I have decided to study the Shimna River as my case study. I picked this case study because I thought it would be both interesting and challenging as well as the fact it was on our doorstep. Before we could do anything we had to plan our investigation.

In planning, it was decided that the width, depth, velocity, temperature, wetted perimeter and the smoothness of the stones would all be measured.  From these results obtained, the cross-sectional area and discharge can be worked out by use of equations.  In order to get a wide range of results, measurements from approximately 16 different points will be taken.  In deciding which locations the readings are to be taken from, stratified sampling can be used, this means selecting a point from each of the main parts of the course of the river, we selected upper, middle and lower.

The equipment listed:

• Siting poles
• Clinometre
• Velocity metre
• Metre stick
• Tape measure
• Temperature probe

• Trundle wheel

Due to hidden dangers and potential accidents we had to make safety a major issue. We took many safety precautions including going up the mountain when water levels weren't dangerously high, choosing a calm day - avoiding hazardous weather. We made sure that we all stayed together and set up lines of communication. It was essential that we wore warm comfortable clothing with a first aid kit always at hand.

Aims

When we set out at the start we had several aims to consider.

1. Does the river discharge increase the further from the source?
2. Is there a relationship between river width and stream velocity?
3. As the wetted perimeter increases, river velocity decreases.
4. The further from the source the stones deposited become smaller, smoother and more rounded.
5. Does river temperature readings increase the further from the source?
   
   

Data Collection

At each of our seventeen stops we recorded readings for river width, average depth, cross sectional area, wetted perimeter, river discharge, types of stones and water temperature.

We systematically obtained our samples by measuring every ten meters at each of our four locations.

In my analysis of the River Shimna I selected three areas within the river study. They were the Upper, Middle and lower part of the river. I accomplished this by stratified sampling. The readings I received from these 3 areas were:

• Upper - 7 readings
• Middle - 6 readings
• Lower - 4 readings

Getting the appropriate data proved to be trickier than what I had predetermined. When we recorded river width and cross sectional area in the lower area of the river the water levels were quite high. We had to carefully step into the river with fishermen's waders to measure river depth at recorded intervals and measure the river width.

Measuring the cross section of the valley was important. The angle of the slope was determined by using a clinometer. Two siting poles were used to mark the region of the valley to the end of each slope. We used a trundle wheel to measure the distance between the two siting poles; this was quite difficult because some of the slopes near the river source where almost vertical.

To find river discharge and river temperature we submerged a metal probe connected to a small computer device which recorded river velocity and temperature at the touch of a button.

When we got back to school we tabulated the data and drew up our final conclusions.