Environmental Impact Study of a Pumped Storage Project on Hilly

Tract of Purulia, - A Remote Sensing GIS Analysis.

*@Abhisek Chakrabarty, ** Dilip Kumar Pal and *** Soumendu Chatterjee

*Lecturer, Dept. of Remote Sensing & GIS, Vidyasagar University, Midnapore-721102, W.B. India.

email: destination_abhisek@yahoo.co.in / abhisek@vidyasagar.ac.in

** Head, Department of Surveying & Land Studies,

The Papua New Guinea University of Technology, Lae, Papua New Guinea.

***Lecturer, Dept of Geography & Env. Management,

Vidyasagar University, Midnapore, W.B. India.

KEY WORDS: PPSP, Remote Sensing and GIS, Environmental Impacts Study, Cost Benefit

Analysis, Optimum Land and Water Use Planning, Sustainable Development.

ABSTRACT: The Purulia Pumped Storage Project (PPSP) on Kistobazar River of Ajodhya

Hills is developed to improve the peaking power scenario of West Bengal in India. The project

involves construction of two reservoirs with rock-fill dams comprising of central clay core, rock

crushing ground, cement mixing plant, staff quarters, service roads and disposal ground, which

in turn claimed a huge amount of forest and agricultural land. On the other hand stream

impoundment for filling the reservoirs created water scarcity in the canal fed agricultural land of

the downstream villages. This study attempts to find out the aerial extent of land use alteration,

and its consequent land degradation took place during the gestation period of the project (1998

to 2007). To accomplish this target a multi-temporal image analysis has been done with an IRS-

LISS-III data (GCR-23.5m) of 1999 and another IRS-LISS-IV MX data (GCR-5.8m) of 2005.

Hence a change detection map is prepared. This map reveals that the alteration of natural forest

and agricultural land to built-up area and permanent fallow were the most remarkable

happenings in this area. Cadastral map overlay on the change detection map clearly shows -

which private ownership lands are acquired by this project and which are simply damaged. Use

of SCS (NRCS) Curve Number method and Modified Universal soil Loss Equation (MUSLE)

helped to estimate the increase in runoff and soil erosion in the study area from 1999 to 2005.

Not only the physical impacts but also the economic and social impacts as a consequence of this

development are taken into consideration, and assessed with the help of “Questionnaire

Checklist” and “Leopold Matrix”. “Monetary Valuation” of all social and environmental

elements and Cost Benefit Analysis (CBA) are also done to judge the economic viability of this

project. Lastly an action plan for land use practices is prepared for the entire study area, which is

optimally suitable for the sustenance of the project and for the maintenance of the environmental

stability.

1.0 INTRODUCTION: The environmental impacts of a project are those resultant changes in

environmental parameters, in space and time, compared with what would have happened had the

project not been undertaken. The parameters may be any of the type of environmental receptors

like air quality, water quality, noise, levels of local unemployment and crime etc. (ref9). For

environmentally compatible and sustainable development In India, Ministry of Environment and

Forest (MoEF) is responsible for environmental concern. One such initiative is the notification

issued on 27 January 1994, making Environmental Impact Assessment (EIA) mandatory for 30

categories of developmental projects among which hydropower generation is significant one.

The main goal of EIA is to influence decision-making procedure of the project developers by

providing sound information on environmental impacts and the means for preventing or

reducing those impacts (ref1). In an advance stage of a project an environmentalist can only

investigate the impacts and take decision on mitigation measures. It is called Environmental

Impact Study (EIS), which is a systematic process that examines the environmental

consequences of development actions. The emphasis, compared with many other mechanisms

for environmental protection, is on mitigation of adverse impacts. Of course planners have

traditionally studied the impacts of developments on the environment, but invariably not in the

systematic, holistic and multidisciplinary way required by ElS.

