For the InstructorThese student materials complement the Water Science and Society Instructor Materials. If you would like your students to have access to the student materials, we suggest you either point them at the Student Version which omits the framing pages with information designed for faculty (and this box). Or you can download these pages in several formats that you can include in your course website or local Learning Managment System. Learn more about using, modifying, and sharing InTeGrate teaching materials.
Summary and Final Tasks
Surface water hydrology on Earth is characterized by immense variability on many different space and time scales. It might at first be daunting to see the immense variability of precipitation, illustrated in figure 1 of this module, if it is your job to tell a developer how big they need to make a detention basin, or to tell an insurance agency how they should set flood insurance rates, or to tell a farmer how likely it is that his/her region will experience a severe drought next year. However, hydrologists have developed a variety of ways to quantify and this variability so that we can make prudent decisions about development, water resource availability, conservation and restoration. We have reviewed some of the simpler approaches, such as developing histograms and probability density functions. These approaches work well in situations with stationary conditions, whereby they vary around some consistent average, but they work less well in situations where the average value and/or the amount of variability is systematically changing. Such non-stationary conditions are increasingly common as climate change manifests in different ways around the world. New techniques are emerging in hydrology to improve our ability to make predictions in such situations. Are dams the answer to all of our hydrologic variability problems? We'll discuss that more in the next module.
Reminder - Complete all of the Module 4 tasks!
You have reached the end of Module 4! Double-check the to-do list on the Module 4 Roadmap to make sure you have completed all of the activities listed there before moving onto Module 5!
References and Further ReadingEM-DAT, Guha-Sapir, D., Hoyois, P., and Below, R. 2013. Annual Disaster Statistical Review 2013: The numbers and trends. Centre for Research on the Epidemiology of Disasters (CRED). Available online: http://www.cred.be/sites/default/files/ADSR_2013.pdf (Acrobat (PDF) 5.5MB Mar28 17)
Federal Interagency Stream Restoration Working Group. 1998. Stream corridor restoration: principles, processes and practices. National Technical Information Service, US. Department of Commerce, Springfield, Virginia. Available online:
IPCC, 2007. A report of Working Group I of the Intergovernmental Panel on Climate Change. Summary for Policymakers. Available online:
IPCC, 2014. Climate Change 2014: Synthesis Report. Summary for Policymakers. Available online: https://www.ipcc.ch/publications_and_data/publications_and_data_reports....