When Precipitation Patterns Change

Introduction

Have you been in a drought? Are you living through one now? Most places in the United States experience drought occasionally. Sometimes, drought causes widespread interruptions of daily life. Other times, drought is milder; people may not even notice it except for the lack of rainy days.

In this activity, you'll develop a working definition of drought and do a hands-on demonstration to understand the role of soil moisture in drought. You'll also examine precipitation data and streamflow levels and use them to predict where drought is most severe in the United States. You'll check your predictions by comparing them to the U.S. monitors drought severity layer.

Keeping Track of What You Learn

In these pages, you'll find two kinds of questions.

• Checking In questions are intended to keep you focused on key concepts. They allow you to check if the material is making sense. These questions are often accompanied by hints or answers to let you know if you are on the right track.
• Stop and Think questions are intended to help your teacher assess your understanding of the key concepts and skills. These questions require you to pull some concepts together or apply your knowledge in a new situation.

Your teacher will let you know which questions you should answer and turn in.