INTRODUCTION TO GIS. Practicals Guide. Chinhoyi University of Technology

Transcription

1 INTRODUCTION TO GIS Practicals Guide Chinhoyi University of Technology

2 Lab 1: Basic Visualisation You have been requested to make a map of Zimbabwe showing the international boundary and provinces. The colour of the international boundary should be thicker and different in colour from the provincial boundaries. The provinces should be labelled by name and each in its own colour. The map should have a legend, a scale bar and a north arrow. Zim boundary line shp Zim provinces shp Zim polygon shp Open ArcMap Add all the layers to ArcMap Right click boundary polygon box, select no colour. Double click on the box, increase outline width, change outline colour. To change colours: Right click province, properties, symbology, categories, value field (Provinve_N), add all values, apply, ok. (Right click on each province name to change the colors independently) To show labels: Right click, properties, Labels, Select label features in this layer, select label field, change font and font sizes of labels, apply, ok. (Font should be Times New Roman, 12) The boundary colour should be different from any of the colours used in the provinces To finalize map go to Layout view. Make the map a half page, fixed zoom functions. Insert, North Arrow and select one of your choice Insert, Scale Bar, Select one, go to properties, change to Kilometres, type Km in the box and OK Insert, legend and follow the next prompts. Click on the legend, Right click on it, convert to graphics, right click and select ungroup. Right click on the first name and select ungroup. Click on name and edit it. Insert title and write your name as title. To save map as picture: Go to File, Export Map, give your name_lab1, change resolution to 350 doi, change file type to JPEG and to TIFF. Expected Output Beautiful map of Zimbabwe showing national boundary and provinces.

3 Lab 2: Basic Visualisation 2 You have been requested to make a map of Zimbabwe showing the international boundary and provinces. The colour of the international boundary should be thicker and different in colour from the provincial boundaries. The provinces should be labelled by name and each in its own colour. You need to show the location of Zimbabwe in Africa on a side map and connect with lines. The map should have a legend, a scale bar and a north arrow. Zim boundary line shp Zim provinces shp Zim polygon shp Africa map shp Go back to Dataview Insert Dataframe Add Africa map shp Add Zim polygon, to new dataframe. Select colour for the zim polygon. Go to Layout view, arrange the 2 dataframes to be side by side. Use the zoom functions to align the maps. Add your name as the title and save it as yourname_lab2 Export the map as a picture Expected Output Beautiful map of Zimbabwe showing national boundary and provinces and the location of Zimbabwe in Africa. Save the whole project as Zim_Africa project.

4 Lab 3: Map Extraction and Attribute Selection You have been requested to make a map of Zimbabwe showing the international boundary and provinces. The colour of the international boundary should be thicker and different in colour from the provincial boundaries. The provinces should be labelled by name and each in its own colour. You need to show the location of Zimbabwe in Southern Africa on a side map and connect with lines. Show names of all SADC countries in the SADC Map. The map should have a legend, a scale bar and a north arrow. Zim boundary shp Zim provinces shp Zim polygon shp Africa Map shp Go back to Dataview (To change between data frames you right click the dataframe name and Activate) So the Africa layer in the ArcMap view Method 1: Go to the select button (with blue colour), select the SADC countries by clicking and moving mouse down). Method 2: Right click Africa layer, open attribute table. Click ctrl button on keyboard, and click the first cell for each sound country. Keep pressing Ctrl until all countries have been selected. While selection is on, right click on Africa layer, data, export data (make sure it reads Export: Selected layers), click the folder browse and give a name eg SADC and click Ok and OK. Add labels to the SADC map and select country names. De-click the Africa layer and you have a SADC map. Go to data view and arrange the maps for saving. Add your name as the title and save it as yourname_lab2 Export the map as a picture Expected Output Beautiful map of Zimbabwe showing national boundary and provinces and the location of Zimbabwe in Africa. Save the whole project as Zim_SADC project

