Concept Review: Water Cycle

  Another name for the water cycle is the hydrologic cycle. I am sure that you can guess that the Greek root, hydr-, means water. Most of the terms you should remember from grade school. 

  A few new ones for the general public might be sublimation, which is the transition of a substance from the solid phase directly to the gas phase. Desublimation would be the opposite, the gas phase transitioning directly to the solid phase. Normally when substances transition phases, they pass through an intermediate liquid phase. Therefore, sublimation and desublimation would only occur in extreme cases of high temperature or pressure gradients. Gradient is the difference between final and initial conditions over time. Remember when you had to learn about slopes of lines in high school geometry? If you remember, you may have talked about how "steep" the slope of the line is. The temperature or pressure profile of a substance sublimation or desublimation would have a steep slope. 

  Another new term for you may be evapotranspiration. You might be able to guess that two processes are involved in this, evaporation and transpiration. However, evapotranspiration takes into account the sum of evaporation across vegetation in habitats as well as transpiration which is the loss of water from plants. 

  My mom taught middle school science for 20 years. An assignment she would give her students for homework was to write a journal entry of a day in the life of a water drop going through the water cycle. I truly think that assignments like this are what help students remember science facts without a lot of worksheets or memorization. If you are a teacher or homeschooler, you may want to try this assignment in your classroom!