Uk river basin

UK River Basin Case Study: The River Tees (OCR A GCSE Geography)

1. Overview of the River Tees

  • Location: Northeast England, flowing east from the Pennines to the North Sea at Middlesbrough.

  • Length: ~210 km.

  • Drainage Basin: Covers around 1,800 km².

  • Key Features: Includes upland areas (Pennines), meanders in the middle course, and an estuary near the mouth.

  • 200,000 people live in the wye

Erosion Processes

  1. Hydraulic Action: Force of water dislodges rocks (e.g., at High Force waterfall).

  2. Abrasion: Rocks scrape the riverbed, deepening the channel.

  3. Attrition: Rocks collide and break into smaller pieces.

  4. Solution: Chemical erosion of limestone in the upper course.

Transportation Processes

  • Traction: Large boulders rolled along the bed.

  • Saltation: Smaller pebbles bounce along.

  • Suspension: Fine sediment carried in the water.

  • Solution: Dissolved minerals transported.

Deposition

  • Occurs when the river loses energy (e.g., on the inside of meanders or in the estuary).

Impact on Geology & Climate:

  • Upper Course (Pennines): Resistant limestone & sandstone lead to steep valleys and waterfalls (e.g., High Force).

  • Middle/Lower Course: Softer rocks (clay, shale) erode easily, forming wider valleys and floodplains.

  • Climate Influence: High rainfall in uplands increases erosion; dry spells reduce river flow, increasing deposition.

3. Climate of the River Tees Basin

  • Upper Course (Pennines):

    • Cooler, wetter (over 2,000 mm/year).

    • High relief rainfall (orographic).

    • Snowmelt in spring increases discharge.

  • Middle/Lower Course:

    • Drier (~600–800 mm/year).

    • More variable flow due to seasonal rainfall.

Impact on River Regime:

  • Peak flow in winter (higher rainfall) and spring (snowmelt).

  • Lower flow in summer, but flash floods possible from intense storms.

4. River Landforms

Upper Course (High Force to Middleton-in-Teesdale)

  • V-shaped valleys: Vertical erosion dominant.

  • Waterfalls (High Force): Formed where hard rock (Whin Sill) overlies softer rock.

  • Gorges: Created by waterfall retreat.

Middle Course (Darlington to Yarm)

  • Meanders: Lateral erosion forms sinuous bends.

  • Floodplains: Deposited silt during floods.

  • Levees: Natural embankments from flood deposition.

Lower Course (Tees Estuary)

  • Estuary: Tidal area where the river meets the sea.

  • Mudflats & Saltmarshes: Sediment deposition at the mouth.5. Impact of Human Activity

Urbanisation & Industry

  • Middlesbrough & Teesside: Factories increase runoff (impermeable surfaces).

  • Pollution: Historical industrial waste (chemicals) affected water quality.

Agriculture

  • Deforestation & ploughing increase soil erosion → more sediment in the river.

  • Fertilizers cause eutrophication (algae blooms).

Flood Management

  • Cow Green Reservoir (1970): Regulates flow, reduces flooding.

  • Yarm Flood Defences: Earth embankments protect the town.

  • Channel Straightening (near Stockton): Speeds up flow but increases flood risk downstream.

6. River Management Strategies

  1. Hard Engineering:

    • Dams (Cow Green) control flow but disrupt ecosystems.

    • Flood walls in Yarm protect property but are expensive.

  2. Soft Engineering:

    • Floodplain zoning restricts building in high-risk areas.

    • Afforestation in uplands reduces surface runoff.

Conflicts:

  • Farmers oppose floodplain zoning (lose land).

  • Dams disrupt fish migration (e.g., salmon).