Before starting with the actual work of population projection it is important to have a look at the factors that are going to have a bearing on the population count:

• Gelephu is a major market place for the nearby hinterlands of Bhutan, as well as India and secondary towns like Sarpang and Damphu.
• Gelephu with the dual advantage of better and established connectivity with the sub-continent and its proximity to the proposed Asian Highway connecting India and countries of East Asia, coupled with the increased connectivity provided by the proposed Sibsu-Daipham highway with the other parts of Bhutan has a great potential for economic related development in the region. Feeder roads will develop to the Trongsa and Bumthang region, north of Gelephu. This will also increase the use of its economic and social infrastructure.
• The proposal of a Special Economic Zone between Gelephu and Sarpang will increase future population.
• Projection of Gelephu town as a major growth center in South Central Bhutan will increase population.
• Likeliness of Gelephu acting as second road entrance to Bhutan for commercial as well as tourist purposes will increase population.
• Likeliness of Gelephu being converted to Dzongkhag Headquarters of the Sarpang Dzongkhag in future and as an important commercial node in South-central Bhutan, thus inviting a considerable amount of floating population.
• Proposal of a Dry port, an Airport and a Rail head in Gelephu will increase population.
• Continued strife in India will reduce population growth.

The population projection of Gelephu, as put forth in this report, is an outcome of using a combination of the first two methods of population projection mentioned in the earlier part of this chapter (i.e) Trend Analysis Method and Induced Growth Rate Method. The first method would help in projecting the population based on the current rate of growth, while the second method would assist us in adding to the population projection the increased population as an out come of the induced activities like the Special Economic Zone, Airport, Dry port, Rail head, tourism etc. What is equally important to be realized is the need for the population projection to be done in two parts; medium term planning and long term planning. The activities attracting the population would be added one by one as they are phased to be executed as per the final Structure Plan time schedule.