User:Thomas.hills

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Standardising & Entering Distributed Water Points

Motivation

Water & sanitation points are often recorded in OSM for a variety of reasons. This database is likely to be very useful in relief situations, but without a systematic tagging scheme it is difficult to quickly find the information required. Development and presentation of a suitable system could allow clearer tagging and more efficient understanding.

Summary

Thomas Hills has been looking at current tagging methods and possible improvements. Tallguy (Nick Allen) has been looking at suitable methods for cross-referencing water point data from external repositories such as the Humanitarian Water Point Data Exchange. This page is meant as a means of communication between OSM users and water point experts to develop a standardised water point tagging method, and a method of cross-referencing water point data using that method.

There is already a page on Water, Sanitation and Hygeine (WASH) on the OSM wiki but it hasn't been updated in a long time. The embryonic ideas there have been partially included in this page. There are HOT tagging presets for various water point types but these have not been updated for about four years.

Suggested project steps

As this is meant to be a collaborative process, this project plan is only a suggestion, and comments and criticism are welcome!

  1. Observe & review current tagging methods to identify what water point information OSM contributors wish to enter into the map
  2. Develop a preliminary standardised tagging procedure which accommodates the relevant information
  3. Send procedure out for review by OSM contributors and water experts
  4. Modify procedure based on feedback
  5. Send preliminary water point cross-referencing procedure for review
  6. Modify cross-reference procedure based on feedback
  7. Launch water point cross-reference programme.

Current tagging methods

There is a great variety of tagging methods for water points, partly due to their heterogeneity and partly due to the lack of an existing clear tagging method. A survey of features with the tag amenity=drinking_water was performed across southern Africa - the results and discussion are shown on a [separate page]. Over 3441 water points, 156 different keys were used. Many were similar to those used on other nodes in the survey, and the tags could be grouped according to the kind of information they conveyed, as shown [here].

Preliminary proposal for a tagging protocol for water points in OSM

The table below sets out the current preliminary proposal for tagging water points in OSM. It is suggested that water points, used for more than simply drinking water, are tagged as amenity=water_point.

Key Description Values
OSM Location Keys
geometry This specifies the type of feature node

way

relation

id The OSM ID
latitude
longitude
coordinates This provides the lat/long of each point on a way.
addr:street Used if it is not obvious where the access to the water point is from.
Specifying water point type
amenity Identifies this feature as one which can provide drinking water water_point
man_made A range of water point types. Mutually exclusive to natural=* water_well

storage_tank

water_tower

water_tap

sand_dam?

content Used in conjunction with man_made=storage_tank water
natural A range of water point types. Mutually exclusive to man_made=* spring

water

water Used in conjunction with natural=water pond

lake

reservoir

pump Explains whether there is a pump or not. More information on the pump can be given by specifying whether it is powered or manual yes

no

manual

powered

pump:type This describes the model of the pump. There are several different manual ones, so this could be quite useful.
pump:fuel I’m not sure about this, but I’d like to find a way to specify what fuel a pump uses, if it’s not manual. diesel

mains

solar

wind

depth The depth of a borehole or well, in metres (Note, this would require a redefining of this tag - it is currently only used offshore) [Number]
Ownership, access & fees
name The regular name of the pump [Text String]
ref A reference name of the pump (perhaps some form of code, see Tanzanian rural waterpoint database for an example) [Text String]
access Used to describe the legal access yes

no

fee Used for specifying whether a fee is usually charged for a service, or for access yes

no

charge Used for specifying how much is charged for use/access to a facility [Text string]
operator Used to name an entity who is directly in charge of the current object [Text string]
operator:type Used to specify the kind of entity the operator is private

government

ngo

community

opening_hours Specifies when the water point is available. There are rules regarding format
start_date This is when the pump was constructed Year
Availability
intermittent Used to describe whether the water point is always open yes

no

[Text string]

