🌊 7th Grade Watershed Studies Unit Test Study Guide 🌊

Basics

Watershed: The entire land area that drains into a particular water body, like rivers, lakes, or oceans.

River Basin: All land drained by streams flowing into a major river.

Diagram:

• Label watershed boundary, tributaries, confluence, river basin, delta.
  
  

🌱 Key Terms and Definitions

Ecosystem & Habitats

• Ecosystem: Interaction of living organisms with their environment.
  
  

• Habitat: The specific environment where an organism lives.
  
  

Water Features

• Aquifer: Underground layers holding groundwater.
  
  

• Groundwater: Water below the Earth's surface.
  
  

• Water Table: Level below which the ground is saturated with water.
  
  

Flowing Water

• Perennial Stream: Always flowing.
  
  

• Ephemeral Stream: Flows only after precipitation.
  
  

• Tributary: Small streams feeding into larger water bodies.
  
  

• Meander: Curves in rivers.
  
  

• Oxbow Meander/Lake: Extreme river curves; lakes formed when curves get cut off.
  
  

• Confluence: Point where rivers join.
  
  

Diagram:

• Illustrate tributaries, meanders, oxbow lake, confluence.
  
  

Stream Sections

• Pools: Deep, slow-moving sections.
  
  

• Riffles: Shallow, fast-moving, rocky sections.
  
  

Stream Loads

• Bed Load: Sediments moving along stream bottom.
  
  

• Dissolved Load: Soluble materials in water.
  
  

• Suspended Load: Particles carried in water column.
  
  

Processes

• Erosion: Movement of weathered materials by wind, water, gravity.
  
  

• Weathering: Breakdown of rock into sediment.
  
  

• Infiltration: Water seeping into permeable soil.
  
  

• Runoff: Water flowing across impermeable surfaces.
  
  

Water Cycle

• Water Cycle: Movement of water (evaporation, condensation, precipitation).
  
  

• Transpiration: Water vapor released from plants.
  
  

Water Quality Terms

• Aerobic: Conditions or organisms requiring oxygen.
  
  

• Anaerobic: Conditions or organisms not requiring oxygen.
  
  

• Dissolved Oxygen (DO): Oxygen present in water; vital for aquatic life.
  
  

• Hypoxia: Low oxygen conditions harmful to organisms.
  
  

Nutrients and Impacts

• Nutrients: Chemicals like nitrogen/phosphorus essential for plant growth.
  
  

• Eutrophication: Excess nutrients causing algal blooms, low oxygen.
  
  

• Algae: Photosynthetic aquatic organisms without true roots/stems.
  
  

• Algal Bloom: Rapid algae growth due to excess nutrients.
  
  

• Decomposition: Breakdown of organic matter by microorganisms.
  
  

Diagram:

• Show algal bloom process leading to hypoxia.
  
  

Aquatic Organisms

• Benthos: Bottom-dwelling organisms.
  
  

• Benthic Macroinvertebrates: Organisms indicating water quality.
  
  

Land Features

• Floodplain: Land beside rivers flooded periodically.
  
  

• Wetlands: Saturated areas like bogs, marshes, swamps; important for water purification.
  
  

• Riparian: Areas along banks of water bodies.
  
  

• Estuary: Coastal areas where freshwater mixes with saltwater.
  
  

• Delta: Landform at river mouths formed by sediment deposits.
  
  

Human Impacts

• Impervious Surfaces: Prevent infiltration; increase runoff.
  
  

📌 Important Concepts

• Human activities can accelerate eutrophication and erosion.
  
  

• Healthy watersheds have diverse habitats, stable banks, and good infiltration.
  
  

• Benthic Macroinvertebrates help scientists assess ecosystem health.
  
  

Tips for the Test:

• Study diagrams closely and understand labels.
  
  

• Review cause-and-effect relationships (e.g., nutrient runoff → eutrophication → algal blooms).
  
  

Good luck on your test! 📚💦