3.1 INTRODUCTION CHAPTER 3 REMOTE SENSING & GIS STUDIES Remote Sensing (RS) data can be considered an essential data source for the appraisal of natural environments as it provides valuable information for interpreting the landscape. This technology has already demonstrated its capabilities to provide information on natural resources such as crop patterns, land use, soils, forest etc on periodic basis. Multispectral characteristics of RS data provide an opportunity to explore intricate details of the area which are not available by normal surveys. Repeated coverage of RS data provides the capability to study both spatial and temporal changes in a region. Similarly, Geographic Information System (GIS) is the latest tool available to store, retrieve and analyze different types of data for management of natural resources. It facilitates systematic handling of data to generate information in a devised format. Thus, it plays an important role in evolving alternate scenarios for natural resources management. Combination of RS and GIS provide multi-dimensional information for mapping of an area. The scope of work in the present study includes rectification and georeferencing of satellite images pertaining to years 2000 and 2009-10, preparation of maps for the area including maps of land use/ land cover, major streams and tributaries etc. using satellite imageries and topographic maps, marking the location of hydropower projects, their area of influence and other features in the Alaknanda and Bhagirathi basins. RS and GIS based analysis has been carried out to provide vital inputs for detailed assessment of cumulative impact of Hydropower Projects in Alaknanda and Bhagirathi basins. 3.2 PROCUREMENT OF SURVEY OF INDIA TOPOSHEETS Survey of India toposheets at the scale of 1:50,000 and 1:250,000 were also used in the study. Toposheet nos. 53I, 53J, 53M, 53N, 62B (5 nos.) at 1:250,000 scale and toposheet nos. 53I/12, 15, 16, 53J/1, 2, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 53M/ 3, 4, 8, 12, 53N/1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 62B/1, 2, 3, 4 (41 nos.) at 1:50,000 scale were used to collect spatial and topographical characteristics of the area. Toposheets at 1:50,000 scale provided better details and information about the area included in the catchment of Alaknanda and Bhagirathi. Although these toposheets provided good planimetric controls and height information, but the available toposheets were surveyed in different years quite some time back. Therefore, latest information about roads and river courses were obtained using satellite images of latest available dates to get the updated spatial data about the project areas.
3.3 PROCUREMENT OF SATELLITE DATA Indian Remote Sensing Satellite s (IRS) Linear Imaging and Self Scanning Sensors (LISS-III and LISS-IV) images have been used for the study. LISS-III sensor images at 23.5 m spatial resolution have been used for study of the entire area of Alaknanda and Bhagirathi basins. LISS-III data has four multispectral bands pertaining to green, red, near infrared (NIR) and short wave infrared (SWIR) wavelengths, which are useful for preparation of land use land cover maps. LISS-III satellite data from IRS P6 and IRS 1D satellites have been procured from National Remote Sensing Centre (NRSC), Hyderabad after browsing the NRSC website for availability of satellite data for required sensor/ date/ area and verifying for minimum cloud cover. Satellite images of two time periods of year 2000 and 2009 have been procured for evaluating the impact of hydropower projects with respect to time. LISS- III data procured and used in the present study is listed in Table 3.1. The spatial extent (layout) of individual LISS-III images pertaining to years 2000 and 2009 are shown in Figs 3.1 and 3.2, respectively. Table 3.1 LISS-III data used for the present study. S. No. Satellite Sensor Path-Row Date 1. 1 D L-3 096-049 28-Oct-2000 2. 1 D L-3 097-049 03-May-2000 3. 1 D L-3 097-050 30-Sep-2000 4. 1 D L-3 098-049 27-Sep-2000 5. 1 D L-3 098-050 27-Sep-2000 6. P 6 L-3 097-049 23-Oct-2009 7. P 6 L-3 097-050 23-Oct-2009 8. P 6 L-3 098-049 28-Oct-2009 9. P 6 L-3 098-050 28-Oct-2009 IRS P-6 LISS-IV data has also been procured for the year 2008-10 to study in detail important hydropower projects. LISS-IV data has three multispectral bands pertaining to green, red and near infrared (NIR) wavelengths, at a better spatial resolution of 5.8 m. It is used for preparation of land use land cover maps for the areas surrounding the HPs. It has relatively lesser swath of 23.5 km, therefore availability of LISS-IV data is some what uncertain for a particular time period. Hence, in case good quality cloud free LISS-IV data pertaining to year 2010 for a particular area was not available, data for year 2009 or 2008 was procured. Area above 4000 m elevation, is covered with snow and glaciers, hence it has not been considered for detailed study. LISS-IV data procured for the present study is listed in Table 3.2. The year 2000 was chosen as base line data as no big hydropower projects had been constructed in the area by then and 2009 data was used for comparison purpose. These two data sets were considered sufficient as the intervening period of 10 years is the period in which construction has taken place on most hydropower projects in the area.
