24 Springtime Meteorology of Damauli Valley, Nepal: Implications for Climatic Comfort and Environmental Hygiene Sangeeta Maharjan National Atmospheric Resource and Environmental Research Laboratory (NARERL) Central Department of Physics, Tribhuvan University, Kirtipur, Kathmandu, Nepal. E-mail: sangeetamaharjan@gmail.com ABSTRACT Springtime spatial and temporal distributions of temperature and humidity over the Damauli valley have been numerically assessed to examine thermal comfort and environmental hygiene. The study reveals that the near surface temperature over valley may remain at 24, 34 and 27C during the morning, afternoon and in the evening, respectively, and the relative humidity may remain in between 25 to 30% during the spring season. The high temperature and low humidity can signifcantly degrade environmental hygiene over the valley. Keywords: Atmospheric modeling, thermal comfort, environmental hygiene, Damauli valley. INTRODUCTION Although mountain meteorology has been an active area of research for many years and also occupies large volume of literature, the meteorology of the high mountainous region of Himalayas has not been extensively studied. Only a few of studies have been reported from this region, (Regmi et. al. 2003) studied the late wintertime local fows over the Kathmandu valley; Ramanathan and Srinivasan (1998) studied the summer time air fow in the Kashmir valley of India, Zängl et al. (2001) studied the diurnal wind in the Himalayan Kaligandaki valley of western Nepal, Ohata et al. (1981) observed the mountain-valley wind system in the Khumbu Himal in the eastern Nepal. This shows that there is much to know about the characteristic meteorological fows over Nepal Himalaya, which can have profound implications in understanding prevailing weather and climate of the whole Asian sub-continent. As part of the ongoing effort to characterize the springtime meteorological fow system over the mid hills of Nepal Himalaya, present study has been conducted over the Damauli valley, a narrow and deep riverbed valley, located in the western development region of Nepal. The valley is typically situated on the confuence of two major rivers, namely, Madi and Seti Rivers and is in proximity to the vast tropical Gangetic Plain of India in the south and the great Himalayan Chain in the north. The valley foor is situated at an average elevation of 650 meters above the mean sea level (AMSL) and accommodates Vyas Municipility with 36000 residents. Mountains and hills rising up to 1640 meters surround the valley. Fig. 1 may refect the topographic complexities of the valley and its surrounding areas. Fig. 1. Three-Dimensional topographic view of Damauli Valley and its surroundings. The circle encloses the valley. Several case studies and research on epidemiology have shown that dehydration, cell membrane contraction, nose tissue infammations or infuenza and fever are closely associated with prevailing temperature and humidity. The prevalence of low humidity is also believed to favor the growth of allergies and respiratory diseases along with the existence of diseases like fungi (e.g., Aspergillusfumigatus, protozoa, house dust mite, bacteria (e.g., Streptococcus, Legionella) and virus (e.g., common cold, fu) (Baughman & Arens, 1996; Ikeda et al. 2003; Sookchaiya et al. 2010). Journal of Institute of Science and Technology, 2014, 19(2): 24-29, © Institute of Science and Technology, T.U.