operational_status Used to describe the current state of the water point open

closed

pump:working Explains whether the pump is of operable quality yes

no

indoor Is the pump inside or outside? May be useful in built-up areas. yes

no

sufficient_quantity Is there enough water to satisfy demand? yes

no

Quality
condition The condition of the water point, rather than the quality of the water contained therein good

fair

deficient

water_purification Whether water purification is applied/available yes

no

chlorine

drinking_water Is the water of drinking water quality? yes

conditional

no

[Covered] Specifies whether the water point is open to the elements or covered. However, covered=yes shouldn’t be used for underground elements. yes

no

Project & contact details
project This is the name of the project. [Text String]
contact:phone [Text String]
contact:email [Text String]
website [Text String]
source This is where the information came from. If it’s from a project on the ground, then it should be survey, not the name of the project. survey
source:date
survey:date
note Extra information [Text String]

Questions to answer

  • Should completely private water points be put on the map as an amenity? If they are private, they are not a community service/amenity.
  • Should more address keys be included?

Review of Water Point Tagging in southern Africa

Summary

All 3441 points with amenity=drinking_water in Africa below 1°S were surveyed. 165 different keys were identified:

  • 3 were present for 100% of features
  • 6 were present for 20–80% of features
  • 18 were present for 5–20% of features
  • 37 were present for 1–5% of features
  • 101 were present for <1% of features

The values attributed to these keys were studied and they were categorised into 52 groups according to function.

This is a preliminary survey of water points to try and develop a method to survey all the tags on water & sanitation points across the developing world.

Aim

The aim of this survey is to understand the requirements of HOT/OSM contributors when they add WASH facilities. This can then be used to develop a clear and useful tagging scheme which will cover most information which they may wish to enter.

Scope

This is only a preliminary survey and so covers only one tag (amenity=drinking_water) across a smaller region of the world. It covers sub-Saharan Africa from the Tanzanian Northern border (1.0°S) to the tip of South Africa, including Madagascar.

Method

A quick survey of the OSM wiki to identify common water point tags was performed. Those chosen for research were:

  • amenity=drinking_water
  • drinking_water=*
  • amenity=water_source
  • man_made=water_well
  • man_made=water_tower
  • man_made=storage_tank AND content=water
  • man_made=water_tap

Due to there being so many water points in the region chosen, only features with the tag amenity=drinking_water were properly assessed. There were 3441 of these, and between them they had 156 different keys. An Overpass Turbo map of their distribution is shown on this page.

An Overpass Turbo map showing the distribution of amenity=drinking_water in southern Africa

The features were extracted as a geoJSON, converted to an Excel file using an online conversion tool ready for analysis. The results are shown below in tabular form, followed by a discussion.

Main Results

Table of Key Frequencies

This table shows the number of times each key was used across the 3441 water points.

