ABSTRACT
The increasing recognition of the association between adverse human health conditions and many environmental substances as well as processes has led to the need to monitor them. Important environmental processes have been monitored for a variety of purposes over a very long time. Concerns about climate change have led to the measurement of sea levels and the extent to which polar ice-caps have receded. Concern for human health and welfare and the need to regulate airborne pollutants by the US Environmental Protection Agency has led to the development of urban air shed monitoring networks; cities out of compliance with air quality standards suffer serious financial penalties. In practice the domains in which the monitors are to be sited are “discretized,” meaning the possible choices lie in a set D of finite size N. Practical considerations may make this set quite small. This chapter explores a variety of approaches designers have developed, along with their rationales.
