---
title: "MIP method for monthly flow in Nepal"
subject: "Engineering Hydrology"
chapter: 4
key: "semester_5/engineering_hydrology:mip-method-monthly-flow"
source: https://www.bctengineer.com/q/semester_5/engineering_hydrology/mip-method-monthly-flow
site: BCT Engineering
---

# MIP method for monthly flow in Nepal

Engineering Hydrology · Chapter 4: Surface Runoff

- Asked in: 2070 Chaitra, 4 marks
- Answer checked by Claude Sonnet 5.5 on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_5/engineering_hydrology/mip-method-monthly-flow
- Whole chapter: https://www.bctengineer.com/md/semester_5/engineering_hydrology/chapter-4

## Question

Write the method of estimating monthly flows in a stream or river by MIP method in a Nepalese river.

## Short answer

The MIP method estimates mean monthly flows for ungauged Nepalese rivers by reading monthly specific discharge q_m from regional curves for the catchment's Monsoon Wetness Index (MWI) and multiplying by catchment area A: Q_m = q_m(MWI)×A.

## Answer

The **MIP (Medium Irrigation Project) method** was developed by the Department of Hydrology and Meteorology (DHM) in 1990 to estimate mean monthly flows of ungauged rivers of Nepal, mainly for small and medium irrigation and hydropower sites. It is a regional regression method based on the catchment area and the monsoon rainfall index of the catchment.

#### Procedure
1. **Delineate the catchment** above the site on topographic maps and measure its area $A$ (km$^2$). The method applies to catchments below about 3000 m elevation without major snow or glacier input.
2. **Find the Monsoon Wetness Index (MWI)** of the catchment from the MWI isoline map prepared from monsoon rainfall data of Nepal.
3. **Select the regional equations or curves** of the relevant region (Nepal is divided into hydrological regions) which relate the monthly specific discharge to MWI for each month.
4. **Compute the discharge of each month** (January to December) from the curve and multiply by the catchment area:
$$
Q_m = q_m(\text{MWI})\times A
$$
5. **Plot** the 12 values as a mean monthly flow series (flow hydrograph) and, if a short flow record exists nearby, adjust the estimates to it.

The method is simple and quick, but it gives only long-term mean monthly flows, not flood or low-flow extremes, and its accuracy is limited where rainfall data are sparse.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. The MIP method is
   A. A flood frequency method
   B. A snowmelt model
   C. A rainfall-runoff model needing daily data
   D. A regional regression method using catchment area and monsoon wetness index
   Answer: D. It was developed by DHM to estimate mean monthly flows in ungauged Nepalese rivers. (Key point: Nature of method)

2. Monthly discharge is computed as
   A. Q = q(MWI) x A
   B. Q = MWI^2
   C. Q = A / MWI
   D. Q = MWI + A
   Answer: A. Monthly specific discharge from the regional curve for the MWI times catchment area. (Key point: Computation)

3. What does the method give?
   A. Sediment load
   B. Long-term mean monthly flows, not flood or low-flow extremes
   C. Flood peaks
   D. Hourly flow
   Answer: B. It gives only mean monthly flows and is limited where rainfall data are sparse. (Key point: Limitation)

## Related in Engineering Hydrology

- [Stream flow by slope-area method](https://www.bctengineer.com/question.md?key=semester_5%2Fengineering_hydrology%3Aslope-area-method-explain) — Engineering Hydrology, chapter 4, asked 3×
- [Stream flow from current meter data](https://www.bctengineer.com/question.md?key=semester_5%2Fengineering_hydrology%3Acurrent-meter-0-035-0-74n) — Engineering Hydrology, chapter 4, asked 2×
- [Stream flow from current meter, V=0.045+0.76N](https://www.bctengineer.com/question.md?key=semester_5%2Fengineering_hydrology%3Acurrent-meter-0-045-0-76n) — Engineering Hydrology, chapter 4, asked 2×
- [Runoff estimation for ungauged basins in Nepal](https://www.bctengineer.com/question.md?key=semester_5%2Fengineering_hydrology%3Anepal-ungauged-runoff-methods) — Engineering Hydrology, chapter 4, asked 4×
- [Slope-area flood discharge, Marin River at Kusuntar](https://www.bctengineer.com/question.md?key=semester_5%2Fengineering_hydrology%3Aslope-area-marin-kusuntar) — Engineering Hydrology, chapter 4

## Related in other subjects

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- [Stream flow from 0.2d and 0.8d measurements](https://www.bctengineer.com/question.md?key=semester_6%2Fhydro_power%3Astream-flow-measurement-data) — Hydro Power, chapter 2
- [Methods of stream flow measurement](https://www.bctengineer.com/question.md?key=semester_6%2Fenergy_resources%3Aflow-measurement-methods-micro-hydro) — Energy Resources, chapter 5