- What was the annual precipitation at this site (in mm)? (1 mark)
- Given that this precipitation fell in a watershed that has an area of 10208 hectares, how many km3 of water fell in this watershed during 2014? (2 marks)
- Given that annual evapotranspiration from this watershed during 2014 was 584 mm, what was the likely runoff from this watershed during 2014 (in m3)? Assume that there was net accumulation of groundwater in the watershed of 19 mm and that storage increased (it stayed wetter) in the watershed by 26 mm over this period. (3 marks)
- Given the total precipitation amount and runoff at this site, ascribe what type of climate (humid-temperate, rainforest, or desert) it is and where you think (geographically) this rain gauge might be located. Why do you say this? Do some research (and cite your sources) if needed. (4 marks)
- Does anything seem odd to you about this precipitation record? What? Given this is data from a standard tipping bucket rain gauge, what do you think the issue underlying this/these oddity(ies) is? (3 marks)
B. Rainfall Intensity and Duration Analysis (use “Hourly Precip Data August.xls”) (19 marks)
- Given the data for August 4 and August 16 only, find the maximum amount of rain to fall in 1, 2, 3, 6, 12, and 24 hours, and find the rainfall intensity during each of these periods. For ease of formatting, provide your answer in two separate tables (1 for each date) using the headings below. For an example calculation, show how you calculated maximum rainfall intensity over 3 hours only. (7 marks)
Date //__
Duration (min) Amount of precip. (mm) Precip intensity (mm/hr-1)
- Plot intensity against duration for both events (i.e. 6 points for each chart) on the same graph using logarithmic y and x scales. Run a line of best fit through your data (one that looks linear when both axes are logarithmic) and provide the equation for each line and its associated R2 coefficient. Describe the relationships you observe for both periods, especially differences between the relationships for the two different events. Make sure to label and annotate your charts properly. (8 marks)
- Ascribe uplift mechanisms to both rainfall events (i.e. what type of rainfall producing mechanism might have resulted in charts such as these). Why do you think this? (4 marks)
C. Tipping Bucket Rain Gauges (10 lines text maximum) (5 marks)
- Describe how a tipping bucket rain gauge works. For the data given here, what depth of rainfall do you think is represented by a single tip? (5 marks)
Sample Solution