Purulia is the western most district of West Bengal, India. The Purulia upland includes

the Baghmundi plateau, which is an extension of the Ranchi plateau of Chotanagpur region and

constituted by the granite-gneiss of oldest Precambrian or Archean formations. Among the

twenty Blocks of Purulia district Jhalda, Arsa, Baghmundi and Balarampur share the hilly tracts

of Ajodhya, with an average elevation of 600m. (ref6). In mid nineties the Government of West

Bengal along with the Major Japanese Corporate such as Mitsubishi Heavy Industries Ltd,

Taisei Corporation, Toshiba and Mitsui of Japan as well as Bharat Heavy Electricals Ltd. has

initiated the construction work for a 2952 crore pumped storage project named Purulia Pumped

Storage Project (PPSP) on the Kistobazar River, a tributary of Sobha River, in the southern

slope of Ayodhya hills (23°12′51′′N, 86°06′10″E). In future two additional Pumped Storage

Projects, i.e. Turga Pumped Storage Project (TPSP) and Kathlajal Pumped Storage Project

(KPSP), will be constructed on either side of PPSP (ref3).

Satellite remote sensing provides a reliable, accurate and updated database on land and

water resources, which is a prerequisite for change detection, environmental impact study and

optimal management of resources of a geographical area. As a demonstration of this concept the

newly built Purulia Pumped Storage Project (PPSP) of Ayodhya Hills and its surrounding area

of Baghmundi and Balarampur Blocks of Purulia, has been chosen as the study area for

Environmental Impact Study (EIS), land use planning and management for sustainable

development of the region. The study area consists of fourteen (14) micro-watersheds of the

southern slope of Ajodhya hills and foothill plains, and altogether form the physical boundary of

the area of interest. As physical boundary does not coincide with the administrative boundary,

mauza boundaries of Baghmundi and Balarampur Blocks covering the physical boundary

presumed as the administrative boundary of the study area. Thus Seventy-nine Mauzas

(villages) and four protected forest patches consisting of fourteen micro-watersheds are

considered as the ultimate study area (23°05′58′′N-23°15′01′′N, 85°58′11″E-86°12′22″E) of this

assignment (fig-1).

2.0 OBJECTIVES AND METHODOLOGY OF THE STUDY: There are three basic

objectives of this study. First one is the measurement of aerial extent of land use alteration, and

its consequent land degradation, that took place throughout the gestation period (1995-2005) of

the project. Change detection map was prepared by “Post Classification Comparison Change

Detection” (Jensen et. al. 1993), which shows changes in land use class for individual pixel and

also the no change pixels. This process needs two classified layers of same Ground Cell

Resolution (GCR). Therefore the LISS-IV data (5.8m) were degraded to match the resolution of

LISS-III data (23.5m). The “Degrade” command in ERDAS Imagine-8.6 is used to reduce the

resolution of an image by an integer factor in the X and Y directions. “Degrade” averages all of

the original "small" pixels that make up the new "big" pixels. These two classified layers of

same resolution are then compared pixel-by-pixel basis using RSI ENVI–4.3 software. A change

detection matrix also prepared with “To↔From” row and column, showing the aerial exchange

between major classes.

Photography and field survey for gully measurement helped to assess the level of land

degradation. In case of land degradation surface runoff and soil erosion of a particular region

will also increase. To fortify our findings, fourteen (14) micro watersheds are delineated inside

the study area from SOI toposheet, and runoff and soil loss from those micro watersheds, are

estimated for both the year 1999 and 2005. Detailed on the SCS Runoff Curve Number (CN)

method is described in Chapter-4 of National Engineering Handbook (NEH-4) of USDA Soil

Conservation Service (SCS 1969). SCS is nowadays known as NRCS i.e. Natural Resource

Conservation Service. The SCS runoff equation is given below (TR55, 1986).

Q=(P-0.3S)2/(P+0.7S)…………..………………[eq.-1]

Q is the daily runoff, P is daily rainfall, S is potential maximum retention after runoff

begins that is (25400 / CN) – 254, where CN refers to the runoff curve number of hydrologic

soil cover complex which is a function of soil type land cover and antecedent moisture

condition. Ia denotes initial abstraction before runoff begins, that can also be substituted by

0.3S. These all values are expressed in mm (ref2).

Computed runoff volume of different years generally shows some variation in their

means and standard deviations and thus become difficult to compare. Therefore these values are

standardized by “Z-Score” or Standard Score”.