Figure 3.1 Spatial Layout of IRS 1D LISS-III Images (Year 2000).
Figure 3.2 Spatial Layout of IRS 1D LISS-III Images (Year 2009).
Table 3.2 LISS-IV data used for the present study. S. Satellite Sensor Path-Row Date No. 1. P 6 L-4 102-020 16-Nov-2008 2. P 6 L-4 202-027 15-Dec-2008 3. P 6 L-4 102-017 08-Jan-2009 4. P 6 L-4 101-005 19-Apr-2009 5. P 6 L-4 101-006 19-Apr-2009 6. P 6 L-4 102-003 16-Nov-2009 7. P 6 L-4 202-021 23-Apr-2010 8. P 6 L-4 102-016 28-Apr-2010 3.4 GEOREFERENCING AND MOSAICING OF SATELLITE DATA Satellite data has been checked for radiometric errors and basic corrections for radiometry for line dropout and striping have been applied. Individual scenes of the satellite data are georeferenced with respect to the Survey of India topographic maps and limited control points from GPS (Global Positioning System). 2 nd order polynomial transformation was used to achieve higher accuracy in georeferencing. This polynomial requires 6 or more ground control points (GCPs) for geometric rectification of satellite data. To ensure better geometric fidelity of the images minimum twenty GCPs, well distributed spatially, have been used for each satellite image. Lambert Conforma1 Conic (LCC) projection system and Modified Everest datum have been used for georeferencing satellite images. LCC is a conical projection, which has good compatibility with polyconic projection of topographic maps, therefore seamless images are obtained after georeferencing and mosaicing. The georeferenced satellite images have been mosaiced using the histogram matching technique for radiometric balancing among the various satellite images. Also, feathering option has been used while mosaicing to get the seamless boundaries between different satellite images. 3.5 PREPARATION OF DEM, SLOPE AND ASPECT MAPS The area under study being an intricate hilly area, DEM (Digital Elevation Model) from ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) at 30 m planimetric resolution has been used. This DEM has good resolution for overlaying and viewing the geographical features over 3-D to have a better visualisation for the terrain for analysts and decision makers. DEM helps in delineating the different slope values with respect to individual cell/pixel of the DEM image. A slope angle or slope percentage has been calculated for each pixel in the raster DEM map, as shown in the figure below: Profile h d h Slope angle in percentage = 100 d Slope angle in degree ( ) = tan 1 h d
where, h is the height difference between two points and d is the distance between them on the map. The slope map has been prepared using ArcMap software. A 3 x 3 pixel window (each pixel being 30 m square) is used to calculate the slope at each pixel. For a pixel, at location (x,y) the elevations around it are used to calculate the slope. The slopes are calculated for x and y directions, then average slope is calculated for that pixel. Aspect (slope direction) map is an image file that is coded according to the prevailing direction of the slope at each pixel. Aspect is expressed in degrees from North direction, clockwise, from 0 to 360. A value of -1 o or 361 is used to identify flat surfaces such as water bodies. Calculation of aspect value has been performed by using a 3 x 3 window around each pixel of the slope map to calculate the prevailing direction it faces. Aspect values are recoded as continuous values from 0 to 360, where 0 aspect denotes the North direction, 90 aspect denotes the East direction, 180 aspect denotes the South direction, and 270 aspect denotes the West direction. The other aspect angles are the values in between these prominent directions. For understanding, the aspect values of 338 360 and 1 22 can be assigned as North direction. Similarly aspect values of 23 67, 68 112, 113 157, 158 202, 203 247, 248 292, 293 337 can be assigned as North-East, East, South-East, South, South-West, West, North-West directions, respectively. The relief, slope and aspect maps of the study area are given as Figs. 3.3, 3.4 and 3.5, respectively. 