Explain How And Why Does Channel Width Change Downstream

Hypothesis

My aims and key questions are as follows;

Aim

“Carding Mill Valley and its river changes downstream from its source.”

Key Questions

1. How and why does the valley width change downstream? 2. How and why does the channel width change downstream? 3. How and why channel cross-section change downstream? 4. How and why does the average velocity change downstream? 5. How and why does the channel gradient change downstream? 6. How and why does the bed-load change downstream? 7. How and why does the human land use of the valley change as the river moves downstream and does this impact on the river?

Introduction

Carding mill valley is in Shropshire, England. It is 22.5km northwest of Droitwich;
I can show this by using my results as I said the valley starts off at a slow rate of widening of 4.27m to 6.2m and again up to 8m so this clearly is a gradual increase. Whereas it jumps to measurements of 15.1m to 29.2m and then to 39m, this shows the rapid increase. This is an increase of 34.73% from the top of the valley to the bottom; this is taken from a minimum measurement of 4.27m and a maximum measurement of 39m. Types of erosion involved in this are abrasion/corasion, which is Rocks that are carried in the river grind and erode the riverside and bed. Some of the rock at the sides and bed of the channel are washed away. This type of erosion widens the channel through lateral erosion and deepens the channel by vertical erosion. Also Hydraulic action is an affect where water travelling at a high speed may enter the line of weakness of rock when it hit against these rocks at the side of the channel. The force may cause the rock to break and the broken pieces of rock are swept away. These causes get stronger as we move down the river as they pick up speed and extra sediment and rocks to cause the erosion. The most important type is abrasion as it is the most destructive erosion and as for the time of year that it is most prolific is winter as the volume of water coming down the river is greater so the amount of rock it
Firstly the excellent walking areas around draw hikers to the area this causes paths and walkways around the area. This will affect the valley as they put down tablets of stone which are impermeable to water cannot get into the soil and make it to the river via through flow this will increase surface run-off which will keep water on top of the ground and increase the chance of flooding, however they space to slabs a little apart and do not cement them down so there fore the water can still enter the earth. On the upland there is beautiful heather which could become ruined by people taking cuttings or dropping litter which affects the wildlife as the heather may be their home and they may try to eat the litter or dropped scraps, this may in turn make them dependant on humans which makes them less wild and move away from their inherited lives but this can be resolved simply by putting fines on litter or putting more bins around the site. Hand gliders love it there to as it is high and beautiful but Para gliders will cause noise and air pollution. Tourist activity has affected it by laying concrete and pavements which are impermeable increasing surface run-off and increasing yet again the possibility of flooding and in turn lowering the amount of water making it to the river and being taken away but they have put a man made drainage system in to combat this