International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 11 Issue: 02 | Feb 2024
p-ISSN: 2395-0072
www.irjet.net
Characteristics And Long-Term Trends of The Outdoor Thermal Comfort Indices in Aligarh City Huma Matloob Assistant Professor, Architecture Section University Polytechnic, AMU, Aligarh ---------------------------------------------------------------------***---------------------------------------------------------------------
Abstract - Outdoor Thermal Comfort Indices (THI, WBGT
RSI allows the effect of clothing and net radiation to be considered along with the effects of temperature and humidity. The RSI for a healthy 25-year-old male, un acclimatized to heat and in a business clothing; with an internal heat production of 100 W/m2 and in the absence of direct solar radiation and a wind speed of 1 m/s [5]. Both indices, RSI and DI, use temperature and relative humidity (RH) meteorological parameters only to deduce the thermal comfort. Unlike PET and UTCI (Universal Thermal Climate Index), other factors such as variation in solar radiation, wind velocity, and clothing condition are not taken into account in these indices. At city level, local comfort assessment requires a large number of monitoring stations which account these parameters. Many studies often focus over temperature and RH data and extrapolate other parameters using Weather Research and Forecasting model (WRF) [9] or obstacle-resolving numerical models [10].
and RSI) were determined for the Aligarh city. It is found that climatic conditions lead to the uncomfortable conditions in (May –September). Long-term trends of annual kurtosis and skewness values indicate negative and positive trends respectively and maximum change is exhibited by THI. Long-term trends of Outdoor Thermal Indices indicated that lower range of indices have increased in last century. Among the indices, the RSI indicated continuous increase throughout the century, while THI and WBGT indicated sudden change in values since, 1980s. Key Words: Aligarh, Outdoor Thermal Indices, Climate Change
1.INTRODUCTION Dramatic changes in land use/land cover is witnessed by developing country particular Indian and China. These changes impact on thermal regime of land especially over the city areas. Changes in urban climate is linked to the industrial output and also impact on health of urban population. Based on climatic parameters numbers of studies at various scales and indices have been developed for thermal comfort and heat stress which gives numerical relations or graphs for evaluating thermal comfort [1]. Based on cities, their climate type, indices used and comfort reporting was studied for selecting appropriate thermal comfort index. Each index has their own strength in terms of comprehensiveness, usability, validity and completeness [2]. PET (Physiological Equivalent Temperature) was observed as a widely used outdoor thermal comfort index in tropics. Other indices such as Thom’s (DI) Discomfort Index [3] and Relative Strain Index (RSI) are commonly used in urban climate studies [ 4, 5]. Temperature Humidity Index (THI) is used to describe thermal sensations experienced by people as a result of modifications in the climatic conditions of the urban areas [6, 7] It is a more suitable index for the tropics [8]. WBGT index (Wet Bulb Global Temperature) is recommended by the International Organization for Standardization (ISO) and widely used in numbers of studies. A comparative formulas table for the various indices is present in table 1.
© 2024, IRJET
|
Impact Factor value: 8.226
Present study is designed to determine the various outdoor thermal indices. Characteristics of the indices were analyzed for the Aligarh city. Indices similarity, monthly distribution, long trends have been discussed in detail.
2. AREA OF STUDY The city is located in the plains between the Ganga and Yamuna rivers (Fig. 1). It is nearly a level plain and slight elevation is the central. Southern part of the city has old habitation and new urbanization is taking place all along the busy National Highways. The northern part of the city has less habitation and currently going under new urban developmental activity. The Aligarh Muslim University, the prominent part of the city was once on the northern edge of the city, now it is surrounded by new urbanization and is currently in middle of the city [11]. Upper Ganga canal passes through in the Northern part of the city, while the southern part of the city has low lying area of the canal and this area is largely affected by saline soil. In the South eastern direction, the famous tourist cities Mathura and Agra are situated. Busy Delhi –Kanpur and other highway (Aligarh – Matura-Agra), National Highway and Railway passes through the main city.
|
ISO 9001:2008 Certified Journal
|
Page 815