Relative Frequency Key Frequency
100% geometry 3441
@id 3441
amenity 3441
20–100% latitude 3361
longitude 3361
name 1066
watsan:type 909
operational_status 874
5–20% watsan:availability 622
operator 617
operator:type 525
watsan:cost 509
access 492
water_point 474
opening_hours 473
watsan:water_public 450
source 409
man_made 397
cost 363
description 310
source:date 236
watsan:water_private 236
watsan:location 225
watsan:description 214
watsan:users_per_day 207
drinking_water 207
1-5% pump 160
watsan:water_availability 134
construction_date 123
owner 123
ownership 123
water_place_access 95
status 92
operator_type 87
water_place_durability 87
water_supply 86
water_purification 81
coordinates 80
building 71
building:levels 71
addr:street 69
building:material 69
watsan:connection 66
Operational_status 65
note 64
url 60
watsan:connection_description 60
ref 58
operator:description 57
project:eurosha_2012 57
operational 52
water_point_type 52
water_quality 52
water_quantity 52
natural 49
addr:hamlet 48
addr:city 47
addr:subdistrict 47
start_date 42
NOTE 40
name:en 40
watsan:location_description 38
category 36
<1% contact:phone 34
media:video_device_number 31
project 31
source_date 31
source_type_GPS 31
hh_served 29
charges 26
damage_status 21
media:camera_number 16
functioning 15
disused:amenity 15
pump:status 15
watsan:kwaho_pet_bottles 13
watsan:kwaho_sodis 13
watsan:kwaho_description 12
watsan:kwaho_hwts 12
place:district 12
place:division 12
place:location 12
watsan:type_description 11
operator:type_description 11
watsan:toilet_public 11
place:village 11
media:camera_device_number 10
watsan:funding 10
pump:active 10
media:video_number 9
watsan:kwaho_health_products 9
governance:facility_type 9
governance:project_quality 9
governance:project_status 9
place:sub_location 9
watsan:toilet_private 7
watsan:storage_tank 7
cosmha 7
generator:source 7
content 6
opening_hours:description 6
watsan:cost_per_20l 6
watsan:litres_per_day 6
watsan:water_availability_description 6
Water_Point:operational_status 6
governance:fund_source 6
refurbished 6
capacity 6
landuse 6
watsan:other 5
fee 5
water:availability_status 5
indoor 5
governance:operator 5
contact:email 4
watsan:bathroom 4
contact:mobile 4
water:water_point 4
highway 3
smoothness 3
surface 3
width 3
watsan:cleaner 3
place:sublocation 3
Water_point:cost 3
location 3
governance:agricultural_borehole 3
watsan:water 3
notes 2
disused 2
image 2
watsan:other_description 2
watsan:features_per_location 2
description:de 2
governance:type 2
governance 2
governance:data_collection 2
designation 2
tank 2
website 1
operational_status:electricity 1
watsan:kwaho_health_products_description 1
governance:fund_quality 1
governance:fund_status 1
water:water_tank 1
source_type_map 1
wetap:status 1
wetap:statusnote 1
users 1
watsan_toilet:type 1
watsan:operator 1
operational_status:status 1
wasan_toilet:owner 1
loc_name 1
public 1
private 1
condition 1
contact:postal 1
governance:cost 1
addr:neighbourhood 1
watsan:water_pubic 1
construction 1
abandoned 1
watsan:dumping_site 1
name:fr 1
name:af 1

Table of tag categories

This table shows keys which seem to convey very similar information, and are therefore suggested as being thought of as one category of information when developing a tagging procedure.

'Correct' key Alternatives in the survey Total frequency
geometry 3441
@id 3441
latitude 3361
longitude 3361
coordinates 80
amenity (alternative tags) water_point

designation

category

tank

water_point_type

water:water_point

water_water_tank

governance:facility_type

governance:agricultural_borehole

governance:type

watsan:type

watsan:description

watsan:water_availability

watsan:connection

watsan:connection_description

watsan:kwaho_description

watsan:storage_tank

watsan:water_availability_description

1989
access private

public

water_place_access

water_availability_status

watsan:water_public

watsan:water_private

watsan:water

watsan:other_description

watsan:water_pubic

1288
operational_status status

Operational_status

operational

pump:status

functioning

pump:active

damage_status

wetap:status

wetap:statusnote

abandoned

operational_status:status

Water_Point:operational_status

governance_project_status

governance:fund_quality

governance:fund_status

2848
name loc_name 1067
operator owner

ownership

operator:description

governance:operator

watsan:operator

governance

926
fee cost

charges

Water_point:cost

governance:cost

watsan:cost

watsan:cost_per_20l

913
[Intermittent] watsan:availability 622
operator:type operator_type 612
opening_hours opening_hours:description 479
note NOTE

notes

description

description:de

watsan:location_description

watsan:type_description

467
source source_type_GPS

governance:data_collection

442
man_made 397
source:date source_date 442
[Users/Capacity] hh_served

capacity

users

watsan:users_per_day

watsan:litres_per_day

249
drinking_water 207
start_date construction_date 165
pump 160
project project:eurosha_2012

cosmha

governance:fund_source

watsan:funding

104
[Purification] water_purification 81
condition water_place_durability 88
website url 61
[Water & Point Quality] water_quality

