The hyetograph is a curve showing

The correct answer is option 'C': Time vs. Intensity of rainfall.

Explanation:

The hyetograph is a graphical representation that shows the variation in rainfall intensity over a specific period of time. It is widely used in hydrology and civil engineering to analyze and design stormwater drainage systems, flood control measures, and water resource management strategies.

The hyetograph is typically plotted with time on the x-axis and rainfall intensity on the y-axis. It represents the temporal distribution of rainfall during a storm event and provides valuable information about the intensity, duration, and frequency of rainfall.

Importance of the hyetograph:

The hyetograph is an essential tool for engineers and hydrologists as it helps in understanding the rainfall pattern and its impact on the hydrological response of a catchment. It provides valuable insights into the following aspects:

1. Rainfall Intensity: The hyetograph helps in determining the peak intensity of rainfall during a storm event. This information is crucial for the design of stormwater drainage systems, as it helps in estimating the maximum flow rates and sizing of pipes, culverts, and detention ponds.

2. Duration of Rainfall: The hyetograph also provides information about the duration of rainfall. This is important for estimating the total volume of runoff generated and designing storage facilities or detention ponds to control the flow rate and attenuate peak flows.

3. Temporal Distribution: The hyetograph shows how the rainfall is distributed over time. It helps in understanding the temporal variability of rainfall and its impact on the hydrological response of a catchment. This information is crucial for flood forecasting, flood control measures, and water resource management.

4. Design Storm Selection: The hyetograph is used to select appropriate design storms for the design of hydraulic structures. By analyzing historical rainfall data and plotting hyetographs, engineers can select design storms that represent the rainfall characteristics of a particular region or catchment.

Conclusion:

In summary, the hyetograph is a curve showing the time vs. intensity of rainfall. It is a powerful tool for understanding the rainfall pattern and its impact on the hydrological response of a catchment. By analyzing hyetographs, engineers and hydrologists can make informed decisions regarding the design of stormwater drainage systems, flood control measures, and water resource management strategies.