Question-Developing hydrographs from index floods & growth curves
Question-Developing hydrographs from index floods & growth curves
(OP)
Background:
I am undertaking a Hydrology study for a specific basin in my Province. There is no Rain gauge data available in that area....but what I do have is flow data from other lakes/basins in areas nearby my area of study.
My boss has asked me to determine the associated hydrographs for the area based on the other flows from similar lakes/basins.
So far I have developed the index floods from the flow data of other basins, as well as the growth curves.
Question:
How do I proceed from here to turn this into the required hydrographs needed for my study? It is required that I use the SCS Synthetic Unit hydrograph.
Thanks.
I am undertaking a Hydrology study for a specific basin in my Province. There is no Rain gauge data available in that area....but what I do have is flow data from other lakes/basins in areas nearby my area of study.
My boss has asked me to determine the associated hydrographs for the area based on the other flows from similar lakes/basins.
So far I have developed the index floods from the flow data of other basins, as well as the growth curves.
Question:
How do I proceed from here to turn this into the required hydrographs needed for my study? It is required that I use the SCS Synthetic Unit hydrograph.
Thanks.





RE: Question-Developing hydrographs from index floods & growth curves
For the SCS method (now NRCS) you will need to specify the appropriate rainfall distribution and rainfall depth, plus the curve number and time-of-concentration for each subcatchment area. If some of this data is lacking, you may be able to make some estimates based on your "flow data" from nearby areas. But these values are critical to the result.
If you need background on the runoff procedure see the "Hydrology" section at www.hydrocad.net/training
RE: Question-Developing hydrographs from index floods & growth curves
Also look at the National Flood Frequency program for an explanation of the procedure. Although it only applicable to the U.S. the approach would be instructive.
Good luck
RE: Question-Developing hydrographs from index floods & growth curves
1. Qavg vs. Drainage Area (Q = 0.89DA^0.78)
2. Q/Qavg vs. Frequency (I have 1/2, 1/10, 1/100, 1/1000 and 1/10,000) - it is pretty much a straight line when plotted on log paper
What I am not sure on is how to take these 2 plots and turn them into a hydrograph.
Any more suggestions?
Thanks.
RE: Question-Developing hydrographs from index floods & growth curves
For more info on the index flood procedure, google turned up a number of documents that might be helpful:
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