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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B3. Istanbul 2004 
  
Table 1: The characterictics of the Kholpetua basin area 
  
  
  
  
  
  
  
Basin Drainage Drainage pattern Tidal Soil Landuse/ 
Segment condition effect landcover 
Upper Level low, well | Meandering Free Silty clay loam Irrigated 
to moderate agriculture 
(ground water 
base) 
Middle to lower | Moderate to | Modified, under polder | Tidal Brakish & mixed, | Mainly shrimp 
middle low project calcarious & non- | faring, very 
calcarious, acid | limited 
sulphate soil agriculture 
Lower part Well, under | Anastomizing, well- | Strongly Saline, Silty clay & clay | Mangrove 
natural interconnected through | tidal 
condition multiple branching of the 
tidal creeks 
  
  
  
  
Anthropogenic Activities with in the Basin: 
Large-scale population increase, expansion of 
human settlements and intensive agricultural 
practices in the Kholpetua basin area has created the 
ground for major environmental transformation. The 
upper part of the Kholpetua basin area (Kolaroa) 
witnessed intense human pressure in the form of 
agriculture. 
The middle and lower mid basin area covering 
lower Satkhira, Debhata, Kaligonj and Shyamnagar 
area under polder/ coastal embankments, since early 
seventies. Being protected against regular tidal 
effects through polder/embankment, the land 
witnessed a transformation from paddy cum grazing 
agriculture to protected agriculture up till the middle 
of 80's, when shrimp farming was introduced. 
Originally, the whole area was under mangrove 
forest even in the late 18" centuries (Rennells 
1779). Fierce competition between low yielding rice 
cum grazing and shrimp within the semi-saline belt 
came into surface (DDP 1985). The local traditional 
agriculture practices are more of local demand 
driven; the shrimp farming, however, is more of 
international market demand based. 
4. Data: 
The study used mainly primary data, were includes 
remote sensing and hydrological data. Besides, 
some secondary data where gathered, like 
population, land use, infrastructure related 
information’s. Historical maps, like Renells map of 
1779 and Thuilier’s Map of 1872 were analyzed to 
record the extent of changes occurred in the 
mangrove forest. Digital images were processed and 
analyzed to identify and classify the basin area into 
different land use and land cover units. BWDB data 
Table 2: Main land use of the Kholpetua basin area 
on tidal records and embankment alignments were 
analyzed for documenting the nature and form of the 
changes occurred in basin landscapes. 
5. Environmental Changes in the Kholapetua 
Basin: 
Environmental changes of a landscape may be 
understood through a comparative analysis of land, 
water, atmosphere and its biotic condition of a 
period with a base period. In the present study, 
environmental changes related to land and water 
were analyzed only. According to B.B.S. (2001) the 
local population of the basin area has increased 
about 58 percent between 1981 to 2001. This extra 
population growth has impacted pressure on local 
resources, particularly on land use and land cover 
Changes in land use /land cover of Kholpetua 
basin area between 1967 to 2001 
The spatial and temporal changes occurred through 
1967 t0 2001 area recorded in figure 3 (land use and 
land cover 1967, 1988 and 2001) and the statistics 
of land cover are given in Table 2. It appears that 
over a period of 3 decades there has been a net gain 
in settlement areas at the cost of agricultural lands. 
Besides, a phenomenal increase in shrimp farming 
took place and on the other hand seasonal grazing 
land has declined. The northern extent of mangrove 
forest was about 20 km interiors as recorded in the 
Rennells map and Thuilier's 1872 map (Figure 4). 
The Debhata, Kaligonj, Asssasuni were at the edge 
of the Sundarbans. The present Shyamnagar upazila 
was well inside the mangrove forest. Unlike, other 
parts of Bangladesh, net water bodies have 
increased due to the expansion of shrimp farming. 
  
  
  
  
  
  
  
  
  
Type of Land use (hectare) 1967 1988 2001 
Settlement 32,318 49,925 56,789 
Agricultural land 79,395 52,637 53,328 
Shrimp farm - 76,839 98,595 
Fallow/ seasonal grazing 79,395 68,205 61,589 
Mangrove forest - 200,708 200,708 
Closed waterbodies 6,325 2,806 1,611 
River/Canal - 108,131 107,630 
  
  
  
  
  
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