[HOT] landslides and imagery

Prabhas Pokharel prabhas.pokharel at gmail.com
Mon May 11 14:10:40 UTC 2015

Another email to add to the list for those interested in doing landslide
We at KLL were forwarded this landslide risk assessment layer:
which comes from here:

It may help those of us interested in finding lanslides have some areas of
high risk where they could start looking.


On Sun, May 10, 2015 at 11:50 AM, Springfield Harrison <stellargps at gmail.com
> wrote:

> Hello John,
> With reference to your moving boulder, just wondering if that could be in
> fact moving, i.e., not an image based coordinate shift as such.  I'm just
> thinking that with aftershocks and general instability, many of these new
> features are still sorting themselves out and traveling downhill.
> Can DG or Bing make stereo pairs available?  Likely a long shot, but
> thought I would ask.
>                 Cheers . . . . . . . . Spring Harrison
> At 09-05-2015 17:49 Saturday, john o'l wrote:
>> I've been focusing on landslides and have located several score that
>> appear recent. Of these, a few are pre-quake and appear relatively stable,
>> some are pre-quake but appear reactivated and many appear to have been
>> associated with the quake and/or aftershocks. I've mapped several dozen of
>> these so far. In my next email, I'll cover why you won't find them in
>> osm... yet. For this one, I'd like to stick to post quake imagery and some
>> of its quirks.Â
>> There is an inhabited hillside that had numerous landslides, some predate
>> the quake, but most are presumably related. So far I've mapped about half
>> of them, those that are largest or appear to threaten buildings and
>> pathways. There is Digital Globe imagery available from May 3 and May 8. It
>> looks like QGIS easily operates with more than one coordinate system at a
>> time. The center of a large boulder in the May 3 imagery (Longitude,
>> Latitude; WGS84 EPSG:3857 x,y) is at
>> 85.85659,27.83609;9557511.789,3228324.329, in the May 8 imagery it is at
>> 85.85669,27.83656;9557522.728,3228382.865. Mind you, this is not a
>> complaint, rather it is a concrete example of the variability with this
>> recent imagery. Â
>> A more extreme example is a slide that appeared to be partially blocking
>> a stream in the May 3 imagery 85.90258,27.87818;9562631.312,3233623.303;
>> -- it was completely obscured by a hillside in the May 8 imagery (probably
>> taken from a more northerly or northwesterly vantage point.)Â
>> Downslope (westward) from a likely reactivated slide located at
>> 85.81987,27.90810;9553423.739,3237391.771 Â is a remote area that
>> appears very hard hit. The May 8th imagery is mostly clouds, but the May
>> 3rd imagery shows a blue rooftop at
>> 85.80644,27.90818;9551929.301,3237402.414, it looks like there are several
>> large boulders in the immediate area and there is not much left to tell
>> there were more than 20 buildings nearby. While the boulders may have
>> contributed, at the moment I think it is probable that the shaking itself
>> was mostly responsible for the extreme level of destruction.Â
>> One advantage of different acquisition angles is that some features may
>> be discernible on slopes that don't ordinarily show up very well.Â
>> Â
>> Question to the HOT folks -- is there a way to specify the date of DG
>> imagery we access through the proxy server?, Some of the May 8 imagery is
>> starting to come up over the May 3 imagery without me telling it to. Â
>> Best regards,
>> John
>> _______________________________________________ HOT mailing list
>> HOT at openstreetmap.org https://lists.openstreetmap.org/listinfo/hot
> _______________________________________________
> HOT mailing list
> HOT at openstreetmap.org
> https://lists.openstreetmap.org/listinfo/hot

Prabhas Pokharel
twitter/skype/facebook/whatever: prabhasp
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/hot/attachments/20150511/10aa6108/attachment.html>

More information about the HOT mailing list