Re: [talk-au] What do you prefer for Barmah-Millewa: swamp or wood?
You are right to point out that OSM offers a different choice of options compared with the NSW LPI BaseMap. Some time ago, when I couldn't find a legend on the BaseMap, I contacted NSW Spatial Services and I was directed to https://portal.spatial.nsw.gov.au/portal/apps/sites/#/home/pages/map-viewers where the NSW Map is shown with an explanatory legend. In regard to swamps etc., the BaseMap shows only (1) land subject to inundation, (2) swamp-wet and (3) swamp-dry. I have studied the map and satellite imagery in other parts of NSW and I have visited some areas. As you have note, the BaseMap's "swamp-wet" does not differentiate the vegetation in the areas. After studying satellite imagery, I have mapped such areas in which trees are a significant features of the vegetation as natural=wetland + wetland=swamp. However where the vegetation has few or no trees and has more grass-type growth, i have used natural=wetland + wetland=marsh. The LPI BaseMap's "land subject to inundation" equates closely with natural=wetland in OSM and "swamp-dry" (seen in drier areas of the state rather than in the Murray River area) seems best mapped in OSM as natural=mud. On Tue, 12 May 2020, at 12:13 PM, Little Maps wrote: > Thanks Michael. Sorry, my last email overlapped with yours. I think a > major problem is that the way the LPI Basemap, and folks in Australia > generally, use the terms forest, swamp and wetland differs slightly > from the way they are described in the OSM wiki pages. For example, the > OSM guidelines restrict the term ‘swamp’ to areas with dense trees, > whereas the Basemap calls many treeless wetlands ‘swamps’. > > I initially mapped most of the forest as ‘swamp’ as this followed the > OSM wiki page guideline, but wasn’t really happy with this, as I always > thought of the place as a ‘flooded forest’ rather than a ‘forested > wetland’. Hence my query to the list server. I’ll follow your > suggestion below and will change the polygons back to wood in the next > day or two, with a ’Wetland’ overlay in most areas to show its > seasonally flooded. In practice there won’t be any great precision to > the wetland overlay as it’s such a mosaic. > > Thanks again for everyone’s great feedback. Best wishes Ian > > > > On 12 May 2020, at 9:55 pm, cleary wrote: > > > > > > One further consideration is that NSW LPI BaseMap shows most of the NSW > > side of this area as wetland, subject to periodic inundation, while only > > small areas are shown as swamp. At the moment, OSM shows most of it as > > swamp while the named swamps are shown as wetland - exactly the opposite of > > the LPI BaseMap. > > > > While the BaseMap is not perfect, it is a reasonably reliable guide in the > > absence of better information. > > > > While the BaseMap shows wetland and swamp, it does not show wooded areas. > > So perhaps the suggestion to show natural=wood and natural=wetland as > > separate polygons might be a useful approach although I suspect that the > > two together might then be rendered much the same as natural=swamp. I too > > would appreciate other views on this topic. > > > > > > > > > >> On Tue, 12 May 2020, at 8:37 AM, Little Maps wrote: > >> Hello everyone, I don’t know if there is any right / wrong answer to > >> this question, hence I’m keen to know your preferences... > >> > >> I’m mapping wetlands and vegetation along the Murray River upstream of > >> Yarrawonga, and am now mapping in Millewa forest. Millewa (in NSW) and > >> Barmah forest (in Vic) support large red gum forests which flood > >> regularly. Some areas flood annually, others less frequently. It > >> depends on how much water flows down the Murray and which stream > >> regulators in the forests are opened or closed. > >> > >> My question is: would it be better to map this as a forest (i.e. > >> natural=wood) or as a ‘swamp’, which OSM defines as ‘an area of > >> waterlogged forest, with dense vegetation’, tagged as natural=wetland, > >> wetland=swamp, seasonal=yes. I’ve read the OSM wiki pages on both > >> options. > >> > >> I’ve made a first stab at the area > >> https://www.openstreetmap.org/#map=14/-35.8026/145.1484 > >> and have mapped all but the extremes as swamp as this indicates that > >> the area floods regularly, which natural:wood does not show. However > >> most other areas on the river I’ve come across are mapped as > >> natural:wood with relatively small inliers for treeless wetlands and > >> some treed swamps. > >> > >> It’s a quick job to change from wetland:swamp to natural:wood and vice > >> versa and I don’t hold any strong preferences myself. If the general > >> consensus is that the area would be better called a wood (i.e. forest) > >> rather than a seasonal wetland I’ll change it immediately. > >> (I haven’t mapped Barmah forest in Vic, as that was already mapped as > >> natural:wood but much of Barmah actually floods even more frequently > >>
Re: [talk-au] What do you prefer for Barmah-Millewa: swamp or wood?
