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GIS in small hydro planning resource management
Arun K. Saraf Department of Earth Sciences University of Roorkee Alternate Hydro Energy Centre University of Roorkee
Abstract This integrated approach of Geographic Information System (GIS) and Remote Sensing (RS) is now being recognised universally as an unique, highly effective and extremely versatile technology for evaluation management and monitoring of natural resources and environment. After the successful launch of IRS-1C in December 1995, now in India, every natural resource and environmental investigation begins with utilising and analysing remote sensing data. Small Hydro Power (SHP) has been one of the earliest renewable energy generation technologies in existence since the beginning of 20th century. There has been various estimation suggesting tht potential of SHP in the country is over 10,000 MW, of which only a small fraction (2-3%) has been harnessed so far, Under UNDP-GEF Hilly Hydro Project (HPP), Ministry of Non-conventional Energy Sources (MNES), Govt. of India an attempt has been made by Alternate Hydro Energy Centre in collaboration with Department of Earth Sciences (DES), Deptt . Of Civil Engineering (CED) (Centre for Remote Sensing), University of Roorkee and Institute of Hydrology (NIH), to identify the real potential available for SHP in India Himalayas. In UNDP-GEF-HPP about 1700 potential small hydro sites in thirteen Himalayan hilly states of India have been identified. In small hydro projects planning and development, GIS and RS was adopted for SHP planning resource management to acquire latest information from the analysis of RS data and manage all these thematic information along with other attribute information on a GIS platform for UNDP-GEF-HPP. All information collected through various sources are now available to the potential developers for site selection and planning purposes. Various types of queries (both spatial an non spatial) can be performed on a GIS platform based on conditions raised by the different users. Introduction Energy is one of the main basic inputs for the accelerated economic development. Small hydro power is probably the oldest and yet the most reliable and environment friendly source of all renewable energy, with bulk of its potential yet to be harnessed in many countries including India. Though hydro power development started with small units of 100 KW and more in the beginning, the attention was diverted to harnessing medium and major hydro because their comparative economics. However continous oil crunch has forced the attention of the concerned for harnessing small hydro at the toe of existing dams, at canal drops and exploiting hill streams to supplement the energy generation. Being environmentally benign and having small gestation period has led many countries to harness these resources in concerted manner with China in the forefront. The integrated approach of GIS and Remote Sensing is being is being recognised universally as an unique highly effective and extremely versatile technology for evaluation, management and monitoring of natural resources and environment. With the concept of multidisciplinary integrated approach got an impetus in monitoring and management of resources and environment. Through, aerial photography, the forerunner of present day satellite remote sensing, has been in vogue for a very long time, however the real spurt in the worldwide usage of the technology came in the launch of Landsat series of satellites, the first of which as put in orbit in 1972. The real advantage of staellite remote sensing system is evident from the fact that they provide a vantage point in space to study the earth and its environment and provide a unique opportunity for inventoring, mapping, and monitoring. Data available from various operational remote sensing satellite are improving in terms of spatial, spectral and temporal resolutions. After alunch of IRS-1C in December 1995, now 5.6m spatial resolution data of any part of the earth can be acquired (Saraf, 1997; Saraf, Kumar 1997). Few potential uses of GIS and RS in SHP planning and resource management have been discussed by Jagdeesha and Adiga (1997) and Rajpal and Mettle (1997) Kulkarni et al., (1997) discussed stream flow simulation study in snow covered areas for estimation of hydropower potential using remote sensing data. Faucher et. Al. (1993) have developed a hydraulic model designed to make use of remote sensing and GIS in SHP planning. FIGURE However, there are not many studies which provide clearly the integrated application of GIS and RS in SHP and particularly in hilly areas such as the Himalayas. The present article brings some applications of integrated GIS and RS in SHP planning and development. Any study pertaining to the environs of the developmental activity must encompass spatial, dynamic and temporal attributes of the environment to obtain comprehensive and reliable results. The simplest way of finding out changes over a period of time is to compare remotely sensed temporal data and demarcate the changed areas using either visual or digital analysis techniques. Remote sensing data can be used to show the quantity and pattern of deforestation, current and historical land use, identify load centres and larger streams, to locate rocky and erosion prone area, and to provide a foundation upon which all other digital data can be georefrenced in the GIS (Rajpal and Mettel, 1997) . Remote sensing data particularly from IRS-1C PAN sensor can also be utilized to generate digital elevation model (DEM) to further support SHP planning and development, however, Himalayas frequent cloud and snow covers poses some problems in acquiring data sets. RS data can also be utilised to assess the positive impacts associated with the development of SHP in the Himalayas, where deforestation is taking place at an alarming rate. GIS have become of increasing significance in recent years. One main reason for this in the field of SHP is the need to compare a great number of area-related data describing the natural resources and environment. Since GIS can be used to couple area-related data will their attributes, and can overlay these, they represent highly efficient instruments for such planning tasks. UNDP-GEF-Hilly Hydro Project Experience In the UNDP-GEF-Hilly Project (UNDP-GEF-HHP) about six hundred Survey of India (SOI) toposheets of 1:50,000 scale were scanned manually about 1700 potential small hydro sites based on perennial channel (>5.0 km)l, catchment area (>10km2), accessibility etc. criteria were identified. All drawing of such sites contain various attribute information as show in Table 1 and Figure 1. Many of the information which collected / retrieve from SOI toposheets were utilized for potential head and regional flow duration curves determinations. All the attribute information were computerised / fed into the Lotus spreadsheet programms. One of the objective of the UNDP-GEF-HHP was to prepare Zonal plan with maps of all thirteen states in order to identify potential clusters for development purpose. It is general belief that if potential sites form clusters than development of such clusters would be preferred by the developers rather than having scattered sites. To achieve this goal, SOI 1:1,000,000 scale map were digitized using ILWIS GIS software (then available with authors). During digitization various information such as river network (all blue lines in SOI maps), state and district boundaries, rail and road network and location of major towns, graticules (latitude and longitude) which were useful for planning and development were digitized and kept in geographic co-ordinate system for further analysis and utilization in GIS . On the base map as discussed above all potential sites location (main channel meeting point with the main river) were plotted in order to prepare cluster maps for all thirteen states (Figure 2). Such maps have been utilized to identify cluster of potential SHP.
Seismicity also plays important role in SHP planning and development. Separate maps containing epicentre locations of all earthquakes (>4.0 magnitude) occurred after 1928 (information was obtained from United State Geological Survey) were also plotted (Figure 3) on the digital base map in GIS. Various seismic zones relevant with different states were also retrieved from Zoning Map of India and overlaid on seismic maps prepared under this project. A combined sets of maps were also prepared under this project. A combined sets of maps were also prepared for all thirteen sates containing base map, potential SHP locations and earthquakes epicentres (Figure 4). The main purpose of this was to provide information about the coincidence of potential SHP cluster with the earthquake epicentre locations, so that necessary.  Figure 3  Figure 4 Precautionary / remedial measured during design of the project can be considered and appropriately incorporated. A quantitative analysis based on spatial random distribution vs nearest - neighbour was also performed using SHP cluster maps and earthquake epicentre maps. This analysis provides further support to quantify cluster identification process (Table 2a & 2b).
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