governance:project_quality

61
ref 58
[Water Quantity] water_quantity 52
natural 49
name:lang 42
contact:phone contact:mobile 38
disused:amenity disused 17
generator:source 7
content [of a storage tank] 6
indoor 5
contact:email 4
image 2
[Under Construction] construction 1
operational_status:electricity 1
building 71
building:levels 71
building:material 69
addr:street contact:postal 70
addr:hamlet place:district

place:division

place:location

place:village

place:sub_location

place:sublocation

watsan:location

332*
addr:city 47
addr:subdistrict 47


Miscellaneous tags

watsan:kwaho_pet_bottles
watsan:kwaho_sodis
watsan:kwaho_hwts
watsan:kwaho_health_products
watsan:other
watsan:cleaner
watsan:features_per_location
watsan:kwaho_health_products_description
watsan_toilet:type
wasan_toilet:owner
watsan:dumping_site
watsan:bathroom
watsan:toilet_private
watsan:toilet_public

Irrelevant tags (for WASH)

media:video_device_number
media:camera_number
media:camera_device_number
media:video_number
capacity
refurbished
landuse
highway
smoothness
surface
width
location

Discussion of major keys with many alternatives

amenity

All points in this survey had the tag amenity=drinking_water, but many also had very similar tags which provided the same information. 18 alternative keys, with 1989 entries, were identified. This suggests that a comprehensive but useful tag describing the water point is required. Many values of the tags described a water tap, a water tank or a water tower, suggesting that people wished to provide more information about the type of water source beyond the fact that it could be drunk.

Note that, once other water point tags are surveyed (man_made=water_well, water_point=yes, drinking_water=*, etc.) more thought may be required to ensure that the new tagging procedure is comprehensive and covers their needs too.

8 of the alternatives are from one project, but give similar information to one another. Another project has 3 very similar ones. A clear tagging strategy in a WASH methodology could help projects such as these to efficiently capture and manipulate their data.

access

This is another popular tag, with 1288 instances of tagging across 10 keys. An interesting point with the alternative tags here is that 5 of the 9 alternatives are from one particular project, but seem to give very similar information. This suggests that there is a need for an access tag which can take a range of values.

operational_status

This tag had 15 alternatives, with 1165 instances of them being tagged. This is a critical tag for WATSAN projects and a suitable range of values could bring clarity to water point data. However, there is often the need to provide more information so a secondary category such as operational_status:note may allow for this to be accommodated.

operator

Several of the six alternatives to this had an owner-style tag, rather than operator. I think it can be assumed for most water points that the operator, rather than the owner, is the important piece of information. There were 926 instances of these seven tags being used.

fee

913 instances of this type of information were recorded across 7 keys. Values were a mixture of numbers and text strings, including currencies as well as costs per unit of water bought. It may be necessary to include two keys here, one which specifies whether there is a fee or not, and another with a text string where, for example, ‘7 KSh per 20L’ can be entered.

note

A mixture of ‘note’, ‘NOTE’, ‘notes’, ‘description’ and other tags were used 467 times across the points surveyed. The key ‘description’ is meant to be used to convey information to end users whereas notes are mainly meant to be read by other mappers. The conveyance of information kept within the ‘description’-style tags should ideally be able to be contained within the tagging protocol that is developed, and this tag can be avoided in the protocol.

Users/Capacity

There are quite a few keys which convey information about the amount of water available, or the number of people who use the water point. This is important to include within the protocol, and it may be split in two to produce better systematic values. There were 249 instances across 5 keys.

project

There are 104 instances of information about the project to which the water point belongs, across 5 keys. This is also important information, especially for finding your water points on the map using overpass turbo or a similar method. However, it is probably not necessary to have a separate key for each project, simply a value. It may also be sensible to include a project:date key to specify when the project was performed.

Addressing

Several water points were given addr: keys, like a building. Information about what settlement the water points are in should be clear from the map, but addr:street may be useful in built-up areas where the route to access the point may not be clear.