Thanks Michael. Sorry, my last email overlapped with yours. I think a major problem is that the way the LPI Basemap, and folks in Australia generally, use the terms forest, swamp and wetland differs slightly from the way they are described in the OSM wiki pages. For example, the OSM guidelines restrict the term ‘swamp’ to areas with dense trees, whereas the Basemap calls many treeless wetlands ‘swamps’. I initially mapped most of the forest as ‘swamp’ as this followed the OSM wiki page guideline, but wasn’t really happy with this, as I always thought of the place as a ‘flooded forest’ rather than a ‘forested wetland’. Hence my query to the list server. I’ll follow your suggestion below and will change the polygons back to wood in the next day or two, with a ’Wetland’ overlay in most areas to show its seasonally flooded. In practice there won’t be any great precision to the wetland overlay as it’s such a mosaic. Thanks again for everyone’s great feedback. Best wishes Ian > On 12 May 2020, at 9:55 pm, cleary wrote: > > > One further consideration is that NSW LPI BaseMap shows most of the NSW side > of this area as wetland, subject to periodic inundation, while only small > areas are shown as swamp. At the moment, OSM shows most of it as swamp > while the named swamps are shown as wetland - exactly the opposite of the LPI > BaseMap. > > While the BaseMap is not perfect, it is a reasonably reliable guide in the > absence of better information. > > While the BaseMap shows wetland and swamp, it does not show wooded areas. So > perhaps the suggestion to show natural=wood and natural=wetland as separate > polygons might be a useful approach although I suspect that the two together > might then be rendered much the same as natural=swamp. I too would > appreciate other views on this topic. > > > > >> On Tue, 12 May 2020, at 8:37 AM, Little Maps wrote: >> Hello everyone, I don’t know if there is any right / wrong answer to >> this question, hence I’m keen to know your preferences... >> >> I’m mapping wetlands and vegetation along the Murray River upstream of >> Yarrawonga, and am now mapping in Millewa forest. Millewa (in NSW) and >> Barmah forest (in Vic) support large red gum forests which flood >> regularly. Some areas flood annually, others less frequently. It >> depends on how much water flows down the Murray and which stream >> regulators in the forests are opened or closed. >> >> My question is: would it be better to map this as a forest (i.e. >> natural=wood) or as a ‘swamp’, which OSM defines as ‘an area of >> waterlogged forest, with dense vegetation’, tagged as natural=wetland, >> wetland=swamp, seasonal=yes. I’ve read the OSM wiki pages on both >> options. >> >> I’ve made a first stab at the area >> https://www.openstreetmap.org/#map=14/-35.8026/145.1484 >> and have mapped all but the extremes as swamp as this indicates that >> the area floods regularly, which natural:wood does not show. However >> most other areas on the river I’ve come across are mapped as >> natural:wood with relatively small inliers for treeless wetlands and >> some treed swamps. >> >> It’s a quick job to change from wetland:swamp to natural:wood and vice >> versa and I don’t hold any strong preferences myself. If the general >> consensus is that the area would be better called a wood (i.e. forest) >> rather than a seasonal wetland I’ll change it immediately. >> (I haven’t mapped Barmah forest in Vic, as that was already mapped as >> natural:wood but much of Barmah actually floods even more frequently >> than Millewa). >> >> Thanks very much for your advice. Best wishes Ian >> ___ >> Talk-au mailing list >> Talk-au@openstreetmap.org >> https://lists.openstreetmap.org/listinfo/talk-au >> > > ___ > Talk-au mailing list > Talk-au@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk-au ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
[talk-au] Barmah thanks
Thanks everyone, it’s been useful to hear the wide range of thoughts. I guess I was uncertain to what degree the Aus OSM group followed the strict definitions of the OSM categories or adapted them to suit the way the terms are used locally. The way the OSM wiki page describes a swamp is very different from how we generally use the term in Australia. Michael’s suggestion of using the forest and wetland tags as separate overlays is a useful idea. In practice, all that can be sensibly mapped in Millewa are the extreme wet and dry areas, i.e. treeless wetlands (or swamps as we tend to call them) at one extreme and the dry grasslands and some dry forests in places such as the higher sandhills. Everything else grades between these extremes, and the patterns vary enormously, often at really fine scales, and between years as evidenced by the dry Bing and wet ESRI images available to OSM. So in practice, the bulk of the forest has to be put into one category or the other (either wood or swamp) with grasslands and open wetlands as minor outliers. I’m new to OSM, so if there’s a general acceptance that the vegetation categories are somewhat flexible, then my tendency is to follow Ian’s suggestion and to map it as a forest (natural=wood) with a ‘wetland’ overlay in most places. I can then map treeless wetlands and some big wet swamps separately. Thanks again for all your feedback, it’s been really useful. Cheers Ian. ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] What do you prefer for Barmah-Millewa: swamp or wood?
