# 17. TO DETERMINE THE BASAL AREA AND WOOD VOLUME OF TREE FROM A FOREST ECOSYSTEM

Contents: Click for quick access

## REQUIREMENTS:

1. Measuring tape
2. Clinometer
3. Tree identification key
4. Compass
5. Rope
6. Notebook etc.

Tree basal area is the cross sectional area of stem -tune of a tree at the height of the chest. A tree basal area actually refers to the ground penetrated by stems. So, the basal area of a tree  is determined in terms of its stem circumference . Stem volume is also a function of basal area along with tree height shape and basic thickness  since basal area is the area occupied by the tree stem , it may be regarded as an under dominance of a species.

A basal area of a tree is measured at breast type (usually 5.3 meter) from the ground surface.

The design flow is calculated by construction of flow duration curve.

### THere are four types of hydropower:

1. Runoff hydropower
2. Storage hydropower
3. Pumped hydropower
4. Off share hydropower

Diagramatic representation of the warning schedule of hydropower.

P.E —-> K.E —> Mechanical energy —> Electrical energy

## Problem no.1:

Rapti river has an average annual monthly mean discharge as shown.

Calculation=PeHQg

= PO/100*103*2.8*9.8

= 2261.056

## Problem no.2:

Construct the flow duration curve.

1. Determine flow(discharge) which can be expected 60% time of exceedence.
2. Water is dependable of flow magnitude of 6m3/s.

## Solution:

Q= 7.2 m3/s

g= 9.8m/s2

H= 103 km

e= 80%

= 0.8

p=eHqg

= 0.8*103*7.2*9.8

= 5814.14

## CONCLUSION:

Hence, the hydropower potential in terms of water resources for a given river was measured.