Modeling Integrated Water-User Decisions with Intermittent Supplies
We present an economic-engineering method to estimate urban water use demands with intermittent water supplies. A two-stage, probabilistic optimization formulation includes a wide variety of water supply enhancement and conservation actions that individual households can adopt to meet multiple water quality uses with uncertain water availability. We embed the optimization in Monte-Carlo simulations to show aggregate effects at a utility (citywide) scale for a population of user conditions and decisions. Parametric analysis provides derivations of supply curves to subsidize conservation, demand responses to alternative pricing, and customer willingness-to- pay to avoid shortages. Results show a good empirical fit for the average and distribution of billed residential water use in Amman, Jordan. Additional outputs give likely market penetration rates for household conservation actions, associated water savings, and subsidies required to entice further adoption. We discuss new insights to size, target, market, and finance conservation programs and interpret a demand curve with block pricing.
Influences of ENSO Events on the Hydropower Production in Brazil
Hydropower is the dominant source of electrical energy in Brazil. A network of more than 60 reservoirs is used for hydropower production. In 2001, Brazil suffered from major energy shortages as the capacity to generate energy was limited by available reservoir storage, leading to a significant socio-economic impact, and a reduction of the GDP associated with the manufacturing sector. The climatic aspects of such events are consequently of great interest. Past analyses have looked at the response of seasonal rainfall to ENSO activity in different parts of Brazil. Here, we explore the connections between ENSO, and the seasonal reservoir inflows, and hence the potential seasonal hydropower production from the Brazilian system. The analysis considers both concurrent and leading season relationships with the NINO3 index. A cluster analysis is used to identify groups of inflow stations with similar attributes. The ENSO response for each cluster is then analyzed using statistical methods ï¿½ composite, correlation, rank correlation. Statistically significant, spatially variable changes are identified over the network, and conditional probability distributions of potential changes in energy production by ENSO phase for different seasons are identified. The spatial variability of the response suggests that an integrated evaluation of the response for the entire reservoir network may be very useful to manage the potentially opposite impacts of ENSO in different seasons and different regions of Brazil. An anticipatory spatial balancing of reservoir storage using ENSO information could potentially avoid adverse climatic impacts, and enhance average hydropower production and reliability.
Urban Flood Risk Insurance Models as a Strategy for Proactive Water Management Policies
To improve the water management through hydrological sciences, novel integration strategies could be underpinned to bridge up both engineering and economics. This is especially significant in developing nations where hydrologic extremes are expressive while the financial resources to mitigate that variability are scarce. One example of this problem is related to floods and their global and regional consequences. Floods mainly cause disasters in terms of human and material losses. In 2002, more than 30% of extreme climatic events occurred worldwide were floods, representing 42% of fatalities and 66% of material losses, mostly related to reactive policies. Throughout the last century, hydrological variability and rapidly growing of urban areas have developed new environmental problems in Brazilian cities, such as inundation occurrences on non-planned river basins. One of the causes of flood impacts is that public funds (national, state or municipal) have barely introduced wise proactive polices to follow up rapidly growing urban areas. Inexistent flood-risk-transfer mechanisms have caused the so-called ï¿½flood poverty cycle' due to reactive polices that have been increasing flood losses and, sometimes, became flood disasters. Flood risk management (FRM) is part of pro-active policies to mitigate inundation losses, in order to sustain environmental, social and economic aspects. Concepts and principles of FRM are part of a process that encompasses three phases: (1) preparedness stage, that consists in structural and non-structural actions to prevent and protect potential risk areas, such as early warning systems and scenarios development; (2) control stage, that refers to help actions and protection facilities during the event, and (3) restoration stage, that is related to rebuild affected areas, restore the river dynamics and transfer the socio-economic risks through flood insurances. Flood risk insurances agree to the goals of losses mitigation programs. Their use is more common in basins affected by alluvial floods. However, most of losses occur in urban areas, as a consequence of flash floods. Quantification of losses is an important basis of flood mitigation programs. It is also a complex task, which involves setting values on not easily quantifiable goods and determining risk and damage curves. This work proposes a flood insurance risk model coupled with a hydrological model as an incentive-based mechanism for achieving economically efficient flood management to be applied in Brazilian urban basins. It consists of integrating an insurance model and hydrological modeling of peak discharge warnings. It sets up curves, such as: water level versus discharge, water level versus inundation areas, and inundation area versus damage. It considers the prediction of future scenarios in order to evaluate the behavior of the insurance fund under climate variability. By using different probability distribution is compared the solvency and efficiency of the flood insurance fund for each premium-covered situation. The methodology is outlined to provide resources for the FRM restoration phase. Results are depicted from an experimental river basin sited on a rapid growing urban area, with some lessons learned valid to approach in other urban basins. This example is envisaged to foster resilience in the integration of hydrological science with policy and economic approaches. KEY WORDS: Flood risks management; flood insurance; hydrological modeling.