3.6 PREPARATION OF DATA LAYERS Different spatial layers (thematic maps) for topographic and man-made features were prepared in the GIS environment using satellite images and ancillary data. The non-spatial database is also created for these layers by inserting the related attribute information. The following major thematic maps are prepared. Some of these maps are given in the relevant chapters. 3.6.1 Preparation of Soil map Soil maps at the scale of 1:500,000 prepared by National Bureau of Soil Survey and Land Use Planning (NBSSLUP), Nagpur have been used. The maps have been georeferenced with respect to LISS-III satellite image and the relevant soil classes pertaining to the catchment area have been digitized. 3.6.2 Preparation of Drainage map Drainage map has been prepared using the LISS-III satellite data of year 2009. At some places, where the drainage is not clearly identified due to shadow and relief effect on the satellite image, the drainages were modified by using the information available in topographic maps. The drainages are also available in topographic maps, but these maps were prepared in years 1965 to 1975, therefore in order to get the updated river network, the drainages are marked over satellite image of 2009 (Fig. 3.6).
Figure 3.3 Relief Map of the Study Area (Using ASTER DAM)
Figure 3.4 Slope Map of the Study Area (Using ASTER DEM)
Figure 3.5 Aspect Map of the Study Area (Using ASTER DEM)
Figure 3.6 Drainage Network and Catchment of Major Rivers
3.6.3 Delineation of catchment and sub-catchments of Alaknanda and Bhagirathi Basins Alaknanda and Bhagirathi are the two major tributaries of Ganga river. Their catchment has been delineated using the ASTER DEM and the drainage map by Arc GIS software. Initially, the sink or depression areas in the DEM raster have been filled to remove small imperfections in the data. Then on the basis of relative slopes between the cells/pixels, flow direction is determined. Flow accumulation grid and feature pour point raster have been prepared using these data. Now the location of catchment outlet has been decided for the Alaknanda and Bhagirathi rivers, which is Devprayag in the current study. Using the above data, output map watershed is delineated in raster format, which is converted into vector to make the catchment boundary. The catchment boundary of Alaknanda and Bhagirathi basin has been overlaid on all the major thematic maps. Similarly, sub-catchments have also been delineated for other tributaries of Alaknanda and Bhagirathi rivers eg. Bhilangna, Mandakini, Dhauliganga, Birahi Ganga, Nandakini and Pinder (Fig. 3.6). 3.6.4 Preparation of other spatial maps Other features like road network (Fig. 3.7), hydropower project sites, district headquarters and towns, transmission line network are plotted over the satellite images and topographic maps. A GIS database has been created for all these layers. 3.6.5 Preparation of base map A base map has been prepared using topographic maps and satellite images, by including the information about major roads, major rivers, location of major towns and hydropower projects etc. This map has necessary information for the use of other team members, which have analysed various aspects of impact of hydropower projects in this region. This map has also been useful for various teams who have carried field visits for collecting ground data related to the study. 3.6.6 Preparation of land use land cover map The satellite images have been processed for the preparation of land use land cover map. Supervised classification has been performed on LISS-III data of year 2000 and 2009, using the training samples collected from limited ground truth data. Major classes delineated are dense forest, open forest, water bodies (including rivers, lakes etc.), sand, other vegetation/ agriculture, snow, settlement etc. The digital classified map has been verified for the accuracy assessment for major land use classes present in the area and land use land cover map has been finalized. A land use land cover map has also been prepared by supervised classification of LISS-IV data of year 2008-10 for the above mentioned classes. This map has more details to facilitate the in-depth analysis of the chosen large hydropower project sites. The land use land cover maps for year 2000 and 2009 are shown in Fig. 3.8 and 3.9, respectively.
