Energy balance and evaporation loss of an agricultural reservoir in a semi‐arid climate (south‐eastern Spain)

A typical agricultural water reservoir (AWR) of 2400 m² area and 5 m depth, located in a semi‐arid area (southern Spain), was surveyed on a daily basis for 1 year. The annual evaporation flux was 102·7 W m^?2, equivalent to an evaporated water depth of 1310 mm year^?1. The heat storage rate G exhibited a clear annual cycle with a peak gain in April (G ～ 45 W m^?2) and a peak loss in November (G ～ 40 W m^?2), leading to a marked annual hysteretic trend when evaporation (λE) was related to net radiation (R_n). λE was strongly correlated with the available energy A, representing 91% of the annual AWR energy loss. The sensible heat flux H accounted for the remaining 9%, leading to an annual Bowen ratio in the order of 0·10. The equilibrium and advective evaporation terms of the Penman formula represented 76 and 24%, respectively, of the total evaporation, corresponding to a annual value of the Priestley–Taylor (P–T) coefficient (α) of 1·32. The P–T coefficient presented a clear seasonal pattern, with a minimum of 1·23 (July) and a maximum of 1·65 (December), indicating that, during periods of limited available energy, AWR evaporation increased above the potential evaporation as a result of the advection process. Overall, the results stressed that accurate prediction of monthly evaporation by means of the P–T formula requires accounting for both the annual cycle of storage and the advective component. Some alternative approaches to estimating R_n, G and α are proposed and discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

An anthropo-ecological approach to landscape use optimization

A method of landscape evaluation based on the anthropo-ecological approach is worked out. The procedure consists of three stages, viz., general, special and optimization. Within the general stage, the structural arrangement of the landscape is evaluated by means of the concept of geo-ecological sites (GES), which are distributed into four zones (A, B, C, D) according to the degrees of their anthropic disturbance. The zoning performed makes it possible to select those geo-ecological sites where eco-critical relationships can be expected to appear; in order to eliminate such situations, transition zones are calculated for the geo-ecological sites concerned. The outcome of this approach is a proposal of a new structural arrangement of the geo-ecological sites, solving eco-critical situations and serving as a basis for the special and optimization stages of the anthropo-ecological method.     

Stick-slip unstable shear failure as a source of high frequency elastic radiation

Summary The results of laboratory measurements on square perspex models with a stress concentrator under uniaxial compression are presented. An attempt was made to interpret these results in order to determine the mutual relations between the mechanical parameters characterizing the treated models, including their focal zones, parameters of model loading, parameters of seismogenic displacement and parameters of radiated elastic pulses. Particular attention was given to the study of slip displacement, slip velocity, rupture velocity, nucleation points of rupture propagation, nucleation points of elastic radiation and to the frequency analysis of radiated pulses. Measurements of the displacement in the focal zone enabled us to determine the source function, to construct theoretical seismograms in a far field and to compare them with the real pulses from ultrasonic transducers located there. This allowed testing theoretical and experimental approaches to the study of how slip displacement, slip velocity and rupture velocity are related to the parameters of radiated pulses.     

Measurement of a freezing nucleus content in a water sample — Evaluation of the method

Summary A drop freezing technique applied in laboratory research to heterogeneous ice nucleation is described. The quality of the obtained experimental data is studied both theoretically and experimentally. Attention is focused on the range of measurable freezing nucleus concentration, the accuracy, the correctness and the reproducibility of the results. Some mechanisms which could influence the correctness of the method are discussed. No mechanism significantly influencing the measurements was found. It is concluded that the present experimental method is an effective method of measuring a freezing nucleus content in a water sample.

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ama na uu m¶rt;a n¶rt;u mauu ¶rt; ¶rt; a ¶rt;. ¶rt;m ama mam n nuu m¶rt;a. uau ua a ¶rt;uana uum mauu ¶rt; ¶rt;, a mm, naum u nmumm mam. umum m uu a naum m¶rt;a, m u u ma.

     

Tidal deformations of viscoelastic body

Summary The tidal deformations of a viscoelastic body are studied using the simple Kelvin-Voigt model. Expressions for the phase lag and amplitude change of the displacement vector are derived. The energy dissipation rate is calculated for the main disturbing bodies and for diurnal and semidiurnal tidal waves.

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am nuu ¶rt;auu n ma ua-ma. ¶rt; au ¶rt; ana¶rt;au a u uu anum¶rt; ma u. aumaa m ¶rt;uunauu uu ¶rt; u a a m u nm .

