Definitions and estimators of water resources system reliability (the probability that the system will remain in a non-failure state), resilience (the ability of the system to return to non-failure state after a failure has occurred) and vulnerability (the likely damage of a failure event) have been thoroughly investigated. A behaviour analysis addressing monotonic behaviour, overlap and correlation between the estimators was carried out by routing time series of monthly runoff through a reservoir with a specified storage volume that is operated according to a fixed operation policy. Estimation based on historical time series is shown to be problematic and a procedure encompassing generation of synthetic time series with a length of at least 1000 years is recommended in order to stabilize the estimates. Moreover, the strong correlation between resilience and vulnerability may suggest that resilience should not be explicitly accounted for.

https://www.tandfonline.com/doi/pdf/10.1623/hysj.49.5.755.55136

Choice of reliability, resilience and vulnerability estimators for risk assessments of water resources systems

Identification of optimal strategies for improving eco-resilience to floods in ecologically vulnerable regions of a wetland

Socioeconomic drought broadly refers to conditions whereby the water supply cannot satisfy the demand. Most previous studies describe droughts based on large scale meteorological/hydrologic conditions, ignoring the demand and local resilience to cope with climate variability. Reservoirs provide resilience against climatic extremes and play a key role in water supply and demand management. Here, we outline a unique multivariate approach as a measure of socioeconomic drought, termed Multivariate Standardized Reliability and Resilience Index (MSRRI). The model combines information on the inflow and reservoir storage relative to the demand. MSRRI combines: (I) a “top-down” approach that focuses on processes/phenomena that cannot be simply controlled or altered by decision makers, such as climate change and variability, and (II) a “bottom-up” methodology that represents the local resilience and societal capacity to respond or adapt to droughts. MSRRI is based on a nonparametric multivariate distribution function that links Inflow-Demand Reliability (IDR) indicator to Water Storage Resilience (WSR) indicator. These indicators are used to assess socioeconomic drought during the Australian Millennium Drought (1998–2010) and the 2011–2014 California Drought. The results show that MSRRI is superior to univariate indices because it captures both early onset and persistence of water stress over time. The suggested framework can be applied to both individual reservoirs and a group of reservoirs in a region, and it is consistent with the currently available standardized drought indicators. MSRRI provides complementary information on socioeconomic drought development and recovery based on reservoir storage and demand that cannot be achieved from the commonly used drought indicators.

/pdf/a-hybrid-framework-for-assessing-socioeconomic-drought-3d6k1jxut6.pdf

A hybrid framework for assessing socioeconomic drought: linking climate variability, local resilience, and demand.

This paper reviews existing approaches to system resilience, and proposes a scheme to quantify the resilience of water resource systems. In general, three aspects of resilience are considered in water resource systems: (1) that against crossing a performance threshold; (2) that for response and recovery after disturbances; and (3) that of adaptive capacity. Conventionally these aspects are treated separately without considering possible functional relationships or interdependencies. We argue that the adaptive capacity of the system is better treated as an input variable of the other two aspects of resilience, and that response/recovery may be considered only when the performance threshold is not crossed. Because of the dynamic and evolving nature of water resource systems, proper consideration of uncertainty and associated information, whether obtained from well-defined numerical data or vague linguistic articulation, is essential for better understanding and proper management of their resilience. Constan...

Resilience Concepts for Water Resource Systems

Thesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2005.

Real Options "in" Projects and Systems Design: Identification of Options and Solution for Path Dependency

Failures in operation of water supply reservoir systems are often unavoidable during critical hydrologic periods. The failure characteristics of such systems can be represented by performance indicators such as reliability, resilience, and vulnerability. A mixed-integer programming model for the operation of a water supply reservoir during critical periods has been presented in the literature that incorporates these performance indicators. An improved formulation of this model that represents resilience more completely is discussed herein. In addition, a set of constraints with binary integer variables are included to account for reservoir spills. The improvements achieved with the modified model is demonstrated using the same example as presented with the original model.

P. Shyam Narayan

Papers

Mixed-Integer Programming Model for Reservoir Performance Optimization