Figure 3.7 Road Network of the Study Area
Figure 3.8 Land Use Land Cover Map (Year 2000) (Using LISS-III Images)
Figure 3.9 Land Use Land Cover Map (Year 2009) (Using LISS-III Images)
3.6.7 Change Detection for year 2000 and 2009 The new state of Uttarakhand came into existence on 9 th November 2001, as the 27 th state of the union of India. Creation of the new state resulted in tremendous growth in infrastructure and economy. New districts have been created with increase of administrative setup. Road network has been enhanced causing larger inflow of tourists and migrant labour. Therefore, change in land use is a cumulative effect of all these developments as well as coming up of hydropower projects. During the period of 2000 to 2009, three major hydropower projects have been completed and work on about ten projects have been taken up. Satellite images of year 2000 and 2009 have provided extensive information on land use land cover changes in the span of ten years. Prominent change in this decadal period is the formation of huge reservoir of Tehri dam. A few other hydropower projects have been commissioned before 2009. The forest areas have encountered only marginal changes. However, statistical comparison of land use in 2000 and 2009 could not be made due to constraints of satellite data. Since the satellite data procured was of different seasons (May to October for year 2000 and October for year 2009), hence results of comparison should be viewed with this limitation in mind. The 23.5 m spatial resolution of LISS-III sensor data is optimum for this work, as ground details at this level will be clear for delineating and mapping ground features. However, the swath (width of one scene of the satellite data) of LISS-III data is 141 km, while the catchment area is quite large in comparison to the size (141 km x 141 km) of a single scene of LISS-III. Therefore, a mosaic of different scenes of LISS-III data needs to be generated. Himalayan region is normally full of clouds for major part of the year and since optical (visible and near infrared) wavelengths can t penetrate clouds; it becomes difficult to get good quality cloud free satellite scenes for the entire area of interest with minimum time gap. Thus the LISS-III scenes procured for the study have considerable time gap, which has induced the change in dynamic land cover e.g. snow etc. It has created a statistical imbalance in the extent of the features delineated and the change detection could not be carried out effectively. Also, scientifically it is not appropriate to compare scenes of different season for different years, since there is a seasonal variation in land use land cover of the same year. 3.7 URBAN SPRAWL ANALYSIS OF MAJOR CITIES LYING IN THE BASIN AREA It has been observed that major cities of Uttarakhand lying in the basin area of Alaknanda-Bhagirathi have expanded considerably during the past decade, especially after the formation of Uttarakhand state. A brief account of growth of a few cities on the basis of analysis of satellite images of year 2000 and 2009-10 given below. 3.7.1 Srinagar Considerable change in the urban area has been observed in Srinagar town. It has become an education hub. Chouras campus of HNB University has also come up in the last decade. Urban areas have expanded for almost the entire city, with increase in density of built-up area for all parts of the city. There has been a decrease in vegetated areas in the vicinity of the city. Agricultural areas have also been reduced. A few minor
landslides have been witnessed in the surroundings of the city, which may be triggered by natural factors. 