Answer:
b. watershed
A watershed is an area of land where all the water from rain, streams, rivers, and other sources converges and flows to a common destination, such as a larger river, lake, or ocean. It is also known as a drainage basin or catchment area. Watersheds are important for managing water resources and understanding the hydrology of a region.
Explanation:
A watershed, also known as a drainage basin or catchment area, is a land area where all the water under it or draining off of it collects into the same place, such as a river, lake, or ocean. Here’s a more detailed explanation:
1. Structure of a Watershed:
- Boundary: The boundaries of a watershed are defined by the highest points of land, such as ridges or hills, from which water flows downwards into the common outlet.
- Tributaries: Within a watershed, there are various smaller streams, rivers, and other bodies of water that feed into the main water body.
2. Function:
- Water Collection: A watershed collects precipitation (rainfall, snowmelt, etc.) and channels it into streams and rivers that eventually lead to a larger body of water.
- Water Movement: The flow of water within a watershed can be influenced by topography, geology, vegetation, and human activities.
3. Ecological and Environmental Importance:
- Water Quality: Watersheds help to filter pollutants from water as it moves through soils and vegetation, contributing to cleaner water in the main water body.
- Habitats: Watersheds provide habitats for diverse plant and animal species.
- Flood Control: Natural watershed functions can help to mitigate floods by slowing down the flow of water and allowing it to be absorbed into the ground.
4. Human Impact and Management:
- Land Use: Human activities such as agriculture, urban development, and deforestation can significantly impact the health and function of watersheds.
- Conservation Efforts: Proper management and conservation of watersheds are crucial for maintaining water quality, preventing soil erosion, and supporting ecosystems.
In summary, a watershed is a critical natural feature that plays a vital role in collecting and directing water flow, supporting ecosystems, and providing resources for human use. Understanding and managing watersheds are essential for sustainable environmental and water resource management.