Talk:Proposed features/Water cover
I like this tag, I was wondering about the coast and if low tide or high tide is marked, this would allow both to be mapped.
Dang, knew I should of walked round the beach with my GPS ;) - LastGrape
I don't agree with the rendering of beach being used for so many things. This might be a more consistent way than using a separate causeway tag Proposed features/Causeway. Smsm1 19:36, 8 July 2007 (BST)
I think that this is a great idea as in some places there can be a difference of up to a mile between high tide and low tide and the inability to mark both reduces the accuracy of the map. Ballysallagh1.
I like it. It allows for a great flexability. But concerning the rendering, I suggest that this tag is applied as a hatching over the "normal" area typt. Example: Along the Nile, there is mainly agricultural land. But Every year this land gets flooded by the annual Nile Flood. Tagging of the area would be landuse=farm, water=intermittend. A beach would be tagged as natural=beach, water=tidal. Both areas would keep their original rendering, enhanced with blue stripes. --Peter.doerrie 10:14, 15 March 2009 (UTC)
How would this work with the existing coastline tag (which is positioned at the average high tide, and therefore overlaps the proposed 'tidal area')? Would the area between low-tide and high-tide be a separate enclosed way (and maybe requiring a layer tag to make it 'below' the existing 'sea')? Or would the coastline be moved to the low-tide mark and the new low-tide->high-tide area inserted between the coastline and the 'land'? Thinking about it, surely the coastline should really be at the low-tide mark, so that the tidal areas can be tagged above the low-tide without overlapping (but unfortunately the 'standard' is for it to be at the high-tide for some reason!)? --Spod 13:21, 29 April 2009 (UTC)
- Coast line should follow high water mark, though a line marking low water mark wouldn't be bad at all. I disagree in tagging this as an area, and it should be up to the renderer what line to use, or if the area in between should be marked in a special way. For most land-based maps, what is below high water mark is of little interest (unless there is a large tidal plain), while maritime maps have little interest of what is above high water mark (some features above are still of interest though). --Skippern 13:46, 29 April 2009 (UTC)
- this is dependant on the purpose of the map; land oriented maps (as is about 95% of OSM right now and maps like Google/Bing) are drawn on average high tide because land below this level is useless for land-based activities, and seamaps are drawn with use of average low tide because sea falling dry at low tide is useless for water based activities (safe navigation) So dependant of what kind of map you are rendering one or the other becomes important. Because OSM is going in both directions it is usefull not to use one or the other but both. Would blue-ing area's (some 30% blue-er rendering) of land below high water level be a workable solution? Than all original land tags still apply, eliminating conflicts with current tagging. Proposition: add to natural=water level=constant/high_tide/low_tide/high_artificial/low_artificial/high_season/low_season. Here the tide tags are used for the 12 hour tidal cycle in water level. Artificial can be used for a (non time dependant) cycle caused by human activity such as power generation or water storage. The season tags can be used for seasonal influences such as dry/wet periods and summer/winter differences. Perhaps a cycle=tag can be added for seasonal and especially artificial cycles. Interesting inconsistency: here in holland, sea is marked at high tide, but rivers at the mean level (not winter high, (almost) similar to summer low) so this also requires a usable rule to make rendering go smooth, and consistent with the rest of the world! Renderer should be able to relate both ways, perhaps a relation is useful for this? Or should the relation of two similar tagged way's (name and water(way) tags) be enough to distinguish the relation?--Vussiewussie 20:49, 21 June 2010 (UTC)
Salt Marshes (Intermittent salt planes or salt lakes) should be considered implemented in natural=wetland, and should not be part of this proposal. Wetland is already an approved feature. --Skippern 13:42, 29 April 2009 (UTC)
"Applies-to: area", but I think there's a good case for permitting this on ways, too. For example, seasonal/intermittent streams and rivers; also roads which are tidally or seasonally flooded.
Oceans, lakes, rivers are all submitted to water level variations. You will show - or not - the extent of these variations depending on the "zoom level" you are working at. The proposition aims at mapping these areas. We can map every water body/course with a tag specifying the permanency of the water over that area (water=intermittent/tidal/permanent) where water=permanent would be the default value.
The main problem is that the coastline is captured at high-water level and these low-level water features are obviously "below" instead of "beside". Why don't we look at this as a real life fact and work rather on its representation? You wish to represent a tidal area? Just add it as proposed without editing the coastline. The rendering is just a question of feature priority as it is already the case for other features (mapnik's z_order). Conceptually, an area feature shows what it "owns" or "contains".
