How to assess environmental impact is one of the keys in land use planning. This article described in detail the concepts of activities, impact zones, functions, and sensitivities, as well as the development of STEPP (strategic tool for integrating environmental aspects in planning procedures) based on Avenue, the secondary developing language of ArcView GIS. The system makes it convenient for planning practitioners exchanging information, and can spatially, visually and quantitatively describe environmental impact and its change.

Peri-urban areas in Africa are usually dynamic with respect to land tenure. Statutory, informal and customary tenure systems often co-exist and interfere with each other. This disclosure of legal pluralism often leads to lower levels of tenure security, especially for people with low incomes. Pro-poor land administration tools have been designed to cater for the poor. The question arises whether these tools have the desired impact. This question is answered by confronting the existing tenure regimes with the pro-poor land administration tools.

The World Food Summit in 1996 set the goal of reducing by half the numbers of malnourished people in the world by 2015. It is unlikely that this will be reached, and particularly not in Sub-Saharan Africa (SSA). Food imports in SSA have increased in the past forty years, since domestic production could not keep up with population growth. Several studies have reported about this stagnating food production in SSA. However, this region encompasses a large number of countries, with a great variety of agro-ecological zones and large differences in land, labour and other resources.