ABSTRACT
This chapter deals with a range of hazards that varies considerably with regard to speed of impact. It describes that the fate of the biosphere can be seen to influence that of the lithosphere: the health and composition of vegetation cover is often a guide to the strength of erosional processes and, especially, to the progress of desertification. Problems of erosion are underestimated in the United Kingdom and northern Europe, taken for granted in much of the Mediterranean Basin, persistently serious in the USA and verging on the catastrophic in China. The hazard of soil erosion is strongly linked to that of landsliding. Shallow landsliding often represents the loss of soil material by sliding or flowing along boundaries within the soil profile. Other hazards can also provoke intense erosion. In the case of fluvial erosion, the system boundary is the watershed or drainage divide. Aeolian erosional systems usually have much less distinct boundaries.