Sediment yield for the year 1999 and 2005 also measured by using the ‘Modified

Universal Soil Loss Equation’ (MUSLE), proposed by Williams (1978). Because of the non-

availability of entire calculation procedure in metric system, FPS system is followed for this

equation and the result later converted to metric system. It follows the structure of the Universal

Soil Loss Equation (USLE) of Williams and Berndt (1972), with the exception that the rainfall

factor is replaced with the runoff factor. The equation calculates sediment yield from a 24hr

storm within each micro-watersheds of less than ten (10) square miles (ref9). The structure of the

MUSLE is:

A = B (Qv*qp)0.56

*K*LS*C*P ………………[eq.-2]

Where -

A=computed soil loss per unit area (tones / mile2)

Qv =volume of Runoff (acre-feet)

qp=peak flow rate (feet3/second)

K= soil erodibility factor (dimensionless)

LS=slope length & gradient factor (dimensionless)

C= cropping management factor (dimensionless)

P=erosion control practices factor (dimensionless)

B is a constant, and the value is 95 in FPS system and 11.8 in metric system.

A 24hr design storm of 105.4 mm for a recurrence interval of 5 years is calculated from

the analysis of 10 years (1996-2005) rainfall data of Baghmundi. The runoff (Q) from the design

storm is computed by SCS Curve Number method and the volume of Runoff Qv is obtained by

multiplying (Q) with the area of the micro-watershed.

Second objective of this study is the assessment of economic and social changes taken

place as a consequence of this development are taken into consideration. “Questionnaire

Checklist” method is adopted for identification of key impacts. Door-to-door household survey

in twenty-six (26) Mauzas (villages) surrounding the project sites (PPSP, TPSP and KPSP) is

done. Once the key impacts are short-listed; “Leopold Matrix” is used to assess the magnitude of

impacts of individual project actions on individual human environmental elements. This matrix

was developed for US geological survey by Leapold et al. (1971). It is based on horizontal lists

of project actions and vertical lists of environmental components. After few modifications of

“Leopold Matrix” fourteen (14) project actions, twenty-one (21) environmental components and

their 294 possible interactions are considered in this study.

Monetary values of tangible impacts were obtained by questionnaire survey in

households, markets and offices. Where as valuation of intangible impacts were done by taking

instances from other literatures or by using “Contingent valuation method” (CVM) where

people are asked what they are willing to pay for keeping ‘X’ or preventing ‘Y’, or what they

are willing to accept for losing ‘A’ or tolerating ‘B’ (ref14

). We have considered all the negative

impacts along with the project expenditure as a ‘cost’ of the project and all the positive impacts

including electricity generation as ‘benefit’. A balance sheet is prepared to get the value of the

total cost with respect to the total benefit.

Lastly it has been strived to prepare an action plan for optimum pattern and method of

land use for mitigation of those impacts. At first watershed prioritization map is prepared based

on the level of degradation taken place in each micro-watersheds. Study of present land use with

other attributes of the land and land capability classification is the second stage of this planning.

“Environmental Approach” is adopted for land capability assessment. In this approach the

capability of land is assessed by taking into account the overall environmental attributes (ref8).

The methodology essentially employs overlay analysis of different GIS layers e.g. satellite

Remote Sensing data to unravel the land use / land cover, geomorphology and soil properties to

assess the land capability. Also the annual range of temperature pattern of rainfall, slope, shape,

sizes and physiographic position of the micro-watershed plays a major role in deriving the

optimum land use plan. Mauza maps showing individual plot or land holding are overlaid on the

ultimate sustainable land and water use map and thus cadastral level action plan map is

prepared.

3.0 RESULTS AND DISCUSSION: Studying each and every impact minutely, it could be

concluded that alteration of land use land cover is the most remarkable upshot of these projects.

During 1995 to 2005 huge infrastructure development has taken place in the study area. Two

reservoirs with rock-fill dam, one power station, one cement mixing plant, three land bridge, 7

km of service roads surrounding Upper and Lower dam and 20 Km of repaired and widened

roads from Balarampur to Baghmundi, one twelve bedded hospital, one fire station, two office

building and fifty staff quarters are constructed in an around the PPSP project site. Most of these

are developed at the cost of 7.9 sqkm. of forest and 3.26 sqkm. of agricultural land of the study

area and twice the amount will be destroyed for construction of TPSP and KPSP. Not only built-

up areas were grown, but also fallow land has increased by 25.77%. Total environmental cost of

deforestation is estimated to be 15.73 billion rupees per year.

