Types of slope and its effect on vegetation and erosion
Answers
Answer:
. Gentle. Contour lines showing a uniform, gentle slope will be evenly spaced and wide apart
b. Steep. Contour lines showing a uniform, steep slope on a map will be evenly spaced, but close together. ...
c. Concave..
Contour lines showing a concave slope on a map will be closely spaced at the top of the terrain feature and widely spaced at the bottom Considering relief only, the defender at the top of the slope can observe the entire slope and the terrain at the bottom, but he cannot use grazing fire. The attacker would have no cover from the defender's observation of fire, and his climb would become more difficult as he got farther up the slope.
d. Convex.
Contour lines showing a convex slope on a map will be widely spaced at the top and closely spaced at the bottom . Considering relief only, the defender at the top of the convex slope can obtain a small distance of grazing fire, but he cannot observe most of the slope or the terrain at the bottom. The attacker will have concealment on most of the slope and an easier climb as nears the top.
Vegetation is one of the key factors affecting soil erosion on the Loess Plateau. The effects of vegetation destruction and vegetation restoration on soil erosion were quantified using data from long-term field runoff plots established on the eastern slope of the Ziwuling secondary forest region, China and a field survey. The results showed that before the secondary vegetation restoration period (before about 1866–1872), soil erosion in the Ziwuling region of the Loess Plateau was similar to the current erosion conditions in neighboring regions, where the soil erosion rate now is 8000 to 10000 t km−2 year−1. After the secondary vegetation restoration, soil erosion was very low; influences of rainfall and slope gradient on soil erosion were small; the vegetation effect on soil erosion was predominant; shallow gully and gully erosion ceased; and sediment deposition occurred in shallow gully and gully channels. In modern times when human activities destroyed secondary forests, soil erosion increased markedly, and erosion rates in the deforested lands reached 10000 to 24000 t km−2 year−1, which was 797 to 1682 times greater than those in the forested land prior to deforestation. Rainfall intensity and landform greatly affected the soil erosion process after deforestation. These results showed that accelerated erosion caused by vegetation destruction played a key role in soil degradation and eco-environmental deterioration in deforested regions.