One further consideration is that NSW LPI BaseMap shows most of the NSW side of this area as wetland, subject to periodic inundation, while only small areas are shown as swamp. At the moment, OSM shows most of it as swamp while the named swamps are shown as wetland - exactly the opposite of the LPI BaseMap. While the BaseMap is not perfect, it is a reasonably reliable guide in the absence of better information. While the BaseMap shows wetland and swamp, it does not show wooded areas. So perhaps the suggestion to show natural=wood and natural=wetland as separate polygons might be a useful approach although I suspect that the two together might then be rendered much the same as natural=swamp. I too would appreciate other views on this topic. On Tue, 12 May 2020, at 8:37 AM, Little Maps wrote: > Hello everyone, I don’t know if there is any right / wrong answer to > this question, hence I’m keen to know your preferences... > > I’m mapping wetlands and vegetation along the Murray River upstream of > Yarrawonga, and am now mapping in Millewa forest. Millewa (in NSW) and > Barmah forest (in Vic) support large red gum forests which flood > regularly. Some areas flood annually, others less frequently. It > depends on how much water flows down the Murray and which stream > regulators in the forests are opened or closed. > > My question is: would it be better to map this as a forest (i.e. > natural=wood) or as a ‘swamp’, which OSM defines as ‘an area of > waterlogged forest, with dense vegetation’, tagged as natural=wetland, > wetland=swamp, seasonal=yes. I’ve read the OSM wiki pages on both > options. > > I’ve made a first stab at the area > https://www.openstreetmap.org/#map=14/-35.8026/145.1484 > and have mapped all but the extremes as swamp as this indicates that > the area floods regularly, which natural:wood does not show. However > most other areas on the river I’ve come across are mapped as > natural:wood with relatively small inliers for treeless wetlands and > some treed swamps. > > It’s a quick job to change from wetland:swamp to natural:wood and vice > versa and I don’t hold any strong preferences myself. If the general > consensus is that the area would be better called a wood (i.e. forest) > rather than a seasonal wetland I’ll change it immediately. > (I haven’t mapped Barmah forest in Vic, as that was already mapped as > natural:wood but much of Barmah actually floods even more frequently > than Millewa). > > Thanks very much for your advice. Best wishes Ian > ___ > Talk-au mailing list > Talk-au@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk-au > ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] What do you prefer for Barmah-Millewa: swamp or wood?
Hey folks, if you're mapping south of the Murray, then perhaps the Vicmap products may be helpful. Vicmap Vegetation - Tree Density dataset could be useful in that DELWP have classified into dense, medium, and sparse tree density polygons and they continue to update the product regularly. More details of classification is available at https://discover.data.vic.gov.au/dataset/tree-density-1-25-000-vicmap-vegetation The web map service is available as an Imagery Layer in JOSM. There's also further products such as Vicmap Hydro - Watercourse Rivers and Vicmap Hydro - Swamps which look useful. DELWP have even numbered every swamp! Licencing is CC-BY-4.0-int with waiver. On Tue, 12 May 2020 at 19:50, Michael Collinson wrote: > Hi Ian, > > Summary: For me wood is physical tree-cover and wetland is the condition > of the ground and they are complimentary rather than exclusive. > > In Sweden, I map both natural=wood and natural=wetland as separate > polygons, with a common border or overlap as appropriate. There is is very > easy from aerial imagery as the trees show distinctive colour and texture, > spot checked in more easily accessible locations from field observation of > the ground below (a very important thing to do IMHO). Here is a random > example: https://www.openstreetmap.org/#map=15/59.5708/18.3099 > > In Australia, I am interested indirectly through work in refining the > Murray River as it flows north of Rutherglen (VIC). I have found that much > harder so haven't yet started any systematic tree/wetland mapping, instead > focusing on the fascinating network of ox box lakes and channels. That's > partly because of the much greater cyclicity in wetness that you allude to > making wetland harder to spot and demarcate on aerial imagery. And partly > that I don't have a local field eye, (I am a city-slicker based in > Melbourne when in Australia). I am therefore tempted to focus on wood > mapping from the arm chair and leave the wetland mapping as a more long > term issue needing a reasonable degree of local observation/knowledge. > > Hope that helps, these are just my personal thoughts and I look forward to > hearing from others. > > Mike > > > On 2020-05-12 09:37, Little Maps wrote: > > Hello everyone, I don’t know if there is any right / wrong answer to this > question, hence I’m keen to know your preferences... > > I’m