Analytical solutions for distributed multipolar vortex equilibria on a sphere

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Evaluation of ECMWF medium-range ensemble forecasts of precipitation for river basins

Providing probabilistic forecasts using Ensemble Prediction Systems has become increasingly popular in both the meteorological and hydrological communities. Compared to conventional deterministic forecasts, probabilistic forecasts may provide more reliable forecasts of a few hours to a number of days ahead, and hence are regarded as better tools for taking uncertainties into consideration and hedging against weather risks. It is essential to evaluate performance of raw ensemble forecasts and their potential values in forecasting extreme hydro-meteorological events. This study evaluates ECMWF's medium-range ensemble forecasts of precipitation over the period 1 January 2008 to 30 September 2012 on a selected midlatitude large-scale river basin, the Huai river basin (ca. 270 000 km2) in central-east China. The evaluation unit is sub-basin in order to consider forecast performance in a hydrologically relevant way. The study finds that forecast performance varies with sub-basin properties, between flooding and non-flooding seasons, and with the forecast properties of aggregated time steps and lead times. Although the study does not evaluate any hydrological applications of the ensemble precipitation forecasts, its results have direct implications in hydrological forecasts should these ensemble precipitation forecasts be employed in hydrology

The monetary benefit of early flood warnings in Europe

Effective disaster risk management relies on science-based solutions to close the gap between prevention and preparedness measures. The consultation on the United Nations post-2015 framework for disaster risk reduction highlights the need for cross-border early warning systems to strengthen the preparedness phases of disaster risk management, in order to save lives and property and reduce the overall impact of severe events. Continental and global scale flood forecasting systems provide vital early flood warning information to national and international civil protection authorities, who can use this information to make decisions on how to prepare for upcoming floods. Here the potential monetary benefits of early flood warnings are estimated based on the forecasts of the continental-scale European Flood Awareness System (EFAS) using existing flood damage cost information and calculations of potential avoided flood damages. The benefits are of the order of 400 Euro for every 1 Euro invested. A sensitivity analysis is performed in order to test the uncertainty in the method and develop an envelope of potential monetary benefits of EFAS warnings. The results provide clear evidence that there is likely a substantial monetary benefit in this cross-border continental-scale flood early warning system. This supports the wider drive to implement early warning systems at the continental or global scale to improve our resilience to natural hazards

HESS Opinions: On forecast (in)consistency in a hydro-meteorological chain: curse or blessing?

Flood forecasting increasingly relies on numerical weather prediction forecasts to achieve longer lead times. One of the key difficulties that is emerging in constructing a decision framework for these flood forecasts is what to dowhen consecutive forecasts are so different that they lead to different conclusions regarding the issuing of warnings or triggering other action. In this opinion paper we explore some of the issues surrounding such forecast inconsistency (also known as "Jumpiness", "Turning points", "Continuity" or number of "Swings"). In thsi opinion paper we define forecast inconsistency; discuss the reasons why forecasts might be inconsistent; how we should analyse inconsistency; and what we should do about it; how we should communicate it and whether it is a totally undesirable property. The property of consistency is increasingly emerging as a hot topic in many forecasting environments

Renewable energy in remote communities

This article is the result of a competitively tendered University-funded project, this brings together two major Government Policy areas: sustainable communities and use of carbon fuels, and is aimed at influencing the policy debate on the difficulties of linking remote communities to renewable energy production because of poor distribution networks. Linkage with the Sustainable Communities agenda is an essential ingredient, as the proposal is that the renewable energy technologies will be installed and maintained by the communities themselves

Reducing inconsistencies in point observations of maximum flood inundation level

Flood simulation models and hazard maps are only as good as the underlying data against which they are calibrated and tested. However, extreme flood events are by definition rare, so the observational data of flood inundation extent are limited in both quality and quantity. The relative importance of these observational uncertainties has increased now that computing power and accurate lidar scans make it possible to run high-resolution 2D models to simulate floods in urban areas. However, the value of these simulations is limited by the uncertainty in the true extent of the flood. This paper addresses that challenge by analyzing a point dataset of maximum water extent from a flood event on the River Eden at Carlisle, United Kingdom, in January 2005. The observation dataset is based on a collection of wrack and water marks from two postevent surveys. A smoothing algorithm for identifying, quantifying, and reducing localized inconsistencies in the dataset is proposed and evaluated showing positive results. The proposed smoothing algorithm can be applied in order to improve flood inundation modeling assessment and the determination of risk zones on the floodplain

Evidence of a topographic signal in surface soil moisture derived from ENVISAT ASAR wide swath data

