都市の雨水排水流域の区分

Question

<\/HEAD>都市の雨水排水ネットワークに寄与する流域を区分しようとしています（数百のinletsが表面の流出水を集め、地下のインフラを通じて運びます）。 ArcHydro / GeoHMSツールは表面の排水ネットワークの区分に優れていますが、最善の進め方がわかりません。 sinkを埋めずに流域を区分しようと試みます（多くのstormdrain inletsは局所的な低地にあります）し、stream定義をかなり小さく設定してから、視覚的にsub-basinsを結合していきますが、これは望まれるよりも手間がかかります。<\/P> <\/P> ありがとうございます、<\/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.