Ans. Water stress refers to the imbalance between water demand and water availability in a particular region. When the demand for water exceeds the available supply, it can lead to water insecurity. Climate change can exacerbate water stress by altering precipitation patterns and increasing evaporation rates. This can result in reduced water availability for agriculture, industry, and domestic use, leading to water scarcity and insecurity. Water stress can also affect ecosystems and biodiversity by disrupting aquatic habitats and reducing water-dependent species' populations.