5 Lab 4: Advanced Map Extraction and Attribute Selection As an officer in the Ministry of Health and Child Welfare, you want to prepare a map that shows the health facilities in Gutu District. You also want to see the location of health facilities in the district in relation to roads and rivers, so you want to include this on the map. You are planning to show a sidemap of the map of Zimbabwe showing the location of Gutu district in Zimbabwe and in Masvingo Province. Another sidemap should show the location of Zimbabwe in SADC. Make sure you include all necessary map elements on you map. Zim boundary line shp Zim provinces shp Zim districts SADC Map shp Roads shp Rivers shp Health centres shp (not projected) You need to work with 3 separate dataframes for this project. One for the main Gutu Map, one for the Zimbabwe map and the other for the SADC map On you main Gutu data frame, extract and save Gutu district shape file in a new folder called Gutu. Add the roads and rivers shapefiles to the layer. To remain with the Gutu roads and Gutu rivers only we need to cut the rivers using the Gutu district shapefile. To cut-out rivers and roads: Go to ArcToolbox, Analysis Tools, Extract, Clip. Put the bigger shapefile as input feature, use the Gutu district layer as clip features, put name and folder to save output feature class. Your naming should be strategic and not exceed 12 letters. Now you should switch off the bigger districts, roads and rivers shapefiles Now we want to add a health facilities layer. Add the layer from the list of shp files. The health facilities layer is not projected and we have to give it the same projection as other layers. To project: Go to ArcToolbox, Data Management Tools, Proj & Transform, Project. Add the Health facilities shp as the Input Dataset (if it has a datum, it will be automatically picked), give projected file name under Output Dataset (make sure you know where the file is being saved). Under output coordinate system, we want to define the projection we want. The easiest way is to just copy the projection from the already projected files. So click on the hand, on the down arrow close to the world map, select import. Now select any layer that has projections, Add, Ok, Ok. This process may take some time (check for the green tick on the right). Now that the layer is projected, we can cut it the same way we have cut other layers. Change colour of rivers to blue, colour of roads to red, district boundary should be dashed and health centres should fairly large green dots with labels. Add your name as the title and save it as yourname_lab2 Export the map as a picture. Add your name as the map name and save it. Save the project as Gutu project

6 Lab 5: Simple Raster Visualisation and Analysis You have been hired as a consultant by Ministry of Local Government and Urban development to determine the potential of areas to be affected by floods and landslides occurring in Zimbabwe. You know that among other factors, floods occur in areas below 500m in altitude if they are less than 10km from a major river. Landslides occur in areas that have steep slopes and an elevation above 1600m. You want to produce a map showing the areas that are likely to have floods and landslides in Zimbabwe as part of your report. ZIM DEM raster Zim districts shp Zim boundary polygon. Add zim rivers shp Add the Zim dem raster layer to ArcMap using the normal way used for shapefiles. Right click on the dem layer and go to properties, symbology. Select stretched and save the output map, including legend, north arrow and scale bar. Save file as yourname_lab5_a Select classified, click on classify, select natural jenks, 5 classes, and put breaks of 500, click ok, ok. Change the colour of each class. Which areas are likely to be flooded and which areas are likely to have landslides?? Save the classified map with all necessary map components. Save file as yourname_lab5_b. What are the differences between the classified and the stretched maps?? Save project

7 Lab 6: More Raster Visualisation and Spatial Analysis As an officer in CAFOD International, you are interested in understanding the impacts of climate change on areas of Zimbabwe, focusing on temperature. You want to use GIS to identify the areas that will have the greatest changes in temperature between now and You want to use this information for planning adaptation measures. Temp now raster Temp 2080 raster Zimbabwe districts Display the temperature raster files in ArcMap. What differences can you see by switching on layer on and off? To see the differences, we simply have to find a way of subtracting one layer from the other. If we say 2050-Now, it means positive areas are warming, negative areas are cooling and those areas with zero have not changed. There is a map algebra function in ArcMap that we can use. Go to ArcToolbox, Spatial Analyst, Map Algebra, raster calculator. Make the function for temp and precipitation to be 2050 now and save the files separately. Save the temperature differences as yourname_tempdiff Save the precipitation differences as yourname_precipdiff Comment briefly on the likely distribution of the impacts of climate change in Zimbabwe. Make sure your maps have all necessary map components. Save project

