Preliminary Site Selection for Small-Scale Hydropower Potentials, in Bulolo, Morobe Province, Papua New Guinea: GIS & RS Approach.

Abstract

The efficacy of hydropower in general is determined by river discharge and falling height (head). Hence this research uses advanced technologies of Geographic Information System (GIS) and Remote Sensing to identify most of the parameters required for hydropower calculations. The parameters such as runoff, head and watershed areas were thoroughly considered. The objectives of this research include; identification of sites having suitable „heads‟ from SRTM DEM, integrating Soil Conservation Service (SCS) runoff equation and sub watershed areas in GIS environment to calculate annual river discharge, estimating annual hydropower energy using above variables (Head and Discharge) and finally to map out preliminary sites showing small- scale hydropower potentials based on annual hydro power estimation. The SRTM DEM data having 30 m spatial resolution, Landsat satellite data together with PNGRIS data sets are used for head determination, watershed delineation & area calculations, Land Use/Land Cover Mapping and finally SCS runoff modelling for annual river discharge estimations. The study utilizes the standard hydropower calculation, which is P = m x h x g, where P is annual hydropower (in W), is density of water (kg/m ), m is Discharge (m3/s), h is Head (m) and g is acceleration due to gravity (m/s ). Head (h) is calculated using focal statistic analysis tool in ArcGIS software, where as annual discharge (m) is obtained from annual runoff, watershed area and total number of seconds in a year. The results indicate that there are 91 sites having good Head (h> 20 m), however lack of river discharge in most of the hilly region has resulted most of the sites unconsidered. The final results indicate that there are 44 potential sites for small-scale hydro power developments in study area. The estimated annual power ranges from 1 – 10 MW.