and sharp declines on either side of the peak. At lower effective rainfalls, sediment discharge is lower because there is less rainfall to erode the hillslope. At effective rainfalls of greater than 10-14 inches, the decrease in sediment yield is interpreted to be the result of increasing vegetation cover. Increasing precipitation supports denser vegetation coverage and prevents overland flow and other methods of physical erosion. This finding is consistent with the Istanbulluoglu and Bras’ findings on the effect of vegetation on erosion and channel formation. The Caineville Badlands The badlands of Caineville, Utah are often cited as a region of extremely high drainage density. The region features steep slopes, high relief, an arid climate, and a complete absence of vegetation. Because the slopes of hillslopes are often greater than the angle of repose, the dominant erosional process in the Caineville badlands is mass wasting. There is no vegetation to provide stability to the slopes and increase the angle of repose and prevent mass-wasting. The regions below the angle of repose, however, are still generally at a significant angle, and hillslope diffusion, according to the following relation, is still a significant source of erosion: Where Ks is a coefficient of diffusivity of the hillslope, z is the elevation of the hillslope, and x is horizontal distance. The range of drainage densities in the Caineville Badlands illustrates the complicated nature of drainage densities in low-precipitation environments. In a study on the region, Alan Howard (1996) found that the effect of increasing relief angles in different basins did not have a constant effect on the drainage density. For regions of relatively low relief, drainage density and relief are positively correlated. This occurs until a threshold is reached at a higher relief ratio, when increase the slope ratio is accompanied by a decrease in drainage density. This is interpreted by Howard to be a result of the critical source area needed to support a channel increasing. At a higher slope, the erosion is faster and more efficiently funneled through fewer channels. The smaller number of channels results in a smaller drainage density for the basin. This qualitative topographic map of a section of a section of the Caineville Badlands shows the extensive drainage network in the arid environment. Relating to Montgomery and Dietrich’s definition of the elementary parts of a drainage basin, the source area for each of the channels is relatively very small,