CONTENTS Page No. CHAPTER 1 INTRODUCTION 1.1 LOCATION OF THE PROJECT 1-1 1.2 BACKGROUND 1-1 1.2.1 Previous Studies 1-2 1.2.2 NHPC Proposal 1-2 1.2.3 Work after Submission of PFR 1-3 1.3 PROJECT AREA 1-3 1.4 TAWANG CHHU RIVER 1-3 1.5 POWER POTENTIAL OF TAWANG BASIN 1-4 1.6 ALTERNATIVE SITES FOR STAGE-I 1-4 1.6.1 Barrage Structures 1-4 1.6.2 Powerhouse Alternatives 1-5 1.7 SALIENT FEATURES 1-5 1.8 CONSTRUCTION SCHEDULE 1-9 1.9 SCOPE OF THE STUDY 1-10 1.10 POLICY, LEGAL & ADMINISTRATIVE FRAMEWORK 1.10 1.10.1 Policy Framework 1-10 1.10.2 Legal Framework 1-11 1.10.3 Administrative Framework 1-12 CHAPTER 2 CONCEPT AND METHODOLOGY 2.1 INTRODUCTION 2-1 2.2 METHODOLOGY 2-2 2.2.1 Study Area 2-3 2.2.2 Surveys 2-3 2.2.3 Physiography 2-4 2.2.4 Geo-physical Aspects 2-4 2.2.5 Hydrometeorology 2-4 2.2.6 Land use and Land cover 2-5 2.2.7 Soil 2-6 2.2.8 Forest Types and Floristics 2-7 2.2.9 Faunal Elements 2-8 2.2.10 Aquatic Ecology, Water Quality, Fish & Fisheries 2-9 2.2.11 Air Environment & Noise Level 2-11 2.2.12 Socio-economic Aspects 2-11 2.3 ASSESSMENT OF IMPACTS 2-12 CHAPTER 3 PHYSIOGRAPHY 3.1 INTRODUCTION 3-1 3.2 DRAINAGE NETWORK 3-1 3.2.1 Tawang Chhu 3-2
3.2.2 Mago Chhu 3-3 3.2.3 Nyukcharong Chhu 3-4 3.2.4 Drainage network within 10km radius from Barrage site and Power house site 3-5 3.3 LAKES AND RESERVOIR 3-6 3.4 STREAM GRADIENT OF TAWANG CHHU AND ITS TRIBUTARIES 3-9 3.5 DIGITAL ELEVATION MODEL 3-10 3.6 RELIEF 3-10 3.7 SLOPE 3-11 3-8 ASPECT 3-12 3.9 INFLUENCE ZONE (POWER HOUSE SITE AND BARRAGE SITE) 3-12 3.9.1 Slope 3-13 3.9.2 Aspect 3-13 3.9.3 Relief 3-13 CHAPTER 4 HYDRO-METEOROLOGY 4.1 INTRODUCTION 4-1 4.2 CATCHMENT CHARACTERISTICS 4-1 4.3 GENERAL CLIMATIC CONDITIONS 4-2 4.4 DATA AVAILABILITY 4-3 4.5 RELATIVE HUMIDITY 4-4 4.6 TEMPERATURE 4-4 4.7 WATER DISCHARGE AND AVAILABILITY 4-5 4.7.1 Water Flow Pattern 4-5 4.7.2 Snow Cover 4-7 4.8 RAINFALL 4-7 4.9 RAINFALL RUNOFF ANALYSIS 4-8 4.10 WIND SPEED/ WIND DIRECTION 4-9 4.11 SEDIMENTATION 4-9 4.12 ENVIRONMENTAL IMPLICATION 4-10 CHAPTER 5 GEOGOLOGY & SEISMICITY 5.1 REGIONAL GEOLOGY 5-1 5.1.1 Sela Group 5-5 5.1.2 Lumla Formation 5-6 5.2 GEOLOGY AROUND PROJECT COMPONENTS 5-7 5.2.1 Barrage site 5-7 5.2.2 Head Race Tunnel 5-8 5.2.3 Powerhouse site 5-9 5.2.4 Reservoir 5-9 5.3 SEISMOTECTONICS AND SEISMICITY 5-10 5.3.1 Earthquake Studies 5-11
CHAPTER 6 SOIL 6.1 INTRODUCTION 6-1 6.2 SOIL RESOURCES MAPPING 6-1 6.2.1 Catchment Area 6-2 6.2.2 Influence Zone 6-2 6.2.3 Project Area 6-2 6.3 SOIL CHARACTERISTICS 6-3 6.3.1 Physical Characteristics 6-3 6.3.2 Chemical Characteristics 6-4 6.3.3 Biological Characteristics 6-4 CHAPTER 7 LAND USE AND LAND COVER 7.1 INTRODUCTION 7-1 7.2 OBJECTIVE 7-1 7.3 CATCHMENT AREA 7-2 7.4 DATABASE 7-2 7.5 METHODOLOGY 7-2 7.6 CLASSIFICATION SCHEME 7-4 7.7 LAND USE/ LAND COVER 7-4 7.8 STUDY AREA (POWER HOUSE SITE AND BARRAGE SITE) 7-5 7.9 SUBMERGENCE AREA 7-6 CHAPTER 8 FLORISTICS AND FOREST TYPES 8.1 INTRODUCTION 8-1 8.2 FOREST TYPES 8-2 8.2.1 East Himalayan Sub-tropical wet hill forests 8-2 8.2.2 Himalayan sub-tropical pine forests 8-3 8.2.3 East Himalayan Wet temperate forests 8-3 8.2.4 East Himalayan mixed coniferous forests 8-3 8.2.5 Alder forests 8-4 8.2.6 Low level blue pine forests 8-4 8.2.7 14 Sub-alpine Rhododendron forests 8-4 8.2.8 Birch-Rhododendron scrub forests 8-4 8.2.9 Dwarf Rhododendron scrubs 8-5 8.2.10 Alpine pastures 8-5 8.3 VEGETATION PROFILE IN THE INFLUENCE ZONE 8-5 8.3.1 Area between Yusum and Tenali (near Tawang) 8-5 8.3.2 Area between Laho and Jang 8-6 8.3.3 Area between Forebridge and Jang village 8-6 8.3.4 Area beyond Jang and its environs 8-6 8.4 FLORISTICS OF PROJECT AREA 8-7 8.4.1 Submergence Area 8-7 8.4.2 Vegetation around Barrage site 8-8 8.4.3 Power House Site 8-8
