Chapter 8, Problem 8.2.1P

A lake had a water surface elevation of 103.2 m above datum at the beginning of a certain month. In that month the lake received an average inflow of 6.0 m3 /s from surface runoff sources. In the same period the outflow from the lake had an average value of 6.5 m3 /s. Further, in that month, the lake received a rainfall of 145 mm and the evaporation from the lake surface was estimated as 6.10 cm. Write the water budget equation for the lake and calculate the water surface elevation of the lake at the end of the month. The average lake surface area can be taken as 5000 ha. (groundwater flow negligible).

Question A 4-hour rainfall in a catchment of 250 km² produces rainfall depths of 6.2 cm and 5 ❤ cm in successive 2-hour unit periods. Assuming the index of the soil to be 1.2 cm/hour, the runoff volume is A 1.6 ha-m B D 16 ha-m 160 ha-m 1600 ha-m

The catchment area of an irrigation reservoir is 60 km^2. The constant water spread during October 2006 was 2 km^2. During that month, the uniform precipitation over the catchment was recorded to be 100 mm, 50% of precipitation reaches the reservoir. Outflow at a constant rate of 1 m^3/sec was recorded in the month of October. Assuming seepage losses to be 50% of the evaporation losses. Find out the daily rate of evaporation (mm/day/m*2) for October 2006. (Note: The number of days in the month of October is 31 days) ≈3.441 mm/day/m*2 ≈8.825 mm/day/m*2 4.344 mm/day/m*2 ≈6.445 mm/day/m*2

During a 3 h storm event, it was observed that all abstractions other than infiltration are negligible. The rainfall was idealized as three 1 h storms of intensities 10 mm/h. 20mm/h and 10 mm/h respectively and the infiltration was idealized as a Horton curve, f = 6.8 +8.7 exp (-t) (f is in mm/ h and t is in h). What is the effective rainfall?

The length of a parking lot is L = 100 m, and it is sloped at So = 0.02. The surface of the lot is bare clay with a Manning roughness factor of n = 0.020. A rainstorm produces a constant rainfall excess at the rate of ?0 = 25 mm/hr. If td = 25 minutes: Determine the runoff hydrograph at the downstream end of the parking lot. Based on your answers in Step 1, draw your estimated hydrograph.   ***Convert i0 to mJs. This conversion is not given and I cannot find it.

a. The streamflow from a 500-hectare catchment due to a storm of constant intensity of 27mm/h for four hours can be represented by a triangle in which the peak flow was 25 m3/s. The flow lasted six (6) hours and peaked at two (2) hours. The soil texture is uniform throughout the catchment and when the surface is ponded, its infiltration rate varies according to the Horton equation, with a decay constant, k, of 0.5 h and a maximum infiltration rate, fo, of 24 mm/h. Use the information to determine; the volume of infiltration (mm); the infiltration rate at soil saturation (mm/h); and i. ii. iii. the runoff coefficient of the catchment. iv. State your assumptions.

Question1: (a) Given a rainfall duration of 1-hour and an effective precipitation of 1.5 cm and the hydrograph in the table below, determine the 1-hour unit hydrograph. Time (hrs) 0 1 2 3 4 5 6 7 8 9 10 Flow (m³/s) 100 100 220 512 585 460 330 210 150 105 100 (b) Use the Unit Hydrograph from the part (a) to determine the hydrograph resulting from the following rain event. Time (hrs) Excess Rainfall (cm) 0.3 1.4 0.9 1 2 3

A reservoir had a water surface elevation of 110 m above the datum at the beginning of the month. In the same month, the reservoir received an average inflow of 7.5 cms (m3/s) from surface runoff sources. For the same period, the outflow from the reservoir had an average value of 5 cms. Further, in the same month, the reservoir received a rainfall of 180 mm and losses due to evaporation of 5 cm. Assume the area of the lake is 50 km2 acres and assume no contribution from groundwater storage. What is the water surface elevation of the reservoir after the month?

Compute the Rainfall Depth and the Rainfall Intensity of the given data. Show all your solution. 田 YEAR MONTH DAY RAINFALL RAINFALL RAINFALL DEPTH INTENSITY 2013 1 2013 2. 8.2 2014 1. 2014 2. -1 2015 1. 1 1.6 2015 0. 2016 1 1 -D1 2016 1 0. 2017 0. 2017 2.3 2018 1 1.3 2018 -1 2019 1 2019 2020 -1 2020 1 10.5 2. 2. 2. 21 1. 1. 1. 1. 1, 1. 1. 1. 1.