The relationship, denudation rate versus topography (i.e. relief and slope), is a key to understanding the controls of sediment flux. Recent studies show that local slope is the most physically meaningful explanatory variable for catchment denudation rate for tectonically inactive and active areas both at catchment level and in a global context. However, geology, climate, tectonic activity, biosphere and anthropogenic activity, also affect the denudation rate. These factors can be translated into criteria using multi-criteria evaluation (MCE) method, and when integrated with elevation data, can provide a framework for the estimation of denudation rate and sediment budget. Recent developments in GIS constitute a major breakthrough in digital mapping of the world, and the SRTM digital elevation data produced by NASA, provide a major advance in the accessibility of high quality elevation data. This paper presents the results of a study of a combined data set of eighty basins across the globe. Exponential regression based on the General Exponential Growth Model (GEGM), for the combined data set, yielded the relationship D = 0.00145e02878 (D = denudation rate, S = local slope, R2 = 0.97, P<0.0001) and indicated that local slope is a more meaningful correlate of denudation rate than relief. We have also tested this relationship near the extreme ends of the catchment continuum, in the Darwin Harbour catchment, Australia, and the Mangla Reservoir catchment, Pakistan, and found dependence of denudation rate on local slope. The study revealed that local slope is the most important criterion and prioritization of other criteria can be achieved by using prioritisation methd that is pair-wise comparison. This study identifies criteria that affect the denudation rate and provides a conceptual framework for estimation of denudation rate and sediment budget, by integrating the GIS and MCE methods.
|Title of host publication||RIMBA 3 - Sustaining Livelihood through Prudent Utilization and Management of Natural Resources|
|Editors||Andrew Alek Tuen, Mohd-Azlan Jayasilan, Jongkar Grinang|
|Place of Publication||Malaysia|
|Publisher||Institute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak|
|Number of pages||9|
|Publication status||Published - 2014|