5. (a) Whatever its form, precipitation results from the condensation of moisture contained in warm air...

 

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5. (a) Whatever its form, precipitation results from the condensation of moisture contained in warm air when the air is cooled or forced to cool. Explain the principal methods for achieving cooling. [6 marks] (b) The measured streamflow data for a 2hr storm over a catchment of area 1.98km2 is shown in Table 1. Assuming a constant baseflow of 1m3/s, derive the 10mm 2hr Unit Hydrograph. Time (hr) Flow (m³/s) Unit conversions 1 litre = 0.001 m³ 1000 litres 1m³ 1 ha = 10000 m² = Table 2: Streamflow data (c) Use the hydrograph developed in (a) to determine the quick response runoff occurring when a storm of duration 4 hours falls on the catchment; total rainfall was 30mm during the first 2 hours and 105mm during the second half of the storm. Assume losses are 15mm/hr. [19 marks] 0 1 2 3 4 5 6 7 8 9 10 1 2 8 14 11 9 8 6 4 2 1 APPENDIX [25 MARKS] 5. (a) Whatever its form, precipitation results from the condensation of moisture contained in warm air when the air is cooled or forced to cool. Explain the principal methods for achieving cooling. [6 marks] (b) The measured streamflow data for a 2hr storm over a catchment of area 1.98km2 is shown in Table 1. Assuming a constant baseflow of 1m3/s, derive the 10mm 2hr Unit Hydrograph. Time (hr) Flow (m³/s) Unit conversions 1 litre = 0.001 m³ 1000 litres 1m³ 1 ha = 10000 m² = Table 2: Streamflow data (c) Use the hydrograph developed in (a) to determine the quick response runoff occurring when a storm of duration 4 hours falls on the catchment; total rainfall was 30mm during the first 2 hours and 105mm during the second half of the storm. Assume losses are 15mm/hr. [19 marks] 0 1 2 3 4 5 6 7 8 9 10 1 2 8 14 11 9 8 6 4 2 1 APPENDIX [25 MARKS]

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5a The principal methods for achieving cooling of air are 1 Adiabatic cooling This occurs when air i... View the full answer