mapping wetlands and vegetation along the Murray River upstream of > Yarrawonga, and am now mapping in Millewa forest. Millewa (in NSW) and > Barmah forest (in Vic) support large red gum forests which flood regularly. > Some areas flood annually, others less frequently. It depends on how much > water flows down the Murray and which stream regulators in the forests are > opened or closed. > > My question is: would it be better to map this as a forest (i.e. > natural=wood) or as a ‘swamp’, which OSM defines as ‘an area of waterlogged > forest, with dense vegetation’, tagged as natural=wetland, wetland=swamp, > seasonal=yes. I’ve read the OSM wiki pages on both options. > > I’ve made a first stab at the area > https://www.openstreetmap.org/#map=14/-35.8026/145.1484 > and have mapped all but the extremes as swamp as this indicates that the > area floods regularly, which natural:wood does not show. However most other > areas on the river I’ve come across are mapped as natural:wood with > relatively small inliers for treeless wetlands and some treed swamps. > > It’s a quick job to change from wetland:swamp to natural:wood and vice > versa and I don’t hold any strong preferences myself. If the general > consensus is that the area would be better called a wood (i.e. forest) > rather than a seasonal wetland I’ll change it immediately. > > (I haven’t mapped Barmah forest in Vic, as that was already mapped as > natural:wood but much of Barmah actually floods even more frequently than > Millewa). > > Thanks very much for your advice. Best wishes Ian > > ___ > Talk-au mailing > listTalk-au@openstreetmap.orghttps://lists.openstreetmap.org/listinfo/talk-au > > ___ > Talk-au mailing list > Talk-au@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk-au > ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] What do you prefer for Barmah-Millewa: swamp or wood?
Hi Ian, Summary: For me wood is physical tree-cover and wetland is the condition of the ground and they are complimentary rather than exclusive. In Sweden, I map both natural=wood and natural=wetland as separate polygons, with a common border or overlap as appropriate. There is is very easy from aerial imagery as the trees show distinctive colour and texture, spot checked in more easily accessible locations from field observation of the ground below (a very important thing to do IMHO). Here is a random example: https://www.openstreetmap.org/#map=15/59.5708/18.3099 In Australia, I am interested indirectly through work in refining the Murray River as it flows north of Rutherglen (VIC). I have found that much harder so haven't yet started any systematic tree/wetland mapping, instead focusing on the fascinating network of ox box lakes and channels. That's partly because of the much greater cyclicity in wetness that you allude to making wetland harder to spot and demarcate on aerial imagery. And partly that I don't have a local field eye, (I am a city-slicker based in Melbourne when in Australia). I am therefore tempted to focus on wood mapping from the arm chair and leave the wetland mapping as a more long term issue needing a reasonable degree of local observation/knowledge. Hope that helps, these are just my personal thoughts and I look forward to hearing from others. Mike On 2020-05-12 09:37, Little Maps wrote: Hello everyone, I don’t know if there is any right / wrong answer to this question, hence I’m keen to know your preferences... I’m mapping wetlands and vegetation along the Murray River upstream of Yarrawonga, and am now mapping in Millewa forest. Millewa (in NSW) and Barmah forest (in Vic) support large red gum forests which flood regularly. Some areas flood annually, others less frequently. It depends on how much water flows down the Murray and which stream regulators in the forests are opened or closed. My question is: would it be better to map this as a forest (i.e. natural=wood) or as a ‘swamp’, which OSM defines as ‘an area of waterlogged forest, with dense vegetation’, tagged as natural=wetland, wetland=swamp, seasonal=yes. I’ve read the OSM wiki pages on both options. I’ve made a first stab at the area https://www.openstreetmap.org/#map=14/-35.8026/145.1484 and have mapped all but the extremes as swamp as this indicates that the area floods regularly, which natural:wood does not show. However most other areas on the river I’ve come across are mapped as natural:wood with relatively small inliers for treeless wetlands and some treed swamps. It’s a quick job to change from wetland:swamp to natural:wood and vice versa and I don’t hold any strong preferences myself. If the general consensus is that the area would be better called a wood (i.e. forest) rather than a seasonal wetland I’ll change it immediately. (I haven’t mapped Barmah forest in Vic, as that was already mapped as natural:wood but much of Barmah actually floods even more frequently than Millewa). Thanks very much for your advice. Best wishes Ian ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
Re: [talk-au] What do you prefer for Barmah-Millewa: swamp or wood?