Runoff Estimation (SCS –CN) Soil Loss Estimation (MUSLE)

1999 (Total

rainfall 1029.8mm)

2005 (Total

rainfall 1057.6mm)

1999 (24 hr storm

105.4 mm / 4.15 inch)

2005 (24 hr storm

105.4 mm / 4.15 inch)

Micro

Water-

sheds

Runoff

Q

(mm) Z-Score

Runoff

Q

(mm) Z-Score

Micro

Water-

sheds

Soil loss

SY

(tons/Sqmile)

Soil loss

SY

(ton's/Hec)

Soil loss

SY

(tons/sqmile)

Soil loss

SY

(ton's/Hec)

MW1 211.63 0.828441 357.66 0.674555 MW1 4853.36 18.74 6684.31 25.81

MW 2 327.26 2.290095 505.33 2.197869 MW 2 599.06 2.314 1125.29 4.341

MW 3 74.36 -0.90676 191.22 -1.04238 MW 3 4091.08 15.79 2703.39 10.44

MW 4 166.48 0.257709 331.13 0.400881 MW 4 6889.00 26.59 15219.72 58.76

MW 5 240.56 1.194138 422.06 1.338884 MW 5 406.50 1.57 981.22 3.79

MW 6 89.64 -0.71361 234.1 -0.60005 MW 6 9663.14 37.31 12545.28 48.42

MW 7 211.67 0.828946 357.66 0.674555 MW 7 3974.40 15.34 5606.32 21.65

MW 8 186.61 0.512168 333.34 0.423679 MW 8 11163.92 43.10 17626.76 68.06

MW 9 42.28 -1.31228 151.99 -1.44707 MW 9 707.81 2.73 749.17 2.89

MW 10 83.93 -0.78579 221.88 -0.7261 MW 10 6283.94 24.26 7115.47 27.47

MW 11 53.28 -1.17323 166.17 -1.30079 MW 11 2464.85 9.52 2061.57 7.96

MW 12 98.66 -0.59959 246.59 -0.4712 MW 12 6909.16 26.68 5801.45 22.39

MW 13 109.14 -0.46711 260.94 -0.32318 MW 13 18276.49 70.56 17764.00 68.59

MW 14 149.8 0.046861 311.69 0.200345 MW 14 23594.24 91.09 21878.96 84.48

Table-1 Runoff and soil loss of the study area of 1999 and 2005.

Land degradation is in its peak at the project site. In micro-watershed No. 6 (project

site), from total annual rainfall of 1999, only 8.7% flowed as surface runoff. But in 2005,

22.13% of total rainfall ran over the surface. Soil loss estimation from a 24hr design storm also

revealed that in 1999 the soil loss was 37.31tons/hac from micro-watershed No. 6 but in 2005 it

increased to 48.42 tons/hec. Micro-watershed No. 7, the downstream agricultural land of PPSP

generated very low amount of sediment (15.34 tons/hec) in 1999 but in 2005 conversion of

agricultural land to fallow land increased the soil loss to 21.65 tons/hec (Table-1). Increase in

runoff and soil erosion indicates land degradation. Massive gully erosion visualise the fact.

Spatial extent of the gullied lands estimated to be 3.46 sq km. In some cases maximum width

and depth of the gullies are found to be more than 4m. Few minor landslides in the hill slopes,

because of removal of underneath lateral support by rock quarrying made them totally exposed

to weathering.

The animal communities of Ajodhya hills were also affected by land use alteration.

Migratory elephants that were trying to migrate from the Saranda to Ayodhya Hills were

stopped due to the PPSP project activities. Migration for food is essential for the elephants.

Because of this obstacle they are facing the threat of extinction and becoming aggressive.

From economic point of view it has been found that during the last ten years more than

thousands of local people have got jobs in this project. At present 265 regular staff and 682

casual labours, are working in the construction site and in future approximately 300 permanent

staff will run the Project. Beside this direct employment roughly 100 people engaged in

transport sector and 50 people as daily use commodity supplier for the workers are also

indirectly employed in this project. These employees will earn 47.05 million rupees annually.

