Take, for instance, the eruption of Mt. St. Helens. The eruption resulted in thousands of hectares of cropland being covered with ash. Initially this was an aesthetic and economic disaster to some people. Subsequent years proved otherwise. The ash soon became invisible as crops grew profusely, resulting in record high crop yields and hence profits.
Geographers have a long tradition of studying land use.
However, there are no special instruments to measure land use that have not been covered already. Cadastral measurements are typically used with existing maps and aerial photographs. The greatest problems in land use description and analyses involve identification and classification . These broad categories can then be sub-divided further. A series of upper and lower case letters and Roman and Arabic numbers can be used for coding.