How is "meteorological drought" defined?

Meteorological drought is defined as a deficiency in precipitation over an extended period, which directly impacts the availability of water resources in a region. This definition focuses on the quantitative measure of precipitation, emphasizing that a significant shortfall relative to the expected or normal precipitation levels can lead to drought conditions.

The concept of meteorological drought is crucial for understanding water supply issues, agricultural practices, and ecosystem health, as it directly affects soil moisture and surface water availability. A prolonged lack of rain can result in severe consequences for various sectors, including agriculture, which relies on sufficient rainfall for crop growth.

The other options do not accurately capture the essence of meteorological drought. An increase in humidity over time does not signify a deficiency in precipitation; rather, it may indicate more moisture in the atmosphere. Excessive rainfall pertains to hydrological or agricultural concerns, not a lack thereof, and unpredictable weather patterns do not specifically define a drought condition, as they may encompass a wide range of weather phenomena but do not necessarily indicate a sustained lack of precipitation.