Rajasthan Geography

Climate and Climatic Regions of Rajasthan

Climate is the statistics of weather over long periods of time. It is measured by assessing the patterns of variation in temperature, humidity, atmospheric pressure, wind, precipitation, atmospheric particle count and other meteorological variables in a given region over long periods of time.

Climatology or climate science is the scientific study of climate, scientifically defined as weather conditions averaged over a period of time. This modern field of study is regarded as a branch of the atmospheric sciences and a subfield of physical geography which is one of the Earth sciences.

Rajasthan Action Plan on Climate Change (RAPCC) builds on the key areas as identified Under the CCAR by prioritizing urgent areas of action in a phased and time-bound manner and it is in coherence with the Rajasthan State Environment Policy and Environment Mission while the RAPCC primarily focuses on risk reduction and adaptation measures. It also looks in to the co-benefits offered by specific strategies in the form of mitigation.

Task Force Constitution: The Rajasthan State Government established a ‘Climate Change and Clean Development Mechanism (CDM) Cell’ in the Rajasthan State Pollution Control Board (RSPCB) to act as a nodal agency for coordinating issues related to climate change in the state. The Cell was constituted in April 2010 and was involved in the drafting of the CCAR. A Steering Committee has also been formed, headed by the Chief Secretary and Principal Secretaries of various key departments as members to monitor the implementation of various actions proposed under the Rajasthan Environment Mission. The state of Rajasthan has constituted a team to review the implementation of the Environment Mission. The composition of the Environment Mission includes:-

Chairperson: Chief Minister

 Convener: Principal Secretary, Environment

 Members: Ministers of the under-mentioned departments, Chief Secretary, Principal Secretaries and Secretaries in-charge of the under mentioned departments:

1. Environment

2. Forests

3. Mines and Petroleum

4. Industries

5. Water Resources

6. Command Area Development

7. Agriculture

8. Urban Governance

9. Transport

10. Energy, renewable energy

11. Science and Technology

12. Plan

13. Finance

14. Policy Planning

The Steering Committee is chaired by the Chief Secretary, headed by the Principal Secretary of Environment and members from each designated department mentioned above. The Steering Committee includes participation from the non-governmental bodies. Their role is to review the implementation of each of the mission. For the implementation of the environment policy, Rajasthan environment mission and climate change agenda task forces have been constituted for different sectors viz.,

1. Industry

2. Water

3. Forestry and bio-diversity

4. Urban governance and sustainable habitat

5. Enhanced energy efficiency including solar energy

6. Strategic knowledge for climate change

The climate of Rajasthan state has varied contrasts. Different experts, each with their own focus parameters have divided Rajasthan into different climatic regions.

However, three main approaches to climatic regions of Rajasthan are:

  1. Climatic regions of Rajasthan based on rainfall intensity
  2. Koeppen’s classification of climatic regions of Rajasthan
  3. Thornthwaite’s classification of climatic regions of Rajasthan

1. Climatic Regions of Rajasthan based on rainfall intensity

The distribution of climatic regions of Rajasthan on the basis of rainfall and temperature variations includes following divisions:

Arid Region:  A region is arid when it is characterized by a severe lack of available water to the extent of hindering or preventing the growth and development of plant and animal life. Arid land or an arid climate is very dry because it has very little rain Water

The Arid region includes Jaisalmer district, northern parts of Barmer, western of the Phalodi Tehsil of Jodhpur, western parts of Bikaner and Southern parts of Ganganagar district and climate of the region is very severe and arid.

  1. Rainfall less than 10 cm in extreme west parts of regions and rest areas record less than 20 cm rainfall.
  2. The average temperature during summer is recorded more than 35degree C and during winters it ranges in between 12 DegC to 16 Deg Celsius.

Semi-arid Region: A semi-arid climate or steppe climate is the climate of a region that receives precipitation below potential evapotranspiration but not as low as a desert climate; Semi-arid regions are those where rainfall is not enough to cover the growth needs of the vegetation all year round. That is aridity index (rainfall/potential evapotranspiration) is below 0.5 per cent.

The average temperature during winter season ranges between 10 deg C and 17 deg C and the summer season temperature range 32 deg C to 37 deg C.

  1. As the region has erratic as well as torrential rainfall it brings floods too each time and rainfall ranges 20 to 40 cm.
  2. The winter season is very short and arid in the northern parts of this region.
  3. This region comprises the western parts of Ganganagar, Hanumangarh, Jodhpur and Barmer districts.