Final answer:
The water level falls if there is no rain for months because the primary source of water for lakes, rivers, and other bodies of water comes from precipitation like rain and snow. Without rainfall, there is no new water to replenish these sources, causing the water level to gradually decrease over time.
Step-by-step explanation:
The water level falls if there is no rain for months because the primary source of water for lakes, rivers, and other bodies of water comes from precipitation like rain and snow. Without rainfall, there is no new water to replenish these sources, causing the water level to gradually decrease over time. Additionally, evaporation and human consumption can also contribute to the lowering of water levels.
For example, in areas with high temperatures and low humidity, evaporation rates can be higher than the amount of rainfall, resulting in decreased water levels. Moreover, human activities such as agriculture, industry, and domestic use can lead to increased water consumption, which further exacerbates the decrease in water levels.
To illustrate, imagine a lake that receives no rainfall for several months and has high evaporation rates due to warm temperatures. As the water evaporates, the lake's water level will decrease steadily. If there are no other sources of water, such as rivers or underground aquifers, to replenish the lake, the water level will continue to fall until new rainfall occurs.