Why doe the amount of water vapour decrease rapidly with altitude?

Answer 1

To know the reason behind it remember one thing that with increasing altitude the temperature decreases eg. in may month there will be high temperature in mumbai that is at low altitude and comparatively low temperature in himalayan region (eg. srinagar) that is at high altitude.Now as we know that high temperature increases the rate of evaporation and if the rate of evaporation is increased through leaves then more water will go into atmosphere and humidity will increase and this gives us our answer that is...............at high altitude because of low temperature the evaporation rate decreases and thus there are less water vapour in atmosphere as compared to low altitude areas where there is high temperature and high vapour rate in air due to evaporation