Land reclamation | EPFL Graph Search

Land reclamation, usually known as reclamation, and also known as land fill (not to be confused with a waste landfill), is the process of creating new land from oceans, seas, riverbeds or lake beds. The land reclaimed is known as reclamation ground or land fill. In some jurisdictions, including parts of the United States, the term "reclamation" can refer to returning disturbed lands to an improved state. In Alberta, Canada, for example, reclamation is defined by the provincial government as "The process of reconverting disturbed land to its former or other productive uses." In Oceania, it is frequently referred to as land rehabilitation. History One of the earliest large-scale projects was the Beemster Polder in the Netherlands, realized in 1612 adding of land. In Hong Kong the Praya Reclamation Scheme added of land in 1890 during the second phase of construction. It was one of the most ambitious projects ever taken during the Colonial Hong Kong era. Some 20% of land

Le temple d'Hathor à Dendara

Pierre Zignani

Dendara, July 16, 54 BCE, began the reconstruction of the temple dedicated to the goddess Hathor. Founded under Ptolemy XII, the temple studied here stands at the end of an architectural tradition developed over three millennia. Its state of conservation is exceptional. It is the latest preserved monumental cult building of the pharaonic civilisation. It is a particularly well-suited testimony for an attempt to comprehend the architectural conception of a culture with which no modern society has kept any direct connection. The starting point of this study is a precise survey which constitutes the scientific documentation. The establishment of these data went along with the observation of indications, dimensions, orientations and alterations which allows to identify constant characteristics belonging to the process of designing the structure of the temple. This study uses no technical methodology but rather presents a research of knowledge through observation, hypotheses and verification. There is no pretension to exhaustiveness. This study tries to find, from the territory to the details, breaches, or to give access, into the knowledge belonging to the way of designing. The plans and sections are accompanied by a research which begins with a presentation of the nature of the architectural study of the building belonging to a disappeared culture. Then follows the study of the Egyptian temple and of the technical details of the survey. A building belongs to a territory. The absence of any documentation, the disappearance of vestiges dug out since the end of the 19th century as well as the actual policy of land reclaiming on the site made a cartography of the whole area of the ancient city necessary as a salvage. This led to some thoughts about the urban shape around the temple and about the limits of the space between the divine and the civil world. The reconstruction of a temenos wall brought with it a large reorganisation and renovation of the city and caused an important tabula rasa of civil districts. A global description of the building precedes the chapter concerning the organisation of the space. The world being set up around the god, it progresses from the most holy place towards the civil environment. The system underlying the height of the different spaces can only be determined when taking the heart of the temple as point of origin. Particular attention was devoted to the means which the ancient builders had at their disposal in order to control the precision of their accomplishment. Although rules concerning the outer measurements of the naos and the inner volume of the cella could be determined, it is impossible to reduce the dimensioning of the Egyptian space to a system of constant proportions. The study of the use of the space confirms this statement as it reveals that the functional elements of doors and windows do not follow any ideal formal rules. They are the result of a topological conception where geometric accuracy sacralises different needs; sometimes trivial when one considers light as a physical agent necessary to the daily functioning of human beings in a structure belonging to the divine. The intelligence and the accuracy of these accomplishments clearly required a global and initial conception of the architectural object. The durability of the building was the ultimate reason for the designers' research of technical quality. No single part of the construction, from the foundations to the top of the cornices, escaped this ancient concern. This led to an evolution towards a monolithic character of the masonry and the integration of solutions to contain factors of degradation, such as the rain. This concern also includes a tradition of a seismic culture as well as an execution which optimises the performance of labour and the materials. In parallel to this evolution on can observe the emergence of an ancient analysis of the phenomenon of differential sinking and the development of details which allow a dynamic management of major sources of destruction. Computer modelling helped to check the pertinence of some of these ultimate systems of management of deformation. From the temple of Hathor at Dendara one can conclude that the competence of building has attained a high degree of complexity and of meaning as far as the production of an architectural form is concerned which had to obey to an ideal of perfection and inalterability. Beyond the secular world, the formal conceptualisation of the divine universe also became an intellectual challenge with various referential levels. The architectural composition went along with an active research of technical solutions in order to optimise the art of building.

