Use of Helicopter in Preinvestment Survey of Forest Resources, India

The paper deals with the scope of using a helicopter in inventory work in difficult or inaccessible forest areas and the experience gained in this field in the Preinvestment Survey of Forest Resources Project in India. It is for the first time that a helicopter has been used in India to assist in inventory work in inaccesible terrain. It has been found that there is an ample scope for developing this technique which could introduce more efficiency and economy in forest inventory work. Besides, the use of a helicopter would be an asset in training photo interpreters and field crews to locate field plots, check the stratification of forest areas on aerial photographs and also to check photointerpretation work by frequent visits to the forest areas. A limited use of a helicopter would also be for delineation and stratification of forest areas and for general reconnaissance purposes. An area of nearly 6000 square kilometres was selected in the Central Zone out of which nearly 40% was inaccessible. A systematic sampling design was laid out and there were 768 plots of 1/10th hectare size to be inventoried. Out of these 376 plots were actually laid out on the ground and enumeration of tree growth over them completed within a short period of 20 days by using a helicopter for reaching all the plots which were inaccessible by road.