Systems Reliability Approach To Spatio-Temporal Probability Of Microbial Water Contamination

Abstract:

Sustainable management of water resources is unattainable without addressing microbial contamination of surface waters. Fecal microorganisms are the leading cause of surface water impairment, presenting a problem of national importance. In the US, approximately 93,000 river and stream miles contain elevated levels of fecal bacteria. Because microbial fate and transport are driven by inherently random environmental processes taking place in complex, multi-component environmental systems, a systems-based stochastic approach is needed to better understand patterns of microbial contamination. We have applied systems reliability theory to compute the spatio-temporal distribution of probability of water contamination in dendritic flow networks. This approach allows to measure probabilistically the impact of watershed components and microbial sources on overall water quality, and to determine watershed characteristics and external environmental parameters to which microbial water quality is most sensitive. This, in turn, helps (1) identify the “hot spots” exerting the highest impact, and (2) quantify of sustainability metrics such as reliability, vulnerability and resilience – all of which will, in turn, guide prioritization of management measures under various conditions.