International Journal of Management and Social Sciences Research (IJMSSR) ISSN: 2319-4421 Volume 3, No. 11, November 2014 i-Explore International Research Journal Consortium www.irjcjournals.org 25 Shoreline Change Analysis Along Hansa and Broken Water Bay Coastal Tract of Papua New Guinea Through Remote Sensing and GIS Sailesh Samanta, Senior Lecturer, Department of Surveying and Land Studies, The PNG University of Technology, Lae, Morobe Province, Papua New Guinea ABSTRACT This study has been undertaken along 120 Km of coastal tract of Papua New Guinea. The study area lies in the Northern part of Papua New Guinea between the Hansa bay of Madang district and Broken Water bay of Sepik district. The study area is characterized by the sea wave erosion during the past five decades. Topographical map with the scale of 1:250000 is used as the base data set. The recent Landsat TM data set is used to find out the changes of coastal track in the study area after comparing with the topographical map during 1962 to 2010. After geo-rectification of the satellite image with GPS ground control points and topographical reference map, the shoreline is identified through visual image interpretation technology. The coastal processes are the major factors behind the shoreline shifting. The near shore, beach, backshore zones are dominated by one major process or a combination of process. The wave braking zone, breaking type and breaking energy are calculates using the standard equations. The result shows accelerated rate of erosion in the Broken water bay and Hansa bay coastal regions. Coastal track deposition is found in the south- east part of Broken water bay in the study area due to the huge sedimentation by Ramu river. The Broken water bay is under threat of encroaching sea, about 850 m at the northern part and 400 m at southern part during 1962 to 2010. Field observations of those areas also indicate severe damages in construction, natural and planted vegetation and pockets of beach erosion in several places in the study area. Keywords Remote sensing, GIS, Coastal process and Shoreline change 1. INTRODUCTION Coastal zone is a broad transitional zone between the land and sea. The shoreline is a boundary line between land and sea. Because of its dynamic nature, the shoreline changes gradually. This change is provided by sequences of storm and cyclones, coastal processes, sea level rise, and seismic events, involving a specific range of space and time (Schwartz, 2005). Cumulative effects of all such long and short-term changes cause overall change in shoreline geometry. Accurate determination of shoreline change rate is important for a wide range of coastal studies, such as development of planning, hazard zoning, erosion accretion studies, and regional sediment budgets (Zuzek et al., 2003). 2. STUDY AREA AND DATA USED The study area lies in the Northern part of Papua New Guinea between the Hansa bay and Broken Water bay, approximately 120 km coastal track (Figure 1). The spatial extent of the study area lies between 3° 48' 22" S to 4° 14' 17" S and 144° 17' 20" E to 144° 58'10" E. The Hansa bay extended from 4° 7' 55" S to 4° 11' 30" S and 144° 53' 05" E to 144° 55' 36" E in the Madang district and Broken Water bay from 3° 53' 11" S to 4° 01' 11" S and 144° 34' 40" E to 144° 40' 27" E in the Sepik district. Army map service (AMS), US, Washington compiled topographical map for the Papua New Guinea in 1962 in the scale of 1:250000 is used as the base data set. Optical bands with standard false color combination (SFCC) of LANDSAT 7 TM satellite images of 2010 are used to identify the coastal track location of the study area. All other details of the dataset, data spans along with the sources were given in the table 1. Table1. List of data used in the study Collateral data Scale/ Resolution Year of publication Source Topographical maps 1:250000 1960 Army map service (AMS), US, Washington Landsat-7, TM 30 m 2010 UNITECH, PNG Wave data Location wise 2012 http://www.tide- forecast.com