     

On the gravitation absorption hypothesis

Summary It is recommended that the data from measurements with supraconducting gravity meters be also analysed with regard to verifying the gravitation absorption hypothesis. Based on theoretical data from a3-year period, the spectrum of the assumed effect of shielding the gravitational influence of the Sun by the Earth's body on the value of the acceleration of gravity has been calculated for the tidal station Brussels (Figs 2a–e).

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¶rt;aam aauuam ¶rt;a uu n¶rt;uaumau ma mu u nuunm n¶rt;auaumauu. a mmuu ¶rt;a a mmu nu¶rt; u nm n¶rt;naa ma auauaumau ¶rt;mu a m a uu u u mmu ¶rt; nuu mauu (u. 2a–).

     

Application of the telluric and magnetotelluric methods in selection of sites for nuclear plants

The paper deals with the application of the telluric method and of magnetotelluric soundings including experimental and model data on the localization of tectonic disturbances in connection with the selection of appropriate sites for nuclear plants.     

Nonlinear adaptive regression predictors based on singular decomposition

Summary The paper deals with a non-linear regression model, linear in parameters. The least-squares adaptation method has been used to determine the model parameters. The conditionality problem in solving equations, which follows from the dependent predictors, has been suppressed by singular decomposition. This model is especially suitable for treating meteorological problems because non-linear processes, e.g. changes of air masses, changes of circulation patterns, etc., can be treated. The model has been tested in connection with the forecast of daily maximum and minimum temperatures. The RMS error lies in the range of 1–2°C, if the principal PPM is supposed.

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Резюме Оnuсывеamся мamемamuческuŭ annaрam нелuнеŭноŭ ре?rt;рессuонноŭ мо?rt;елu, лuнеŭноŭ оmнос umельно naрaмеmров. Для оnре?rt;еленuя naрaмеmров мо?rt;елu uсnользуеmся меmо?rt; нauменьщuх квa?rt;рamов. Плохaя обусловленносmь сuсmемы нauменьщuх квa?rt;рamов, коmорaя вызвaнa взauмноŭ зaвuсuмосmью nре?rt;uкmоров, всmрaняеmся nрu nомощu сuн?rt;улярноŭ ?rt;екомnозuцuu. Эma мо?rt;ель nо?rt;хо?rt;um ?rt;ля nрuмененuя в меmеороло?rt;uu, maк кaк онa nозволяеm рaбоmamь с нелuнеŭносmямu, кaк нanрuмер uзмененuе воз?rt;ущных мaсс, uзмененuе хaрaкmерa цuркуляцuu u m. n. Мо?rt;ель nроверяеmся нa nро?rt;нозе ?rt;невных мuнuмaльных u мaксuмaльных mемnерamур. Сре?rt;няя квa?rt;рamuческaя ошuбкa нaхо?rt;umся в uнmе?rt;рaле оm 1 ?rt;о 2° (uсnользовaн nрuнцun РРМ).

     

Volcanic hazards in the surroundings of Pico de Orizaba,eastern Mexico

Volcanic hazards from Pico de Orizaba volcano are presented here tor the first time. Some 1.3 million people live within the hazard zone, which in the most severe case would encompass the Mexican Gulf coast, east of the volcano. Three major cities located in the eastern part of the hazard zone account for 800 000 of this population and about 200 000 people live within a 20 km radius of the volcano. Probability calculations are presented as an attempt to quantify the hazards in the surroundings of the volcano. Such quantification can be of use in planning for future land use within the hazard zones.A zone of about 10 km radius centred on the top crater is a high hazard zone for gravity-driven flows and fallout ejecta. For large volume eruptions, the radius could be extended to 120 km to the east and 60 km to the west. The asymmetrical distribution is related to the topography of the volcano. Hazards from Pyroclastic-fall deposits are principally to the west of the volcano, since easterly winds are dominant in the area lava-flow hazards are greatest within a 10 km radius from the summit crater. Pyroclastic flow hazards are high up to 20 km from the volcano summit.In the case of reactivation of the volcano, melting of a glacier covering the summit of Pico de Orizaba having a volume equivalent to some 45 × 10⁹ litres of water, would produce lahars which would descend the flanks of the volcano.     

Optimization of determining the additional constant of an electronic distance meter

Summary The optimization of the method of determining the addition constant of an EDM is discussed. The advantages of the optimization procedure from the point of view of efficiency and improvement of accuracy are reported.

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nuuu ¶rt; n¶rt;u a¶rt;¶rt;uu n ¶rt;. u nu n u uu u nu u.