3.7.2 Tehri Tehri area has witnessed maximum change in the last decade of the twentieth century. With the commissioning of the Tehri Hydropower project in year 2006, the formation of reservoir on Bhagirathi river was started which has become a large lake with an area of 42 sq.km. by year 2010. Only marginal change has been observed in the New Tehri town (from the year 2000 onwards since major construction activity had already been completed by that time) in terms of enhancement in the built-up area. Density of vegetation has appeared to be slightly on the lower side. No major landslide has been witnessed in the surroundings of the city. 3.7.3 Uttarkashi Appreciable changes have been observed in Uttarkashi town, with considerable increase in settlements along the Uttarkashi - Chinyalisaur road and Uttarkashi - Gangotri road. Density of built-up area has also increased. The Maneri-Bhali Phase-II project has been completed and there is a remarkable increase in settlements and other activities in that area. There has been a reduction in agricultural areas, while a marginal decrease in vegetated area has also been observed. A major landslide is visible on the Varunavart hill. 3.7.4 Gopeshwar Gopeshwar is the district headquarters of Chamoli. It has gone through marginal changes. It is observed that most of the urban sprawl has taken place towards the southern side or towards the Gopeshwar - Chamoli road, although density of the builtup area has increased for almost the entire town. There is an appreciable change in areas covered with vegetation, while areas under agriculture appeared to have marginally increased. No major landslide is visible in the vicinity of the town due to natural or developmental activities. 3.7.5 Joshimath Joshimath is an important town, as it is considered as the first halt for pilgrims of Char Dham Yatra who are heading towards the Badrinath shrine. It is also the gateway of Hemkunt Sahib, one of the most important religious places for Sikhs. Joshimath has also seen only a marginal change in terms of development of the town. Density of the built-up area has not increased much. The town has witnessed some expansion towards the northern side, in the direction of Joshimath - Vishnuprayag road (one reason may be due to commissioning of the Vishnuprayag Hydropower project) and towards the eastern side in the direction of Joshimath - Tapovan road. There isn't any appreciable change in the vegetated area in and around the town. A few minor landslides are visible towards the eastern side of the town towards Tapovan, which may be trigged due to widening of the Joshimath-Tapovan road.
3.8 ASSESSMENT OF LAND USE LAND COVER CHANGES IN THE VICINITY OF SELECTED HYDROPOWER PROJECTS Area of influence of hydropower projects has been delineated along the river on the basis of subjective assessment of the possible impact of HP on the surroundings. A rectangular region covering an area approximately 5 km upstream (U/S) and 5 km downstream (D/S) of the river in the buffer of about 1 to 2 km on either side of the river, has been considered for the study of impact of HPs. However, for a few large HPs, e.g. Tehri HP, Srinagar HP etc., a larger region has been covered as the area of influence for that particular project. At the same time, if appreciable impact is not visible on the U/S and D/S side, a smaller area has been considered. An index map of areas of LISS IV images is given in Fig. 3.10. 3.8.1 Bhilangna Hydropower Project Assessment of land use land cover changes has been carried out for the area surrounding the Bhilangna Hydropower Project using the IRS 1D LISS-III image of September 2000 and IRS P6 LISS-IV image of April 2010. 12.32 sq.km. area surrounding the hydropower project, 3.5 km U/S and 5 km D/S, has been taken as the approximate influence area of the HP. Both images have been georeferenced. Their geometric fidelity with respect to each other is also checked. Since the spatial resolution of LISS-III image is 23.5 m, this image has been resampled to 5 m pixel size in order to get pixel by pixel comparison of LISS-III of year 2000 and LISS-IV image of 2010 and to obtain a difference image for the land use land cover changes. A brief account of the land use land cover classes surrounding the Bhilangna Hydropower Project in year 2000 and 2010 has been given in Table 3.3. Table 3.3 Comparison of area under various land use land cover classes surrounding the Bhilangna Hydropower Project for year 2000 and 2010 Class Area (%) Sep. 2000 Apr. 2010 Dense Forest 5.36 3.33 Open Forest 65.01 68.09 Scrub 25.97 20.85 Water Body 2.46 2.36 River Bed 1.22 5.36 Total 100.00 100.00 Land use land cover map of the area surrounding the Bhilangna Hydropower Project prepared by using LISS-IV image of year 2010, is shown in Fig. 3.10(a).