Infrastructure and public utility services are also better than before and 162 million rupees are

invested for that. But at the same time forestland acquisition and deforestation has weakened the

forest-based economy of the hills and about 898 households of 16 villages are suffering from

that and at the same time it has increased illegal deforestation in the adjoining forests which is

another negative impact of this project. 1403 households dependent on agriculture in

downstream areas also adversely affected by stream impoundment. Supply of irrigation water,

15-28 cusecs for Kharif and 10-12 cusecs for Rabi crops, for 60.25 hec of multi-crop land are

totally stopped after 2005. Influx of outsiders with comparatively higher purchasing power

created a price hike for all daily use commodities and native villagers are suffering from that.

Altogether the inhabitants of the study area are loosing 96.52 million rupees annually.

From social point of view transformation of a forest based agrarian economy to an urban

industrial economy affected the physical and mental health of the local people. Till date 14

labours died in accidents at the construction site. Sound of heavy vehicles and stone blasting is

creating a lot of noise in the relatively noise free zone of Purulia; dry dust from the roads and

crushing stones are creating smog; cement mixing plant near the Lower dam polluting the water

of KIP reservoir. These all are detrimental to the health and hygiene of the villagers. They have

lost many traditional values and customs of their society. Alcohol addiction among local people

is now greater than before. Increase in social crime is also another noticeable fact. Total social

cost of the project is estimated to be 1.03 billion rupees per year.

From monetary valuation and cost benefit analysis it may be concluded that if we

consider only the tangible annual cost (Rs.7642.3367 million) and benefit (Rs.8371.12 million)

of the project, the project appears to be economically viable and profit making too. An annual

profit of 728.8 million rupees is observed. But when we add the intangible cost and benefit with

the tangible one, the total annual cost of the project goes to 23475.4 million rupees, where as

total annual benefit remains 8727.12 with a deficit of 14748.28 million rupees per year. Thus in

an economist’s point of view this project is viable but to an environmentalist it is a destructive

one. Still considering the ever-growing demand of electricity instead of only criticizing the

project we must try to find out the mitigation measures to reduce these adverse environmental

impacts.

4.0 SUGGESTIONS FOR FUTURE LAND USE AND ECONOMIC PRACTICES: To

mitigate the adverse impacts of the project on the environment and the economy of the area the

first step should be immediate afforestation / replantation in the deforested lands by

Participatory Forest Management (PFM) involving rural communities in planning, management

and rejuvenation of degraded forests. Forests of that region will not only provide fuel, fodder

and other minor forest products but also have the potentiality of development of ecotourism near

the dams and water falls of Ajodhya hills. Therefore few strategies like involvement of local

administration in site selection for ecotourism; social forestry and participatory forest

management; formation of co-operative societies to produce agro-horticultural and animal

products, operating restaurants and tourist canteens; employment of local people specially

women in the tourism sectors; encouraging local folk cultures and their inclusion in tour

packages; expenditure of 50% of annual profit from ecotourism in protection of forests and

forest animals etc., are to be adopted for development of ecotourism in Ajodhya hills.

In the agricultural lands of the catchment where water is scarce and immature laterite is

the dominant soil, surface water harvesting and Agro-forestry / Agro-hortipasture is advised.

Intimate and interacting association of agricultural crops and woody perennials will prevent soil

erosion and reduce siltation in the reservoirs. In the stony wastes of structural hills, shrubs and

grasses could be grown for fodder and for road or building materials rock querying could be

done where necessary. The double-cropped lands of the canal fed down stream area are to be

allotted for intensive agriculture. Loamy soil with alluvium is suitable for agriculture. The

deficit of irrigation water must be compensated by ground water exploitation. In the adjoining

single cropped area where soil moisture content is less agro-horticulture, floriculture or cash

crops will be the best suit. In Rabi season when the lands are left fallow, it should be utilized for

fruit, flower, vegetable and fodder production. Other than two reservoirs of PPSP pisciculture

and aquaculture should be practiced in the remaining water bodies. Comparatively elevated

grounds are to be used for settlements and other constructions. Artificial rainwater harvesting

structures and ground water recharge structures (including percolation tank) are proposed to

build up in all the settled areas as well as in office and school compounds. Cadastral level action

plan maps are prepared for twenty-six (26) Mauzas covering PPSP, TPSP and KPSP project

sites, but because of space limitation only the action plan map of Bareriya (Fig-2C) is displayed

here.

