ANCE which controls the level of vulnerability. Resistance depends on numerous factors such as land-use patterns, population and development densities, the quality and implementation of design and the ability to arrest the action of destructive forces in their initial stages thereby avoiding the development of chains of destructive events. The ESTIMATED LEVEL OF RISK should be calculated as a fundamental element of any physical development planning exercise in the following categories: - post-disaster settlements reconstruction, - settlement renewal and modemization, - expansion of existing settlements, - building of new settlements, - development and/or restructuring of the national/regional settlements networks and systems. The definition of an estimated RZSK for alternative site selections and alternative develop- ment programmes, should be seen as a major tool in planning and decision-making procedures for preventing or mitigating the consequences of the natural phenomena on the one hand, and to limit development and operational costs on the other. Policy formulation should encompass the concept of LOCALLY ACCEPTABLE RISK. 6 In order to define LOCALLY ACCEPTABLE RISK, alternative policy and planning options should be formulated and examined. Predictably, each alternative solution will present some internal conflicts between locally acceptable levels of risk and socio-economic goals. Nevertheless, the general notion and philosophy of RISK and of ACCEPTABLE IZISK should be applied to alI physical planning activities in order to ensure a safer and more appropriate process of urban and regional development. To that end, at the very least a simplified methodology and concept of RISK should be elaborated taking into account availability of local data, planning technology and trends in these fields. It is also imperative to define the reasonable minimum requirements for a meaningfull RISK definition exercise. This challenge could be seen as an important element of UNDRO’s work programme. IV. TYPES OF INFORMATION REQUIRED 
**Analysis**
The text appears to be focused on the concept of risk assessment and mitigation in the context of urban and regional development. It discusses the importance of considering natural phenomena and the need for a simplified methodology to define locally acceptable risk levels. This suggests that the text is related to the field of urban planning and disaster risk reduction.

**Category**
Natural resources and environment, Humanitarian aid and relief