This paper reports a current GIS research project which is being undertaken in the Tweed area of north coast New South Wales. The project focuses on drainage management problems which are of increasing concern for land and environmental management for the sugar industry in this area. GIS network capabilities are employed with enhancements of specific needs for the drainage simulation. Natural a...

In GIS and in terrain analysis, drainage systems are important components. Due to local topography and subsurface geology, a drainage system achieves a particular drainage pattern based on the form and texture of its network of stream channels and tributaries. Drainage pattern recognition helps to provide a qualitative description of the terrain for analysis and classification and is useful for...

This is the second of two papers that elaborate on an integrated drainage network analysis system (IDNAS) for agricultural drainage management. In the ®rst paper, the system components, functions and implementation were presented. This paper focuses on the system applications to agricultural drainage management, particularly on the acid drainage problems in an estuarine acid sulfate soil ̄oodpl...

An automated process for the delineation of drainage basins, using as input only the vector based drainage network, is described which provides an alternative to DEM based methods. The procedure involves an approximation of the line Voronoi diagram for the network using a constrained Delaunay triangulation of the network's Planar Straight Line Graph. The constrained triangulation, which include...

In this paper, the river network is divided into sub-networks forming a hierarchy of drainage systems following the Horton order. Then, drainage systems are rearranged based on their pattern to obtain more homogeneous drainage systems which do not necessarily follow the Horton order. Such reorganization facilitates the description of the network system. Such organization can be useful for terra...

This paper describes a new method for hypsometric tinting for small-scale maps. The method generalises digital elevation models by removing small unnecessary details and accentuating major valleys and ridgelines. The elevation data are filtered with lower and upper quartile filters that are combined using a drainage network. The lower quartile filter is applied in valleys, delimited by the drai...