QGIS training class 2

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合同会社マイクロベースのQGIS演習資料(ver.1.8)です。ご希望にしたがって研修内容を構成します。研修のご依頼をご希望の方は弊社ホームページよりお問い合わせください。
http://microgeodata.com/

製作・協力: 仙石裕明・東郷直子・秋山祐樹

Published in: Education, Technology

QGIS training class 2

  1. 1. Copyright (C) 2013 microbase.LLC All Rights Reserved. Geographic Information System QGIS Introduction(2) microbase.LLC http://microgeodata.com/
  2. 2. Copyright (C) 2013 microbase.LLC All Rights Reserved. Agenda 1st 2nd 3rd What’s QGIS? Basic usage Basic data management Spatial Analysis Spatial data andling Geocording Create Vector data About coordi nate system Create KML data Utilize OSM data
  3. 3. Copyright (C) 2013 microbase.LLC All Rights Reserved. Contents Today 2nd session 1 Spatial Analysis 2 Spatial Data handling Homework
  4. 4. Copyright (C) 2013 microbase.LLC All Rights Reserved. Lecture data lecture1_data tokyo23 homework2
  5. 5. Copyright (C) 2013 microbase.LLC All Rights Reserved. 1 Spatial Analysis
  6. 6. Copyright (C) 2013 microbase.LLC All Rights Reserved. 1.1 Buffering A buffer in GIS is a zone around a map feature measured in units of distance or time.A buffer is often used for spatial analysis. make 200m buffer polygons from a highway.
  7. 7. Copyright (C) 2013 microbase.LLC All Rights Reserved. Add railway.shp in “tokyo23” folder and make 100m buffer polygons from the railways.tokyo23. 2 Input “100” in the form. 3) Check the checkbox of “Dissolve buffer results”. ->An optional dissolve can be performed to combine overlapping buffers. 1) Choose railway.shp as a vector data. Vector > GeoprocessingTool > Clip
  8. 8. Copyright (C) 2013 microbase.LLC All Rights Reserved. A buffer polygon can be created from not only poline data but also point data and polygon data.
  9. 9. Copyright (C) 2013 microbase.LLC All Rights Reserved. Exercise 1 Create 250m buffer polygon data from each station and save it as “station_buffer250.shp”.
  10. 10. Copyright (C) 2013 microbase.LLC All Rights Reserved. ANSWER
  11. 11. Copyright (C) 2013 microbase.LLC All Rights Reserved. Integrate features which locate in same extent. seven elevenセブ ンイレブンの影 響圏 population in Meguro city seven eleven’s market scale 1.2 Overlay
  12. 12. Copyright (C) 2013 microbase.LLC All Rights Reserved. Various kinds of Overlay Intersect Union Clip Input Output Inersect feature Union feature Clip feature Output features have each attribute table of input features Just clip features
  13. 13. Copyright (C) 2013 microbase.LLC All Rights Reserved. Meguro city can be selected by “Select layer by attribute” or “Select Features” from “ku.shp”. Add “library.shp” and “ku.shp”. Clip libraries only in Meguro city. Check the check box of “Use only selected features” and you can clip the target layer based on a clip layer which is selected. Clip feature Overlay1: Clip Vector > GeoprocessingTool > Clip
  14. 14. Copyright (C) 2013 microbase.LLC All Rights Reserved. Libraries in only Meguro city are clipped.
  15. 15. Copyright (C) 2013 microbase.LLC All Rights Reserved. Intersect railways in Meguro ward using “library.shp” and “ku.shp”. Inersect feature Overlay1: Intersect Vector > GeoprocessingTool > Intersection Check the check box of “Use only selected features” and you can clip the target layer based on a clip layer which is selected.
  16. 16. Copyright (C) 2013 microbase.LLC All Rights Reserved. Railways in only Meguro city are intersected.
  17. 17. Copyright (C) 2013 microbase.LLC All Rights Reserved. 1) Choose following features only in Setagaya ward. • dentist.shp • station.shp • road.shp 2) Create following features in Setagaya ward. • 250m buffer polygons from each station. Exercise2
  18. 18. Copyright (C) 2013 microbase.LLC All Rights Reserved. dentist station road ANSWER 1)Clip(or intersect) a dentist, a station and a road using “ku.shp” selecting Setagaya ward.
  19. 19. Copyright (C) 2013 microbase.LLC All Rights Reserved. ANSWER 2) Dentists in the buffers are shown.
  20. 20. Copyright (C) 2013 microbase.LLC All Rights Reserved. 2 Spatial Data Handling
  21. 21. Copyright (C) 2013 microbase.LLC All Rights Reserved. 2.1Select Layer By Location Features can be selected by not only an attribute but also location. Example Select a dentist within 500m from a station Select a ward which a highway go through. Select a ward which borders on Meguro ward Select a seven eleven in Meguro ward
  22. 22. Copyright (C) 2013 microbase.LLC All Rights Reserved. Add “station.shp” and “dentist.shp” in “tokyo23” folder into layer. Choose a dentist within 500m from a station inTokyo special districts.
  23. 23. Copyright (C) 2013 microbase.LLC All Rights Reserved. Create 500m buffer polygons from each station.
