UNIVERSITY OF THE CORDILLERAS
COLLEGE OF ENGINEERING AND ARCHITECTURE
Civil Engineering Department
HYDRO 2
Hydrology
Enhancement
Activity No and Title:
1 – The Hydrologic Processes and Precipitation
Name of Student:
Date Given:
Date Submitted:
Program and Yr Lvl
Enhancement Activity: (Problem Set No. 1)
The Hydrologic Processes and Precipitation
Topic Learning Outcomes (TLO):
By the end of this module, the student must be able to:
a. Solve practical problems using the continuity equation and the water balance
concept.
b. Adequacy of rain gauge stations
c. Estimation of Missing Rainfall Data
d. Estimating Mean Precipitation Over an Area
1. A lake with a surface area of 525 acres was monitored over some time. During one
month the inflow was 30cfs, the outflow was 27cfs, and a 1.5-in. seepage loss was
measured. During the same month, the total precipitation was 4.25 in. Evaporation loss
was estimated at 6.0 in. Estimate the storage change for this lake during the month.
Hint: 1 acre = 43, 560ft2
2. The shape of the drainage basin can be approximated by a polygon, whose vertices
are located at the following coordinates: (5, 5), (-5, 5), (-5,-5), (0.-10), and (5,-5). The
rainfall amounts of a storm were recorded by a number of rain gages situated within
and nearby the basin as follows:
UNIVERSITY OF THE CORDILLERAS
COLLEGE OF ENGINEERING AND ARCHITECTURE
Civil Engineering Department
All coordinates are expressed in kilometers. Determine the average rainfall on the basin
by (a) arithmetic-mean method, (b) the Thiessen method,
Hints: For the Thiessen method, begin by drawing the polygon around gage 9, then
draw the polygons around gages 2,3,5,and 7;
UNIVERSITY OF THE CORDILLERAS
COLLEGE OF ENGINEERING AND ARCHITECTURE
Civil Engineering Department