We know every river starts its journey from its source. In the upper course of the river, the channel is at a high above its base level i.e. its mouth. Thus the gradient is high. Due to the height, it has a lot of potential energy. So it uses this energy to reach its base level. So the process mainly at work is vertical erosion. Further it has got a lot of interlocking spurs. There is less lateral erosion taking place. So the bed load is composed of bigger rock particles with irregular size. When it reaches the middle course, the river is quite near to its base level. So it uses its surplus energy to erode sideways. Hence the processes like abrasion, attrition, hydraulic action smoothens the rough edges making the shape circular. The lateral erosion and transportation may give rise to features like meanders and oxbow lakes. When it reaches the lower course, it is almost near to its base level. So it doesn’t have sufficient energy to erode or transport bed load. So the main process at work is deposition leading to features like floodplain and deltas. Expected outcomes
River pang is one of the tributaries of the River Thames. Since the river doesn’t flow into a sea it should have a confluence not a mouth. So it doesn’t have a delta in its lower course.it has a confluence at village of Pangbourne in Berkshire. Also as it’s just a tributary, the features like interlocking spurs, waterfall, meanders, oxbow lakes, deltas and floodplain is less likely to be seen. However basic features about gradient, bed load size, velocity will have changes as we move down the stream. The gradient should decrease. Also the bed load size should decrease due to continued (vertical + lateral) erosion. The velocity should increase as well. Location
It is located in the West Berkshire. It runs for approx. 23 kms from its source at Compton to its confluence with Thames in the village of Pangbourne. The source is not stationary it differs as per rainfall patterns. At first, as shown in the map above, it flows south from Compton through the villages of Hampstead Norris and Frilsham before turning east to flow through the village of Bucklebury, Stanford Dingley and Bradfield. To the east of Bradfield, the Pang is joined by River Bourne and turns to North to flow through the village of Tidmarsh and Pangbourne. Eventually it enters the Thames between Whitchurch Lock and Whitchurch Bridge. It flows to Thames at Pangbourne on the border of AONB. Site 1- Compton
Site 4-Moor copse
Description of fieldwork techniques
We went to river Pang on 24th June Friday. The aim was to study the hydrological characteristics and how it changed downstream. Many measurements were taken with channel at different sampling points. We measured the following things: * Wetted perimeter
It is the region of river bed that is in contact with the water. We used a tape measure and took it along the channel by moving along with it. * Channel depth
For this we first put the ranging poles and then measured it with tape. * Gradient
For this we required the ranging poles and the clinometer. After adjusting the ranging poles in a straight line we used the clinometer to find the gradient. * Velocity
* Bed load size
For this we picked up random of 10 stones from different parts of each site and took an average of them. Also we analysed the shapes of the bed load.
The data we had for wetted perimeter was a crude one. This was because the tape needed to be stretched along the river bed under water which was quite difficult. However the data for bed load was quite accurate as we repeated the expt. and took the average.
3. Data presentation and analysis
From the graph, the river slowly increased its velocity and the width as it travelled downstream. When the river reaches the middle course it is quite...
Please join StudyMode to read the full document