100 year flood with HEC1, HEC-RAS
100 year flood with HEC1, HEC-RAS
(OP)
I wish to calculate a 100-yr (or any other return period) flood and I was wondering which would be the better/easier method to use in the HEC series of models.
I am also curious about the difference between HEC1/HEC2/HEC-RAS. Can I use HEC1 or HECRAS to calculate these floods. Many thanks.
Santosh A
I am also curious about the difference between HEC1/HEC2/HEC-RAS. Can I use HEC1 or HECRAS to calculate these floods. Many thanks.
Santosh A
RE: 100 year flood with HEC1, HEC-RAS
I have no experience with HEC2, other than everyone saying: "So you escaped that nightmare, aren't you lucky?" HEC-RAS is the software you'll want to use to determine the 100-year elevation.
HEC1 is grotesquely outdated. Its input and output is text-based, with data fields refered to as "cards", and my first experience with HEC1 output left me with a 64,000-page output file. I would recommend that you give it a big swerve.
I recommend that you look at FEMA guidelines for their studies as a basis for your methodology.
RE: 100 year flood with HEC1, HEC-RAS
HEC-1 is a hydrologic model whereas Hec-2 is a hydraulic model, as francesca stated. Both are old dos versions. Now we have available to us both HECHMS & HECRAS, hydrologic and hydraulic respectively. Other methods are available for computing discharges. I would suggest that you contact your regulating entity (city, county or state authority) to see what they recommend. For example in my area we use the rational method for watersheds less than 160 acres and HEC-1/HMS for anything larger.
RE: 100 year flood with HEC1, HEC-RAS
HEC-1 is old and cumbersom. HEC-HMS is newer but requires a lot of input.
HEC-II and HEC-RAS do NOT calculate flows. They calculate water surface profiles for the flows you provide from some other source or method.
If you are not in the US I don't know where to direct you.
good luck
RE: 100 year flood with HEC1, HEC-RAS
RE: 100 year flood with HEC1, HEC-RAS
Also depending on drainage area size and the location you are in! What I mean by location, is the results of using the regression equations are very unrealistic in my area for the 100 yr Q. Therefore, use more than one method to double check you Q's.