> On May 30, 2019, at 9:03 AM, Joseph Eisenberg <joseph.eisenb...@gmail.com> > wrote: > > We have lots of these in Indonesia, in the rice-growing areas with > irrigated fields, but most are more like deep ditches, dug directly > into the ground and unlined
I imagine ~100 years ago, it was just like that in Japan. you can find sections of that old ditch system still. There are pretty big ditches that still handle supply for a very large field set. Japan spent an insane amount of money to turn all their large & small ditches into interconnected concrete drains, added sluice gates & weirs to all the streams, built levees around all the rivers, and dug aqueducts to balance the river flows (for irrigation). I have cycled ~600Km of riverbanks and rice fields, from very remote areas down into major cities. It doesn’t really vary - it is all built to the same standard. They are widening the levees in my area after a breach elsewhere in 2015. they are always working on the water management system. Most farming access roads were paved and now maintained as public roads that would otherwise be mud or gravel tracks in the rest of Asia. there are a lot of tracks, but a lot of “alleys” as well. this is another side-effect of Japan having spent so much money to pave and upgrade the quality of so many roads in rural areas. (rather than being merely grade 1 or 2 tracks). I grew up in Southern California, and most roads have little-to-no drainage of any kind - rain is so uncommon. ditches, drains, and other water management features are sparse. The freeways flood in a rainstorm. living in rural/suburban Japan, I marvel at the drainage system they built for even the smallest set of fields, and the culverts under almost every single road intersection in Japan, no matter how small and remote. This irrigation/rain management system is as pervasive as the water/sewer/power/telecom services - perhaps more so. This requires expanded levels of tagging, similar to how we have for roads, because the scale and complexity of the system (that is mappable from imagery) is far greater than what you would find elsewhere. This means there is room for aquaducts, drains and ditches, even if it might seem unnecessarily detailed. I will try to take some pictures this weekend of different irrigation features to help define the tagging. Javbw _______________________________________________ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
