Sharad, Could you upload your data, or do I have to keep asking!?? Justin
On Thursday, August 7, 2014 12:31:01 PM UTC-4, Sharad Lele wrote: > > Dear Eric: > > Here is my understanding: > > 1. The census does not create any category, be it tehsil, block or mandal. > These are statutory or administrative categories created under various > state laws and programmes at various points in time. Note that "Block" is > same as "Community Development Block or CD Block". Taluk and tehsil are > synymous, and come from the revenue side. Block comes from the rural > development department. Mandal comes from panchayati raj (decentralised > governance). > > 2. Note also that different states have different decisions about how > blocks are demarcated. At one end, Karnataka says CD blocks are same as > tehsils/taluks. Some states have 1-2 blocks per tehsil. Some states found > tehsils too big and have lots of blocks per tehsil. But as far as I know, > blocks are strict subsets, and don't straddle tehsil boundaries. > > 3. Census only has to decide at what level to provide data to the user for > a given state. E.g. ,in a district census handbook, whether to have > chapters organized by tehsil or by block. So the table you refer to only > tells us what choices they made in different states. It does not mean > (e.g.,) that there are no tehsils in Jharkhand. Just that Census did not > use that level. But yes, since Census says that MP data are reported at > Tahsil level, I would think that the GADM boundaries for MP will match the > tehsil boundaries and hence the census data. But the GADAM data may be > outdated: tehsils have also sometimes been added (districts being split is > more common). > > Hope this helps. > Sharad > > On 07-Aug-14 8:15 PM, Eric Dodge wrote: > > This is very interesting Sharad. > > I've been looking for maps of what I've been calling administrative > blocks, that is, the units overseen by block development officers. MGNREGA > data is aggregated at this level and I've been hoping to use the data to do > some mapping exercises. > > The census sub-districts are called differently across states (tahsil, > taluk, mandal, etc). You can see the list here: > > > http://censusindia.gov.in/Tables_Published/Admin_Units/Admin_links/subdistrict_nomeclature.html > > I know that in all the states where census sub-districts are called > taluk, mandal, or CD block (with the exception of TN), the census > sub-district is identical to the administrative block. > > I've already completed a mapping exercise for Bihar using the census > sub-district map and the data matched up pretty well. If the IND_adm3 data > is indeed the administrative blocks then I could do a similar exercise with > Madhya Pradesh. I'll take a look to see if the data lines up correctly. > > Has anybody dug into this issue any deeper? I've heard that tehsil comes > from the revenue side whereas taluk, mandal, etc comes from the > administrative side but that doesn't explain why the census uses different > sub-district units across states. > > Best, > Eric > > > On Thu, Aug 7, 2014 at 7:39 AM, Sharad Lele <[email protected] > <javascript:>> wrote: > > If I am right, then Justin may want to rename his layer as CDBlocks_2001... > > Sharad > > > On Thursday, August 7, 2014 4:28:17 PM UTC+5:30, Sharad Lele wrote: > > I think I have the explanation for why I am seeing a good match and you > are not: > > The problem lies in defining what is the 'sub-district' unit (in > IND_adm3). Administratively speaking, it is tehsil, below which lies CD > block. Unfortunately, census gives information by CD block. So there are > more 'sub-district' units in Census than tehsils in the country. GDAM seems > to have followed the tehsil concept. > > To check: Karnataka is one state in which tehsil and CD block are one and > the same. That is why the sub-district layer IND_adm3 matches perfectly for > Karnataka, but not for other states. There might be some other states where > this holds good, I don't know. > > Anyway, so if one really wants CD block level boundaries, we have to look > at Justin, I guess. > > But the GDAM boundaries are not 'wrong'. > > Sharad > > On 07-Aug-14 9:48 AM, Devdatta Tengshe wrote: > > In Continuation of my previous email, here is a CSV file which shows > just how bad the GDAM dataset is. > > Regards, > Devdatta > > > On Thu, Aug 7, 2014 at 9:06 AM, Devdatta Tengshe <[email protected] > <javascript:>> wrote: > > Hi Sharad, > > I just download the GDAM data again, to confirm what you have said. > > I'm going to have to disagree with you about the quality of the IND_adm3 > data. > > > Acoording to the 