%0 Journal Article
%T Effects of Urban Configuration on Human Thermal Conditions in a Typical Tropical African Coastal City
%A Emmanuel Lubango Ndetto
%A Andreas Matzarakis
%J Advances in Meteorology
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/549096
%X A long-term simulation of urban climate was done using the easily available long-term meteorological data from a nearby synoptic station in a tropical coastal city of Dar es Salaam, Tanzania. The study aimed at determining the effects of buildings¡¯ height and street orientations on human thermal conditions at pedestrian level. The urban configuration was represented by a typical urban street and a small urban park near the seaside. The simulations were conducted in the microscale applied climate model of RayMan, and results were interpreted in terms of the thermal comfort parameters of mean radiant ( ) and physiologically equivalent (PET) temperatures. PET values, high as 34¡ãC, are observed to prevail during the afternoons especially in the east-west oriented streets, and buildings¡¯ height of 5£¿m has less effect on the thermal comfort. The optimal reduction of and PET values for pedestrians was observed on the nearly north-south reoriented streets and with increased buildings¡¯ height especially close to 100£¿m. Likewise, buildings close to the park enhance comfort conditions in the park through additional shadow. The study provides design implications and management of open spaces like urban parks in cities for the sake of improving thermal comfort conditions for pedestrians. 1. Introduction Dar es Salaam is a hot, humid tropical city situated along the Tanzanian coast on the Western Indian Ocean coast. It enjoys the sea-land breezes system which is observed to be more organised during the months of March, April, September, and October [1, 2]. On the other hand, sultriness is not uncommon particularly during the December¨CFebruary (DJF) season. Such sultry conditions bring an undesirable thermal discomfort especially to pedestrians and street vendors. Most biometeorological studies done elsewhere have revealed the effects of street orientation and height to width ratio on the variation of local thermal comfort at an urban canyon level [3¨C6]. Although the human thermal comfort is influenced by four meteorological parameters of air temperature, humidity, wind speed, and radiation flux (usually quantified in terms of mean radiant temperature), it is the wind speed and mean radiant temperature which can be significantly varied by changing the street orientation and height to width ratio [7]. A past urban climate research in Dar es Salaam has suggested that the observed sea-land breeze effect could improve the thermal comfort at high ground places in the city like at the university of Dar es Salaam campus which is about 12£¿km to the west from the city centre
%U http://www.hindawi.com/journals/amete/2013/549096/