TABLE OF CONTENTS A model of terrain is often a necessary requirement in identifying, analyzing, and mitigating problems in many fields including hydrology, geomorphology, and environmental modeling. In this chapter, we provide some illustrations of the ways in which digital terrain models can be used in analysis of the environment. Note that this chapter is by no means intended to detail the full range of applications of DTMs to environmental modeling. Instead, this chapter will highlight the more common uses for DTMs and their impact on modeling results.
Table 8.1 provides some insight into the range of possible uses of DTMs in environmental modeling. Huggett (2003) noted that both primary attributes (first-order derivatives, or parameters derived directly from elevation) and secondary attributes (second-order derivatives, or parameters stemming from first-order derivatives) are used extensively in geomorphology and environmental modeling. The table includes some attributes described by Huggett (2003).
| Attribute | Application |
|---|---|
| Altitude | Climatic variables (temperature, pressure, and so forth); Vegetation and soil patterns; Potential energy determination. |
| Slope | Overland and subsurface flow; Erosion. |
| Aspect | Solar irradiance; Evapotranspiration. |
| Curvature | Flow acceleration; Erosion and deposition patterns and rates; Soil and land evaluation indices. |
| Drainage basin slope, area, and length | Time of concentration; Contributing volumes to runoff; Runoff attenuation times and velocities. |
| Stream lengths and slopes | Channel flow rates and velocities; Erosion rates and sediment yields. |
As Table 8.1 demonstrates, DTMs are used throughout all spheres of the Earth's system, including the...
