About this previous year paper
SECTION A — Very Short Answers (2 Marks Each)
a. Methods of Reducing Flood Impact
Flood embankments
Dams and reservoirs
Channel improvement
Flood forecasting
b. Vegetation Management
Use of plants and grasses to reduce runoff and soil erosion
c. Types of Soil Erosion due to Water
Sheet erosion
Rill erosion
Gully erosion
Stream bank erosion
d. Universal Soil Loss Equation (USLE)
A=R×K×L×S×C×PA = R \times K \times L \times S \times C \times PA=R×K×L×S×C×P
e. Effects of Erosion
Loss of fertile topsoil
Reduced crop yield
Sedimentation of reservoirs
Land degradation
f. Biological Methods of Soil Erosion Control
Afforestation
Strip cropping
Cover crops
Grassland development
g. Evaporation Losses
Loss of water from surface water bodies due to heat and wind
h. Aquifer
Underground layer storing groundwater
Example: Sandstone aquifer
i. Fertilizers & Pesticides
Fertilizers: Urea, DAP, NPK
Pesticides: DDT, Malathion
j. Soil Loss Estimation
Estimation of soil removed due to erosion using empirical equations
SECTION B — Descriptive Answers (10 Marks)
a. Methods of Soil Erosion Control
Mechanical methods: Contour bunding, terracing
Biological methods: Crop rotation, afforestation
Agronomic methods: Mulching, strip cropping
b. Sources of Agricultural Water Pollution
Excess fertilizers
Pesticides
Animal waste
Irrigation runoff
c. Need for Planned Utilization of Water Resources
Increasing water demand
Uneven rainfall
Prevent water scarcity
Sustainable development
d. Mechanism of Soil Erosion
Detachment of soil particles
Transportation by runoff
Deposition downstream
e. Groundwater Recharge through Wells
Rainwater directed into recharge wells
Increases groundwater table
Reduces water scarcity
SECTION C — Hydrology & Wind Erosion (10 Marks)
Hydrologic Cycle Evaporation
Condensation Precipitation
Infiltration Runoff
Wind Erosion & Control
Factors: Wind velocity
Soil texture Moisture content
Control Measures: Windbreaks
Shelter belts Strip cropping
SECTION D — River Engineering (10 Marks)
River Training Works Embankments
Guide banks Spurs
Levees Sediment Deposition in Rivers
Deposition occurs when velocity reduces Leads to reduced channel capacity
Causes flooding
SECTION E — Soil Erosion & Grassland (10 Marks)
Soil Erosion Removal of topsoil by water or wind
Causes: Deforestation
Overgrazing Heavy rainfall
Types: Sheet, rill, gully, wind erosion
Grassland Management Controlled grazing
Reseeding Fertilization
Prevents soil erosion
SECTION F — Soil Loss & Gullies (10 Marks)
Soil Loss Estimation USLE and MUSLE used
Helps in conservation planning
Modified USLE (MUSLE): Includes runoff volume
Gullies Deep channels formed by water erosion
Classification: Permanent
Temporary
Stages: Formation
Development Stabilization
SECTION G — Wind Erosion & Land Capability (10 Marks)
Wind Erosion Removal of soil particles by wind
Factors Affecting Wind Erosion: Wind speed
Soil size Vegetation cover
Land Capability Classification Classification of land based on suitability for agriculture
Classes I to VIII