SWAT requires daily or monthly values of precipitation, maximum and minimum temperature, solar radiation, relative humidity and wind speed for modeling.
This data includes daily mean air temperature, dew point (minimum, mean and max), relative humidity (minimum and maximum), maximum wind speed, air pressure (minimum and maximum) as well as maximum solar radiation.
The maximum solar radiation is available from March to April, and the minimum insolation is experienced between December and January [13, 30].
During the summer solstice, the obstruction is total throughout the day, whilst during the winter solstice the obstruction is minimum, to allow solar radiation to enter the building.
The site layout consisting of four parallel reference buildings was designed, taking into account the chosen minimum duration of solar radiation during the year, calculated with the iso-shadows module of the 'SENCE' programme.
Other meteorological data such as minimum and maximum temperature, solar radiation, relative humidity and PET were collected from Department of Forestry and Environment, Sam Higginbottom Institute of Agriculture, Technology and Sciences, Allahabad.
Variables extracted included various measures of temperature (annual mean, mean daily minimum and maximum), rainfall, solar radiation and vapour pressure deficit.
This was further supported by that there were tight linear relationships between grain yield with mean maximum and minimum temperatures and accumulative solar radiation during grain filling period.
Based on last 7 years data, the average annual potential evapotranspiration (ETo), precipitation, solar radiation, minimum and maximum temperatures at the study site are 1.84, 0.15 m, 21.6 MJ m−2, −10 and 41°C, respectively.
We performed cross-validations for five meteorological variables (solar radiation, minimum and maximum temperatures, humidity, and precipitation) with a truncated Gaussian filter, ordinary kriging and inverse distance weighting and achieved comparable success among all interpolation methods.
