Thornthwaite classification
Topic: World Climate Classification: Koeppen's Scheme · NCERT: Beyond NCERT
Meaning
C.W. Thornthwaite made this climate classification in 1931 and revised it in 1948. It is based on precipitation effectiveness (how useful the rain really is to plants) and potential evapotranspiration. Potential evapotranspiration is the water a place could lose through evaporation and through plants giving off water. So the scheme compares the water a place gets with the water it could lose. That makes it a good measure of whether a place is truly wet or dry.
Example
Thornthwaite's method has also been used to classify India's climates. In western Rajasthan, the water the hot air could take up is far more than the rain that falls, so the region comes out as dry.
Don't confuse with
- Koeppen classification: Koeppen sets his limits by temperature and rainfall values linked to vegetation. Thornthwaite's scheme is built on the balance between water received and water lost.
Related concepts
- Empirical classification
- Genetic classification
- Koeppen climate classification
- Koeppen seasonality letters
- Koeppen temperature letters