Francisco José de Caldas's Unaccomplished Life-Project – His Map Provincias Unidas de la Nueva Granada, 1811/ 1815

The first attempted republican map of present-day Colombia remained unachieved. Francisco José de Caldas worked on it since 1797 and, come the revolution and Nueva Granada's republican inception, he prepared two successive cartouches to introduce it: the first one in 1811, the latter in 1815. Finally entitled Provincias de la Nueva Granada, Caldas's map remains understudied. In this article, I establish its basic cartographic parameters, discuss the political context of its unfinished making and link it to its pertinent cartographic precedents.     

Mapping conservation priorities and connectivity pathways under climate change for tropical ecosystems

Climate change and land use conversion are global threats to biodiversity. Protected areas and biological corridors have been historically implemented as biodiversity conservation measures and suggested as tools within planning frameworks to respond to climate change. However, few applications to national protected areas systems considering climate change in tropical countries exist. Our goal is to define new priority areas for biodiversity conservation and biological corridors within an existing protected areas network. We aim at preserving samples of all biodiversity under climate change and facilitate species dispersal to reduce the vulnerability of biodiversity. The analysis was based on a three step strategy: i) protect representative samples of various levels of terrestrial biodiversity across protected area systems given future redistributions under climate change, ii) identify and protect areas with reduced climate velocities where populations could persist for relatively longer periods, and iii) ensure species dispersal between conservation areas through climatic connectivity pathways. The study was integrated into a participatory planning approach for biodiversity conservation in Costa Rica. Results showed that there should be an increase of 11 % and 5 % on new conservation areas and biological corridors respectively. Our approach integrates climate change into the design of a network of protected areas for tropical ecosystems and can be applied to other biodiversity rich areas to reduce the vulnerability of biodiversity to global warming.     

Recent trends in annual snowline variations in the northern wet outer tropics: case studies from southern Cordillera Blanca,Peru

TL-moments approach has been used in an analysis to identify the best-fitting distributions to represent the annual series of maximum streamflow data over seven stations in Johor, Malaysia. The TL-moments with different trimming values are used to estimate the parameter of the selected distributions namely: Three-parameter lognormal (LN3) and Pearson Type III (P3) distribution. The main objective of this study is to derive the TL-moments (t ₁,0), t ₁?=?1,2,3,4 methods for LN3 and P3 distributions. The performance of TL-moments (t ₁,0), t ₁?=?1,2,3,4 was compared with L-moments through Monte Carlo simulation and streamflow data over a station in Johor, Malaysia. The absolute error is used to test the influence of TL-moments methods on estimated probability distribution functions. From the cases in this study, the results show that TL-moments with four trimmed smallest values from the conceptual sample (TL-moments [4, 0]) of LN3 distribution was the most appropriate in most of the stations of the annual maximum streamflow series in Johor, Malaysia.     

A procedure to estimate the probability distribution of recurrence times in the west-northwestern Hellenic arc

The determination of the probability distribution of recurrence times is the most important problem in the calculation of long-term conditional probabilities for the recurrence of large and great earthquakes.The principle of maximum entropy in conjunction with a goodness-of-fit test (chi-square or Kolmogorov-Smirnov test) may be employed to obtain estimates of these densities using recurrence data for some seismic regions.Four different distributions are characterized by the property of maximum entropy, as possible laws for recurrence times of the largest earthquakes: uniform, exponential, Gaussian and log-normal. To discriminate among these different probability distributions we use the probability theory and the chi-square test to check the goodness-of-fit to the distribution of recurrence time of shocks of magnitude 6.5 and largest occurred in the west-northwestern zone of the Hellenic arc from 1791 to 1983.It is found that the recurrence times data for the west-northwestern zone of the Hellenic arc cannot be represented by the uniform and the Gaussian probability densities. The recurrence times data for the west-northwestern zone of the Hellenic arc can be described accurately by the exponential and log-normal probability densities, which were predicted from the principle of maximum entropy. In other words, the principle of maximum entropy does not necessarily lead to a unique solution. In turn, the mathematical properties of these distributions could be used to derive different physical properties of the earthquake process in the west-northwestern zone of the Hellenic arc.     