Opportunities and Challenges in Using Hydrologic Information and Decision Support Tools to Improve Livelihoods in Burkina Faso, West Africa
Burkina Faso is part of the Sahel-Sudan climatic zone south of the Sahara Desert. The rainfall of the region is characterized by extreme seasonal and annual temporal and spatial variability. Soils are generally of low fertility. The major livelihood activity in Burkina Faso, one of the lowest ranked countries in the world in the Human Development Index where 80 percent of the population rely on subsistence farming, is rainfed cultivation of cereal crops. Cotton is the dominant export crop and is mostly grown in the southwest. Livestock management is an important complement to farm activities, especially in the Sahelian zone. There are several major rivers flowing through the region and many ephemeral streams. Surface water resources are becoming more important to Burkina Faso as it tries to improve food security and water supplies, and increase energy production. One of the major opportunities to improve livelihoods in the region has been improvements in seasonal rainfall forecasting based upon global sea surface temperatures. In the past decade, the generation and use of forecasts in Burkina Faso has evolved from the nation just receiving forecasts almost as an after thought from USA and European meteorological services to the Burkina Faso Meteorological Services generating their own forecasts with support from these services. There is now also more focused international research on improving the forecasts for this region. The use of stochastic decision support tools (DST) that combine the seasonal forecasts with hydrologic and crop models, land conditions, and information on farmer and policy maker goals could improve both rainfed and irrigated agricultural systems. Their implementation requires overcoming many technical and socio-economic challenges. Examples include forecasting the start and end of rains, dissemination and explanation of forecasts, streamflow forecasting in data scarce regions, possible different incentives for subsistence and cash crop farmers and water managers, and using sometimes complex technology in rural, traditional societies.
Climate Informed Economic Instruments to Enhance Urban Water Supply Resilience to Hydroclimatological Variability and Change
Hydroclimatological variability presents acute challenges to urban water supply providers. The impact is often most severe in developing nations where hydrologic and climate variability can be very high, water demand is unmet and increasing, and the financial resources to mitigate the social effects of that variability are limited. Furthermore, existing urban water systems face a reduced solution space, constrained by competing and conflicting interests, such as irrigation demand, recreation and hydropower production, and new (relative to system design) demands to satisfy environmental flow requirements. These constraints magnify the impacts of hydroclimatic variability and increase the vulnerability of urban areas to climate change. The high economic and social costs of structural responses to hydrologic variability, such as groundwater utilization and the construction or expansion of dams, create a need for innovative alternatives. Advances in hydrologic and climate forecasting, and the increasing sophistication and acceptance of incentive-based mechanisms for achieving economically efficient water allocation offer potential for improving the resilience of existing water systems to the challenge of variable supply. This presentation will explore the performance of a system of climate informed economic instruments designed to facilitate the reduction of hydroclimatologic variability-induced impacts on water-sensitive stakeholders. The system is comprised of bulk water option contracts between urban water suppliers and agricultural users and insurance indexed on reservoir inflows designed to cover the financial needs of the water supplier in situations where the option is likely to be exercised. Contract and insurance parameters are linked to forecasts and the evolution of seasonal precipitation and streamflow and designed for financial and political viability. A simulation of system performance is presented based on ongoing work in Metro Manila, Philippines. The system is further evaluated as an alternative strategy to infrastructure expansion for climate change adaptation in the water resources sector.
Drought Analyses of the California Central Valley Surface-Groundwater-Conveyance System
Historically, California has experienced periods of long drought conditions. Isotopic analyses have indicated that naturally occurring droughts were most pronounced during the 15th century, when S.F. Delta inflows were less than 50 percent of the long term mean flows. During the last 150 years there has been an above average mean flow concurrent with the onset of agricultural development. More importantly, is the advancement of the California water conveyance system and irrigation farming that came into existence during the latter half of the 20th century. This was during a period of historically wet conditions, and until recently, water resource managers have relied on stationary conditions as part of their management strategy. To provide water resources decision makers with the tools needed for better understanding the consequences of persistent droughts, we have begun a series of numerical investigations to determine system behavior and economic impacts under a range of conditions. Our investigations of California Central Valley impacts of sustained droughts are based on a series of specified reductions (10 to 70 percent) in net surface flows for periods ranging from 10 to 60 years and applied to the California Department of Water Resources' California Central Valley Simulation Model (C2VSIM). This simplified methodology represents a means to evaluate the impacts of reductions in net surface flow from reservoirs. The goals of this study are to understand how reductions in surface water are handled within C2VSIM, how groundwater pumping compensates the reduced inflow, to what degree the water table is reduced, and how this system recovers. Pumping costs will also be calculated for each case. Finally, an economic analysis of the impacts on agriculture as related to changes in farming practices that may be needed to maintain a sustainable agricultural economy in the Central Valley under the range of imposed drought conditions is presented.
Framework for Integrated Water, Energy, and Environmental Resources Assessment, Planning, and Management: Lake Victoria Case Study
This article describes a recent assessment study for Lake Victoria in East Africa. The study includes three interlinked components. The first pertains to Lake Victoria regulation and includes climate and hydrologic forecasting (seasonal, inter-annual, and centennial), and outflow regulation (water resources planning). The second pertains to energy system planning, and the third to environmental and socio-economic impact assessments. These components converge at the operational level where water, energy, and environmental management are harmonized through the use of a decision support system, the Lake Victoria Decision Support Tool. Some of the broad study findings are summarized below: (1)Lake Victoria is entering a new era in which sustainable water resources management is tightly linked to and can only be achieved by proactive energy planning. To meet this new challenge, and maximize the benefit of the decision support system, water and energy sector decisions must be institutionally coordinated. (2)Climate and hydrologic forecasts of sufficient skill are critical for effective water resources and energy planning and management. More specifically, extensive assessments with several GCMs and climate scenarios indicate that Lake Victoria will most likely be adversely impacted by climate change with potentially serious local and regional consequences. Furthermore, seasonal and inter-annual forecasts are very important in meeting medium term water and energy demands and minimizing the costs of thermal energy generation. (3)Wetland ecological and socio-economic benefits are comparable to power sector benefits, underscoring the need for more comprehensive evaluations of non-power water uses and integrative water, energy, and environmental planning and management. (4)Integrated forecast-decision systems are excellent means to bring to bear and make practically available advances in various water-related disciplines for the benefit of managers and policy makers.