Note on the pumped storage potential of the Onslow-Manorburn depression, New Zealand

The Onslow-Manorburn depression in the South Island of New Zealand has possibility for development as the upper reservoir of the world's largest pumped storage scheme, as measured by an energy storage capacity of 10,200 GWh of realisable potential energy. This would more than triple the total national hydro-power energy storage capacity. It is envisaged that the scheme could either operate on a seasonal cycle or act as a passive energy reserve to buffer existing hydro-power capacity against the effect of dry years

The sustainable global energy economy: Hydrogen or silicon?

A sustainable global silicon energy economy is proposed as a potential alternative to the hydrogen economy. This first visualisation of a silicon energy economy is based on largescale and carbon-neutral metallic silicon production from major smelters in North Africa and elsewhere, supplied by desert silica sand and electricity from extensive solar generating systems. The resulting “fuel silicon” is shipped around the world to emission-free silicon power stations for either immediate electricity generation or stockpiling. The high energy density of silicon and its stable storage make it an ideal material for maintaining national economic functioning through security of base load power supply from a renewable source. This contrasts with the present situation of fossil fuel usage with its associated global warming and geopolitical supply uncertainties. Critical technological requirements for the silicon economy are carbon-neutral silicon production and the development of efficient silicon-fired power stations capable of high-temperature rapid oxidation of fuel silicon. A call is made for the development of research effort into these specific engineering issues, and also with respect to large-scale economical solar power generation

A goodness of fit measure related to r² for model performance assessment

Checking the predictive worth of an environmental model inevitably includes a goodness of fit metric to quantify the degree of matching to recorded data, thereby giving a measure of model performance. Considerable analysis and discussion have taken place over fit indices in hydrology, but a neglected aspect is the degree of communicability to other disciplines. It is suggested that a fit index is best communicated to colleagues via reference to models giving unbiased predictions, because unbiased environmental models are a desirable goal across disciplines. That is, broad recognition of a fit index is aided if it simplifies in the unbiased case to a familiar and logical expression. This does not hold for the Nash–Sutcliffe Efficiency E which reduces to the somewhat awkward unbiased expression E = 2 – 1/r², where r² is the coefficient of determination. A new goodness of fit index V is proposed for model validation as V =  r²/(2-E), which simplifies to the easily communicated V = r4 in the unbiased case. The index is defined over the range 0 ≤ V ≤ 1, and it happens that V < E for larger values of E. Some synthetic and recorded data sets are used to illustrate characteristics of V in comparison to

A simple graphical technique for conditional long range forecasting of below-average rainfall periods in the Tuvalu Islands, Western Pacific

For the Tuvalu Island group in the western Pacific, a simple graphical method is proposed as a means of forecasting whether rainfall totals for the next 1, 2,…,6 months will be below average. The method is based on scatter plots where the points are color-coded as above- or below-average rainfall, with the plot axes being lag-1 and lag-2 NINO4 sea surface temperatures. Within the scatter plots there are reasonably clear data fields with higher frequencies of below-average rainfalls associated with cooler precursor NINO4 temperatures. These data fields are defined by subjectively emplaced separation lines which bifurcate the scatter plots into “predictable” and “unpredictable” fields. If two precursor NINO4 temperature values define a point located in a predictable field then a warning would be issued for below-average rainfall over the next n-month period, depending on the time scale of the scatter plot. A long rainfall record at Funafuti in Tuvalu indicates that success in predictable-field forecasting of below-average rainfalls would range between 68% for 1-month rainfall totals and 89% for 6-month totals. The forecasting success derives from persistence of cooler NINO4 sea surface temperatures which are associated with lower rainfalls in Tuvalu. However, many dry periods are also located in the unpredictable field and cannot be forecast by this method

Rent Seeking and Judicial Bias in Weak Legal Systems

We model rent seeking in litigation in weak legal systems as a Tulloch contest in which litigators may seek to influence the court directly through bribery as well as through the merit of the legal case that they bring. If the local firm has a competitive advantage in influencing the court then there is a strategic asymmetry between the players: the local firm regards expenditure by the foreign firm as a strategic complement, but the foreign firm regards local expenditure as a strategic substitute. This leads to different attitudes to commitment: the local firm would like to commit to a high level of effort to influence the court, the foreign firm to a low one. There is also an asymmetry in the commitment technology. It is not easy to commit to a low level of bribery, but it is feasible to commit to a high one: once a payment is made it cannot easily be recovered. We model the interaction as a two stage game: the players simultaneously commit to a minimum level of effort, then they play a simultaneous Tulloch influence game. We find a continuum of equilibria. An equilibrium selection argument selects a unique equilibrium that is outcome equivalent to the Stackelberg equilibrium of a simple Tulloch contest in which the local firm moves first. We thus find an argument for endogenous timing: the local firm moves first and secures a first mover advantage.judicial corruption, Tulloch contest, strategic asymmetry, commitment games, endogenous timing

Contract Design for Biodiversity Procurement

Market based instruments are proving e¤ective in biodiversity procure- ment and in the management of regulatory schemes to preserve biodiversity. The design of these schemes brings together issues in auction design, con- tract theory, ecology, and monitoring. Using a mixed adverse selection, moral hazard procurement model, we show that optimal contract design may di¤er signi?cantly between procurement and regulatory policy environ- mentsbiodiversity; procurement; adverse selection; contract theory

An expression for land surface water storage monitoring using a two-formation geological weighing lysimeter

Field studies have demonstrated that ground surface rainfall accumulation can be detected at depth by synchronous increases in static confined groundwater pore pressures. This opens the way for “geological weighing lysimeters” providing disturbance-free water storage monitoring of the surface environment, in effect by weighing a significant land area in real time. Such systems require specific hydrogeological conditions, which are not easily verified by field observations and replicated observations from multiple geological formations are a prerequisite for quality control. Given replication over two monitored formations, we introduce an expression which utilises the respective formation piezometric water levels to give an improved combined estimate of the ground surface water budget. The expression utilises raw piezometric levels and has the advantage of direct correction for Earth tide noise, which may sometimes be influenced by local effects in addition to the pure solar/lunar tidal potential. The expression is particularly simple, if the two formations have similar (but possibly unknown) undrained Poisson ratios and porosities. Surface water budgets can then be estimated using only the respective formation barometric coefficients and piezometric levels. An example application to two vertically separated confined aquifers at a New Zealand site indicate an improved accuracy over single-formation observations. The two-formation expression for surface storage could find use as an accurate water budget tool with particular application to monitoring diffuse hydrological systems such as wetlands, arid regions, and heavily forested localities

Developing Key Working

The Guide to Developing Key Working aims to offer guidance to those involved in developing, managing and delivering key working for children and young people with special educational needs and disabilities, and their families. The primary audience is commissioners and managers in local areas and in the private, voluntary and independent (PVI) sector implementing key working, but it is also intended to be of use for a wider range of people including policy makers and those carrying out key working functions