Tuesday, December 3, 2013



 STORM WATER DRAINAGE NETWORK IN DIGHA

Absence of a properly implemented drainage system is causing adverse effect on the hygienic condition in the town of Digha. The drains are too few and were constructed mainly to flush out excess water during high tides. More importantly, the drains also are carrying sullage water and the polluted water is discharged into the sea causing appreciable deterioration in the quality of sea water.

It is a fact that the area lying near the sea coast is mainly of silty sand allowing high rate of percolation of surface run off to ground for which widespread water logging is not in evidence in the area till now, yet with the town getting more populated day by day, incidence of tourists visit looking up along with hotels and institutional buildings getting concentrated in localized area, the need for commissioning an engineered drainage system has been badly felt to discharge the water efficiently into the sea without causing any harmful effect on the environment.


Such a drainage system will exclude any chance of water logging and at the same time will offer a clean and pleasant look for the town. Covered surface drains, to be built with brick masonry and concrete cover, have been designed and planned for implementation at Digha only to collect the surface run off and carry the water by gravity flow.
Sankarpur, being sparsely populated and having a very few hotels / lodges all surrounded by vast expanse of agricultural lands, has been left out of such drainage facility at present.
Construction of storm water drains is an allowed item under CRZ regulation.
To take care of the septic waste separate scheme under PHED has been developed for setting up of STP and development of underground sewerage lines.
For the storm water drainage scheme under DSDA, the project area is basically divided into 2 parts, one the seaside, and the other landside of the foreshore road. The seaside being sloped towards the sea, so it was advisable to follow the outfall at “Jatra Nala” the major outfall of this area.

But the seaside of the old Digha is too far to drain it to this Nala. Considering the proposed landscape of the beach front it was not advisable to drain it to the sea. It will be diverted towards the landside along the main road leading to the major outfall of the landside that is the canal along the newly constructed bye-pass. Most of the landside portions naturally tend to slope towards the drainage canal of the bypass making it an easy and natural drainage system without the help of any mechanical means.
As per the available data, an average intensity of rainfall of 50 mm/hr has been considered. The design has been done as per the rainfall data collected, time of concentration, the graph of the CPHEEO manual and the empirical formulas developed for the most towns situated in the Indian plains.                       
As per CPHEEO manual the residential, commercial and greenery has 75%, 90% and 20% respectively of imperviousness.


Considering the proposed development according to the CRZ rules, it was assumed that the project area will be divided into different zones.
·         Zone 1 : Already built to an average of 30-40% and will remain same.
·         Zone 2 : Already built to an average of 50-60% but considered to be 80% in future.
·         Zone 3 : Very less built form, with public buildings and so may develop to 30% built form in future.
·         Zone 4 : Existing open and green area on sea which will remain to be green (20%).
·         Zone 5 : Heavily built new digha area of average 50-60% but considered to be 90% in future.
·         Zone 6 : Existing open and green area on sea which will remain to be green (20%).
·         Zone 7 : Village area, but most prospective area for controlled development (30%).
Masonry covered drains has been considered for the storm water drainage of the project area. Considering the size of the drains, widths of the road, it has been proposed to cover the drain with precast perforated RCC slab. Cast iron gratings have been avoided considering theft, the cost aspect as well as the weathering effect of the sea. The size, number, orientation of the drains has been done absolutely as per Individual road conditions.
The different conditions of the drains are as follows.
·         Narrow roads will have one side drain with adequate RCC slab to take normal load.
·         RCC underground box drains to cater to the localized thumps of the road due to land form.
·         Totally RCC culvert type drains with flared ends at major road crossings.
·         Drop drains at steep fall in level of the road and invert level beyond 60 cm to maintain the self-cleansing velocity.
·         Ground levels, probable type of future development considered in designing the size and level of proposed drains.
·         No lifting / pumping station has been proposed.
·         The maximum ratio of 1:2 (width : depth) of the drain has been maintained all throughout the area for easy maintenance, construction and to avoid blocking of drains.
·         The major roads will have both side drains to facilitate better inlet of rainwater, as well as easy connection to individual plots.
The storm water drain have been designed with sufficient capacity to avoid frequent flooding of the drainage area and not designed for the peak flow of rare run of such as once in 50 years or more. There may be flooding when any natural calamity occurs or when the precipitation exceeds the design value, which has to be permitted. Though such flooding causes inconvenience, it may have to be accepted once in a while considering the cost economy.
.......................................

