; and Displaying of Buffer_linriv.shp o Convert to Shapefile the result of linriver buffering as Buffer_linriv.shp as Figure 8. C. Union Buffer_riv.shp and Buffer_linriv.shp o First, activate Geoprocessing by open the File menu and chose Extensions. In the Extensions dialog, click the GeoProcessing check box and click OK. To begin union process, click View menu then chose Geoprocessing Wizard. Define geoprocessing dialog. Figure 9. Union ( Buffer_riv.shp and Buffer_linriv.shp ) dialog box; and Displaying of Buffer_river.shp o Convert to Shapefile the result of union process as Buffer_river.shp as Figure 9. Step 4. Union Buffer_river.shp and Agriculture.shp A. Manipulating attribute of Buffer_river.shp o Open attribute table of Buffer_river.shp, activated it s window o Click Table menu and chose Start Editing o Click Edit menu then chose Add Field. Fill the Field Definition dialog, then click OK Figure 10. Field Definition dialog box 4

6 o Sets River_id field with number 1, then clicks Stop Editing from menu Table as Figure 11 below: Figure 11. Attributes table of Buffer_river.shp after manipulating B. Union Buffer_river.shp and Agriculture.shp o Create union Buffer_river.shp (after attribute manipulating) and Agriculture.shp by open View menu then chose Geoprocessing Wizard. Define geoprocessing dialog as Figure 12. Figure 12. Union ( Buffer_river.shp and Agriculture.shp ) dialog; and Displaying of the result ( Union_river_agric.shp ) o Convert to Shapefile the result of union process as Union_river_agric.shp Step 5. Perform query from Union_river_agric.shp o Clicks button from menu toolbar, to make query from Union_river_agric.shp then cliks New Set button. o Convert to Shapefile by click Theme menu\covert to Shapefile (as river_agric.shp ) Figure 13. Query dialog box; and Displaying of river_agric.shp 5

7 Step 6. Intersect between river_agric.shp and Buffer_road.shp as result (study area) o From toolbar menu, click View menu\geoprocessing Wizard\Intersect two theme o Intersect between river_agric.shp and Buffer_road.shp and get result.shp as study area Figure 14. Suitable area according to criteria of the analysis Step 7. Creating Layout The final step is to make layouts for every step that have been made (each study area). This step can be done by clicking View menu and choose Layout to make the layouts. The result can bee seen in the appendix 2. All the layouts can be exported into graphic format files (e.g. BMP, JPEG). Figure 15. Layout functionality in ArcView Step 8. Avenue Script Avenue script is used in this assignment as syntax to make two buttons (previous button and next button ). These two buttons are used to display a series of layouts. When we click button, the previous layout will be displayed and if we click button, the next layout will be displayed. The result can be shown in this Figure 16. Lists of avenue script used in this assignment can bee seen in Appendix 3. Figure 16. Adding New Button in The Toolbar 6

8 III. CONCLUSSION 1. Spatial analysis was done using the ArcView Spatial Analyst Extension. The Spatial Analyst presents generic spatial analysis functionality on grid and feature themes that is added to ArcView as an extension. Among other functionalities the Spatial Analyst Extension enables the following operations to be carried out: establishing distance, assigning proximity, calculating density, calculating cell statistics, map querying, neighborhood statistics, reclassifying, interpolating grid, deriving slope, computing hill shading and converting to grid. 2. Before doing a decision regarding spatial problem, first we should do geographical analysis to ensure that our location occupy the criteria that has been determined by the user or by the law. There are several commands in ArcView that might be used in performing geographical analysis, e.g. buffering, union, intersect, overlay, attribute manipulation, querying, etc. 3. Buffer analysis is used for identifying areas surrounding geographic features. The process involves generating a buffer around existing geographic features and then identifying or selecting features based on whether they fall inside or outside the boundary of the buffer. IV. RECOMENDATION There are many locations that satisfy the criteria that have been determined for Tobacco Processing Manufacture. But in performing decision, geographic criteria is not the only one that has to be considered, there are many other criteria should be included also, for example Tobacco production data for each sub district. So for further analysis, another supported data such as production data should also be included so that our result would be more reliable. 7