A Simple Framework for Incorporating Seasonal Streamflow Forecasts into Existing Water Resource Management Practices1

Gong, Gavin, Lucien Wang, Laura Condon, Alastair Shearman, and Upmanu Lall, 2010. A Simple Framework for Incorporating Seasonal Streamflow Forecasts Into Existing Water Resource Management Practices. Journal of the American Water Resources Association (JAWRA) 46(3):574-585. DOI: 10.1111/j.1752-1688.2010.00435.x Abstract: Climate-based streamflow forecasting, coupled with an adaptive reservoir operation policy, can potentially improve decisions by water suppliers and watershed stakeholders. However, water suppliers are often wary of straying too far from their current management practices, and prefer forecasts that can be incorporated into existing system modeling tools. This paper presents a simple framework for utilizing streamflow forecasts that works within an existing management structure. Climate predictors are used to develop seasonal inflow forecasts. These are used to specify operating rules that connect to the probability of future (end of season) reservoir states, rather than to the current storage, as is done now. By considering both current storage and anticipated inflow, the likelihood of meeting management goals can be improved. The upper Delaware River Basin in the northeastern United States is used to demonstrate the basic idea. Physically plausible climate-based forecasts of March-April reservoir inflow are developed. Existing simulation tools and rule curves for the system are used to convert the inflow forecasts to reservoir level forecasts. Operating policies are revised during the forecast period to release less water during forecasts of low reservoir level. Hindcast simulations demonstrate reductions of 1.6% in the number of drought emergency days, which is a key performance measure. Forecasts with different levels of skill are examined to explore their utility.     

Determinants of adaptation practices to climate change by Chepang households in the rural Mid-Hills of Nepal

This study analyzes the factors influencing the adoption of various adaptation practices by a highly marginalized indigenous community in the remote rural Mid-Hills of Nepal. The analysis is based on a household survey conducted among 221 Chepang households selected randomly. A multivariate probit model was used to analyze five categories of adaptation choices against a set of socio-economic, institutional, infrastructural, and perception variables. Perception of rainfall changes, size of landholding, status of land tenure, distance to motor road, access to productive credit, information, extension services, and skill development trainings are all influential to enable households to deviate away from traditional coping strategies and adopt suitable practices to adapt to climate vagaries. Policies and development activities should be geared to address these determinants in order to facilitate adaptation.     

Temporal size distribution and concentration of particles near a major highway

Ultrafine particles (UFP, diameter < 100 nm), as reported in recent findings of toxicological and epidemiological studies, could represent health and environmental risks. Motor vehicle emissions usually constitute the most significant source of UFP in an urban environment. Number, surface and mass concentration of particles were determined at increasing distances from the most important Italian road: the “Autostrada del Sole” A1 highway. Particles in the size range from 0.0059 to 20 μm were measured with a Scanning Mobility Particle Sizer (SMPS) and an Aerodynamic Particle Sizer (APS) spectrometers.The A1 highway was selected because it is characterized by two different traffic conditions: a daily and a weekly traffic. During the weekdays the average traffic flow was about 50 vehicles min^?1 with more than 30% of vehicles being heavy-duty (HD) diesel trucks. The weekly traffic component is characterized by an increased traffic up to approximately 100 vehicles min^?1 during Monday mornings and Friday afternoons because of light-duty vehicles, with substantial reduction of the percentage of HD diesel trucks (typically only 10%).The purpose of this study is the characterization of the A1 highway in terms of evolution of particle size distribution (PSD) and total number concentration at different distances from the highway. This analysis is interesting because Italian traffic presents a higher i) percentage of diesel light-duty vehicles and ii) mean traffic speed in respect to US and Australian traffics. Particle number, surface and mass, exponentially decreases as one moves away from the freeway, whereas UFP number concentration measured at 400 m downwind from the freeway is indistinguishable from upwind background concentration.     

