48362 - HYDRAULICS AND HYDROLOGY
48362 - HYDRAULICS AND HYDROLOGY
ASSIGNMENT 2 - Hydrology
Each student is to submit an individual report detailing their analysis.
Part A Flood frequency analysis (5 marks)
Undertake a flood frequency analysis using FLIKE and the data provide (on UTSonline) to determine the 1% AEP discharge (Note 1% AEP is equivalent to 100 yr ARI). Use GEV distribution.
Submit
Flood Frequency Curve
Table of recurrence interval with expected quantile, confidence limits
Part B Catchment Modelling with HEC HMS (20 marks)
Model the catchment using HEC-HMS and the data provided (on UTSonline).
Draw the Thiessen polygon based on the rainfall gauges. Use the Thiessen Polygon method to determine the average rainfall over the catchment. The total area of the catchment is 65 km2.
Calculate the initial loss and continuing loss for use in HEC-HMS.
Calibration For calibration event adjust model parameters to obtain a good fit with the gauged flows. The observed gauge calibration flow data contains baseflow which should be separated before uploading to HEC HMS and for comparison with HEC HMS computed flows at the catchment outlet. The roughness and manning n are adjusted to get the best fit between observed calibration gauge flow data and the HEC HMS computed flows at the catchment outletVerification For verification event without any further adjustment to model parameters (roughness, and manning n), check if a good fit is obtained with the verification gauged flows. The same values of roughness, and manning n should be used for calibration and verification. If a good fit is not obtained redo the calibration and verification with revised model parameters (roughness and manning n) so that a good fit is obtained with observed gauged flows for both calibration event and verification events.As before, baseflow needs to be separated from the observed gauge verification flow data.
Following calibration and verification determine the 1% AEP dischargeSubmit
Thiessen polygon, areas, Thiessen weights and average rainfall
Baseflow separation, initial loss and continuing loss, rainfall excess including calculations for calibration event and verification event.
hydrograph for calibration event with comparison between computed and observed flows.
hydrograph for verification event with comparison between computed and observed flows.
Parameters (roughness, manning n) used to obtain calibration and verification. These should be the same for both events1% AEP hydrograph and 1% AEP peak discharge
Part C - Discussion (10 marks)
The flood frequency method and HEC HMS modelling produces the 1% AEP discharge by different means. In theory the flood frequency method and HEC HMS modelling produces virtually the same estimate for the 1% AEP discharge. Give an explanation for this indicating what more can be done to get a closer fit.
A good fit for both calibration and verification events is required for a credible result. In the past a comparison your 1% AEP discharge with other student colleagues would have shown a sizable variation. Comment on this variation and provide an adequate explanation.
The discussion for Part C need not be longer than 2 paragraphs. Be concise as possible.
