Vymezení městské dešťové kanalizace

Question

<\/HEAD>Snažím se vymezit povodí, která přispívají do městské dešťové kanalizační sítě (stovky vpustí sbírají povrchový odtok a vedou ho podzemní infrastrukturou). Nástroje ArcHydro \/ GeoHMS jsou skvělé pro vymezení povrchových odtokových sítí, ale nevím, jak nejlépe pokračovat. Zkusím vymezit povodí bez vyplňování prohlubní (mnoho vpustí dešťové kanalizace je v místních nízkých bodech) a s definicí toku nastavenou poměrně nízko, poté vizuálně sloučit podpovodí, ale to bude pracnější, než bych si přál.<\/P> <\/P> Děkuji,<\/P> Andy<\/P><\/BODY><\/HTML>

andrewjack1 · Answer

Hi Andy

I just went through this process and didn't really find a great automated approach. Even the Hydro tools didn't seen to give me exactly what I needed. I ended up doing a combination of arc hydro and manual editing to delineate tributary area to each inlet. I essentially started at the larger watershed scale (huc 12) and then worked my way back from every outfall. 2nd Nature llc. outlines, nicely, a methodology for doing this.  They have a tutorial on their site under MAP MS4 TO MEET PHASE II PERMIT REQUIREMENTS- http://www.2ndnaturellc.com/client-access/central-coast-stormwater-ms4-support/ .

DarrenWiens2 · Answer

The way I'm thinking about this, you can make two watershed layers: one over ground, one underground. The pour points over ground would be your drains. The pour points underground are up to you (sewer junctions or something). Then Extract Values to Points​, to transfer underground watershed number to the drains. If the values are the same, then merge those corresponding over ground watersheds together.

edit: this assumes you have some sort of underground sewer data. Do you?

DanPatterson_Retired · Answer

the only application I have seen similar to this, is the individual had to create "trenches" in the DEM so that water could "flow" from one side of the road to the other.  It was for a thesis and looked pretty good but it required manual editing to connect one side of the road to the other.