Patrick A. Ray

Confronting climate uncertainty in water resources planning and project design : the decision tree framework

Water infrastructure projects are a significant portion of the World Bank’s lending portfolio and a major need for developing countries throughout the world. Many water resources projects have long periods of economic return, with significant uncertainties in the behavior of the natural system as well as that of human factors (technology, population dynamics, economic development, and the like). The uncertainties associated with climate change, however, have led to a reconsideration of whether the water development community is adequately taking into account the uncertainties that characterize the future. The goal of this book is to outline a pragmatic process for risk assessment of Bank water resources projects that can serve as a decision support framework - a decision tree to assist project planning under uncertainty. The decision tree described in this book is based on the growing consensus that robustness-based approaches are needed to address uncertainty and its potential impacts on infrastructure planning. These approaches emphasize assessment of individual projects and their ability to perform well over a wide range of future uncertainty, including climate and other uncertainties. The decision tree is designed to address the fundamental issues to provide a path forward for project planners who face decisions potentially affected by climate change uncertainty. The decision tree was also designed so that human and financial resources can be used economically. The goal of this work was to develop a tool that will be applicable to all water resources projects, but that will also allocate climate risk assessment effort in a way that is consistent with each project’s potential sensitivity to that climate risk. Report is organized as follows: chapter one gives introduction. Chapter two provides background on the risks relevant to water systems planning, describes the different approaches to scenario definition in water systems planning, and introduces the decision scaling methodology upon which the general structure of the decision tree framework is based. Chapter three describes the decision tree tool and explains each of the steps and processes that make up the tool. Chapter four focuses on a case study of a small hydropower project as an illustration of the decision tree procedure. Chapter five describes some of the tools available for decision making under uncertainty and methods available for climate risk management. Concluding thoughts on implementation are presented in chapter six.

Estimation of flood damage functions for river basin planning: a case study in Bangladesh

Located at the low-lying deltaic floodplain of Ganges–Brahmaputra–Meghna river basin, Bangladesh suffers damages from flooding with regularity. From the perspective of long-term planning and management, a reliable flood damage function is a critical component in the estimation of flood-induced economic loss. Such functions are, however, notoriously difficult to develop. This study utilizes in-stream water level and flood-affected area (FAA) data from Flood Forecasting and Warning Center and Bangladesh Water Development Board to evaluate the best form and data input characteristics of flood damage functions for Bangladesh. The performance of various function configurations (geographic data, water level data, and function form) was tested. The Nash–Sutcliffe efficiency and residual error analysis results suggest that, in general, the logistic function performs better than the other two function forms, and the maximum of daily-maximal water level is the best suited to estimate (FAA). As expected, when information is available from all basins (the Ganges, the Brahmaputra, and the Meghna), the resulting flood damage functions provide the most accurate estimations of FAA. Furthermore, the comparison between single- and multivariable flood damage functions does not demonstrate a clear advantage of using multivariate function in our study area. When flood damage functions with finer spatial and temporal resolution can be constructed using remote sensing technology or hydrodynamic modeling, the intra-year and district-level changes to FAA can be evaluated. These findings provide a better flood management plan for Bangladesh and have potential to be generalized to other similarly flood-affected nations.

A user-friendly software package for VIC hydrologic model development

The Variable Infiltration Capacity (VIC) hydrologic and river routing model simulates the water and energy fluxes that occur near the land surface and provides useful information regarding the quantity and timing of available water within a watershed system. However, despite its popularity, wider adoption is hampered by the considerable effort required to prepare model inputs and calibrate the model parameters. This study presents a user-friendly software package, named VIC-Automated Setup Toolkit (VIC-ASSIST), accessible through an intuitive MATLAB graphical user interface. VIC-ASSIST enables users to navigate the model building process through prompts and automation, with the intention to promote the use of the model for practical, educational, and research purposes. The automated processes include watershed delineation, climate and geographical input set-up, model parameter calibration, sensitivity analysis, and graphical output generation. We demonstrate the packages utilities in various case studies. We introduce VIC-Automated Setup Toolkit (VIC-ASSIST).VIC-ASSIST framed within a MATLAB GUI aids building and calibrating the VIC model.VIC-ASSIST helps users navigate the model building processes through automation.We demonstrate the packages utilities in various case studies.