8.5 COMMUNITY STRUCTURE 8-11 8.5.1 Density and Basal area 8-12 8.5.2 Species Diversity 8-20 8.5.3 Plant Biodiversity 8-21 8.6 LOWER PLANT DIVERSITY (CRYPTOGAMS) 8-21 8.7 FOSSIL RECORD FROM THE CATCHMENT AREA 8-23 8.8 TAXONOMIC DIVERSITY 8-24 8.9 RARITY AND ENDEMISM 8-24 8.10 EPIPHYTES 8-25 8.11 PARASITIC FLORA 8-25 8.12 PHYSIOGNOMIC DIVERSITY 8-25 8.13 PHYTOGEOGRAPHY 8-26 8.14 ECONOMICALLY IMPORTANT PLANTS 8-27 8.14.1 Medicinal Plants 8-27 8.14.2 Food Plants 8-28 8.14.3 Fodder Plants 8-29 8.14.4 Timber Trees and Fuelwood 8-29 8.14.5 Miscellaneous uses 8-29 CHAPTER 9 FAUNA 9.1 INTRODUCTION 9-1 9.2 SPECIES DISTRIBUTION IN THE CATCHMENT & INFLUENCE ZONE 9-2 9.2.1 Mammals 9-2 9.2.2 Avian Fauna 9-5 9.3 HERPETOFAUNA 9-13 9.4 BUTTERFLIES AND OTHER INVERTEBRATES 9-13 9.5 ANIMAL SIGHTINGS IN PROJECT AREAS 9-14 9.5.1 Mammals 9-14 9.5.2 Avifauna 9-14 9.5.3 Butterfly species 9-16 9.6 CONCLUSION 9-17 CHAPTER 10 AQUATIC ECOLOGY & WATER QUALITY 10.1 INTRODUCTION 10-1 10.2 AQUATIC ECOLOGY 10-1 10.2.1 Physical & Chemical Characteristics 10-1 10.2.2 Biological Characteristics 10-3 10.2.3 Community Structure 10-3 10.3 WATER QUALITY 10-8 10.4 FISH & FISHERIES 10-12 10.5 FISH COMPOSITION 10-12 10.5.1 Snow trout 10-12 10.5.2 Brown trout 10-13
10.5.3 Loaches 10-13 10.5.4 Cat fish 10-13 10.5.5 Sisorids 10-13 10.6 ADAPTIVE CHARACTERISTICS IN THE FISH SPECIES 10-14 10.6.1 Streamlined shape 10-14 10.6.2 Development of suckers 10-14 10.6.3 Special attachment device 10-14 10.6.4 Flattening of the body 10-15 10.7 FISHERIES 10-15 10.8 FISH MIGRATION 10-15 10.9 LIKELY IMPACTS 10-16 10.9.1 Habitat Alteration 10-16 10.9.2 Exotic Trout 10-16 10.9.3 Deterioration of Water Quality 10-17 10.10 FISH LADDER 10-17 CHAPTER 11 AIR ENVIRONMENT 11.1 INTRODUCTION 11-1 11.2 AMBIENT AIR QUALITY 11-2 11.2.1 Traffic Density 11-2 11.2.2 Air Pollution 11-2 CHAPTER 12 SOCIO-CULTURAL & ECONOMIC PROFILE 12.1 INTRODUCTION 12-1 12.2 ARUNACHAL PRADESH 12-1 12.3 HISTORY OF ARUNACHAL PRADESH 12-3 12.4 TAWANG DISTRICT 12-6 12.5 HISTORY OF TAWANG DISTRICT 12-7 12.6 ADMINISTRATIVE CIRCLES OF PROJECT AREA 12-8 12.6.1 Demography 12-8 12.6.2 Educational Profile 12-8 12.6.3 Crop and Occupation Pattern 12-9 12.6.4 Other Amenities 12-9 12.7 AFFECTED VILLAGES 12-10 12.7.1 Demography 12-10 12.7.2 Educational Profile 12-11 12.7.3 Cropping and Occupation Patterns 12-12 12.7.4 Other Amenities 12-13 12.8 AFFECTED FAMILIES 12-14 12.8.1 Demographic profile 12-14 12.8.2 Education profile 12-15 12.8.3 Occupation pattern 12-16 12.8.4 Livestock 12-17 12.8.5 Vulnerability 12-18
12.8.6 Quality of Life 12-19 12.8.7 Public Perception 12-27 CHAPTER 13 ASSESSMENT OF IMPACTS 13.1 INTRODUCTION 13-1 13.2 PREDICTION OF IMPACTS 13-1 13.2.1 Terrestrial Ecosystem 13-2 13.2.2 Aquatic Ecosystem & Downstream Impacts 13-5 13.2.3 Anthropogenic Impacts 13-8 13.2.4 Socio-economic Environment 13-8 13.2.5 Impacts on Wildlife 13-10 13.2.6 Impacts on Air Environment and Sound Levels 13-11 13.2.7 Geo-physical Impacts 13-11 13.3 IDENTIFICATION OF IMPACTS 13-12 13.3.1 Construction Phase (Short Run Impacts) 13-12 13.3.2 Operational Phase (Long Run Impacts) 13-12 13.3.3 Negative Impacts 13-13 13.3.4 Positive Impacts 13-13 13.3.5 Local (Area specific) Impacts 13.14 13.3.6 Strategic Impacts 13-14 13.3.7 Major Impacts 13-14 13.3.8 Minor Impacts 13-14 BIBLIOGRAPHY 1-5 ANNEXURES (I-III) PLATES
