Measurement of depth of reservoirs is necessary at hydrological and biological researches, for investigation under design and construction, for navigation. If you were going to investigate fauna in the next reservoir, first of all it is necessary to know its depth. For this purpose lot which it is possible to make with own hands is required. Lot – very ancient tool, also consists it of a rope with knots and cargo.
It is required to you
- Boat or raft
- Rope
- White and red threads
- Piece of an inch water pipe 20 cm long
- Drill
- Needle
- Ruler 1 m long
Instruction
1. Since one end of a pipe, near edge, drill an opening and fix on it a rope by strong knot. Beginning from this end of a rope, mark it as follows. Through 0.5 m stitch it a white thread so that the noticeable tag was formed. Through 0.5 m stitch a rope a red thread – it will be a meter mark. Thus mark all rope.
2. Learn to use lot. For this purpose the boat or a raft is required. Ship lot on the watercraft and come to that place where you will perform measurements. Prepare lot for dumping. Tie the free end of a rope to any structural element of the boat that accidentally not to lose it. Lay a rope so that it lay the free bay, without forming knots or loops.
3. Begin to lower lot overboard, gradually etching a rope. It is necessary to etch it smoothly, observing a constant tension, until, so far the rope completely will not weaken. It will mean that cargo (pipe) laid down on soil. From this point begin to perform measurements.
4. Pull a rope till the moment when you begin to feel resistance. That point of a rope which is at the level of a water surface is depth tag. It can be noted in knot or in a different way. After that extend lot and count on red knots the number of meters of depth, on white – the next half-meter mark. The distance from it to a point which was on a water surface can be measured just a ruler.