How does extreme weather, such as heatwaves and heavy rainfall, affect the spread of vector-borne diseases in India?
Monsoon failures in India can occur due to several primary causes, which can have significant impacts on agriculture and food security: El Niño Southern Oscillation (ENSO): Cause: El Niño events in the Pacific Ocean can lead to warmer-than-normal sea surface temperatures, which can disrupt the monsoRead more
Monsoon failures in India can occur due to several primary causes, which can have significant impacts on agriculture and food security:
- El Niño Southern Oscillation (ENSO):
- Cause: El Niño events in the Pacific Ocean can lead to warmer-than-normal sea surface temperatures, which can disrupt the monsoon circulation over the Indian subcontinent.
- Effect: During El Niño years, India often experiences below-average monsoon rainfall, leading to drought conditions in many parts of the country. This results in reduced water availability for agriculture, impacting crop yields and food production.
- Indian Ocean Dipole (IOD):
- Cause: The IOD is a climate phenomenon characterized by temperature anomalies in the Indian Ocean. Positive IOD events can lead to cooler-than-normal sea surface temperatures in the eastern Indian Ocean and warmer-than-normal temperatures in the western Indian Ocean.
- Effect: A positive IOD tends to suppress the monsoon over India, leading to reduced rainfall and drought conditions. This affects agriculture by reducing soil moisture, affecting crop growth and food production.
- Western disturbances:
- Cause: These are extra-tropical weather systems that originate in the Mediterranean region and move eastwards towards South Asia, particularly affecting northern parts of India.
- Effect: While western disturbances bring winter rainfall to northern India, their interaction with the monsoon can sometimes disrupt the normal monsoon flow, leading to erratic rainfall patterns and localized deficits. This can affect crop planting schedules and overall agricultural productivity.
- Pacific Decadal Oscillation (PDO):
- Cause: PDO is a long-term climate pattern in the Pacific Ocean characterized by alternating phases of warm and cool sea surface temperatures.
- Effect: Shifts in PDO phases can influence atmospheric circulation patterns globally, including over the Indian Ocean region. This can affect the strength and distribution of the Indian summer monsoon, leading to variations in rainfall patterns and impacting agriculture and food security.
Impacts on Agriculture and Food Security in India:
- Crop yields and production: Reduced monsoon rainfall directly affects crop yields, especially rain-fed crops such as rice, millets, and pulses. Farmers may face water shortages for irrigation, leading to crop failures and reduced agricultural productivity.
- Water scarcity: Monsoon failures can lead to water scarcity in reservoirs, rivers, and groundwater sources. This affects not only agriculture but also drinking water availability for rural and urban populations.
- Livelihoods: Agriculture is a major source of livelihood for a large population in India. Monsoon failures can lead to income loss, debt accumulation among farmers, and migration from rural to urban areas in search of alternative livelihoods.
- Food prices: Shortages in food production due to monsoon failures can lead to increased food prices, affecting food affordability and access for vulnerable populations. This can exacerbate food insecurity and malnutrition issues.
In conclusion, monsoon failures in India are due to factors like ENSO, IOD, western disturbances, and PDO can have severe repercussions on agriculture, water resources, livelihoods, and food security. Understanding these causes and their impacts is crucial for developing effective strategies to mitigate the risks associated with monsoon variability and ensure sustainable food production in India.
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To understand the spread of vector-borne diseases in India due to extreme weather conditions such as heat waves and heavy rains, it is essential to consider how these are significantly influenced by three main factors: 1- Breeding habitats 2- Vector behaviour 3- Human vulnerability 1- BreRead more
To understand the spread of vector-borne diseases in India due to extreme weather conditions such as heat waves and heavy rains, it is essential to consider how these are significantly influenced by three main factors:
1- Breeding habitats
2- Vector behaviour
3- Human vulnerability
1- Breeding Habitats : Heavy rains create stagnant water, ideal breeding grounds for mosquitoes, which are vectors of diseases such as dengue, malaria, and chikungunya. This can be exacerbated by flooding and the establishment of additional breeding sites in unexpected areas.
2- Vector behavior : Heat waves may modify vectors’ behaviour and their lifetime. The development of pathogens in vectors may be accelerated, the incubation period shortened and transmission rates increased due to higher temperatures. For example, in hotter conditions the development cycle of an Anopheles mosquito that disseminates malaria is accelerating.
3- Human Vulnerability : Extreme weather events frequently result in displacement and overcrowding of shelters, increasing the risk for spread of disease. The risk of vector borne diseases is further increased by poor infrastructure and lack of access to clean water and sanitation during such events.
These factors contribute to a favourable environment for the proliferation of vector borne diseases in India, which poses significant health problems.
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