LIST OF TABLES Table 1.1 Table 1.2 Table 3.1 Table 3.2 Table 3.3 Table 3.4 Table 3.5 Table 4.1 Table 4.2 Table 4.3 Table 4.4 Table 4.5 Table 5.1 Table 6.1 Table 6.2 Table 6.3 Table 7.1 Table 7.2 Table 8.1 Table 8.2 Table 8.3 Table 8.4 Table 8.5 Table 8.6 Table 8.7 Table 8.8 Table 8.9 Table 8.10 Table 9.1 Table 9.2 Table 9.3 Table 9.4 Table 10.1 Table 10.2 Table 10.3 Alternative sites studies for Tawang H.E. Project Salient features of the proposed Tawang Chhu H.E. Project Drainage network of the Tawang Chhu River and catchment characteristics in western Arunachal Pradesh Gradient profiles of the Tawang Chhu and its tributaries Elevational range and corresponding area of Tawang H.E. Project catchment Slope categories and their areas in the Tawang H.E Project catchment Aspect categories and their areas in the Tawang H.E Project catchment Discharge data availability status of G&D sites Relative humidity at Tawang The 10-daily discharge of Tawang Chhu river at barrage site Average monthly rainfall data (mm) in project catchment Rainfall-runoff correlation at Murga Bridge Earthquake history of the area in 300 km vicinity of the project area Soil groups and their characteristics in Tawang H.E. Project Physical and chemical characteristics of soil at different sites Fungal and bacterial communities in the soils of different sites of Tawang H.E. Project Database used for land use and land cover mapping of the Tawang Chhu catchment Area (ha) of the different categories of land use/ land cover in the Tawang H.E. Project List of flowering plants in submergence area Some of the common pteridophytes of submergence area of Tawang H.E. Project Various ecological attributes of trees and shrubs in the project area Various ecological attributes of herbaceous vegetation in the project area Species Diversity Indices (H) for different vegetation components at different sampling sites in Tawang H.E. Project Number of herb species encountered on three project sites in different seasons Some of common pteridophytes in the influence zone of Tawang H.E. Project Some important medicinal plants of project area List of some common useful plant species of the project area List of Gymnosperms and Angiosperms of study area of Tawang H.E. Project Distribution of mammals in the catchment and the surrounding areas of the proposed Tawang H.E. Project Avifaunal composition of catchment and the surrounding areas of the proposed Tawang H.E. Project stage-i Species composition of avifauna recorded from the project areas of Tawang H.E. Project Butterfly species and their relative abundance in the project areas and its close vicinity Physico- and chemical characteristics of water of Tawang Chhu River Densities of different biotic communities in Tawang Chhu River Species composition and range of relative abundance in the benthic and plankton
communities Table 10.4 Generic composition in macro-invertebrates of Tawang Chhu near the proposed barrage site Table 10.5 Permissible limit of various parameters of surface water quality, prescribed by CPCB Table 10.6 Composition and conservation status of fish fauna of Tawang Chhu in Arunachal Pradesh Table 11.1 Traffic density in the impacted zone of Tawang H.E. Project area Table 11.2 Air quality in the impacted zone of proposed Tawang H.E. project area Table 11.3 Average Sound/Noise level (in db) at various sites of surrounding area of the proposed project