(a) For a given year, a catchment with an area of 3000 km? received 160 cm of precipitation. The average flow rate measured in the river draining the catchment was 40 m/s. Find DRO" (i) How much runoff reached the river for the year (in m')? TRO = P+A (ii) Estimate the amount of water lost due to the combined effects of evapotranspiration and infiltration etc (in m')? (iii) How much precipitation is converted into river runoff (in percentage)? 26

Compute the diameter (cm) of the outfall required to drain storm water from the watershed described in figure below. Use rainfall intensity = 4 cm/hr. Average velocity of flow is 1 m/s. Other data are for: Area 1: C=0.5, area=0.005 km2. Area 2: C=0.4, area =0.01 km2. Area 3: C=0.7, area=0.015 km2.

The table below shows the monthly data for the catchment area.a. Compute the annual catchment volume in km3b. Determine the month where the catchment volume is the highest.c. What is the highest monthly catchment volume in km3.

9.4. A small farm reservoir behaves as two identical CFSTRs in series. Flow into the reservoir consists of runoff from pasture land having an average BOD, of 50 g/m³ and an average flow rate of 0.5 m³/s. Volume of the reservoir is 2.16 x 106 m³. If k = 0.2 d-¹ and k, = 0.35 d-¹ at 20°C, determine the dissolved-oxygen concentration if the water temperature is 20°C, the inflow is anaerobic, and steady-state conditions exist.