The evaporation from a lake is to be calculated by the Water balance method. Inflow to the lake occurs through three small rivers A (15.0 m/s), B (20.0 m³/s), and C (17.0 m³/s). The outflow occurs through river D (45.0 m/s). Calculate the evaporation from the lake surface during summer (May-August) if the water level was at +571.04 m on May 1 and +571.10 m on August 31. The lake surface area is 9536/100 km?. The precipitation during the period was 9536/90 mm.

Calculate the minimum fluidization velocity for an anthracite bed having following characteristics; d90 = 2.9 mm, ?anthracite = 1600 kg/m3, ?water = 998 kg/m3 at 20°C; µ = 1.002x 10-3 kg/m.sec

Given the earth dam and flow net shown, calculate the seepage loss under the dam if the water height behind the dam is 15ft. The soil has a hydraulic conductivity of 100 ft/year. EL 0 EL-10 Water Level 730 ft³/year O 650 ft³/year 500 ft³/year 890 ft³/year Water Level Yail=130 lb/ft³ Impervious Stratum

The plan area of a reservoir is 1 km2. The water level in the reservoir is observed to decline by 20 cm in a certain period. During this period, the reservoir receives a surface inflow of 10 ha-m and 20 ha-m are abstracted from the reservoir for irrigation and power. The pan evaporation and rainfall recorded during the same period at a nearby meteorological station are 12 cm and 3 cm respectively. The calibrated pan factor is 0.7. The seepage loss from the reservoir during this period in hectare-m is