The newest version of the ITC GIS and Remote Sensing software ILWIS offers an integrated set of modules to perform geostatistics. Its functionality for image processing, geographic analysis and digital mapping combined with extensive geostatistical tools make it a modern product for education and research in the field of G.I.S. It incorporates spatial correlation tools like semi-and cross vario...

Geographical Information System and Remote Sensing are tools which integrated can perform different environmental analysis. The Netherlands ITC (Institute for Aerospace Survey and Earth Sciences) developed in 1984 on Integrated Land and Water Information System (ILWIS), that combines raster (satellite image and aerial photo analysis), vector and thematic data operations in one comprehensive int...

The mapping of squatter settlements has been a difficult task for geographers (Manoj, 2008). This is due to the dynamic nature of the settlement and the organic growth that these types of settlements take on (Brian, and Ranvinder, 1995). It has proven extremely difficult to accurately map individual households in these settlements and even boundary discernment can be difficult. These issues of ...

A method has been developed in the present study for the determination of the sediment yield from a catchment using a GIS. The method involves spatial disaggregation of the catchment into cells having uniform soil erosion characteristics. The surface erosion from each of the discretized cells is routed to the catchment outlet using the concept of sediment delivery ratio, which is defined as a f...

This paper discusses site selection process for biological soil conservation planning. It was supported by a valuefocused approach and spatial multi-criteria evaluation techniques. A first set of spatial criteria was used to design a number of potential sites. Next, a new set of spatial and non-spatial criteria was employed, including the natural factors and the financial costs, together with t...

DTMs derived from digitized contour lines often suffer from limited quality. The quality can be enhanced by automatically extracting skeleton lines from the contours prior to triangulation and subsequent interpolation. A hybrid set of raster and vector techniques is used for skeleton extraction and TIN generation, including distance transformation, Dirichlet tessellation, thinning, gap filling,...

Oil spillage has been a major environmental problem in Nigeria for more than two decades. Between 1976 and 1996 Nigeria recorded a total of 4835 oil spill incidents, which resulted in a loss of 1.9 million barrels of oil into the environment. From 2006 to 2008 reported oil spill occurrences amounted to 1260, where 40,000 barrels of oil from Mobil platform off the Akwa Ibom coast were spilt, cau...

Lake Chad commonly serves as a major hub of fertile economic activities for the border communities and contributes immensely to the national growth of all the countries that form its boundaries. However, incessant and multi-decadal drying via climate change pose greater threats to this transnational water resource, and adverse effects on ecological sustainability and socio-economic status of th...