5.0 CONCLUSION: It cannot be presaged how much these Pumped Storage Projects will

improve the level of peak power scenario of West Bengal, but from the above study it is obvious

that PPSP has caused a great damage to the environment and economy of the study area. Cost

benefit analysis also shows that this type of project in this drought prone region is not

economically viable if we consider the intangible costs that the society and environment have

already paid. Therefore immediate mitigation measures are required to restore environmental

stability and ensure economic prosperity of this region. Only intimate interaction, consultation,

and co-ordination, of Government Officials with local inhabitants can materialize these plans.

Otherwise the entire project will pass through a great phase of uncertainty.

References:

1. Agrawal Mohan Lal, Dixit Anil Kumar and Ghosh Mrinal Kanti (2003), Impact Assessment on Soil Erosion due to Highway Construction using GIS. Dept. of Civil Engineering Indian Institute of

Technology Kharagpur (W.B.), India. http://www.ejge.com/2003/Ppr0339.html

2. Anonymous (1986), TR-55. Computation of Runoff for Small Watersheds, U.S. Dept. of Agriculture

(USDA), Natural Resource Conservation Service (NRCS), Conservation Engineering Division –

Technical Release-55 (210-IV-TR-55, 2nd Ed. June-1986).

3. Anonymous (2003), West Bengal State Electricity Board (WBSEB), Purulia Pumped Storage Project (PPSP). http://www.ppsp-wbseb.com

4. Anonymous (2006), Ananda Bazar Patrika 24th Dec, 2006. 6 Prafulla Sarkar St. Kolkata – 700001.

(Editor – Abhik Sarkar). http:// www.anandabazar.com.

5. Balaszczynski Jacek (2003), Estimating Watershed Runoff and Sediment Yield Using a GIS Interface

to Curve Number and MUSLE Models. BML Science & Technology Center–Denver, Colorado, USA.

http://www.bml.gov/nste/resourcenotes/resnotes.html.

6. Bhattacharya Birendra Kr., Roy P, Chakrabarty B.R, Sengupta S, Sen N.N, Sengupta K.S, Mukherji

S and Maity T (1985), West Bengal District Gazetteers - Purulia. Published by Narendra Nath Sen,

State Editor, WB. Distt. Gazeeteers.

7. Bhattacharya Swaroop (2005), The Purulia Pumped Storage Project: People, Environment Suffer for

Uncertain Peaking Power. Published in Dams, Rivers & People (SANDRP) Sep-Oct. 2005.

http://www.sandrp.in/hydropower/prlia-artcle.pdf

8. De N.K & Jana N.C. (1994), The Land, Multifaceted Appraisal & Management. Sribhumi Publishing

Co. Kolkata.

9. Glasson John, Therivel Riki and Chadwick Andriw. (1999), Introduction to Environmental Impact

Assessment 2nd Ed. Spon press, London.

10. Panda Tapan K, Mishra Sitikantha, Parida Bivraj Bhusan (2004), Tourism Management – The

Socioeconomic and Ecological Perspective 1st Ed. Orient Longman Pvt. Ltd. Hyderabad.

11. Rajora Rajesh (1998), Integrated Watershed Management – A Field Manual for Equitable,

Productive and Sustainable Development. Rawat publication, Jaipur & New Delhi.

12. Singh V.P. (1994), Elementary Hydrology 1st Ed. Prentice-Hall of India Pvt.Ltd. New Delhi-110001.

13. Tiwari K.N, Kumar P, Sebastian M and Pal D.K (1991), Hydrological Modeling for Runoff

Determination. Water Resource Development Vol.7, No.3. Sep-1991, Butterworth – Heinemann Ltd.

14. Vanclay Frank, Bronstein D.A. (1995), Environmental and Social Impact Assessment 1st Ed. John

Wiley and Sons, England.