Symposium on Remote Sensing for Resources Development and Environmental Management / Enschede / August 1986 
Studies on human interference in the Dhaka Sal (Shorea robusta) 
forest using remote sensing techniques 
Md.Jinnahtul Islam 
Bangladesh Space Research and Remote Sensing Organization (SPARRSO), Agargaon, Sher-e-Bangla Nagar 
ABSTRACT: Bangladesh ie one of the most densely populated countries in the World. Because of the increasing 
population her demand for land and food are increasing day by day. Consequently the human interference on the 
forest areas are also increasing. The landless peasants encroach the forest areas cut and remove trees over 
night and convert forest land into dwelling houses and agricultural fields. In the hilly forests, the forest 
vegetation of the plateaus and valleys are cleared and terraced for cultivation. The present investigation 
indicates that fresh encroachment by raising new huts and clearing new forest areas for cultivation are going 
on thus causing severe problem. The objectives of this study are to identify on the aerial photographs and 
Landsat imagery the agricultural lands, villages, huts, ponds and market places in and near the forest area. 
The work also includes collection of data on human resources. The compilation of the data and information 
will be useful for development, management and protection of forest vegetation. The data will also be useful 
for the study of the human and economic resources of the environment. 
1 INTRODUCTION 
The Dhaka forest is a tropical moist deciduous forest. 
This is one of the oldest natural forest of Bangla 
desh. It is situated between 23°50' and 24°25' North 
Latitude and 90°10' and 90 40' East Longitude. The 
forest tract exists in 200 Mouza of 30 Union Councils 
of Sadar North Subdivision of Dhaka District. It is 
situated only 20 miles away from the Dhaka Metropo 
litan city towards the North direction. The Dhaka 
forest is a pure Sal (Shorea robusta) coppice forest 
stands on the raised hillock like scattered patches 
of land. Besides the Sal (Shorea robusta) other 
species like Dhaman (Grewia species) Gandhi Gazaril, 
Amloki, Palash, Bohera, Kuteswar (Holerhena antidy- 
sentrica), nonkata (Randia dumetorum), khutikat 
(Glochindion velutinum), Gadila (Careya arborea), 
Piralu (Randi uliginosa) etc. are found to be sca 
ttered in the forest. Along the edges of the forest 
various kinds of herbs and shrubs are also found to 
grow along with Sal. Wild life have already been 
eradicated from the forest area without some minor 
species of birds and animals. The forest patches are 
of different size extending up to the maximum size 
of 500 acres. Some of them have only few trees and 
some of them have converted into scrub forest. The 
forest is inextricably mixed with habitation and 
agriculture. 
The mean maximum temperature of the area were 
found to be 85 F over the last ten years. The mean 
annual rainfall were found to be 70 inches over the 
same period. The relative humidity ranges from 96$- 
41$ during the early and late hours of the day time. 
Thus the climate of the area may be taken as mode 
rately humid and the area always remain pleasant. 
Due to high population density and subsequent 
loss of ecosystem the forest area has lost its ori 
ginal cover density and vigour. The changes has been 
taken place mainly due to human interference in the 
forest. The type, cause and the result of human 
interference has been discussed in the main context. 
2 HUMAN INTERFERENCE 
Illegal encroachment and thereby deforestation of 
the forest land is the worst type of human inter 
ference in the forest. The increasing rate of the 
propulation has created severe land hunger in the 
area. For the increased pupulation more lands are 
required for habitation and cultivation. The arable 
lands are already insufficient and the habitation 
are thickly populated. As a result they do not find 
any other alternative way without clearing some forest 
land adjoining their agricultural land and homesteads 
to meet a portion of their demand. Some times they 
clear lands in the deep forest areas and start a new 
settlement. As the forest is inextricably mixed with 
habitation and scattered in small patches, the pro 
tection of the forest from the encroachers is very 
difficult by limited number of forest staff whose 
head quarters are miles away. The sudden change of 
Government and their policies, the disturbance period 
during the sixties, the liberation war of 1971 and 
the subsequent deterioration of law and order situa 
tion in the country exerted substancial influence 
upon this forest area. A s a result about one third 
of the total area of the forest went under the illegal 
possession of the encroachers. 
Illicit felling and pilferage of forest produces 
is another type of human interference in the forest. 
As there is no large industry and cottage industry, 
unemployment problem is increasing day by day with 
the increase of population. The landless and unemploy 
ed people finding no other alternative way of earning 
their livings, gradually practice to collect forest 
produces by illicit felling and selling them in the 
near by market. Due to excessive price of the forest 
produce they become habitual smuggler. 
The fuel problem of the people living in the forest 
area is another cause of deforestation. They do not 
get gas and electricity for their daily common use. 
Naturally they have to depend upon the fire wood to 
meet up their coocking fuel, A s the fuel wood is out 
of their buying capacity they generally extract them 
from the forest. Besides the fire wood they also 
collect the house posts and thatching material from 
the forest. A s a result a vast area has been converted 
into scrub forest of little value. 
3 AGRICULTURAL FRACTICE IN THE FOREST 
It has been stated that the forest area is an undulat 
ing landscape consisting of high lands locally called 
"chalas" which are intercepted by numerous narrow 
depression called "Baid". The chalas look like float 
ing islands over the areas. The forest crop and the 
habitation exist on these chalas. The "Baids" are used 
as paddy field. Both the Aus and transplanted Aman are 
practiced there. On the "chalas" fruits and seasonal 
vegetables are grown. Due to insufficiency of agri