 |  |  |
Some examples of questions follow:
1. Let's assume that I am interested in relating soil erosion rates to rainfall rates. That is very general because it does not specify a single event or a longer period of time. After consideration, I decide that I am interested in single events. From previous observations, I suspect that higher rainfall rates increase erosion rates. Therefore, I pose the question, does higher rainfall rates cause higher erosion rates? It is answerable by a simple yes or no. Much more explanation is appropriate, but now it is easier to fashion an effective null hypothesis for statistical analysis.
2. Another aspect of soil erosion that intrigues me is vegetative cover. From experience, I suspect that bare soils have a higer rate of erosion than those covered with vegetation. So I pose the question, does vegetative cover reduce soil erosion? As I set up my experiment, I find two areas on the landscape that are available for experimentation. One is a bare heavy clay soil on a steep slope and the second is a heavily vegetated silt loam on a relatively flat upland area.
I suspect that you, the reader, recognize some problems with my experimental design. That is, I have not considered the whole system. I have taken vegetative cover as a factor out of context of both slope and soil type. You may have recognized this because you have been exposed to the USLE (universal soil loss equation) which is a mathematical model, or because you have read or heard a word model that described the interactions involved in the system of interest that taught you that slope and soil characteristics affect erosion rates.
Return to posing questions.
| | | |