Probabilistic macroseismic hazard assessment for Nicaragua (preliminary results)

A probabilistic macroseismic hazard assessment has been done for Nicaragua. For this, the most complete catalogue for Central America, compiled by NORSAR in Norway has been used. In this catalogue, empirical intensity attenuation relations were found. Using these empirical relations, magnitudes were changed to epicentral intensities expected in sites where no intensities had been reported. The calculated intensities from a polygon surrounding Nicaragua were used to assess the macroseismic hazard in the region. For the whole polygon, the cumulative intensity frequency was calculated resulting in a b-value of 0.60 for an intensity interval of V–IX. The time completeness was also studied indicating that, for strong events causing higher intensities (I ₀ VII), the catalogue is complete for events that have been recorded since 1840. The whole polygon was cut into independent seismotectonic regions where the statistical procedure (intensity frequency and time completeness) was done.     

A multiresolution strategy for solving landslides using the Particle Finite Element Method

We present an approach for the simulation of landslides using the Particle Finite Element Method of the second generation. In this work, the multiphase nature (granular phase and water) of the phenomenon is considered in a staggered fashion using a single, indeformable Finite Element mesh. A fractional step and a monolithic strategy are used for the water flow and granular phase, respectively. In this way, the maximum accuracy with minimal computational times is reached. The method is completed by adding the interaction terms due to drag and pressure forces, together with a moving mesh strategy to reduce the size of the computational domain.     

Due casi di grave inquinamento di acque sotterranee

Riassunto Ricercate le cause e le modalità secondo le quali si è verificato un vasto inquinamento da cromati alcalini nella falda acquifera della zona di Spinetta Marengo (Alessandria), l'A., mediante il rilevamento chimico-colorimetrico della diffusione dell'inquinamento, esaminate le caratteristiche della falda, introduce un nuovo metodo per determinare analiticamente e graficamente le variazioni della concentrazione. — A proposito di altro inquinamento da arseniato sodico verificatosi in un pozzo al Muggiano (La Spezia) vengono esaminate le caratteristiche in rapporto alla natura geologica del terreno.

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Summary The A. had researched the cause and modality of the large defilement of alkalines chromates in the ground-water-flow of the zone of Spinetta Marengo (Alessandria). By means of chemical and colourimetrical methods, he examined the characteristics of the diffusion of the defilement and present a new method to determine analytically and graphically the variation of the concentration in every point of the zone. — After, the A. examined an other defilement of sodium-arseniate in a well of Muggiano (La Spezia) in reference to the geological feature of the ground.

     

Internal tidal bore warm fronts and settlement of invertebrates in central Chile

We studied the occurrence of large high frequency temperature fluctuations and their potential association with settlement of intertidal invertebrates during the spring/summer period 1999/2000 at Las Cruces, on the coast of central Chile. Our results showed the existence of internal tidal bores, characterized by sharp drops in water temperature at the surface and near the bottom, and subsequent temperature increases, which occurred with a semidiurnal periodicity. Measured currents support the hypothesis of alternating onshore and offshore movement of warm-water fronts. The frequency of the events varied through the summer and their amplitude seems to be modulated by onshore winds. The strongest events were observed when strong onshore winds occurred in late afternoon hours and the entire water column showed a semidiurnal temperature signal. Highest values of chlorophyll concentration in the intertidal zone and daily settlement of bivalves, gastropods and crustaceans were observed at times when conditions were favorable for occurrence of internal tidal bores. Results suggest that internal tidal bore warm fronts could play an important role in the transport of neustonic larval invertebrates and the delivery of phytoplankton to at least some intertidal sites along the coast of Chile.     

Modeling the influence of hydroperiod and vegetation on the cross-sectional formation of tidal channels

The evolution of the cross section of a salt-marsh channel is explored using a numerical model. Deposition on the marsh platform and erosion and deposition in the channel affect the tidal prism flowing through the cross section, such that the model captures the evolution of the stage–discharge relationship as the channel and marsh platform evolve. The model also captures the growth of salt-marsh vegetation on the marsh platform, and how this vegetation affects flow resistance and the rate of sedimentation. The model is utilized to study the influence of hydroperiod and vegetation encroachment on channel cross section. Numerical results show that a reduction in hydroperiod due to the emergence of the marsh platform causes an infilling of the channel. Vegetation encroachment on the marsh surface produces an increase in flow resistance and accretion due to organic and mineral sedimentation, with important consequences for the shape of the channel cross section. Finally, modeling results indicate that in microtidal marshes with vegetation dominated by Spartina alterniflora, the width-to-depth ratio of the channels decreases when the tidal flats evolve in salt marshes, whereas the cross-sectional area remains proportional to the tidal peak discharge throughout channel evolution.