Indian Forest Service Examination Forest Hydrology & Watershed Management: practice questions

1 · Interception, throughfall, stemflow and infiltration under forest · easy

With gross rainfall 1200 mm, throughfall 900 mm and stemflow 30 mm, interception loss as a percentage of rainfall is:

1. 25.0%
2. 22.5%
3. 77.5%
4. 2.5%

2 · Evapotranspiration of forests and water yield · hard

Restoring trees on severely degraded, compacted land can increase dry-season flow mainly because:

1. Trees never transpire during the dry season in any climate
2. Trees create enough rainfall locally to refill streams
3. Infiltration gains outweigh water use
4. Compacted soils already infiltrate as well as forest soils

3 · Effects of harvesting, plantations and fire on streamflow · medium

Forest roads increase storm peak flows mainly by:

1. Increasing interception by the remaining trees
2. Slowing water on the surface
3. Adding litter to channels
4. Compacting soil and routing water quickly to streams

4 · Effects of harvesting, plantations and fire on streamflow · hard

The FAO–CIFOR 2005 review concluded that forests:

1. Have limited effect on the largest floods in big basins
2. Prevent all floods in every river basin, whatever its size
3. Always increase flood peaks
4. Have no effect on erosion

5 · Watershed concept, delineation and prioritisation · hard

Which Indian body developed the Sediment Yield Index for prioritising sub-watersheds above reservoirs?

1. Forest Survey of India
2. Central Water Commission's flood wing
3. India Meteorological Department
4. All India Soil and Land Use Survey

6 · Erosion processes and sediment yield from forest land · hard

After clear-felling on steep slopes, shallow landslides often increase for several years mainly because:

1. Rainfall increases sharply after felling on the slope
2. Bedrock rises
3. Roots decay before regrowth roots reinforce the soil
4. Stumps add weight to slopes

7 · Integrated and participatory watershed management programmes · medium

Ralegan Siddhi in Maharashtra is an example of:

1. Industrial forestry by a paper company
2. A national park managed by the state
3. Community water harvesting
4. Urban drainage improvements in Pune city

8 · Integrated and participatory watershed management programmes · medium

The Integrated Watershed Management Programme launched in 2009–10 was later merged into:

1. National Afforestation Programme of the ministry
2. Green India Mission
3. MGNREGA only
4. Pradhan Mantri Krishi Sinchayee Yojana

9 · Paired-catchment studies and hydrological monitoring · easy

For a 90° V-notch weir with Q = 1.38 H^2.5 (m³/s, H in m), what is the discharge at a head of 0.2 m?

1. 0.025 m³/s
2. 0.276 m³/s
3. 0.055 m³/s
4. 1.380 m³/s

10 · Paired-catchment studies and hydrological monitoring · medium

The calibration period of a paired-catchment study is used to:

1. Treat both catchments identically from the very start
2. Build roads in both catchments to test their effect
3. Relate the two catchments' flows
4. Measure only rainfall, not streamflow, in each catchment