Page - 319 - in Book of Full Papers - Symposium Hydro Engineering

In order to study the mechanism of how reservoir water storage change climate,air temperature and humidity measurements in the district of A County and collection of climate data around the reservoir were promoted carefully in the past six years.The research mainly concentrated on topics of climate changes pre (2011-2013) and post (2013-2016) the reservoir construction, comparative study on water storage rate and air temperature,humidity, etc.Quantitative and qualitative analysis results of the giant reservoir could form laws,which are beneficial to hydropower station design,local vegetation and residents,avoiding extreme disasters in the region. 3. THEORY ANALYSIS Heat and moisture transfer occurs between the air and the reservoir water surface, according to equation (1).When there is a temperature difference at the reservoir water surface,sensible heat,latent heat and moisture would transfer continuously to approach the equilibrium state[18]. (1) Where E represents evaporation capacity of reservoir water surface(Kg).It is determined by surface areas S(m2) and moisture difference value between air moisture concentration and saturated concentration,L for latent heat of water evaporation(KJ/Kg),Rv for specific gas constant of water and vapor,t for reservoir surface water temperature(K),T for air temperature(K) and rvfor density of water vapor(Kg/m3). The air boundary layer transfers sensible heat to the reservoir water surface, when the air temperature of the boundary layer is higher than that of the water surface,and water vapor transfers from the reservoir water surface to the air boundary layer,if its molecular solubility does not reach the saturated solubility of air vapor.Thus,heat and moisture transfer mainly depends on the temperature difference and moisture solubility of the air boundary layer,and the macroscopic computational complexity of the process could be solved by followed equation (2). (2) Where PE represents possible evaporation amount(mm/d),Rn for surface net radiation[MJ/(m*d)],G for soil heat flux[MJ/(m*d)],Ta for daily mean temperature(K), u2 for wind velocity at 2m height(m/s),es for saturated vapor pressure(kPa),ea for actual vapor pressure (kPa),Δfor curve slope of saturated vapor pressure(kPa/℃),γfor psychrometric constant (kPa/℃). 319