8 Lab 7: Georeferencing and Digitizing You have scanned an old paper map of Gonarezhou National Park which shows the roads, rivers and campsites around the area. You want to use the roads and rivers for identifying potential areas for setting up a luxury hotel with your Chinese investors in the area, using set criteria. You therefore need to develop a digital map of the area through georeferencing and then create new GIS datasets from digitizing. Gonare scanned picture file Protected areas layer shp (with reference) Georeferencing Add the protected areas shp to ArcMap Add the Gonare picture from the folder Click on the georeferencing down arrow and fit to display Now we want to match the 2 maps to have same spatial reference On the georefencing tab click Add control points, and click the unreferenced image first and match it with the gonarezhou national park shp layer. Select 8 points that you can match and click update georeferencing. Assess the accuracy of the georeferencing. Digitizing After georeferencing you can now digitize the map, which simply means making the map digital To digitize, you first have to create empty shapefiles according to the data type (polygon, line or points). We want to create campsites (points) and roads/rivers (lines). We can also create polygons if we want. Go to ArcCatalog, look for your GIS folder, right click and create new folder called Gona. Right click on new folder and create new shapefile. Give name as camps and select points as data. To give spatial reference, click on Edit and import reference from the protected areas file and click Ok, Ok. Go back to ArcMap and check if the new layer has been added. Go to Editor on the ribbon, Click start Editing and select the empty file type, click on create new feature. Move your mouse and click where you want your points to be. When done, go to Editor, Save Edits and Editor stop editing. Now you can change the symbology of the points as you wish. When the empty polyline(for line features) is created, got to Editor, start editing, create feature. Follow each of the line features creating vertices and double clicking when done. Finish all of them and save edits and stop editing. You can now change the symbology for the line feature and that is done. Save the new map showing beautiful symbology for the roads and camps in Gonarezhou and add north arrow, scale bar and legend. Save as yourname_lab7. Save project

9 Lab 8: Spatial Analysis: Buffer Zones You are working as a field officer for Action Contre la Faim in Mberengwa district. You have a project to improve water supply in the area through installation of boreholes for communities. The rule is that each household should not walk more than 5km to fetch water in the borehole, provided they are 2km from a river. You therefore want to use GIS to identify areas that require additional boreholes and are not close to rivers. Using your very good GPS, you have taken coordinates of current borehole locations and imported them into ArcGIS through Boot Camp. Borehole location points shp Rivers shp Mberengwa district shp Go to analysis tools, proximity, buffer. Put the boreholes as input, put the borehole buffer name, put the distances in the linear unit, OK. Now put the rivers as input, put the rivers buffer name, put the distances in the linear unit, OK Change your symbologies. Save output as yourname_lab8. Put all map components. Comments something about the general availability of boreholes in the district and the areas that require boreholes. Save project

10 Lab 9: GIS Data Creation You have been elected a new member of parliament for Bubi constituency. Your priority is delivering health services to the people in your constituency. USAID has promised you $ for construction of 2 additional clinics in your constituency. You now want to determine the areas that you have to site these 2 clinics based on the current distribution of clinics in the area. You want to use GIS to determine average distances from clinics and put the new clinics in the areas where distances to clinics are more.. Districts layer shp Health centers shp Select and save Bubi as an individual shp layer Project the health centers layer into spatial reference of Bubi layer Clip the health centers to Bubi district only Change the sympology and export the map showing distribution of health centers in Bubi district Now we want to create a raster surface that shows distance from each health center in the district. Go to ArcToolbox, Spatial Analyst, Distance, Euclidian distance. On input file, put the Bubi health centers layer, select and create name for output distance map, put 500 as output cell size and click ok. Rick click the created distance map, properties and put stretched as symbology. Which areas in the district travel more distances to clinics. Save that map as yourname_lab9a. Use the classified as symbology and put 5km distance classes, and save the map. Make brief comments about the areas that require clinics in the area. Discuss the weaknesses of this approach. Save project

11 Lab 10: Overlay functions Introduction to GIS