Friday, April 19, 2013


Wildlife Rescue Operation

Operation carried out by the team of officials’ from Forest Directorate, engaged in the implementation of ICZM Project, West Bengal

Ecology will lose its balance if the variety and volume of wildlife is destroyed. We all know it. But, unfortunately human activities do play an important role in extinction of wildlife varieties from the face of earth. Poaching is the deadliest crime committed against wildlife by humankind. Thus, any conservation initiative should have measures to regulate and stop illegal hunting of wild animals.   

Forest Directorate, West Bengal has taken up anti-poaching measures in coastal areas of East Midnapore under ICZM Project West Bengal. 

One anti-poaching van is purchased by Directorate of Forest, West Bengal under ICZM Project West Bengal. Forest officers from different ranges are utilizing the van for carrying out wildlife rescue the operations in Purba Medinipur.

 

Name of rescued animal
Conservation status
by IUCN
Found/caught at -Forest Range
Rehabilitated/
released at
-      Forest Range
Rescued Zone - Forest Range
Olive Ridley Turtle (Lepidochelys olivacea)
 
Endangered-National
 
 
Bhadua village, Marichda, Purba Medinipur
Shankarpur rehabilitation centre, Purba Medinipur
Bajkul and Contai
Gangetic dolphin (Platanista gangetica)
Bhagwanpur, Purba Medinipur
Rupnarayan river, Kolaghat
Bajkul
Russell’s viper (Daboia russelii)
----
Tamlik, Purba Medinipur
Lodhashuli jungle, Paschim Medinipur
Tamluk
Lesser adjacent stork (Leptoptilos javanicus)
 
Hatiberia, Haldia, Purba Medinipur
Jhargram, Paschim Medinipur
Haldia
Monkey
------
Panshkura, Purba Medinipur
Lodhashuli jungle, Paschim Medinipur
Panshkura
Fishing Cat (Prionailurus viverrinus)

Endangered (IUCN 3.1)
Khejuri, Purba Medinipur
Kadirabadchar mangrove, Purba Medinipur
 
Bajkul
Brydes Whale (Balaenoptera brydei)
Data Deficient (IUCN 3.1)
Digha Mohana
Skeleton will be preserved by Zoological
Survey of India
Tamluk

 




 

Monday, February 18, 2013

WHALE ON THE SHORE
 
 
 
A Bryde’s Whale was dragged accidentally onto the shore of Digha by the fishing trawlers. the entire sequence of events was painfull.... the tragic accident that took place underneath the sea ( Bay of Bengal) had shaken the sensibilities of the coastal community. The  video clip tries to portray what may have happened under the sea.......... 
 
 
 
 
 
 
 
Scientific information about Bryde’s  Whale

Family: Balaenopteridae, Order: Cetacea, Class : Mammalia

Scientific name : Balaenoptera edneni Anderson, 1878

                               Balaenoptera  brydei

Morpho-taxonomic characters:

Head ‘V-shaped’, three prominent ridges on the head anterior to blowhole, forty five ventral pleats / throat- furrows extend up to naval/umbilicus,  baleen fringes coarse, stiff and thick.

Total length is 41.4 ft (curved measurement), matured male, dorsal fin moderate in size and located posterior one-third of back and black in colour., pectoral flippers oblong and black in colour, tail fluke horizontally flattened and grey in colour.

From literature:   

Average weight about 13.6ton, group size is 1-7 individuals, baleen is 42x24cm in size, 230-370 plates on each side, 15-35 bristles per sq.cm, female is slightly larger than male

Food: Krills, bonito and cephalopods

Distribution: Generally found in tropical and warm temperate waters of the world (between 40°N and 40°S latitude), both off and close to the shore. Recorded from Sri Lanka (Trincomalee and Koddiyar Bay), Arabian Sea off Pakisthan, Persian Gulff and Bay of Bengal during 1977-87).

Threats : It has been subjected to coastal whaling off Peru, Chile, S. Africa, Japan, USSR etc., and pelagic whaling in N. Pacific and S. Atlantic.
Commercial value: Oil,meat, blubber and collagen peptide are of commercial use. About 1.660 tonne of oil and 9.3 tonne of usable products were obtained from one animal.