I have visited Millewa in NSW and I've seen a little of Barmah but not much. I have a 4WD vehicle but I would not have left the road in either place as I would have become seriously bogged. It was quite wet in both places when I visited (some years apart, not at the same time). I think they are both swamp. In contrast I have visited forest/wood and could safely drive off the road without getting bogged - they were not swamp. It is a matter of judgment but if I can't comfortably drive through it because of the water (like Millewa and Barmah areas) then I think they are swamp. On Tue, 12 May 2020, at 8:37 AM, Little Maps wrote: > Hello everyone, I don’t know if there is any right / wrong answer to > this question, hence I’m keen to know your preferences... > > I’m mapping wetlands and vegetation along the Murray River upstream of > Yarrawonga, and am now mapping in Millewa forest. Millewa (in NSW) and > Barmah forest (in Vic) support large red gum forests which flood > regularly. Some areas flood annually, others less frequently. It > depends on how much water flows down the Murray and which stream > regulators in the forests are opened or closed. > > My question is: would it be better to map this as a forest (i.e. > natural=wood) or as a ‘swamp’, which OSM defines as ‘an area of > waterlogged forest, with dense vegetation’, tagged as natural=wetland, > wetland=swamp, seasonal=yes. I’ve read the OSM wiki pages on both > options. > > I’ve made a first stab at the area > https://www.openstreetmap.org/#map=14/-35.8026/145.1484 > and have mapped all but the extremes as swamp as this indicates that > the area floods regularly, which natural:wood does not show. However > most other areas on the river I’ve come across are mapped as > natural:wood with relatively small inliers for treeless wetlands and > some treed swamps. > > It’s a quick job to change from wetland:swamp to natural:wood and vice > versa and I don’t hold any strong preferences myself. If the general > consensus is that the area would be better called a wood (i.e. forest) > rather than a seasonal wetland I’ll change it immediately. > (I haven’t mapped Barmah forest in Vic, as that was already mapped as > natural:wood but much of Barmah actually floods even more frequently > than Millewa). > > Thanks very much for your advice. Best wishes Ian > ___ > Talk-au mailing list > Talk-au@openstreetmap.org > https://lists.openstreetmap.org/listinfo/talk-au > ___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
[talk-au] What do you prefer for Barmah-Millewa: swamp or wood?
Hello everyone, I don’t know if there is any right / wrong answer to this question, hence I’m keen to know your preferences... I’m mapping wetlands and vegetation along the Murray River upstream of Yarrawonga, and am now mapping in Millewa forest. Millewa (in NSW) and Barmah forest (in Vic) support large red gum forests which flood regularly. Some areas flood annually, others less frequently. It depends on how much water flows down the Murray and which stream regulators in the forests are opened or closed. My question is: would it be better to map this as a forest (i.e. natural=wood) or as a ‘swamp’, which OSM defines as ‘an area of waterlogged forest, with dense vegetation’, tagged as natural=wetland, wetland=swamp, seasonal=yes. I’ve read the OSM wiki pages on both options. I’ve made a first stab at the area https://www.openstreetmap.org/#map=14/-35.8026/145.1484 and have mapped all but the extremes as swamp as this indicates that the area floods regularly, which natural:wood does not show. However most other areas on the river I’ve come across are mapped as natural:wood with relatively small inliers for treeless wetlands and some treed swamps. It’s a quick job to change from wetland:swamp to natural:wood and vice versa and I don’t hold any strong preferences myself. If the general consensus is that the area would be better called a wood (i.e. forest) rather than a seasonal wetland I’ll change it immediately. (I haven’t mapped Barmah forest in Vic, as that was already mapped as natural:wood but much of Barmah actually floods even more frequently than Millewa). Thanks very much for your advice. Best wishes Ian___ Talk-au mailing list Talk-au@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-au
