Environmental Impact Assessment and Investment under Uncertainty. An Application to Power Grid Interconnection

We consider a firm that must undergo a costly and time-consuming regulatory process before making an irreversible, lagged investment whose value varies randomly. We analyze two cases: regulatory approval is valid forever or it expires after some time. We apply our model to Hydro-Québec's project of building a 1250 megawatts interconnection with Ontario. We find that the firm may start the regulatory process earlier if regulatory approval is valid long enough or if uncertainty is high enough; it postpones it otherwise. When to start the regulatory process and when to invest depend on the duration of the regulatory green light.Regulation, uncertainty, irreversibility, real options, interconnections

Environmental Impact Assessment and Investment under Uncertainty. An Application to Power Grid Interconnection.

We consider a firm that must undergo a costly and time-consuming regulatory process before making an irreversible, lagged investment whose value varies randomly. We analyze two cases: regulatory approval is valid forever or it expires after some time. We apply our model to Hydro-Québec's project of building a 1250 megawatts interconnection with Ontario. We find that the firm may start the regulatory process earlier if regulatory approval is valid long enough or if uncertainty is high enough; it postpones it otherwise. When to start the reglulatory process and when to invest depend on the duration of the regulatory green light.Regulation, uncertainty, irreversibility, real options; interconnections

Environmental Impact Assessment and Investment under Uncertainty: An Application to Power Grid Interconnection

We consider a firm that must undergo a costly and time-consuming regulatory process before making an irreversible, lagged investment whose value varies randomly. We analyze two cases: regulatory approval is valid forever or it expires after some time. We apply our model to Hydro Québec's project of building a 1250 megawatts interconnection with Ontario. We find that the firm may start the regulatory process earlier if regulatory approval is valid long enough or if uncertainty is high enough; it postpones it otherwise. When to start the regulatory process and when to invest depend on the duration of the regulatory green light. Nous considérons une firme qui doit se soumettre à un processus réglementaire long et coûteux avant de réaliser un investissement irréversible. La valeur de cet investissement est aléatoire et un délai de mise en service est nécessaire. Nous analysons deux cas : l'approbation réglementaire est toujours valide ou elle a une durée finie. Nous appliquons notre modèle à un projet d'Hydro Québec : la construction d'une interconnexion de 1250 mégawatts avec l'Ontario. Nous montrons que la firme débute le processus réglementaire plus tôt si l'approbation réglementaire est suffisamment longue ou si l'incertitude est assez élevée; autrement elle le retarde. Ces décisions dépendent aussi de la durée de l'approbation réglementaire.regulation, uncertainty, irreversibility, real options, interconnections, réglementation, incertitude, irréversibilité, options réelles, interconnexions

Feature contingencies when reading letter strings.

Many models posit the use of distinctive spatial features to recognize letters of the alphabet, a fundamental component of reading. It has also been hypothesized that when letters are in close proximity, visual crowding may cause features to mislocalize between nearby letters, causing identification errors. Here, we took a data-driven approach to investigate these aspects of textual processing. Using data collected from subjects identifying each letter in thousands of lower-case letter trigrams presented in the peripheral visual field, we found characteristic error patterns in the results suggestive of the use of particular spatial features. Distinctive features were seldom entirely missed, and we found evidence for errors due to doubling, masking, and migration of features. Dependencies both amongst neighboring letters and in the responses revealed the contingent nature of processing letter strings, challenging the most basic models of reading that ignore either crowding or featural decomposition

Hydrological behaviour of the granitic Strengbach catchment (Vosges massif, Eastern France) during a flood event

A field campaign combining monitoring devices and determination of isotopes and chemical elements has been performed during a summer thunderstorm in the small granitic Strengbach catchment (Vosges, France). The collected ground data were used in a hydrological modelling exercise including two conceptual rainfallrunoff models (GR4, TOPMODEL). The predominant role in flood generation of pre-event water coming from the superficial layers of the water saturated area has been shown and a conceptual scheme has been proposed derived from the field observations. The two tested modelling structures and assumptions are not able to take into account fully the complexity of the physical processes involved in flood generation

Hydrograph separation using isotopic, chemical and hydrological approaches (Strengbach catchment, France)

The streamflow components were determined in a small catchment located in Eastern France for a 40 mm rain event using isotopic and chemical tracing with particular focus on the spatial and temporal variations of catchment sources. Precipitation, soil solution, springwater and streamwaters were sampled and analysed for stable water isotopes (18O and 2H), major chemical parameters (SO4, NO3, Cl2, Na1, K1, Ca21, Mg21, NH4, H1, H4SiO4, alkalinity and conductivity), dissolved organic carbon (DOC) and trace elements (Al, Rb, Sr, Ba, Pb and U). 18O, Si, DOC, Ba and U were finally selected to assess the different contributing sources using mass balance equations and end-member mixing diagrams. Isotopic hydrograph separation shows that the pre-event water only contributes to 2% at the beginning of the stormflow to 13% at the main peak flow. DOC associated to Si and U to Ba allow to identify the different contributing areas (upper layers of the saturated areas, deep layers of the hillslope and rainwater). The streamflow (70%) originates from the deep layers of the hillslope, the remaining being supplied by the small saturated areas. The combination of chemical (both trace and major elements) and isotopic tracers allows to identify the origin of water pathways. During the first stage of the storm event, a significant part of the runoff (30±39%) comes from the small extended saturated areas located down part of the basin (overland runoff then groundwater ridging). During the second stage, the contribution of waters from the deep layers of the hillslope in the upper subcatchment becomes more significant. The final state is characterised by a balanced contribution between aquifers located in moraine and downslopes. Indeed, this study demonstrates the interest of combining a variety of hydrometric data, geochemical and isotopic tracers to identify the components of the streamwater in such conditions