Ulrik Mårtensson

Rapid generation of Digital Elevation Models from topographic maps

Abstract In this article we demonstrate that substantial gains in time can be made when using point sampling rather than contour line digitising for generation of Digital Elevation Models (DEMs). A simple sampling scheme, based on regularly distributed points, was used supplemented with points near break-lines in the terrain. An evaluation of surfaces created with three different interpolation methods at three different resolutions shows that the statistical distribution was better when using points as opposed to contours, and that the accuracy was comparable despite the much smaller amount of input data.

Using geographical information systems to analyse accessibility to health services in the West Bank, Occupied Palestinian Territory

Accessibility to adequate health services is a basic human right. Israeli road blocks and checkpoints inhibit access to health care for the Palestinian population. While other studies have dealt with the impact of the barriers, few are based on actual measurements of transport times between locations. Geographical information systems (GIS) and network analysis were used to generate different estimations of accessibility based on the existing road network and transport barriers. The population negatively affected were mainly people living outside urban centres and in governorates with no general hospital. Quantitative measurements using GIS can be used to confirm qualitative studies based on interviews and questionnaires and improve the understanding of the results. Working with a spatial analysis tool also helps to pinpoint weaknesses in the current infrastructure, thus improving the efficiency of future investments to improve health care in the West Bank.