EPFL2004

Tropical soils degraded by slash-and-burn cultivation can be recultivated when amended with ashes and compost

Muhammad Saleem Arif, Alexandre Buttler, Leia Soraya Véronique Falquet, Justine Marie Gay des Combes, Vincent Eric Jules Jassey, Robert Thomas Edmund Mills, Bjorn Jozef Maria Robroek, Clara Sanz Carrillo

In many tropical regions, slash-and-burn agriculture is considered as a driver of deforestation; the forest is converted into agricultural land by cutting and burning the trees. However, the fields are abandoned after few years because of yield decrease and weed invasion. Consequently, new surfaces are regularly cleared from the primary forest. We propose a reclamation strategy for abandoned fields allowing and sustaining re-cultivation. In the dry region of south-western Madagascar, we tested, according to a split-plot design, an alternative selective slash-and-burn cultivation technique coupled with compost amendment on 30-year-old abandoned fields. Corn plants (Zea mays L.) were grown on four different types of soil amendments: no amendment (control), compost, ashes (as in traditional slash-and-burn cultivation), and compost + ashes additions. Furthermore, two tree cover treatments were applied: 0% tree cover (as in traditional slash-and-burn cultivation) and 50% tree cover (selective slash-and-burn). Both corn growth and soil fertility parameters were monitored during the growing season 2015 up to final harvest. The amendment compost + ashes strongly increased corn yield, which was multiplied by 4-5 in comparison with ashes or compost alone, reaching 1.5 t/ha compared to 0.25 and 0.35 t/ha for ashes and compost, respectively. On control plots, yield was negligible as expected on these degraded soils. Structural equation modeling evidenced that compost and ashes were complementary fertilizing pathways promoting soil fertility through positive effects on soil moisture, pH, organic matter, and microbial activity. Concerning the tree cover treatment, yield was reduced on shaded plots (50% tree cover) compared to sunny plots (0% tree cover) for all soil amendments, except ashes. To conclude, our results provide empirical evidence on the potential of recultivating tropical degraded soils with compost and ashes. This would help mitigating deforestation of the primary forest by increasing lifespan of agricultural lands.

Wiley2017

Sustainable, Reshapable Surfactant-Polyelectrolyte Plastics Employing Water as a Plasticizer

Paul Joseph Dyson, Zhaofu Fei, Zhangjun Huang, Haiyan Jia, Antoine Philippe Van Muyden

Natural polymers such as those present in foods contain abundant noncovalent intra- and intermolecular interactions, notably hydrogen bonds, which make them rigid when dry, but on exposure to water soften, due to disruption of these interactions. This softening process allows them to be reshaped. Food-derived materials, however, have limited practical use due to their high brittleness and gradual degradation. Nevertheless, inspired by such properties, surfactant-polyelectrolytebased polymers that contain abundant ionic interactions and can be repeatedly reshaped using water as plasticizer are described. The polymers, on the basis of main chain anionic poly(styrene sulfonates) combined with phosphonium surfactant, are readily synthesized with well-defined lamellar domains through interfacial metathesis reactions. The polymers present typical stress-strain characteristics of plastics, and their modulus undergoes a decrease of ca. 3 orders of magnitude upon shear and stretch forces after plasticizing with water. Since recycling of plastics generally involves complicated and energy-intensive processes (that leads to the majority of plastics being land-filled or incinerated), it is envisaged that reshapable polymers, such as those described here, could reduce the amount of plastic waste as they can be remolded as and when required, thus reducing pollution and the depletion of resources, ultimately contributing to a more sustainable society.

2019

Le temple d'Hathor à Dendara

Pierre Zignani

EPFL2004

Tropical soils degraded by slash-and-burn cultivation can be recultivated when amended with ashes and compost

Wiley2017