Heat Wave and Cold Wave

2020-11-10 10:48: 33

Heat Wave

IMD criterai for decl is 40°C for plains and 37°C for coastal areas 30° for Hilly areas
Dec when departure from normal temp is 4.5-6.4° C
Severe when > 6.4° C
For plains heatwave is considered based on actual max temp > 45 and severe > 47C.
Period of abnormally high tem, occur b/w March June.

Hot winds blowing from deserts, anticyclone formation, rising global temp, shift in air current/weather pattern, depletion of Ozone layer, Jet stream.
High temp 9 degress, humidity, duration of 5 days min, lack of moisture.
concrete and paved surfaces show magnified effect, Urban heat islands, high intensity of UV rays.

Heat stroke, exhaustion, cramps, dehydration, nausea, dizziness, headaches, lead to D,

4 imp criteria forecasting, build capacity, community outreach, inter agency coop, build green cover, estd cooling centres, Public awareness, protect environment
Id heat hot spots and implement local Heat action plans, inter agency coordination
promote traditional adaptation practices, policy intervention and adaptation across sectors
simple design features in houses ![[4.1 Environment, Pollutions, EIA and DM Feb 2020 Onwards#^590110]]

Lack of research, narrow analysis, of urban ward level data, less active usage of public message delivery, lack of Public awareness, half-hearted attempts

![[Pasted image 20221230150729.png]]

IMD declares cold wave when min temp is equal or less than 10deg Celsius at weather stations 4.5deg - 6.4deg below normal temp in the plains.
Very cold air over large area, preceded by weather events, blizzards or ice storms.
Associated w/ EL Nino, cyclones, Jet Streams, western disturbances, cold wave risks
Distribution pattern.
- DEC JAN in PUN, HAR, RAJ; snowfall in Himalayas, cold winds from Caspian sea.
Impact - damage to agriculture, roads, hypothermia etc.

Reasons for Cold wave In India

Lack of western disturbance which bring down temp during day due to precipitation and keep night temp steady.
Snowfall in Upper Himalayas
Downward subsidence of cold air over north India from upper Himalayas bring down temp
La Nina conditions favors cold wave.

Impact of cold wave conditions

CW creates wider day and night temp impacting agricultural practices in Rabi season.
Would affect the productivity of cash crops ex coffee.
Increases incidence of diseases.

Mitigation

Location specific measures, light irrigation to farmers per need, convert schools etc to shelters, promote outreach
Lack of preparation, preparedness, community participation