Posts about runoff, groundwater, infiltration, RDII etc
Subject: How is Capillary Suction Head Used in SWMM 5 Green-Ampt?
How sensitive is the infiltration loss and rate to the capillary suction head parameter in the SWMM 5 Green-Ampt infiltration method. Figure 1 shows how the total infiltration loss and total loss rate vary … Read the rest
Subject: How is the Soil Saturated Conductivity Used in SWMM 5 Green-Ampt?
How sensitive is the infiltration loss and rate to the Soil Saturated Conductivity parameter in the SWMM 5 Green-Ampt infiltration method. Figure 2 shows how the total infiltration loss and total loss rate … Read the rest
There are Four factors in Rainfall Dependent Infiltration and Inflow or RDII in SWMM 5:
1. The fractional response to Rainfall or R from 0 to 1
2. The Time Base of the Unit Hydrograph or T in hours * Dimensionless K Shape Factor
3. The Sewershed Contributing Area … Read the rest
Subject: How is RDII Storage Simulated in SWMM 5?
If you are using the SWMM 5 Rainfall Dependent Infiltration and Inflow(RDII) feature you can also use the RDII storage parameters to change the RDII runoff by simulating the storage in the Sewershed. The code in RDII.C … Read the rest
Note: Types of Stormwater Inlets from HEC12 and HEC22
Stormwater Inlets consist of four main types (http://onlinemanuals.txdot.gov/txdotmanuals/hyd/storm_drain_inlets.htm) with most common shown in Figure 1.
1. Curb opening inlets either at a sag or continuous on the street,
2. Grate Inlets either at a sag or in combination … Read the rest
Subject: How to Subdivide Subcatchments in SWMM 5
If you want to subdivide a larger Subcatchment in SWMM 5 and get around the same peak flow then a good suggestion would be to make sure that (Figure 1):
1. The sum of the new areas equals the original Subcatchment Area … Read the rest
Subject: Low Impact Development Options in H2OMAP SWMM and InfoSWMM
The five options are:
1. Rain Barrel
2. Bio Retention Cell
3. Infiltration Trench
4. Vegetative Swale
5. Porous Pavement
and be entered as controls in the Hydrology Section of the Operations Browser of H2OMAP SWMM or InfoSWMM (Figure 1)… Read the rest
Subject: Rules for NRSCS Unit Hydrographs in InfoSWMM and H2OMap SWMM
Rules or Guidelines for NRSCS Unit Hydrographs if used as the Hydrology Option in InfoSWMM and H2OMAP SWMM:
1. The Unit Hydrograph CN comes from the Subcatchment Table and the NRCS_CN Column
2. Time of Concentration is from the … Read the rest
Continuous Simulation using SWMM 5 LID and Groundwater Features in a Linked 1D/2D Network using InfoSWMM 2D for a 50 Year Period
A poster at the recent ECI conference on the Past, Present and Future of Watershed modeling.
via Blogger http://www.swmm5.net/2013/08/continuous-simulation-using-swmm-5-lid.html… Read the rest
Singapore - Catching Every Drop of Rain
The source of the map of the rivers of Singapore is the Singapore PUB
As a small island that doesn't have natural aquifers and lakes and with little land to collect rainwater, Singapore needs to maximize whatever it can harvest.
Currently, Singapore uses … Read the rest
Subject: 1000 Year Simulation with Rainfall
This sketch summarizes what happens in a SWMM 5 Subcatchment for Horton Infiltration during a storm event:
1. The event starts out with the potential infiltration rate at the maximum infiltration rate but
2. Decay starts happening right away and the potential infiltration rate starts decreasing until it reaches the
Subject: Mass Balance for Water Quality in SWMM 5
The rainfall concentration is listed in the wet deposition row of the Runoff Quality Continuity Table, the washoff such as EMC washoff is listed in the Surface Runoff row. If you are simulating groundwater quality then it is listed as a … Read the rest
Subject: Convolution of the RDII UH from R, T and K in SWMM 5
The convolution uses the value of R and the Time Base to estimate the amount of Infiltration and Inflow in the Sewer Network. The short, medium and long term UH's are estimated at each Wet … Read the rest
Subject: How does the Infiltration Maximum Time to Drain the Upper Soil Zone Work in SWMM 5 Green Ampt?
You can use the monthly soil recovery factor (Figure 1) in SWMM 5 to change how the Infiltration Maximum Time to Drain the Upper Soil Zone (Figure 2) is computed … Read the rest
Subject: Example Groundwater Model in SWMM 5
The attached model shows three ways in which the groundwater model of the SWMM 5 subcatchments interact with the node depths of the hydraulic network. The hydraulic network interaction can be either:
1. At a fixed water surface elevation,
2. At a time
Subject: Example SWMM 5 Snowmelt Model
Attached is a simple sample snowmelt model in SWMM 5 that has built in snowfall and temperature in a one subcatcment model with snowmelt. You define the separation of precipitation into snowfall and rainfall by setting a base temperature in the Snow Pack Editor.
Subject: SWMM 5 Precipitation Options
You can have design storms, monitored storms of any length of the time from minutes to centuries, use intensity, volume or cumulative precipitation, use both rainfall and snowfall in the same rain gage depending on temperature, use both time series or external files for … Read the rest
Subject: Runoff Routing Options Example in SWMM 5
There are six options for runoff routing in SWMM 5:
· All Runoff to an Outlet Node
· All Runoff to another Subcatchment
· All Runoff to the Pervious Area of the Subcatchment or other Subcatchment
· All Runoff to the Impervious