Figure 3.10 Index Map of Areas of LISS-IV Images
3.8.2 Maneri Bhali - I and Maneri Bhali - II Hydropower Projects Land use land cover change assessment for the area surrounding the Maneri Bhali - I and Maneri Bhali - II hydropower projects using the LISS-III image of October 2000 and LISS-IV image of November 2008 has been carried out. 9.49 sq km area surrounding the Maneri - I hydropower project and 11.05 sq.km. area surrounding the Maneri - II hydropower project have been taken as the approximate influence areas of the HPs. Satellite images for both projects have been georeferenced. Their geometric fidelity with respect to each other is also checked. Since spatial resolution of LISS-III image is 23.5 m, this image has been resampled at 5 m pixel size in order to get pixel by pixel comparison of LISS-III of year 2000 and LISS-IV image of 2008 and to obtain a difference image for the land use land cover changes. A brief account of land use land cover classes surrounding the Maneri Bhali - I and Maneri Bhali - II Hydropower Projects in year 2000 and 2008 has been given in Tables 3.4a and 3.4b. Table 3.4a Comparison of area under various land use land cover classes surrounding the Maneri Bhali - I Hydropower Project for year 2000 and 2008. Area (%) Class Oct. 2000 Nov. 2008 Dense Forest 7.68 10.67 Open Forest 63.89 53.09 Scrub 20.64 22.44 Water Body 0.78 2.99 River Bed 7.06 10.82 Total 100.00 100.00 Table 3.4b. Comparison of area under various land use land cover classes surrounding the Maneri Bhali - II Hydropower Project for year 2000 and 2008. Area (%) Class Oct. 2000 Nov. 2008 Dense Forest 19.19 27.32 Open Forest 64.80 44.69 Scrub 12.40 19.27 Water Body 2.00 2.57 River Bed 1.60 6.15 Total 100.00 100.00
Land use land cover map of the area, surrounding the Maneri Bhali I and Maneri Bhali - II Hydropower Projects prepared using LISS-IV image of year 2008, has been shown in Fig. 3.10(b). 3.8.3 Alaknanda Hydropower Project Assessment of land use land cover changes has been carried out for the area surrounding the Alaknanda Hydropower Project from the LISS-III image of September 2000 and LISS-IV image of April 2009. An area of 8.12 sq km surrounding the hydropower project has been taken as the approximate influence area of the HP. Both images have been georeferenced. Their geometric fidelity with respect to each other is also checked. Since the spatial resolution of LISS-III image is 23.5 m, this image has been resampled to 5 m pixel size in order to get pixel by pixel comparison of LISS-III of year 2000 and LISS-IV image of 2009 and to obtain a difference image for the land use land cover changes. A brief account of land use land cover classes surrounding the Alaknanda Hydropower Project in year 2000 and 2009 has been given in Table 3.5. Table 3.5 Comparison of area under various land use land cover classes surrounding the Alaknanda Hydropower Project for year 2000 and 2009. Class Area (%) Sep. 2000 Apr. 2009 Dense Forest 13.79 12.46 Open Forest 20.92 22.93 Scrub 48.75 49.93 Water Body 2.75 3.93 River Bed 0.08 0.12 Snow 13.80 10.63 Total 100.00 100.00 Land use land cover map of the area, prepared using LISS-IV image of year 2009, surrounding the Alaknanda Hydropower Project has been shown in Fig. 3.10(c). 3.8.4 Tehri Stage - I and Tehri Stage - II Hydropower Projects Land use land cover change assessment has been carried out for the area surrounding the Tehri Stage - I and Tehri Stage - II Hydropower Projects from the LISS-III image of September 2000 and LISS-IV image of April 2010. Tehri Hydropower project has a large reservoir, therefore its influence area is covered in two LISS-IV images dated 23 Apil 2010 and 28 April 2010. Thus a mosaic of two images of year 2010 has been taken in the analysis. 217.50 sq.km. area surrounding the hydropower project, (16 km U/S for river Bhagirathi and 19 km U/S for river Bhilangna; 4 km D/S after the confluence of Bhagirathi and Bhilangna rivers) has been taken as the approximate influence area of the HP. Both images have been georeferenced. Their geometric fidelity with respect to each other is also checked. Since the spatial resolution of LISS-III image is 23.5 m, this image has been resampled to 5 m pixel size in order to get pixel by pixel comparison of LISS-III of year 2000 and LISS-IV image of 2010 and to obtain a difference image for land use land cover
