Land Use

I

Introduction

Land Use, the different ways in which people use land and the study of these ways and of the processes of land-use decision-making. Traditional land uses include agriculture, mining, and forestry; a more recent one is conservation. Less than 30 per cent of the Earth's surface area of 510.1 million sq km (197 million sq mi) is land. Not all land can be utilized by humans, so that which is usable is a valuable natural resource, and one under pressure in many parts of the world. Because of this, obtaining an accurate picture of how land is being used, and whether it is being used optimally is important. In recent years, increasingly sophisticated analytical and mapping techniques have been used to study land use, while the size of land areas to be studied has increased.

II

Classifying Land Use

There are numerous systems of land-use classification, but all group land into one of four broad categories—rural, urban, recreational, and non-developed. Each of these categories is normally broken down into subdivisions. For example, the urban category may include land used for residential, industrial, and communications purposes, whereas non-developed land may be divided into unutilized and deliberately preserved wilderness areas such as national parks. Most countries and organizations which use land-use maps employ classification systems which best reflect their circumstances and which can be mapped with reasonable ease.

III

Mapping Land Use

Direct observations in the field using previously surveyed base maps, and aided by aerial photographs, have traditionally provided most land use information. However, the introduction of remote sensing techniques using satellites such as the American Landsat series or the French SPOT, and of computer-based geographical information systems (GIS) capable of processing and comparing very large quantities of data, has led to more detailed and accurate land-use information becoming available. Mixes of mosaics of different land uses can now be mapped accurately, changes in land use can be monitored on a fine scale, and better judgements made about land capability. Land capability indices integrate a range of factors such as soil, micro-climate, slope, and ground stability, and are designed to help make the best use of land.

IV

Land-Use Models

Land-use patterns often appear to lack order and organization. In an attempt to explain their development, models have been devised to demonstrate the influence of both natural features and economic factors.