About this video
- Video Title: 3.1 Watersheds
- Channel: scorpiogal1023
- Speakers: None indicated
- Duration: 00:15:50
Overview
This video explains the concept of a watershed, using the Chesapeake Bay as a primary example. It defines what a watershed is, how water flows within one, and identifies the major watersheds in Virginia. The video also discusses the Chesapeake Bay Watershed's size, its contributors, the difference between fresh and saltwater environments, and the concept of an estuary. Finally, it touches upon the impact of human activities on watersheds and the distinction between "green filters" and "gray funnels."
Key takeaways
- Definition of a Watershed: A watershed is the land area where all water runoff flows to a common body of water, like a stream, lake, or wetland. It's compared to a bathtub where all water leads to the drain.
- Watersheds in Virginia: Virginia has three major watersheds: the Chesapeake Bay Watershed, the North Carolina Sounds (Southern Watershed), and the Gulf of Mexico/Mississippi River Watershed.
- Ridge Lines/Divides: Areas of higher elevation, like the Appalachian Mountains, act as ridgelines or divides that separate different watersheds. Water naturally flows downhill and cannot flow over these divides.
- River Systems and Runoff: Watersheds are comprised of river systems, including tributaries (smaller streams) that feed into larger rivers. As water flows downhill, it picks up sediment and pollutants, a process called runoff.
- The Chesapeake Bay Watershed: This is a very large watershed (over 64,000 square miles) encompassing parts of six states (Delaware, New York, Pennsylvania, Maryland, Virginia, West Virginia) and the District of Columbia. The Susquehanna River is the largest contributor of freshwater to the Bay.
- Estuaries and Salinity: The Chesapeake Bay is an estuary because it's a mix of freshwater from rivers and saltwater from the Atlantic Ocean. This creates varying salinity levels, supporting diverse habitats and serving as a nursery for many species.
- Human Impact: Human activities, such as building impervious surfaces (roads, buildings) that create "gray funnels," can negatively impact watersheds by increasing untreated runoff. "Green filters" like vegetation and wetlands help to naturally filter pollutants.