changes. A brief account of land use land cover classes surrounding the Tehri Stage - I and Tehri Stage - II Hydropower Projects in year 2000 and 2010 has been given in Table 3.6. Figure 3.10(a) Land Use Land Cover Map of the area surrounding Bhilangana and Tehri I & Tehri II Hydropower projects, prepared by using IRS P6 LISS-IV Satellite Image of April-2010
Figure 3.10(b) Land Use Land Cover Map of the area surrounding Maner Bhali I & Maneri Bhali II Hydropower projects, prepared by using IRS P6 LISS-IV Satellite Image of Nov-2009
Table 3.6 Comparison of area under various land use land cover classes surrounding the Tehri Stage-I and Tehri Stage - II Hydropower Projects for year 2000 and 2010. Class Area (%) Sep. 2000 Apr. 2010 Dense Forest 17.75 5.35 Open Forest 59.65 71.55 Scrub 21.30 13.78 Water Body 1.21 8.19 River Bed 0.09 1.14 Total 100.00 100.00 It has been observed that there is a manifold increase in the area under water body. It is due to the formation of reservoir of Tehri dam, which did not exist in year 2000. Land use land cover map of the area, prepared using LISS-IV image of year 2010, surrounding the Tehri - I and Tehri - II Hydropower Projects has been shown in Fig. 3.10(a). 3.8.5 Srinagar Hydropower Project Assessment of land use land cover changes has been carried out for the area surrounding the Srinagar Hydropower Project from the LISS-III image of September 2000 and LISS-IV image of January 2009. An area of 50.10 sq.km. surrounding the hydropower project, 2.5 km U/S and 13.5 km D/S has been taken as the approximate influence area of the HP. Both images have been georeferenced. Their geometric fidelity with respect to each other is also checked. Since spatial resolution of LISS-III image is 23.5 m, this image has been resampled to 5 m pixel size in order to get pixel by pixel comparison of LISS-III of year 2000 and LISS-IV image of 2009 and to obtain a difference image for land use land cover changes. A brief account of land use land cover classes surrounding the Srinagar Hydropower Project in year 2000 and 2009 has been given in Table 3.7. Land use land cover map of the area, prepared using LISS-IV image of year 2009, surrounding the Srinagar Hydropower Project has been shown in Fig. 3.10(d). Table 3.7. Comparison of area under various land use land cover classes surrounding the Srinagar Hydropower Project for year 2000 and 2009. Class Area (%) Sep. 2000 Jan. 2009 Dense Forest 28.52 25.20 Open Forest 62.02 55.83 Scrub 8.64 11.74 Water Body 0.32 0.51 River Bed 0.50 6.74 Total 100.00 100.00
Figure 3.10(c) Land Use Land Cover Map of the area surrounding Alaknanda Hydropower projects, of (April 2009) prepared by using LISS-IV Satellite Image of April 2009
Figure 3.10(d) Land Use Land Cover Map of the area surrounding Srinagar Hydropower projects, prepared by using IRS P6 LISS-IV Satellite Image of January 2009
