

Hydrology Civil Engineering Project – a study concerned with engineering application like design dam, our project given realistic case study (og catchment) in west bank. In our project we want to calculate the peak flow that produced from the excess rainfall at the area that we want to design the Dam.
In this project we want to determine the hydrograph for subcatchment area 1 and 2 is 84 km² and 64 km² respectively.
Hydrology Civil Engineering Project Analysis:
To estimate the volume, calculate each value for each hour of total rainfall by multiplying the percentage of rainfall by total amount of rainfall (32mm). Calculate the excess rainfall from the total rainfall by subtracting the losses (Φindex which 2.5mm/hr) from each value for each hour of total rainfall which is not less than 2.5mm/hr.
Analysis is provided in project report.
 Estimate the volume of direct runoff and volume of infiltration (in million cubic meters) for 1 and 2 subcatchments.
V= d*A
depth under ⱷindex 
23.2 
depth of excess rainfall 
8.8 
Area(KM² )  vol. of infil.m³  vol. of dir. runoff m³  vol. of infil. Mm³  vol. of dir.runoffMm³  
1  84  1948800  739200  1.9488  0.7392 
2  64  1484800  563200  1.4848  0.5632 
 We calculate the hydrograph then estimate the volume of direct runoff from hydrograph (Compare your results with those of part 1.) Will be discussed in discussion and conclusion part(1).
We have 1 h.u.H , and the storm divide by 1 hr so, we don’t need convert between D h.u.H.
for subcatchment 1 and 2 as follow:
Analysis is provided in project report.
 We use the SCS method to derive a 1hrUH using the SCS method (Compare your results with the given UHs.) Will be discussed in discussion and conclusion(2). By using SCS Dimensionless method unit hydrograph, this method is analyzed andillustrated in the next tables.
Analysis is provided in project report.

 we calculate the hydrograph after 3km because we want to design the dam as follow, first we calculate the constant for the equation
k=  2 
x =  0.2 
t  1 
Kx=  0.4 
kkx+.5t  2.1 
C0  0.05 
C1  0.43 
C2  0.52 
1 
Discussion and Conclusion:
(1) From part 1, the volume of direct runoff and volume of infiltration (in million cubic meters) for 1 and 2 subcatchments.
vol. of dir.runoffMm³  
1  0.7392 
2  0.5632 
From part 3, the volume of direct runoff from hydrograph (in million cubic meters) for 1 and 2 subcatchments.
vol. of dir.runoffMm³  
1  0.749232 
2  0.562003 
By comparing between it, approximate equal but there very small error , this inequality is because the depth of the given 1mm UH for each catchment doesn’t equal 1mm.
(2) Compare between derive a 1hrUH using the SCS method and results with the given UHs.
From 1hrUH using the SCS method:
atchment 1:
Tp=  2.9  hr 
Tb=  7.743  hr 
Qp=  60.24828  m³/s 
From given 1hrUH
As we shown 1hrUH
The peak of the given 1hr UH and the peak of the estimated 1hr UH by SCS method are the same for each catchment. But the time base different from those in the given 1hr UH.
The time base of 1 catchment for the given 1hr UH is 35 hrs, but for the estimated 1hr UH by SCS method is 14.5 hrs.
The peak of the given 1hr UH and the peak of the estimated 1hr UH by SCS method are the same for each catchment. But the time base different from those in the given 1hr UH.
The time base of 2 catchment for the given 1hr UH is 31 hrs, but for the estimated 1hr UH by SCS method is 14.5 hrs.
Also, note that the two time base for the estimated 1hr UHs by SCS method for the two catchments are the same and equal 10 hrs.

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