Stage 1: Evaporation in the Water Cycle Diagram
Evaporation is the first stage shown in any water cycle diagram. When the sun heats water in oceans, lakes, and rivers, the water molecules gain energy and escape into the air as invisible water vapor. This process happens constantly - about 90% of atmospheric moisture comes from ocean evaporation.
In a water cycle diagram, you'll see arrows rising from water bodies toward the sky. The sun provides the energy needed for this transformation. Interestingly, evaporation cools the water surface - that's why you feel cold when wet skin dries. Every day, the sun evaporates approximately 1 trillion tons of water from Earth's surface.
Plants also contribute through transpiration - releasing water vapor through tiny pores in their leaves. Together, evaporation and transpiration are sometimes called "evapotranspiration" in detailed water cycle diagrams. Plants contribute about 10% of atmospheric water vapor.
Stage 2: Condensation in the Water Cycle Diagram
Condensation is the second stage in the water cycle diagram. As water vapor rises high into the atmosphere, it cools down. When the temperature drops enough, the vapor transforms back into tiny liquid water droplets. This is why you see clouds forming in water cycle diagrams at high altitudes.
For condensation to occur, water vapor needs something to cling to - tiny particles like dust, pollen, or sea salt floating in the air. These are called condensation nuclei. Billions of these microscopic droplets cluster together to form the clouds we see in the sky.
A water cycle diagram shows this stage as clouds forming. The process is the same as when you see water droplets on a cold glass of water - warm, moist air meets the cool surface and condenses. At high altitudes, temperatures can drop below -40°C, causing rapid condensation.
Stage 3: Precipitation in the Water Cycle Diagram
Precipitation is the third stage depicted in water cycle diagrams. When cloud droplets combine and grow heavy enough, gravity pulls them down as rain, snow, sleet, or hail. A typical raindrop contains about 1 million cloud droplets merged together.
The type of precipitation depends on temperature. If the air between clouds and ground stays above 0°C, we get rain. Below freezing, water falls as snow. Sleet forms when rain freezes mid-fall, while hail develops in thunderstorms where strong updrafts toss ice pellets up and down, adding layers.
In a water cycle diagram, precipitation is shown as arrows pointing downward from clouds. Globally, about 505,000 cubic kilometers of water falls as precipitation each year. Most falls over oceans (about 78%), while land receives the rest - crucial for sustaining terrestrial life and freshwater supplies.
Stage 4: Collection in the Water Cycle Diagram
Collection is the final stage in the water cycle diagram, where water gathers in various reservoirs. When precipitation reaches the ground, it follows different paths: some flows across the surface as runoff into rivers and lakes, some infiltrates into soil to become groundwater, and some is absorbed by plants.
Water cycle diagrams show collection happening in multiple locations: oceans (holding 97% of Earth's water), glaciers and ice caps (69% of freshwater), groundwater (30% of freshwater), and surface water like lakes and rivers (less than 1% of freshwater).
The journey doesn't end here - the water cycle diagram is circular. Collected water eventually evaporates again, restarting the cycle. A single water molecule can take anywhere from 9 days to 40,000 years to complete one full cycle, depending on where it travels. Water in the deep ocean may take thousands of years to resurface.
