[HOT] Mapping Bassikounou, Mauritania - ICRC request

[Severin Menard]

Hi,

Sorry for coming back to you late. Finally, the ICRC Water and Habitat
Specialist will not use the "ponds" data, so we can avoid to map it. I wish
they come directly to discuss with the community on the list in the future.

Sincerely,

Severin



On Mon, Mar 10, 2014 at 6:03 PM, Tom Taylor <tom.taylor.stds at gmail.com>wrote:

> On 10/03/2014 1:32 AM, David Litke wrote:
>
>> Hello,
>> I am fairly new to mapping towns in Africa, but would like to help out
>> on this project, especially since it is a water-related project and I am
>> a hydrologist. I have a few comments/questions:
>>
>
>  As a new mapper relatively unfamiliar with Africa, I cannot stress the
>> importance of any on-the-ground information that can be made available
>> about how to interpret imagery. Otherwise, how can I guess what I am
>> looking at? For example, in the Bassikounou imagery, what are these
>> strange (sometimes very large) white spots (sometimes in the shape of a
>> bow-tie), for example at 15.8604986, -5.9610567? Some kind of tent?
>> Buildings, walls and roads: I can understand the importance of a good
>> base map to the ICRC so they can use it for on-the-ground surveys of
>> water-development information.
>>
>
> [PTT] That square has the look of an institution (health centre or
> school). Anyway, I would surmise that is a fairly new permanent piece of
> construction financed from abroad.
>
>  Intermittent ponds: Since this is very dry country, it seems to me that
>> we happen to have imagery taken after a fairly strong thunderstorm event
>> (like the one seen at the nearby refugee camp in 2012
>> <http://intersos.org/en/bulletin/news/malian-refugee-
>> camps-under-water-floods>),
>>
>> and the water we see is essentially puddles left over from this storm.,
>> which will be very temporary in duration. What we are mapping
>> essentially are the low spots in the topography where the water
>> collects. I do not believe this has any relation to where groundwater is
>> located. If the ICRC is interested in topography, they might be better
>> off using SRTM elevation data - this also could be processed to find
>> possible dry river and stream channels.
>>
>
> [PTT] In Mali, it was obvious where standing water persisted throughout
> the year from the darkness of the vegetation relative to surroundings. I
> mapped such areas because of their impact on roads (generally have to
> bypass) and farming use.
>
>
>  Trees: Are these Acacia trees? Since it is quite time consuming to map
>> these, is it proven that the tree density is indicative of water
>> availability?
>>
>
> [PTT] You can quickly map trees by creating one node, then copying the
> node (click on it and select copy from the edit menu), then clicking on
> each successive tree location and doing paste. My purpose in mapping trees
> was just to provide landmarks for navigating through the town streets.
> Sometimes away from town a cluster of trees will be a meaningful indication
> of water (e.g., oasis).
>
>  Wells: Although we are not mapping wells, I was very interested in the
>> email thread about wells (in Mali). I am very surprised that wells can
>> be located by looking at imagery. It seems that only a small fraction of
>> wells could be discernable, mostly only those that have paths converging
>> at the well, or by the animal tracks made by oxen pulling up the
>> buckets. It is very interesting to learn about these animal track
>> patterns though - the length of the animal tracks might be used as to
>> estimate the (maximum) depth to water).
>> Dave
>> *From:* Severin Menard <mailto:severin.menard at gmail.com>
>> *Sent:* Thursday, March 06, 2014 10:14 AM
>> *To:* hot at openstreetmap.org <mailto:hot at openstreetmap.org>
>> *Subject:* [HOT] Mapping Bassikounou, Mauritania - ICRC request
>>
>> Hi,
>> ICRC requested us to map an AOI (Area Of Interest) around Bassikounou, a
>> town close to the border with Mali, for a development project about
>> drinkable water. The approach is the same than for Walikale in DRC. To
>> know more: http://tasks.hotosm.org/job/447
>> As you can see, I added a banner to make clear what the job is from, for
>> and about. For sure HTML and wording could be improved, please make
>> suggestions.
>> The map features are a bit more various than usual (eg intermittent
>> ponds - please find a link provided by the local Watsan specialist tp
>> have an idea how to identify them on Bing imagery - and trees).
>> I also added a picture and a video of Bassikounou that I found in the
>> web, to have a better idea of what look like the streets and the
>> outskirts.
>> Sincerely,
>> Severin
>>
>> ------------------------------------------------------------------------
>>
>> _______________________________________________
>> HOT mailing list
>> HOT at openstreetmap.org
>> https://lists.openstreetmap.org/listinfo/hot
>>
>>
>> ------------------------------------------------------------------------
>> <http://www.avast.com/>
>>
>> This email is free from viruses and malware because avast! Antivirus
>> <http://www.avast.com/> protection is active.
>>
>>
>>
>>
>>
>> _______________________________________________
>> HOT mailing list
>> HOT at openstreetmap.org
>> https://lists.openstreetmap.org/listinfo/hot
>>
>>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/hot/attachments/20140317/598fb1cf/attachment.html>