Book Review: Juridical Positivism and Human Rights

Book Revie

Probabilistic estimates of climate change impacts on UK water resources

Climate change will increase temperatures and change rainfall across the UK. In turn, this will modify patterns of river flow and groundwater recharge, affecting the availability of water. There have been many studies of the impact of climate change on river flows in the UK, but coverage has been uneven and methods have varied. Consequently, it has been very difficult to compare different locations and hard to identify appropriate adaptation responses

Low flow response surfaces for drought decision support: a case study from the UK

Droughts are complex natural hazards, and planning future management is complicated by the difficulty of projecting future drought and low flow conditions. This paper demonstrates the use of a response surface approach to explore the hydrological behavior of catchments under a range of possible future conditions. Choosing appropriate hydrological metrics ensures that the response surfaces are relevant to decision-making. Examples from two contrasting English catchments show how low flows in different catchments respond to changes in rainfall and temperature. In an upland western catchment, the Mint, low flows respond most to rainfall and temperature changes in summer, but in the groundwater dominated catchment of the Thet, changes in spring rainfall have the biggest impact on summer flows. Response surfaces are useful for understanding long-term changes, such as those projected in climate projections, but they may also prove useful in drought event management, where possible future conditions can be plotted onto the surface to understand the range of conditions the manager faces. Developing effective response surfaces requires considerable involvement and learning from catchment decision-makers at an early stage, and this should be considered in any planned application

INCORPORATING SAFETY-FIRST CONSTRAINTS IN LINEAR PROGRAMMING PRODUCTION MODELS

A recent survey indicated that many procedures view risk in a safety-first context. Traditional methods used to impose safety-first constraints in optimization models have often been difficult to implement. This is particularly true when endogenous decisions affect the distribution of the chance-constrained random variable. This paper presents a method whereby probabilistic constraints can be easily imposed upon finitely discrete random variables. The procedure uses a linear version of the lower partial moment stochastic inequality. The resulting solutions are somewhat conservative but are less so than the results using the previously published mean income-absolute deviation stochastic inequality.Production Economics, Research Methods/ Statistical Methods,

PERFORMANCE OF RISK-INCOME MODELS OUTSIDE THE ORIGINAL DATA SET

Selected risk programming solutions (i.e., profit maximization, Target-MOTAD, and MOTAD) are tested in an economic environment outside the data set from which they were developed. Specifically, solutions are derived from either a longer 10-year (1965-74) or shorter 6-year estimation period (1969-74), and then, they are tested for consistent risk-income characteristics over a later 10-year period (1975-84). Risk solutions estimated from earlier periods perform well in the later test period in spite of different economic conditions between time periods. However, favorable performance may be related to the specific example used in this analysis. Further testing for other farm situations is needed before general conclusions can be reached.Risk and Uncertainty,

Atmospheric River orientation determines flood occurrence

Atmospheric Rivers (ARs) have been linked to many of the largest recorded UK winter floods. These large-scale features can be 500–800 kilometres in width but produce markedly different flood responses in adjacent catchments. Here we combine meteorological and hydrological data to examine why two impermeable catchments on the west coast of Britain respond differently to landfalling ARs. This is important to help better understand flood generation associated with ARs and improve flood forecasting and climate-change impact assessment. Analysis of 32 years of a newly-available ERA5 high-resolution atmospheric reanalysis and corresponding 15-minute river flow data show that the most impactful ARs arise through a combination of the orientation and magnitude of their water vapour flux. At the Dyfi catchment, AR orientations of between 238-258o result in the strongest hydrological responses, whereas at the Teifi the range is 224-243o. We believe this differential flood response is the result of catchment orientation and topography enhancing or suppressing orographic rainfall totals, even in relatively low-relief coastal catchments. Further to the AR orientation, ARs must have an average water vapour flux of 400–450 kg m-1 s-1 across their lifetime. Understanding the preferential properties of impactful ARs at catchments allows for the linking of large-scale synoptic features, such as ARs, directly to winter flood impacts. These results using two test catchments suggest a novel approach to flood forecasts through the inclusion of AR activity

Climate change and water in the UK – past changes and future prospects

Climate change is expected to modify rainfall, temperature and catchment hydrological responses across the world, and adapting to these water-related changes is a pressing challenge. This paper reviews the impact of anthropogenic climate change on water in the UK and looks at projections of future change. The natural variability of the UK climate makes change hard to detect; only historical increases in air temperature can be attributed to anthropogenic climate forcing, but over the last 50 years more winter rainfall has been falling in intense events. Future changes in rainfall and evapotranspiration could lead to changed flow regimes and impacts on water quality, aquatic ecosystems and water availability. Summer flows may decrease on average, but floods may become larger and more frequent. River and lake water quality may decline as a result of higher water temperatures, lower river flows and increased algal blooms in summer, and because of higher flows in the winter. In communicating this important work, researchers should pay particular attention to explaining confidence and uncertainty clearly. Much of the relevant research is either global or highly localized: decision-makers would benefit from more studies that address water and climate change at a spatial and temporal scale appropriate for the decisions they make