Consider the following statements regarding Evaporative Demand:
1. It is a measure of the atmosphere’s potential to absorb moisture from land and vegetation.
2. Higher evaporative demand increases the likelihood of drought and the risk of wildfires.
3. It is commonly estimated using reference evapotranspiration over a well-irrigated crop surface.

Which of the statements given above is/are correct?
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

Question

Consider the following statements regarding Evaporative Demand:
1. It is a measure of the atmosphere&rsquo;s potential to absorb moisture from land and vegetation.
2. Higher evaporative demand increases the likelihood of drought and the risk of wildfires.
3. It is commonly estimated using reference evapotranspiration over a well-irrigated crop surface.

Which of the statements given above is/are correct?
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

ONLiNE UPSC · Accepted Answer

Recently, the rise in evaporative demand has highlighted significant gaps in India&rsquo;s data collection and research capabilities.

Statement 1 is correct: Evaporative demand refers to the potential amount of water the atmosphere can absorb from land, plants, and water surfaces if water were unlimited. It is often described as how &ldquo;thirsty&rdquo; the atmosphere is, and is determined by meteorological factors such as temperature, humidity, wind speed, and solar radiation.

Statement 2 is correct: Periods of high evaporative demand lead to faster drying of soil and vegetation. This reduces soil moisture, stresses plants, and makes vegetation more flammable, thereby increasing the risk of droughts and wildfires.

Statement 3 is correct: The most commonly used way to measure evaporative demand is the Standardized Short-Crop Reference Evapotranspiration (ETos). It is based on a well-watered grass surface with plenty of water available. This method gives a consistent measure of how much water the atmosphere would take up, regardless of how much moisture is actually in the soil.

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M Question 1	⏱ 0
Consider the following statements regarding Evaporative Demand: 1. It is a measure of the atmosphere’s potential to absorb moisture from land and vegetation. 2. Higher evaporative demand increases the likelihood of drought and the risk of wildfires. 3. It is commonly estimated using reference evapotranspiration over a well-irrigated crop surface. Which of the statements given above is/are correct? (a) 1 and 2 only (b) 2 and 3 only (c) 1 and 3 only (d) 1, 2 and 3