Exercises 5

Description

1. The approximate volume of water retained in soil moisture and groundwater is given in Table 5.1. Use the data in Fig. 5.1 to calculate the time it would take for precipitation over land to deliver an amount of water equal to the soil water and groundwater. How long would it take to replace the groundwater and soil moisture if only 10% of the runoff could be redirected to replenishing the groundwater?

2. Use the bulk aerodynamic formula (4.32) to calculate the evaporation rate from the ocean, assuming that CDE = 10–3, U = 5 m s–1, and that the reference-level air temperature is always 2°C less than the sea surface temperature. Calculate the evaporation rate for the following:
a. T = 0°C, qs* = 3.75gkg−1, RH = 50%
b. T = 0°C, qs* = 3.75gkg−1 , RH = 100%
c. T = 30°C, qs*= 27 gkg−1 , RH = 50%
d. T = 30°C, qs* = 27 gkg−1 , RH = 100%

Assume a fixed air density of 1.2 kg m–3. How would you evaluate the importance of relative humidity versus the importance of surface temperature for determining the evaporation rate?