  24. 24. Copyright (C) 2013 microbase.LLC All Rights Reserved. Select a dentist within the buffers. Choose a target layer in “selected features” and an overlapped layer in “intersect features”. Vector > ResearchTool > Select by location “Select by location” covers the following spatial relationship among features. - within - contain
  25. 25. Copyright (C) 2013 microbase.LLC All Rights Reserved. Selected features color yellow. The result show about 70% dentists locate in the place within 500m from station. 5129 in 6985 are selected. It may take a little while to select features. Selected rows color blue in the attribute table.
  26. 26. Copyright (C) 2013 microbase.LLC All Rights Reserved. If more advanced search methods than “Contains” and “Within” are required, the plugin “Spatial Query Plugin” will be useful. - “Spatial Query Plugin” will appear if the checkbox in “QGIS Plugin Manager” is checked. - Intersects A intersects B - Contains A contains B - Is disjoint - Equals A equals B - Overlaps A overlaps B - Crosses A crosses B - Touches A touches B - Within A within B Vector > Spatial Query
  27. 27. Copyright (C) 2013 microbase.LLC All Rights Reserved. 1) Search the ward which intersect the highway. 2) Count the number of a supermarket within 250m from each station using “station_buffer250.shp” created at Exercise1. Exercise3
  28. 28. Copyright (C) 2013 microbase.LLC All Rights Reserved. ANSWER 1) the borders which intersect highways.
  29. 29. Copyright (C) 2013 microbase.LLC All Rights Reserved. 467 shops ANSWER 2) Count the number of a supermarket within 250m from each station.
  30. 30. Copyright (C) 2013 microbase.LLC All Rights Reserved. 2.2 Spatial Join Joins attributes from one feature to another based on the spatial relationship.The target features and the joined attributes from the join features are written to the output feature class. a A city shop a b c shop city a C b A c B B city C city b c
  31. 31. Copyright (C) 2013 microbase.LLC All Rights Reserved. Add “convenience.shp” in “tokyo23” and save only “seven eleven” as “seven_eleven.shp”.Then join the attribute from “ku.shp” to it. Check the checkbox of “Take attributes of first located feature”. Vector > Data ManagementTool > Join attributes by location
  32. 32. Copyright (C) 2013 microbase.LLC All Rights Reserved. Attribute of “ku” is joined to “seven eleven”. Attributes of “seven eleven” Attribute of “ku”
  33. 33. Copyright (C) 2013 microbase.LLC All Rights Reserved. a A city shop sale a 2500 b 3000 c 2000 d 1500 shop sale city a 2500 C市 b 3000 A市 c 2000 B市 d 1500 B市 B city C city b c d Join type varies depending on how joins between the target features and join features. city number whole sale A 1 3000 B 2 3500 C 1 2500 Main target JOIN_ONE_TO_ONE JOIN_ONE_TO_MANY
  34. 34. Copyright (C) 2013 microbase.LLC All Rights Reserved. Add Census of commerce of 500m scale units (H16_commerce.shp) and Census of population of block scale unit(pop.shp).Then join the attributes from “H16_commerce” to “pop”. Exercise4
  35. 35. Copyright (C) 2013 microbase.LLC All Rights Reserved. A block unit sometimes contains 500m grids and has more than 2 grids.Attribute summary should be “Take summary of interesting features. HINT
  36. 36. Copyright (C) 2013 microbase.LLC All Rights Reserved. If you want get an attribute value more accurately among different unit features, It would be one of the method to divide the value based on area of the features. ANSWER
  37. 37. Copyright (C) 2013 microbase.LLC All Rights Reserved. Another functions for spatial analysis are available.
  38. 38. Copyright (C) 2013 microbase.LLC All Rights Reserved. )( 1 )( 1 2 i n i XxK nh xf −= ∑= )()( 3 )( 2 hx h xh xK < − = π ! Spatial interpolation Kernel density estimation See geostatistics in more detail. ・Kriging interpolation ・Sprine interpolation ・Spatial autocorrelation etc...
  39. 39. Copyright (C) 2013 microbase.LLC All Rights Reserved. Path Search Shortest Path can be detected by Dijkstra method. Service area analysis
  40. 40. Copyright (C) 2013 microbase.LLC All Rights Reserved. Contents Today 2nd session 1 Spatial Analysis 2 Spatial Data handling Homework
  41. 41. Copyright (C) 2013 microbase.LLC All Rights Reserved. H O M E W O R K
  42. 42. Copyright (C) 2013 microbase.LLC All Rights Reserved. Data homework2 university.shp highschool.shp jr_school.shp el_school.shp firestation.shpfire station elementary school junior high school high school college
  43. 43. Copyright (C) 2013 microbase.LLC All Rights Reserved. Find the area thought to have high disaster risk in Tokyo special districts. 1) Describe characteristics and reasons of the area thought to have high disaster risk. 2) Create a map about 1) and paste it to your report. <Hint> The data today and in “homework2” folder may be good for describing the disaster risk! • population • population density • • school as rescue facility • elevation • public transpotation

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