Degree Type


Date of Award


Degree Name

Doctor of Philosophy


Agricultural and Biosystems Engineering

First Advisor

Brian L. Steward


Terrain modeling is one of the prime approaches that can be used to assess the spatial variability of agricultural fields and their surrounding ecosystems. The representation of terrain in the form of digital elevation models (DEMs) can be used to help the implementation of the applications of precision conservation management practices. GPS-equipped farm vehicles enable landowners to utilize elevation data during normal field operations for the development of agricultural field DEM. Generation of DEMs from measurements acquired with such systems provided users with additional benefits from the original capital investment in the equipment. This research provided extensive but useful guidance on appropriate procedures involved in the development of field DEMs for land users to take full advantage of the existing technology. Digital elevation models, like other maps, are models that deviate from reality. Depending on process, methods and procedures to generate the DEMs, the topographic parameters derived from a DEM contain uncertainties. In this study, the uncertainty of DEM estimates was assessed and found to be useful to enhance the sampling strategy in improving the accuracy of the DEMs. The effect of DEM uncertainty on topographic parameters was investigated and found that DEM uncertainty has a substantial impact on soil erosion prediction which may affect the consequence management decisions such as the decision on how much biomass need to be removed from the field for conservation practice. Many users particularly farmers, may not be knowledgeable about the theory, so they will appreciate the guidance about appropriate analysis that helps them make good choices for their data and applications.


Copyright Owner

Samsuzana Abd Aziz



Date Available


File Format


File Size

134 pages