From May 19th to 24th the Japan Geoscience Union (JPGU, 日本地球惑星科学連合) will be holding their annual meeting at Makuhari Messe near Tokyo. Just like in the past two years I will also be attending and presenting there. This year I will speak in session H-TT09 “GIS”, starting from 14:15 on Monday, May 20th. There will also be presentations by other members of my lab:
Author / Konstantin Greger
“Alles neu macht der Mai”…
… is a famous saying in Germany (where I’m from – in case you didn’t know). In English it’s “May gives birth to the fruits of April’s wet labor”, which sounds even nicer. The reason I’m writing this is that I decided to make some changes to this website. Oh, and because it’s May…
The first change is quite obvious, since I modified the layout of the site completely. The second change might be more subtle, as it’s about the contents of the site. Both are closely connected, as I will briefly explain below.
AAG 2013: Spatial Methodologies for the Analysis of Vulnerability in Urban Areas
This is the slide set for my presentation at the 2013 Annual Meeting of the AAG in Los Angeles on April 9th, titled “Spatial Methodologies for the Analysis of Vulnerability in Urban Areas”. It has been butchered quite a bit by SlideShare and is probably a bit abstract without my spoken comments, so I will upload a brushed up written version here, soon.
Upcoming Event: 2013 Annual Meeting of the Association of American Geographers (AAG)
From April 9th to 13th 2013 the Association of American Geographers (AAG) will hold their 2013 Annual Meeting in Los Angeles. The business centers of three hotels in downtown LA (Westin Bonaventure, LA Downtown Hotel, Millennium Biltmore Hotel Los Angeles) are being prepared to host more than 6,000 sessions about all topics related to geography. Have a look at the preliminary program posted on the AAG website to get an idea of the breadth of topics covered.
Batch-Loading and Merging Shape Files Into PostGIS
Today I was faced with the task of having to load a massive amount of shape files into my PostGIS database. The data in question is the Advanced Digital Road Map Database (ADF) (拡張版全国デジタル道路地図データベース) by Sumitomo Electric System Solutions Co., Ltd. (住友電工システムソリューション株式会社). It contains very detailed information (spatial and attributive) about the road network of all Japan and is thereby quite heavy.
Therefore, it was split into a plethora of files using the following naming schema: mmmmmm_ttt.shp, where mmmmmm represents a six-digit mesh code and ttt represents a 2- to 3-digit thematic code. The mesh code is a result of the data being split spatially into small, rectangular chunks. It follows a simple logic, whereby bigger mesh units (represented by the first four digits) are further subdivided into smaller units (represented by the last two digits). It took only a small amount of time to figure out this naming schema and filter the files that would be necessary for my analysis.
Basically I wanted to merge the shape files into PostGIS tables divided by their topic (i.e. road nodes, road links, additional attribute information, etc.). So I had to find a way to batch import the shape files into PostGIS and merge them at the same time. Yet, since the node IDs were only unique within each mesh unit (i.e. shape file), I also had to find a way to incorporate the mesh codes themselves into the data, so I could later on create my own ID schema for the nodes, based on the mesh code and the original node ID (e.g. mmmmmmnnnnn, where mmmmmm represents a six-digit mesh code and nnnnn represents the original 5-digit node ID).