GENERATION AND EVALUATION OF DIGITAL MICROTOPOGRAPHY ELEVATION MODELS USING A LASER DISTANCE-METER

摘要

Sediment is the leading cause of water quality degradation in the world. Numerous conservation measures have been proposed to reduce erosion and deposition, but to date; field-scale documentation of the success of these practices has been limited. To accurately assess soil erosion and deposition processes, digital microtopography elevation models were developed using a laser distance-meter. The equipment provides great advantages over other procedures such as close-range photogrammetry and laser scanners to generate microtopography models due to its simplicity and equipment cost. At first, a series of laboratory experiments were conducted to evaluate the ability of laser distance-meter to accurately measure the sediment deposition process. The equipment was used to scan the surface with various sediment deposition stages to generate digital surface models. These models have been shown to be a good representation of physical reality and have been successfully used to quantify the total volume of soil deposited. The field applications of this study have been demonstrated by applying the equipment to generate digital surface models and evaluate the performance of different best management practices in constructed ditches and hillslopes after a sequence of erosive events.