1. Clear Lake has a surface area of 708,000 m2 (70.8 ha). For a given month the lake has an inflow of 1.5 m3/s and an outf1ow of 1.25 m3/s. A +1.0 -m storage change or increase in lake level was recorded. If a precipitation gage recorded a total of 24 cm for this month, determine the evaporation loss (in cm) for the lake. Assume that seepage loss is negligible.
2. In a given year, a watershed with an area of 2500 km'J received 130 cm of precipitation. The average rate of flow measured in a gage at the outlet of the watershed was 30 m3/sec. Estimate the water losses due to the combined effects of evaporation, transpiration, and infiltration due to ground water. How much runoff reached the river for the year (i n cm)?
3. Using the data from problem 2, what is the runoff coefficient?
4. If we approximate the atmosphere to be 79 percent nitrogen (N2) by volume and 21 percent oxygen (O2), estimate the density of air (kg/m3) at STP conditions (0 °C, 1 atm).