Land use management is vital on the regional scale to achieve food security through prudent land management of agro-ecosystems. Land use/cover changes affect the hydrological cycle influencing how precipitation is intercepted, evapo-transpired and retained in soils. This in turn determines the amount and speed of runoff. Land cover change also influences local soil erosion and nutrient losses. At the scal eof river basins, it determines water availability and the intensity and frequency of flooding. In addition, ecosystems and land in general store waste materials and provide critically important purification function. The ability to provide these services is threatened by pollution and land degradation due to inappropriate land use or overexploitation that transgresses capacity thresholds.
This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the United Nations Commission on Sustainable Development and implemented through national and local authorities. Agenda 21 recommends selecting combinations of land uses and production systems appropriate to land units through multiple goal optimization procedures, and strengthening delivery systems. Agenda 21 also recommends the development of fiscal incentives and land-use control measures, including land-use planning solutions, for a more rational and environmentally sound use of limited land resources.