12A lake has a surface area of 15km2. From an inventory of streams flowing into a lake, it is estimated that the average inflow rate in a given day is48m/s. In the same day, the c vaporation rate is about 5.0mm/day and the lake stage (the water level) increases about 10cm. Neglecting ground water flow, estimate (1) the average flow rate to the main out flowing river in m/s,and (2) the outflow volume during the one-day period in m3.

Fig: 1