A City Wide Assessment of the Financial Benefits of Rainwater Harvesting in Mexico City

We assess the potential financial benefits of rooftop rainwater harvesting (RWH) in Mexico City from the perspective of property owners and entrepreneurs. A bottom‐up approach was followed by evaluating RWH at individual buildings and aggregating the results to a borough/city level. We consider sector‐specific water demands, potable and nonpotable uses, and user‐specific water tariffs. We find that RWH is economically most beneficial for nondomestic users rather than for small domestic users, who are often the target of RWH interventions. Based on a net present value analysis, a potable RWH system is not favored for most domestic users under the current subsidized municipal water tariff structure. Our analysis only considers capital and maintenance expenses, and not other benefits related to increased access to water and reliability, or social benefits from a switch to a RWH system. If the initial capital expense for RWH is partly financed by transferring the water subsidy to an entrepreneur, then RWH becomes financially attractive for a wide range of domestic users. To improve water access in Mexico City, RWH is attractive in the most marginalized boroughs where water use is currently lower and precipitation is higher. For domestic users relying on trucked water, RWH can have great financial benefits. Our approach provides quantitative data with high spatial specificity, highlighting the places and types of users that would benefit most from RWH.     

Water and economic development: The role of variability and a framework for resilience

The article advances the hypothesis that the seasonal and inter‐annual variability of rainfall is a significant and measurable factor in the economic development of nations. An analysis of global datasets reveals a statistically significant relationship between greater rainfall variability and lower per capita GDP. Having established this correlation, we construct a water resources development index that highlights areas that have the greatest need for storage infrastructure to mitigate the impacts of rainfall variability on water availability for food and basic livelihood. The countries with the most critical infrastructure needs according to this metric are among the poorest in the world, and the majority of them are located in Africa. The importance of securing water availability in these nations increases every day in light of current population growth, economic development, and climate change projections.     

基于自组织理论的重大水利工程建设的社会系统稳定性研究

重大水利工程项目建设对社会系统稳定影响巨大。本文从系统稳定性的角度研究重大水利工程项目建设的社会稳定问题,将重大水利工程建设和社会系统作为一个复杂巨系统进行研究,基于自组织理论研究"重大水利工程建设——社会"(LHPS)系统稳定演变,以此探讨重大水利工程建设的社会稳定风险。首先运用ISM模型对LHPS系统结构进行分析,结果表明LHPS的社会保障子系统直接作用社会分配、移民安置和移民心态等子系统的稳定性,是LHPS系统稳定的关键因素;其次建立LHPS子系统稳定性演变模型,仿真分析了重大水利工程的经济影响和社会影响作为序参量的社会保障子系统自组织演化过程,结果显示,一个完善、稳定的社会保障子系统能有效降低外部扰动对其稳定性的干扰,以及降低社会矛盾和风险对整个社会系统稳定性的冲击,反之,外部扰动将会增大社会保障子系统的不稳定性,带来社会系统稳定性的紊乱。     

County‐Scale Rainwater Harvesting Feasibility in the United States: Climate,Collection Area,Density, and Reuse Considerations

Roof rainwater harvesting (RWH) has the potential to augment water supplies for urban and suburban uses throughout the United States (U.S.). Studies of the performance of RWH at the building and city scales in the U.S. are available, but a countrywide overview of the potential performance of RWH at the county scale has not been done before. Three approaches were taken: (1) assess the viability of RWH in terms of the rainfall that could be captured in relation to the water demand in each county (excluding agriculture), (2) evaluate the performance of a “typical” domestic RWH system across all counties with metrics related to its ability to supply the potable and nonpotable demand, and (3) evaluate the effect of adding a 50% rainwater reuse component to the analysis. We find RWH could be a viable supplemental water source in the U.S., particularly in counties of the Pacific Northwest, Central, and Eastern regions (percent demand covered >50%). Low population density counties have the potential to meet their annual water needs with RWH, while high‐density counties could only source a small portion (~20%) of their annual demand with RWH. Typical RWH systems in counties in the Central and Eastern U.S. performed better than in Western counties. Adding a reuse component can be a key factor in making RWH attractive in many areas of the country. This work can inform future water infrastructure investment and planning in the U.S.