HEC-HMS has long been considered as a deterministic model which produces modeling results such as flow rates and volumes by assuming fixed input. A deterministic hydrology model sometimes could not…
HEC-HMS has long been considered as a deterministic model which produces modeling results such as flow rates and volumes by assuming fixed input. A deterministic hydrology model sometimes could not…
A previous post about how to model a pump station can be found here and this post is about how to model a force main on the discharge side of…
SWMM uses a node-link scheme to represent storm sewer networks and the movement of water through such a network is governed by the mass and momentum conservation equations for conduits…
In 1D storm sewer network modeling, it is important to understand how a modeling tool handles the system flooding or overflowing which will impact HGL and flow calculations in the…
The modified puls storage routing technique is widely used to size a detention basin by routing inflow hydrographs (Figure 1). The two unknowns, O2 and S2 , can be solved…
A lateral structure (LS) in HEC-RAS, parallel to the centerline of a river, is often used to connect a river reach to a 2D flow area, a storage area, or…
A watershed average slope value is often needed in some hydrologic calculations, for example, Time of Concentration (TOC) estimation using NRCS Lag Time Method. The slope tool in AcrGIS or…
Even if 2D modeling by XPSWMM, PCSWMM, HEC-RAS, and InfoWorks has become popular these days, 1D modeling still holds its ground on storm water management and flooding study due to…
Head Losses (or energy losses) associated with conduits in a storm sewer system include pipe friction losses and minor losses. Pipe friction losses are normally solved by Manning’s equation, while…
A DEM, before it can be used for watershed delineation, often needs to be reconditioned and pre-processed by “filling” any depressions or sinks (an area lower than its surroundings) to…