While standardising
the above, there should be a realisation upon who needs which level of LU data.
Jeffers (1970) opined about two-fold aims of conventional LU surveys:
* estimating the actual area of land devoted for various defined purposes and
the proportions of land used for such purposes (This will be refered in this present
volume as studying the LU Pattern i.e. LUP)
* producing maps showing the spatial distribution of the various LU classes in
the concerned area. (This will be refered in the present volume as preparation
of LU maps).
Coppock (1970) opined the need of LU data mainly to guide formation of new policies.
From the list of Dueker and Talcott (1973) the need of LU data may be listed as
follows:
* producing representative maps reporting land put in any specific use
* producing data on proportion of land used for specific purpose over a total
area and hence a basis for statistical analysis of LUP of the area
* identifying rate of change in LUP
* knowing physical factors responsible for the observed LUP
* knowing socio-economic factors responsible for the observed LUP and any change
in LUP
*carrying out statistical analysis on the factors responsible for any LUP change
(old or new)
* comparing LUP of two areas.
Considering the variety of needs of LU data it has been opined that no single
set of data can be ideal for all the purposes. The only alternative is multiple
survey to meet the most stringent demands (Rhind & Hudson, 1980)
Dickinson & Shaw (1978) reported clearly the wide range of variation in the classification
system, dissimilar areal units and the degrees of precision in the data available.
The fact is that, the form of data depend upon the purpose or activity carried
or planned to carry and the concern for which the data is generated. While preparing
land capability maps, the capability classes were identified based upon physical
restraints to development (e.g. stoniness, depth of soil etc.), but rarely other
limitations to development (distance to market, communication facility, managerial
efficiency etc.) were considered (Khingebiel & Montgowery, 1961). "Land-Use" had
been defined (Clawson & Stewart, 1965) as "man's activity on land which are directly
related to land" while an almost alike term "land-cover" had been defined (Burley,
1961) as "the vegetation and artificial constructions covering the land surface".
To record the LULC data there must be some well defined classification scheme.
As such, two such were developed by the USGS and the Department of Environment
(DoE). The major difference among the two was the USGS classification was extensive
covering both rural and urban LUs while the DoE one was primarily suiting the
urban areas. The American classification differs in being produced by an inter-agecy
committee which included representatives of the Association of American Geographers
and the International Geographical Union. This produced several classification
systems, later which were reviewed and a prototype classification system was evolved,
field tested and published as USGS circular no. 67. In contrast the DoE classification
was created and used to produce speedy, country-wide set of consistent LU figures.
The National Land Use Classification (NLUC) and the National Gazetteer Pilot Study
(NGPS) were the two classification schemes which were more detailed. Two important
concepts of LU were "multiple use" and "sequential use" (Cargo & Malovy, 1973).
The terms are self explanatory, e.g. a same reservoir can be used simultaneously
for water supply, flood control and an item of scenic beauty; or if a same reservoir
is being used as a fishery, sweeming pool and irrigation, these are cases of multiple
use. Similarly a forest can be a "National park", as well as camping ground. Instead
a village playing ground or a street may be used as a market at each week end,
this is a case of sequential use. Other alike examples are:
* farm land ----> strip mining ----> recreation, or
* underground quarry ----> industrial storage; or
* surface mines ---> land fill ---> real estate development
To obtain LU data of present days remote sensing is considered as the best tool.
Aerial photographs and stellite imageries of different varieties are available,
which are of different resolution and cost. Even repeatative data can help assessing
LUP changes, while for base line data collection toposheets are still considered
as the best source because remote sensing is a technique developed rather recently
in comparison to the date for which the baseline data may be required.
While analysis of aerial photographs may be possible under mirror stereoscope
and those of stellite imagery even vissually, dealing with huge volume of data
becomes more effective by computer based methods only.
A view towards LU in Britain can be obtained from the seminal work by Coppock
& Gebbett (1978). The first moderately reliable figures for urban areas in the
UK was those derived from land utilisation survey of the early 1930s (Stamp 1948).
Several models of agricultural LU, urban LU have been suggested since the moves
set in motion at the 1949 IGU Congress in Lisbon with the intention of establishing
a common international classification system (Haggett 1966, pp.158, Haggett et
al., 1977 pp.197). Even attempts have been made for reforming the previous LU
models, on this account mention may be made of Heady & Egbert (1964), Wolpert
(1964), Sinclair (1967), Stevens (1968), Abler et al. (1972), Harvey (1973), Castels
(1976), Turner (1977), and Massey & Catalano (1978).
According to Rhind & Hudson (1980 pp.215), to pretend that LU decisions have reached
in an environment free of state intervention, is perhaps the greatest myth. For
example, the collectivisation of agriculture in the USSR and China had considerable
impacts on rural LUP. The LU planning system in Britain is often regarded as the
most sophisticated in Western World (Hall, 1973, Hall, 1974).
After considering different LU models and the alternate interpretations it can
be concluded that "there can be no --------- general LU theory------- Rather---------
must be historically specific relating ------- stages of development within a
given mode of production". (Rhind & Hudson 1980, pp.239, last sentence). Thus
there can be no universal LU theory of real merit. The broad theoretical task
remaining for future workers is to show why LUPs take particular forms within
different societies. (Rhind & Hudson, 1980, pp.240). .
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