Question

Match LIST I with LIST II
\[ \begin{array}{|l|l|} \hline \textbf{LIST I} & \textbf{LIST II} \\ \hline A. \ \text{Isohyetal method} & I. \ \text{Peak runoff rate} \\ B. \ \text{Rational method} & II. \ \text{Reingauge station} \\ C. \ \text{Point rainfall} & III. \ \text{Mean areal rainfall} \\ D. \ \text{Nash model} & IV. \ \text{Flood routing} \\ \hline \end{array} \]
Choose the correct answer from the options given below:

• A. A-III, B-I, C-II, D-IV
• B. A-II, B-I, C-IV, D-III
• C. A-III, B-I, C-II, D-IV
• D. A-III, B-II, C-I, D-IV

Hint:

Associate keywords: - \textbf{Isohyet/Thiessen} \(\rightarrow\) Mean Areal Rainfall - \textbf{Rational/SCS} \(\rightarrow\) Peak Runoff - \textbf{Nash/Clark/Snyder} \(\rightarrow\) Unit Hydrograph / Flood Modeling - \textbf{Point Rainfall} \(\rightarrow\) Raingauge

Answer 1

The Correct Option is A

Step 1: Match each hydrological term/method in LIST I with its purpose or definition in LIST II.
- A. Isohyetal method: This is a technique for calculating the III. Mean areal rainfall over a watershed by drawing contours of equal rainfall depth (isohyets). It is generally the most accurate method.
- B. Rational method: A simple empirical formula (\(Q=CIA\)) used to estimate the I. Peak runoff rate from small catchments.
- C. Point rainfall: This is the rainfall measured at a single location by a II. Reingauge station.
- D. Nash model: The Nash model conceptualizes a watershed as a cascade of linear reservoirs. It is a conceptual model used to derive a synthetic unit hydrograph, which is then used for tasks like IV. Flood routing or predicting runoff from rainfall.
Step 2: Compile the correct pairings.
- A \(\rightarrow\) III
- B \(\rightarrow\) I
- C \(\rightarrow\) II
- D \(\rightarrow\) IV
This combination corresponds to option (A).