For all other cases, you create different features for permanent and intermittent water as proposed. We should also be able to add the tag on an existing water feature (waterway=stream; water=intermittent).
Finally the difficult rendering question. I would propose a "textured" blue showing the intermittence of water instead of colors that display material type --Daniel 20:55, 24 February 2010 (UTC)
Agreed, I'de like to see something like this implemented. I have started mapping area's as such around Southport (UK) where there is vast array of Sand Beaches and Marshland. It' difficult to understand how these area's should be tagged in the current system. Martin Renvoize 15:07, 15 July 2010 (UTC)
In Proposed features/marine-tagging and User:Skippern/INT-1 there is need for tagging of various features in tidal zone as well as some intermittent lakes, rivers etc. Suggested use of the values are also shown there. --Skippern 14:09, 27 August 2010 (BST)
I've been looking for a tag for an island (river) which is only sometimes un-covered. It's clearly not wetland in any normal use of the word, nor would it seem sensible to tag it as 'beach' if it's made of stone/rock. I'm also struck by the need for something which covers causeways (where tidal) and even perhaps fords. I like water=intermittent and water=tidal. These make a great deal of sense for such issues. Might suggest also water=usual and water=occasional. I do wish the original proposal had been for water_cover= not water= though, as this would have clarified the difference between this and any description of water conditions for other purposes - but I think it's too late to worry about this. Rostranimin 12:27, 2 March 2012 (UTC)
Beyond coastline discussion
I'm struck by how useful this tag would be for causeways, paths/tracks across mud/sand and so on. I've been following up conversations about the difficulties with this, and I think this tag suits well - so added a few words to the page to indicate this. Rostranimin 12:27, 2 March 2012 (UTC)
Confusion with other uses of Key:water
Note that there's also a conversation going on here: Key:water which may change things. Again, suggest that changing (despite the hassle) water=intermittent to be water_coverage=intermittent would solve all sorts of issues. As well as those indicated at Key:water I've also come across confusion with water=tidal as being used to describe the water itself (as opposed to the land uncovered) - an issue causing confusion for mappers of sea areas (particularly where they become tidal rivers). Rostranimin 12:53, 2 March 2012 (UTC)
I would definitely like something like this.. natural=wetland unfortunately is limited to mainly wetlands. What is the status of this proposal? One problem I see is that the name of the tag is really not so good. Not that I can think of something better in this moment.. RicoZ (talk) 13:30, 16 November 2013 (UTC)
- I would also like something like this... Unfortunately as of January 2018 JOSM says water = intermittent is deprecated, use natural = water + intermittent = yes. I would love more granularity in this field. Reservoirs are a huge headache, there's no consensus in how to map the intermittent range, the shallowest reservoirs have massive intermittent areas, some of them with ammenities built on top of them, because the water maybe only stays a few days every other year. Tracks, bridges and ruins go almost into the old river bed. I would like some multipolygon with an area tag like water_cover = intermittent for non permanent water levels, and a linear tag for the outer and inner ways like water_cover = flood | draugth, where flood is the max level defined by the dam, and draught is the all time min level record, and render this acordingly. I would even like to separate mainly dry (with ocasional flooding) and mainly covered (with ocasional draught) areas. I hope all this is posible in the near future. We need to discuss this now. --Iagocasabiell (talk) 12:20, 25 January 2018 (UTC)
- In the meantime I'm mapping reservoirs like this: Land multypolygons (natural=*, landuse=* tags) |way| Max level of reservoir, only covered in floods, with Marsh multipolygons (type=multipolygon + natural=wetland + wetland=marsh) if it grows grass and most of the time it is wet and soft |way| Normal high level of reservoir, covered by water except in draught periods, with Reservoir multipolygons from shore to shore (type=multipolygon + natural=water + water=reservoir + seasonal=yes) |way| River bed, only visible in drought periods, just like a normal river bed multipolygon, covered by the reservoir multipolygon (type=multipolygon + natural=water + water=river + name=*) |way // ending in the middle of the reservoir with relation waterway indicating the main river linear course. --Iagocasabiell (talk) 12:59, 26 January 2018 (UTC)
- Cross section of a reservoir. I can't upload an image here, can someone explain how? --Iagocasabiell (talk) 14:19, 26 January 2018 (UTC)