I just want to say that this contribution is awesome! Thanks to all who worked on it, I know it was a big project. What a fine job!
Did I miss something?, have the national parks been imported?
No, it was just me being stupid and wishful thinking. For some reason, the earlier outlines of the parks were just rendered on my computer.
I think quite a few users have been adding national parks in the past few months. The data is still incomplete, though. Perhaps we could create a subpage on the Wiki to document and coordinate such efforts. It would be nice to continue the work started in February’s hackathon.
Short of actually copying data that the Thai government considers its own property I don’t see a way forward on obtaining definitive park boundaries. They appear in Google Maps so the data is present and available somewhere but I have no clue as to how we might get permission to use it. We stumbled on a big collection of Thai topographic maps at the Chiangmai hackathon, maps that were actually done by a now defunct agency of the United States government. According to information on the maps, the U.S. government claims no copyright on them but the Thai government does. I tried to locate someone in the U.S. government that knew something about those maps but ran out of patience. Tracking down ownership and permissions through the U.S. bureaucracy was just too much work at the time.
I don’t know where those users you mentioned are getting their data but I would sure like to know their sources. Can anyone point me to a national park that has been recently added?
I recall seeing from the Open Data Day’s hackpad that searches were being made in the Royal Thai Government Gazette for legal proclamations of the national parks? As part of legislation, those should be public domain.
I’ve started a page on the wiki. https://wiki.openstreetmap.org/wiki/WikiProject_Thailand/Protected_areas
Very nice, thanks Paul.
I don’t see the “new national parks” you’re referring to unless you mean the ones added as only nodes. I did a search with Overpass and discovered a few parks added some years ago by user:webrian. He has some journal entries in his OSM account and in them he talks of using ESRI shapefiles as a reference. His maps of the parks are quite nice and use many points to describe the park boundaries. This is the sort of data we need. The PDF maps in the Royal Thai Government Gazette are handy but they cannot be easily used to draw boundaries.
So, in my opinion, we still lack a source of quality boundary data for Thailand’s national parks.
Btw, the topo maps I mentioned in my previous post and that were discovered at the Chiang Mai hackathon are here:
http://www.dnp.go.th/tak/Home_files/Secret_Data/Index_8_1.htm (choose tiff, jpg, or ecw file formats)
We also found this site:
http://www.dnp.go.th/tak/Home_files/Secret_Data/dataProgramGoogleEarth/Index3.htm (shapefiles for 14 parks in Tak province)
All these maps and shapefiles are for features in Tak Province. I searched around looking for similar sites for Chiang Mai Province and came up empty.
PS: Sorry for the late response. I’ve been traveling pretty steady since leaving Chiang Mai in early April.
I contacted user:webrian and he gave me this link to the source shapefiles he used. The site is run by the Asian Development Bank whose mission is to increase economic opportunity in the SE Asia region.
I will try to contact them for usage rules and copyright restrictions but I assume there are none. The few boundaries I inspected briefly were not as nice (fewer points, less accuracy) as the ones webrian used for his additions and one I looked at in detail, for Ob Khan NP in Chiangmai Province, did not seem accurate because the park headquarters wasn’t inside the boundary. The boundaries in the shapefile are all labeled “protected area” and as such, may not line up perfectly with the national park boundaries.
I’ll post more when I have anything new to report.
That’s great. In the meantime, I guess it can’t hurt if anyone wanted to manually trace those maps from the Royal Thai Government Gazette. I’ve been using the PicLayer plugin in JOSM to do so for some of the national parks, though I’ll admit it’s quite a tedious process.
Did you manage to get the projection right? If I remember February right in Thailand is Indian 1975 used.
That’s nearly a kilometer off when not corrected. I found this on the web:
The shift parameters from Indian 1975 to WGS84 have been derived many times. The current ones are:
∆X = +204.4 m, ∆Y = +837.7 m, ∆Z = +294.7 m
(Prof. Itthi Trisirisatayawong, Chulalongkorn University, November 2010)
Not really. I tried some coordinate conversion tools, but they didn’t align well. Seeing as there was going to be some degree of error anyway manually tracing from scans of relatively small-scale printed maps of variable quality, I chose to manually align the maps to existent major features instead.