Introduction to Environmental Modeling

Introduction

Humans, as do all species, interact with their environment [105]. In contrast to other species, humans strive to understand these interactions rather than merely experience them passively or as random coincidents. Understanding of physical, chemical, and biological processes, as well as the ability to control these processes, makes us better stewards of our world. The quest for understanding allows us to change from seeing events as mere happenings to gaining knowledge of the mechanisms that are responsible for those events. In searching for mechanisms, we encounter patterns and processes in the things that we observe. Our earliest ancestors observed simple patterns, such as the formation of ice when the temperature became cold. They learned the repeatable pattern of four seasons of the year and the cycles of life that occurred in those seasons. The correlation between formation of ice from pure water and temperature is near perfect. Changes in season provide a definite pattern, but there are also variations from year to year that require further searches. We are able to project the time of sunrise and sunset with excellent accuracy based on knowledge of the consistent behavior of the revolution of the earth as it orbits around the sun; but we do not know, with comparable accuracy, what the temperature will be when the sun rises.

Modeling has a long history and has impacted advancements and understanding in a wide range of disciplines. Modeling must be structured and disciplined if it is to be effective. Statements about what constitutes modeling and how to deconstruct modeling into a sequence of tasks or elements continue to propagate as efforts to make use of the latest theory, computation, and experimental opportunities impact our ability to model well [e.g. 155, 169, 185, 186]. Here we will consider consistent descriptions of processes in the environment and use those descriptions as bases for modeling the processes. If 100 individuals were sent out to make some sort of measurement, and each individual were to return with a different value for the variable of interest, we might not have gained much insight. For example, measurements of the length of time it takes a leaf to fall 50m from a tree branch to the earth will vary from realization to realization.