Table 11.4 National ambient air quality standards as per CPCB Table 12.1 Demographic profiles of administrative circles of project area of Tawang H.E. Project Table 12.2 Literacy rate of administrative circles of project area of Tawang H.E. Project Table 12.3 Occupation pattern of administrative circles of project area of Tawang H.E. Project Table 12.4 Demographic profile of affected villages Table 12.5 Literacy profile in affected villages Table 12.6 Occupation pattern in the affected villages Table 12.7 Demographic profile of project affected families Table 12.8 Education status in project affected families Table 12.9 Occupation pattern in the project affected families Table 12.10 Livestock population in the project affected families Table 12.11 BPL families and vulnerable persons in the project affected families Table 12.12 Mode of energy consumption among the project affected families Table 12.13 Village-wise list of affected khatedars / landowners
LIST OF FIGURES Figure 1.1 Location map of Tawang H.E. Project Figure 1.2 Layout map showing various activities of Tawang H.E. Project Figure 2.1 Sampling sites of different parameters of the proposed Tawang H.E. Project Figure 2.2 Inputs and outputs related to evaluation of impacts Figure 3.1 Drainage map of Tawang Chhu up to proposed barrage site of Tawang H.E. Project Figure 3.1(a) Drainage map of the influence zone of the proposed Tawang H.E. Project Figure 3.2 Stream gradient profile of the Tawang Chu river and its tributaries in Tawang district, Arunachal Pradesh, NE India. Figure 3.3 Digital Elevation Model (DEM) of the proposed Tawang H.E. Project Figure 3.4 Relief map of Tawang chhu catchment area of the Tawang H.E. Project Figure 3.5 Slope map of the catchment area of Tawang H.E. Project Figure 3.6 Aspect map of the Tawang H.E. Project up to the proposed dam site Figure 3.7 Slope map of Influence zone of the proposed Tawang H.E. Project Figure 3.8 Aspect map of Influence zone of the proposed Tawang H.E. Project Figure 3.9 Relief map of Influence zone of the proposed Tawang H.E. Project Figure 4.1 Average relative humidity measured at Tawang Figure 4.2 Average monthly minimum and maximum temperature at Tawang Figure 4.3 Average 10-daily discharge at various sites of Tawang Chu basin Figure 4.4 Average monthly water discharge at proposed barrage site for different years Figure 4.5 Monthly rainfall variation in the Tawang Chhu catchment area Figure 5.1 Geological Map of Arunachal Pradesh Figure 5.2 Geological plan of project area Figure 5.3 Siesmotectonic map of Northeast India showing Tawang H.E. Project catchment area Figure 5.4 Seismic Zoning map of India Figure 6.1 Soil map of the Catchment area of Tawang H.E. Project Figure 6.2 Soil map of Influence zone of the proposed Tawang H.E. Project Figure 7.1 False color composite (FCC) generated from IRS-P6 LISS-III, November 2005 of influence zone of the proposed Tawang H.E. Project Figure 7.2 False color composite (FCC) generated from IRS-P6 LISS-III scene, November 2005 of Tawang H.E. Project up to the proposed barrage site Figure 7.3 Flow diagram for land use/ land cover classification Figure 7.4 Land use/ land cover map of the catchment area of the proposed Tawang H.E. Project Figure 7.5 Land use/ land cover map of influence zone of the proposed Tawang H.E. Project Figure 7.6 Land use/ land cover map of the submergence area of the proposed Tawang H.E. Project Figure 10.1 Physical and chemical characteristics of Tawang Chhu