2001 Census, there are 5454 Sub Districts in India > <http://www.socialjustice.nic.in/pdf/tab11.pdf>. The GDAM dataset has > just 2299 features. > > So clearly these taluk features do not correspond to the 2001 Census. I > cross checked for some areas I have ground knowledge of, and I can say that > this dataset is not from any specific era. Some tehsils in the file were > created post 2001, while others created in the 90's were not present. > > In my opinion the GDAM data is pretty much unusable. > > > Regards, > Devdatta > > > On Wed, Aug 6, 2014 at 11:36 PM, Sharad Lele <[email protected] > <javascript:>> wrote: > > I have downloaded and checked the GADM boundaries (my version is 2011). > The taluka boundary layer probably holds good today, becuase few talukas > get split. Districts get split regularly (every so many years) so the > district boundary layer in this GADM set is quite of date (may apply to > 2001 or so). The spatial registration (positional accuracy is ~1km, and the > spatial detail is of course not as good as the boundaries given in a Survey > of India 50k topo, but then that is an unfair standard, so by a more > generalized standard, the quality is okay. > > Sharad > > > On Monday, August 4, 2014 7:20:38 PM UTC+5:30, Dilip Damle wrote: > > Mr Thakkar, > > Please also look at another post (more than one) on this group about > Taluk Shapefiles by Justin Meyers > > So far as I know GADM is the source that has Taluk files. > I am not sure about its completeness and accuracy as on today > > http://www.gadm.org/ > > On Monday, August 4, 2014 6:23:07 PM UTC+5:30, D Thakker wrote: > > thanks Dilip for your hardwork. > I have been on a lookout for all taluka / tehsil shape file, so how do I > be in a loop as I am very keen to see the repository mail / list. > > > On Monday, August 4, 2014 9:50:26 AM UTC+5:30, Dilip Damle wrote: > > Sharad, > > I am working on some things will revert in about a week or may be more. > > Thejesh, > > Go ahead, > > Actually there was one more source a Low Resolution (vertices) District > map by VDS technologies. > I have it as Polylines in Autocad. I seem to have lost the original file. > If anyone has then please share it. (it does not seem to be on their site > now) > > On Sunday, August 3, 2014 11:32:43 PM UTC+5:30, Thejesh GN wrote: > > Actually its not a bad idea to list it on the wiki. Let me know i will > create an account. > > -- > Thejesh GN ⏚ ತೇಜೇಶ್ ಜಿ.ಎನ್ > http://thejeshgn.com > GPG ID : 0xBFFC8DD3C06DD6B0 > On Aug 3, 2014 10:15 PM, "Sharad Lele" <[email protected]> wrote: > > Dear Dilip and others: > > I have been following this thread with interest, but to be honest am a bit > lost now. Can someone post a summary of which maps mentioned so far have > what features (which coverage, pertaining to which year, what attributes > (such as census codes), etc.)? Would be most helpful. > > Sharad > > > On Friday, August 1, 2014 9:03:58 PM UTC+5:30, Dilip Damle wrote: > > Hello, > > This is an old post. > However this is the appropriate place to add an additional source. > > I had downloaded the set from Grid Geneva many years ago. > The original complete source was named as GNV197 which is 24 MB > Titled as "HUMAN POPULATION AND ADMINISTRATIVE BOUNDARIES DATABASE FOR > ASIA" > I am attaching the South Central Asia E00 file. > > That set contains The disputed areas under the country name IN1 and IN2 > > This dataset can not be easily found at present on the GRID Geneva site > http://www.grid.unep.ch/index.php?lang=en in the same name. > may be it is still there somewhere with some other name. > > For copyright check the metadata file which is here > > http://geonetwork.grid.unep.ch/geonetwork/srv/en/iso19139.xml?id=835 > > rgds > Dilip Damle > > On Wednesday, January 4, 2012 9:52:57 AM UTC+5:30, Karthik Shashidhar > wrote: > > All the shapefiles for India that I have downloaded do not show PoK and > Aksai Chin as part of India. Does anyone here have access to shapefiles > that include these territories? Basically looking to publish (online) some > maps, so want to make sure that it's accurate. > > (I looked through the group archives, and all sources mentioned there do > not show these regions as part of India) > > Thanks > Karthik > > -- > Datameet is a community of Data Science enthusiasts in India. Know more > about us by visiting http://datameet.org > --- > You received this message because you are subscribed to the Google Groups > "datameet" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > > -- > Datameet is a community of Data Science enthusiasts in India. 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