The National Weather Service offers information on the processes that make up the water (hydrologic) cycle, including evaporation and transpiration, precipitation, run-off, infiltration, and percolation. Has a good illustration and information on how long these processes take.

Students apply their understanding of the natural water cycle and the urban "stormwater" water cycle, as well as the processes involved in both cycles to hypothesize how the flow of water is affected by altering precipitation. Student groups consider different precipitation scenarios based on both intensity and duration. Once hypotheses and specific experimental steps are developed, students use both a natural water cycle model and an urban water cycle model to test their hypotheses. To conclude, students explain their results, tapping their knowledge of both cycles and the importance of using models to predict water flow in civil and environmental engineering designs. The natural water cycle model is made in advance by the teacher, using simple supplies; a minor adjustment to the model easily turns it into the urban water cycle model.

Through an overview of the components of the hydrologic cycle and the important roles they play in the design of engineered systems, students' awareness of the world's limited fresh water resources is heightened. The hydrologic cycle affects everyone and is the single most critical component to life on Earth. Students examine in detail the water cycle components and phase transitions, and then learn how water moves through the human-made urban environment. This urban "stormwater" water cycle is influenced by the pervasive existence of impervious surfaces that limit the amount of infiltration, resulting in high levels of stormwater runoff, limited groundwater replenishment and reduced groundwater flow. Students show their understanding of the process by writing a description of the path of a water droplet through the urban water cycle, from the droplet's point of view. The lesson lays the groundwork for rest of the unit, so students can begin to think about what they might do to modify the urban "stormwater" water cycle so that it functions more like the natural water cycle. A PowerPoint® presentation and handout are provided.

This lesson covers the process of photosynthesis and the related plant cell functions of transpiration and cellular respiration. Students will learn how engineers can use the natural process of photosynthesis as an exemplary model of a complex yet efficient process for converting solar energy to chemical energy or distributing water throughout a system.

What do plants need? Students examine the effects of light and air on green plants, learning the processes of photosynthesis and transpiration. Student teams plant seeds, placing some in sunlight and others in darkness. They make predictions about the outcomes and record ongoing observations of the condition of the stems, leaves and roots. Then, several healthy plants are placed in glass jars with lids overnight. Condensation forms, illustrating the process of transpiration, or the release of moisture to the atmosphere by plants.

Students gain an understanding of the parts of a plant, plant types and how they produce their own food from sunlight through photosynthesis. They also learn about transpiration, the process by which plants release moisture to the atmosphere. With this understanding, students test the effects of photosynthesis and transpiration by growing a plant from seed. They learn how plants play an important part in maintaining a balanced environment in which the living organisms of the Earth survive. This lesson is part of a series of six lessons in which students use their evolving understanding of various environments and the engineering design process, to design and create their own model biodome ecosystems.

Students explore whether rooftop gardens are a viable option for combating the urban heat island effect. Can rooftop gardens reduce the temperature inside and outside houses? Teams each design and construct two model buildings using foam core board, one with a "green roof" and the other with a black tar paper roof. They measure and graph the ambient and inside building temperatures while under heat lamps and fans. Then students analyze the data and determine whether the rooftop gardens are beneficial to the inhabitants.

This tutorial examines how water moves through a plant. Follow the pathway that water takes through plants from the roots to evaporation from cells in the leaves. Learn what controls rates of transpiration, how environmental conditions alter rates of transpiration, and how the plant itself can change rates of transpiration. Includes a glossary and a detailed animation.

Groundwater is one of the largest sources of drinking water, so environmental engineers need to understand groundwater flow in order to tap into this important resource. Environmental engineers also study groundwater to predict where pollution from the surface may end up. In this lesson, students will learn how water flows through the ground, what an aquifer is and what soil properties are used to predict groundwater flow.

Animation and text explain the water--or hydrologic--cycle, which is the process that water undergoes in nature.

Water is the source of life on earth. It exists in many forms and is constantly changing. The circulation and conservation of earth's water is called the hydrologic (or water) cycle. Find out how water evaporates, condensates, precipitates, transpires, and is transported around the earth.

Engineers design and implement many creative techniques for managing stormwater at its sources in order to improve and restore the hydrology and water quality of developed sites to pre-development conditions. Through the two lessons in this unit, students are introduced to green infrastructure (GI) and low-impact development (LID) technologies, including green roofs and vegetative walls, bioretention or rain gardens, bioswales, planter boxes, permeable pavement, urban tree canopies, rainwater harvesting, downspout disconnection, green streets and alleys, and green parking. Student teams take on the role of stormwater engineers through five associated activities. They first model the water cycle, and then measure transpiration rates and compare native plant species. They investigate the differences in infiltration rates and storage capacities between several types of planting media before designing their own media mixes to meet design criteria. Then they design and test their own pervious pavement mix combinations. In the culminating activity, teams bring together all the concepts as well as many of the materials from the previous activities in order to create and install personal rain gardens. The unit prepares the students and teachers to take on the design and installation of bigger rain garden projects to manage stormwater at their school campuses, homes and communities.

This animation from NASA visualizes the steps of the water cycle, including precipitation, evaporation, transpiration, and condensation. [0:52]

Learn about the four phases of the water cycle, the ways in which watersheds are crucial to healthy water, and the best ways to manage local watersheds with this interactive lesson.

Students learn about the Earth's water cycle, especially about evaporation. Once a dam is constructed, its reservoir becomes a part of the region's natural hydrologic cycle by receiving precipitation, storing runoff water and evaporating water. Although almost impossible to see, and not as familiar to most people as precipitation, evaporation plays a critical role in the hydrologic cycle, and is especially of interest to engineers designing new dams and reservoirs, such as those that Splash Engineering is designing for Thirsty County.

The engineers at Splash Engineering (the students) have been commissioned by Thirsty County to conduct a study of evaporation and transpiration in their region. During one week, students observe and measure (by weight) the ongoing evaporation of water in pans set up with different variables, and then assess what factors may affect evaporation. Variables include adding to the water an amount of soil and an amount of soil with growing plants.

Learn about the different stages of the Earth's water cycle, and about processes involving water, including runoff, infiltration, and the differences between hard and soft water.