# GCSE Geography Coursework: Strand 4 - Interpertation of Data

Riyadh Abdulla         Data Interpretation                 Instructor: Mr Walker

This is the Data Interpretation section of the coursework folder for the geographical investigation conducted on the River Calder around Garstang; based on the following hypothesis - ‘Does the River Calder fit the Bradshaw Model.’ The Bradshaw model is in figure 1.

These are the locations which were investigated:

• #1approximately 4km from source. Grid reference 548 487.

• #2- approximately 5.2km from source. On Grid reference 539 482.

• #3 – On Calder Vale; approximately 8.3km from source. Grid Reference 533 482.

• #4 – Sandholme Mill; approximately 11.4km from source, grid reference 517 434.

• #5- Catterall playing fields; approximately 14.3km form source, grid reference 494 433.

These are the factors which were measured and are going to be explained:

• Channel Width
• Channel Depth
• Water velocity
• Discharge

Analysis of each factor in-respect to the River Calder’s attributes:

1.  Channel Width:

According to the Bradshaw Model, the channel width is expected to increase moving downstream from the source.

There is an abnormal decrease of 3.4m in the channel width between sites 2 and 3; approximately 7KM from source.

This anomaly is due to the abstraction of water from the Calder Intake to the Barnacre and Grizedale Lea reservoirs, grid-reference 5448. A reduce in water will make the channel width narrower. This is because less (lateral) erosion will occur, in-order to deepen the channel.

From sites 3 to 5, the channel gradually re-widens; rising significantly from 2.7m to 6.7m.

This increase happens, especially from site 4 to 5, because River Calder’s 34 tributaries are constantly adding water back to the river; thence increasing erosive processes, mainly hydraulic action and abrasion, widening the channel.

This can be linked to show an overall increase of the Discharge. There will be more water flowing over a wider and deeper channel, because of the greater surface area. The velocity increases because as one moves downstream from the source – there will be less boulders; hence obstacles which initially slow down velocity despite the river being at a greater slope from source.

1.  Channel Depth:

According to the Bradshaw Model, the channel depth is expected to increase moving downstream from the source.

Like channel width, there is a decrease of 0.11m in the result of the average channel depth between sites 1 and 2, approximately 7KM from source.

This anomaly is due to the abstraction of water from the Calder intake to the Barnacre and Grizedale Lea reservoirs. Hence, this leaves the volume of the water sparse.

Between sites 3 to 5, the channel depth is increases from 0.14 to 0.32m; a total of ...