The susceptibility of a catchment to flooding is affected by its soil moisture prior to an extreme rainfall event. While soil moisture is routinely observed by satellite instruments, results from previous work on the assimilation of remotely sensed soil moisture into hydrologic models have been mixed. This may have been due in part to the low spatial resolution of the observations used. In this study, the remote sensing aspects of a project attempting to improve flow predictions from a distributed hydrologic model by assimilating soil moisture measurements are described. Advanced Synthetic Aperture Radar (ASAR) Wide Swath data were used to measure soil moisture as, unlike low resolution microwave data, they have sufficient resolution to allow soil moisture variations due to local topography to be detected, which may help to take into account the spatial heterogeneity of hydrological processes. Surface soil moisture content (SSMC) was measured over the catchments of the Severn and Avon rivers in the South West UK. To reduce the influence of vegetation, measurements were made only over homogeneous pixels of improved grassland determined from a land cover map. Radar backscatter was corrected for terrain variations and normalized to a common incidence angle. SSMC was calculated using change detection. To search for evidence of a topographic signal, the mean SSMC from improved grassland pixels on low slopes near rivers was compared to that on higher slopes. When the mean SSMC on low slopes was 30–90%, the higher slopes were slightly drier than the low slopes. The effect was reversed for lower SSMC values. It was also more pronounced during a drying event. These findings contribute to the scant information in the literature on the use of high resolution SAR soil moisture measurement to improve hydrologic models

Key myths about corruption (Briefing Paper)

Corruption has been one of the major international concerns of the past decade. It is an issue that affects all countries, rich and poor, in different ways and to differing degrees. Exactly how corruption affects particular societies has, however, been the subject of some discussion in the literature. The major international institutions promoting governance reforms have, for example, persistently argued that corruption has a direct negative impact upon overall economic growth levels and can depress the climate for attracting international investment; although these are far from universally-held assumptions, even in the mainstream economics literature. Amidst heightened international concern for tackling the abject poverty which continues to affect such large sections of humanity (expressed most clearly in the evolution of the millennium development goals or MDGs), perhaps the most important concern that has been expressed about corruption is that it disproportionately affects the poor and marginalized, through excluding them from access to services or reducing the funds available for direct use in social programmes. Donor-country fears over corruption in the handling of development aid monies may also act to erode the political will necessary to ensure adequate international funding of the actions needed to meet MDG targets, whilst within Southern countries perceptions of widespread corruption within political life can act decisively to depress popular support for state reforms and/or open democratic political systems. Clearly, then, corruption – its extent, nature, dynamics, causation and how it might be tackled – is an issue of fundamental importance to those working in the field of international development. One of the things noticeable on a first exploration of the literature on corruption and development is the singular lack of attention that was devoted to the issue for most of the period since the second world war and, in turn, the sudden rediscovery of the issue towards the end of the 1980s and the explosion of international legislative initiatives, institutional formation and academic work that has occurred since then. Clearly, the end of the bipolar geopolitical world of the cold war and the onslaught of contemporary globalization appear to have presented considerable opportunities for international collaboration in placing the issue at the centre of the international stage. Nevertheless, those very same global processes also present Preliminary version – not for citation without the permission of the authors important challenges to the international community in dealing with the issue because of the difficulties involved in tracing international flows of capital, the increasing complexity of international criminal networks and non-criminal tax evasion networks and the complex and hazy lines between the private and public sectors. Since the early 1990s large amounts of public money have been spent on the development of new legislation at national and international levels, the creation of national anti-corruption programmes and the evolution of anticorruption departments within just about every major international development institution. The impact of such measures, however, has been, at best, partial. As such, whilst the international community should continue to do what it can to raise the international profile of corruption and how it might be better combatted, we argue that it is even more important that a more detailed independent assessment of the effectiveness of existing interventions is carried out. Our position is that the first steps towards such a review of international anticorruption initiatives must involve subjecting the ways in which the issue has been constructed in the mainstream development arenas to closer scrutiny. This workshop is intended to be a first step in this direction. As such, this paper is intended to generate debate about the meaning of corruption, its complexity, how it relates to particular areas of development policy intervention and the means whereby it might be combated (if indeed this is considered feasible or even desirable). Given this, what follows is (i) deliberately provocative, (ii) deliberately broad and (iii) deliberately polemical. We thought long and hard about how best to organize this session and in the end decided to organize it around the presentation of a series of key myths which we have identified as important amongst those involved in anticorruption activities and research. Some of these myths relate to the academic community, some to a kind of general common sense amongst development practitioners and some to those involved in the implementation of anti-corruption initiatives. Here, they are organized into four broad sections dealing with (a) basic definitions, (b) states and markets, (c) actors and anticorruption initiatives and (d) economic factors

What are the key issues regarding the role of geothermal energy in meeting energy needs in the global south?

Globally, the potential of geothermal far exceeds that of all other renewable sources together, although investment in the other sources to date has far exceeded investment in geothermal. World Energy Assessment estimates in 2000 for the global potential of all renewables (EJ/yr) were Geothermal 5000, Solar 1575, Wind 640, Biomass 276, Hydro 50, giving a total of 7541 (UNDP, 2000). When installed, geothermal plants have a far higher capacity factor than other sources (solar depends on the level of direct insolation, wind power on wind, etc.); estimates (REN21, 2009) give wind-power 21%, solar PV 14% but geothermal is at least as high as 75% and often more than 95%, given that once a plant is established it operates continuously except for routine down-time for maintenance and rare break-downs