Climate and Soils of Odisha

Learning Outcomes:

1. Understand Odisha’s tropical monsoon climate and its influence on seasons.
2. Learn about different seasonal divisions and their impact on agriculture.
3. Analyze the variability in rainfall distribution across regions in Odisha.
4. Examine the types of soils in Odisha, their characteristics, and management practices.
5. Identify the climate and agro-climatic zones influencing soil fertility and crop patterns.

Climate of Odisha

Odisha has a tropical monsoon climate, significantly influenced by its proximity to the sea. The state experiences three main seasons: summer, rainy, and winter. Locally, the year is further divided into six distinct seasons, each impacting agriculture and daily life. Despite temperature and rainfall variations, the climate remains relatively equable.

Summer Season

1. Duration: March to June.
2. Temperature: Often exceeds 40°C; Western districts experience 40-46°C throughout the year.
3. Regions: Districts such as Sundargarh, Sambalpur, Baragarh, Balangir, Kalahandi, and Mayurbhanj bear the highest temperatures.

Rainy Season

1. Duration: July to mid-October.
2. Rainfall Variability: North and North-East parts: <15%; South and South-West parts: 15-20%.
3. Rainfall Source: South-West Monsoon influences rain patterns, arriving in early June and receding by mid-October.
4. Average Rainfall: Around 200 cm, concentrated between July and September.
5. Cyclones: Coastal areas frequently experience cyclones and tornadoes. July is notably the wettest month.
6. Humidity: Coastal regions have about 75% relative humidity; inland regions approximately 60%.
7. High Annual Rainfall Regions: Catchment basins of rivers like Budhabalanga, Baitarani, Brahmani, and Ib, found in districts such as Mayurbhanj, Kendujhar, Angul, Sundargarh, and Sambalpur.
8. Low Annual Rainfall Regions: Includes catchment basins of the Vamsadhara and Rushikulya rivers, as well as areas east of Lake Chilika, Koraput, and Ganjam.

Winter Season

1. Duration: Mid-October to February.
2. Temperature: Coastal areas: 18-25°C; Interior areas can dip to 7°C.
3. Notable Regions: Koraput and Kandhamal districts experience temperatures as low as 3-4°C.
4. Rainfall: Occasional during October-November; January-February remain dry.

Important Note: Cyclones heavily impact the coastal and riverine regions of Odisha, causing fluctuations in rainfall and affecting agricultural patterns.

Local Seasonal Divisions

1. Grishma (Summer): Vaisakha and Jyestha (Mid-April to Mid-June).
2. Barsa (Rainy): Ashadha and Sravana (Mid-June to Mid-August).
3. Sharad (Autumn): Bhadraba and Aswina (Mid-August to Mid-October).
4. Hemanta (Early Winter): Kartik and Margasira (Mid-October to Mid-December).
5. Sisira (Late Winter): Pausa and Magha (Mid-December to Mid-February).
6. Basanta (Spring): Falguna and Chaitra (Mid-February to Mid-April).

Rainfall in Odisha

Odisha receives rainfall mainly during the monsoon and winter seasons. The distribution and impact of rainfall vary across regions, affecting crop production.

Monsoon Rainfall

1. Importance: Controls crop production; essential for paddy cultivation.
2. Classification: Rainfall above 140 cm considered high; below 120 cm is low, often insufficient for optimal crop yield.
3. High Monsoon Regions: Includes parts of Ib River, Northern Baitarani basin, Phulbani, and Phiringia.
4. Low Monsoon Regions: Southwest Odisha, parts of the middle Baitarani basin.

Winter Rainfall

1. Significance: Supports the growth of rabi crops.
2. Classification: Above 5 cm is high; below 2.5 cm is low.
3. High Rainfall Areas: North Odisha (from Baripada to Sundargarh), coastal areas like Puri and Khurda, and plateaus such as Phulbani.
4. Low Rainfall Areas: Mainly in Southwest Odisha, including Koraput.

Important Note: Variability in rainfall leads to significant shifts in cropping patterns and soil management practices in Odisha.

Climatic Regions in Odisha

Various geographers have provided classifications of Odisha’s climate:

1. Koppen’s Classification: Tropical Savannah (AW).
2. Thornthwaite’s Classification: Sub-humid with deficient winter rains.
3. SB Chatterjee’s Classification: Coastal Odisha falls under the tropical savannah type.

Agro-Climatic Zones in Odisha

Odisha’s diverse agro-climatic zones significantly influence its soil types and agricultural productivity. The state is divided into 10 zones based on climate, topography, and soil composition:

Cyclones in Odisha

Odisha frequently experiences cyclonic storms due to its coastal location along the Bay of Bengal. These cyclones cause significant destruction and influence the region’s climate.

1. Odisha Cyclone (1999): Occurred from 25th October to 4th November; known as a super cyclonic storm.
2. Cyclone Titli (2018): Impacted Ganjam and Gajapati districts.
3. Cyclone Hudhud (2014): Affected 16 districts.
4. Cyclone Phailin (2013): Impacted Odisha, Andhra Pradesh, and Andaman.

Soils in Odisha

Soil is a crucial natural resource influenced by factors like parent rock, climate, and vegetation. Odisha’s soils vary due to its diverse climatic and topographical features. They are broadly classified based on formation and relief features.

On the Basis of Formation

1. Transported Soils: Mixture of eroded materials; heterogenous.
2. Residual Soils: Formed by erosion; found in interfluves, mountains, and plateaus.

On the Basis of Relief Features

1. Red Soil: Formed due to iron deposits; coarse texture, low water holding capacity; found in Koraput, Rayagada, and Kalahandi.
2. Laterite Soil: Rich in aluminium, iron; found in high-rainfall areas like Eastern Ghats.
3. Red and Yellow Soil: Found in undulating terrains; rich in iron, moderately acidic.
4. Coastal Saline and Alluvial Soil: Contains high soluble salts; found along coastal belts.
5. Deltaic Alluvial Soil: Varies in texture from sand to clay; found in floodplain regions.
6. Black Soil: Formed by weathering of basic rock; clay texture with angular blocky structure.
7. Mixed Red and Black Soil: Association of both red and black soils; found in Western districts.
   8. Brown Forest Soil: Found in forest-covered regions; light in texture, acidic.

Important Note: The fertility and productivity of these soils depend on regular management practices such as adding organic manure, lime, and improving drainage systems.

Problems and Management of Soils

1. Low Fertile Acidic Soils: Constitute red and lateritic soils; managed through organic manure application and liming.
2. Iron-Toxicity in Lowland Soils: Occurs due to seepage in valley slope areas; managed by deep drainage systems and embankments.
3. Coastal Salt-Affected Soils: High salt content managed by adding soil nutrients and suitable crop selection.

Important Note: Regular management of soil fertility is key to sustaining agricultural productivity in Odisha’s diverse agro-climatic zones.

MCQ:
Which of the following soils in Odisha is rich in aluminium and iron?:

1. Red Soil
2. Laterite Soil
3. Black Soil
4. Coastal Saline Soil
   Answer: 2. Laterite Soil