3.8.6 Rajwakti Hydropower Project Land use land cover change assessment for the area surrounding the Rajwakti Hydropower Project from the LISS-III image of September 2000 and LISS-IV image of April 2009 has been carried out. 47.89 sq.km. area surrounding the hydropower project has been taken as the approximate influence area of the HP. Both images have been georeferenced. Their geometric fidelity with respect to each other is also checked. Since spatial resolution of LISS-III image is 23.5 m, this image has been resampled to 5 m pixel size in order to get pixel by pixel comparison of LISS-III of year 2000 and LISS-IV image of 2009 and to obtain a difference image for the land use land cover changes. A brief account of land use land cover classes surrounding the Rajwakti Hydropower Project in year 2000 and 2009 has been given in Table 3.8. Table 3.8. Comparison of area under various land use land cover classes surrounding the Rajwakti Hydropower Project for year 2000 and 2009. Class Area (%) Sep. 2000 Apr. 2009 Dense Forest 40.37 46.76 Open Forest 38.00 36.95 Scrub 18.21 13.43 Water Body 0.78 0.91 River Bed 2.63 1.96 Total 100.00 100.00 Land use land cover map of the area, prepared using LISS-IV image of year 2009, surrounding the Rajwakti Hydropower Project has been shown in Fig. 3.10(e). 3.8.7 Phata-Bhyang Hydropower Project Assessment of land use land cover changes for the area surrounding the Phata- Bhyang Hydropower Project from the LISS-III image of May 2000 and LISS-IV image of December 2008 has been carried out. 40.50 sq.km. area surrounding the hydropower project, 6.5 km U/S and 6.5 km D/S has been taken as the approximate influence area of the HP. Both images have been georeferenced. Their geometric fidelity with respect to each other is also checked. Since spatial resolution of LISS-III image is 23.5 m, this image has been resampled to 5 m pixel size in order to get pixel by pixel comparison of LISS-III of year 2000 and LISS-IV image of 2008 and to obtain a difference image for land use land cover changes. A brief account of land use land cover classes surrounding the Rajwakti Hydropower Project in year 2000 and 2008 has been given in Table 3.9.
Figure 3.10(e) Land Use Land Cover Map of the area surrounding Rajwakti Hydropower projects, prepared by using IRS P 6 LISS-IV Satellite Image of April 2009
Figure 3.10(f) Land Use Land Cover Map of the area surrounding Phata Bhyang Hydropower projects, prepared by using IRS P6 LISS-IV Satellite Image of December 2008
Table 3.9 Comparison of area under various land use land cover classes surrounding the Phata-Bhyang Hydropower Project for year 2000 and 2008. Area (%) Class May 2000 Dec. 2008 Dense Forest 59.93 45.17 Open Forest 36.92 46.95 Scrub 2.73 5.23 Water Body 0.37 2.57 River Bed 0.05 0.08 Total 100.00 100.00 Land use land cover map of the area, prepared using LISS-IV image of year 2008, surrounding the Phata-Bhyang Hydropower Project has been shown in Fig. 3.10(f). 3.8.8 Deval Hydropower Project Land use land cover change assessment has been carried out for the area surrounding the Deval Hydropower Project from the LISS-III image of September 2000 and LISS-IV image of November 2009. An area of 21.21 sq km surrounding the hydropower project, 3.5 km U/S and 5 km D/S has been taken as the approximate influence area of the HP. Both images have been georeferenced. Their geometric fidelity with respect to each other is also checked. Since spatial resolution of LISS-III image is 23.5 m, this image has been resampled to 5 m pixel size in order to get pixel by pixel comparison of LISS-III of year 2000 and LISS-IV image of 2010 and to obtain a difference image for the land use land cover changes. A brief account of the land use land cover classes surrounding the Deval Hydropower Project in year 2000 and 2009 has been given in Table 3.10. Table 3.10 Comparison of area under various land use land cover classes surrounding the Deval Hydropower Project for year 2000 and 2009. Area (%) Class Sep. 2000 Nov. 2009 Dense Forest 53.87 45.41 Open Forest 42.04 38.10 Scrub 1.22 13.88 Water Body 1.44 1.57 River Bed 1.41 1.04 Total 100.00 100.00 [Land use land cover map of the area, prepared using LISS-IV image of year 2009, surrounding the Deval Hydropower Project has been shown in Fig. 3.10(g)].
Figure 3.10(g) Land Use Land Cover Map of the area surrounding Deval Hydropower projects, prepared by using IRS P6 LISS-IV Satellite Image of Nov 2009