Evaluate Accessibility and Centrality of Road Network in The Mahaweli System C, Sri Lanka

In the field of transport geography and planning, road accessibility analysis is one of the important analysis. The evolution of transportation systems has currently led to changes in urban form.Accessibility is the measure of the capacity of a location to be reached by, or to reach different locations. Therefore, the capacity and the arrangement of transport infrastructure are key elements in the determination of accessibility.Centrality refers the most closeness and betweenness places in a road network and it helps to establish new developments in that area.This study attempts to examinepotentials for expanding cities in the area according to the road infrastructure facilities. The objective of the study is identifying the level of accessibility and centrality of the Mahaweli C region. Data gathered from the department of survey and to analyze, accessibility in this area have been used geographic accessibility matrix and potential accessibility matrix. As well as to identify the closeness and betweenness centrality of the region and road densities have been used Spatial Design Network Analysis (SDNA) tool in QGIS and Kernel density analysis tool in ArcGIS (10.3). The Mahaweli system C is a resettled area under the Mahaweli Development Project. Basically, the hierarchical structure of the roads which are A, B, C and D class roads. According to the results of connectivity of the area centers and townships, mora accessible places are Dehiattakandiya, Sandunpura, Girandurukotte, Mahawanawela and Nawamedagama. Node Dehiattakandiya has more emissive than attractiveness (14377 versus 9622), while Node Siripura has more attractiveness than emissive (4202 versus 3559). When considering the closeness values and betweenness values Girandurukotte, Mahiyanganaya and Dihiattakandiya town centers can accessible than other area centers. According to the Kernel Density of the centrality of closeness, built-up landscape is shown from northern to south area. According to the results Girandurukotte area is the most accessible and centralized place in the region. It has more potentials for the development and more accessible place for people who are living in theMahaweli System C area.