Grid plan | EPFL Graph Search

In urban planning, the grid plan, grid street plan, or gridiron plan is a type of city plan in which streets run at right angles to each other, forming a grid. Two inherent characteristics of the grid plan, frequent intersections and orthogonal geometry, facilitate movement. The geometry helps with orientation and wayfinding and its frequent intersections with the choice and directness of route to desired destinations. In ancient Rome, the grid plan method of land measurement was called centuriation. The grid plan dates from antiquity and originated in multiple cultures; some of the earliest planned cities were built using grid plans in Indian subcontinent. History Ancient grid plans By 2600 BC, Mohenjo-daro and Harappa, major cities of the Indus Valley civilization, were built with blocks divided by a grid of straight streets, running north–south and east–west. Each block was subdivided by small lanes. The cities and monasteries of Sirkap, Taxila and Thimi (

Étapes marquantes du développement urbain de la Chaux-de-Fonds

Tearanel Te

The city planning of La Chaux-de-Fonds, they way we know it today, is the result of a long evolution. It starts the day after a fire which, in 1794, practically devastated the whole village. With the human and material loss which the fire caused, this disaster offered the possibility to reconstruct on a new basis. The fear of fire and the demands of the watch industry, will dictate the policy of city planners and architects. As of this event, the urban expansion of La Chaux-de-Fonds is characterised by three major stages. All three are continuous and interrelated. Each is the product of a particular person. Their coming corresponds to a precise period in time and a given context. The resulting "urban matrix", called massif, will serve for a long period of time as a model for the extension of the city. The continuous use of this model will serve until to the beginning of the 20th century and will only be abandoned at the end of the 1st world war. The present study comprises two distinctive parts, complementary and of equal importance: - A written part and - An illustrated part The choice of these two means for the research is to insure a better understanding of complex subject: - Stage 1: 1794-1795: The reconstruction of the burned down village is assigned to Moïse Perret-Gentil (1744-1815) with the introduction of the first elements of orthogonal planning. It initiates the system of the grid plan which will define future works. - Stage 2: 1831-1835: The continuous and accelerated development of the watch industry pushes the local authorities to hire the engineer Charles-Henri Junod (1795-1843) to plan an extension at a larger scale. The document is named the "General Plan of Alignments". Thanks to its singularity and its urban impact, the Junod plan occupies a significant place in this doctorate thesis. - Stage 3: 1854-1859: The arrival of the railroad, the Industrial Jura, will profoundly modify the urban configuration. The intervention of Charles-Frédéric Knab (1822- 1874) is based on the works of his predecessor. It includes the railroad as a complete part of his Plan of Alignments. It results from this study that the city plans of La Chaux-de-Fonds conceived by the engineers Charles Junod and Charles Knab are not just a simple grid plan applied at random. Their characteristics are far from the image of a checker board plan to which La Chaux-de-Fonds is usually associated to. Instead, these plans result respectively from a combination of refined imbrications of grids which perfectly connect to the existing urban tissue. Behind their apparent regularity, the Junod and Knab plans, hold a series of irregularities which insure at the same time their complexity and their richness. The works of these two engineers constitutes an exemplary case of an urban transformation, a model for a remarkable case of city planning.

EPFL2011

Spatio-Temporal Relationship between Land Cover and Land Surface Temperature in Urban Areas: A Case Study in Geneva and Paris

Roberto Castello, Xu Ge, Dasaraden Mauree, Jean-Louis Scartezzini

Currently, more than half of the world’s population lives in cities, which leads to major changes in land use and land surface temperature (LST). The associated urban heat island (UHI) effects have multiple impacts on energy consumption and human health. A better understanding of how different land covers affect LST is necessary for mitigating adverse impacts, and supporting urban planning and public health management. This study explores a distance-based, a grid-based and a point-based analysis to investigate the influence of impervious surfaces, green area and waterbodies on LST, from large (distance and grid based analysis with 400 m grids) to smaller (point based analysis with 30 m grids) scale in the two mid-latitude cities of Paris and Geneva. The results at large scale confirm that the highest LST was observed in the city centers. A significantly positive correlation was observed between LST and impervious surface density. An anticorrelation between LST and green area density was observed in Paris. The spatial lag model was used to explore the spatial correlation among LST, NDBI, NDVI and MNDWI on a smaller scale. Inverse correlations between LST and NDVI and MNDWI, respectively, were observed. We conclude that waterbodies display the greatest mitigation on LST and UHI effects both on the large and smaller scale. Green areas play an important role in cooling effects on the smaller scale. An increase of evenly distributed green area and waterbodies in urban areas is suggested to lower LST and mitigate UHI effects.

2020

Performance Comparative Assessment of Grid Connected Power Converters Control Strategies

Mario Paolone, Giacomo Piero Schiapparelli

Renewable energy sources are generally interfaced with the electric distribution and transmission grid via power converters. The displacement of the traditional generating plants requires the new resources to be involved in the grid control strategy. This has driven the research to the so called grid supporting control strategies which allow power converters to be involved in the grid voltage and frequency regulation. This paper presents a performance based comparison of three families of converter control strategies: grid forming, grid-following converters and virtual synchronous machines. The CIGRE medium voltage benchmark system is used as a test bench and the performance of the three strategies are compared each other and with those of a traditional reciprocating generator. The analysis is made thought real time simulations.

IEEE2020

Étapes marquantes du développement urbain de la Chaux-de-Fonds

Tearanel Te

EPFL2011