public List <double> GetMonthlyAvgEvapotranspiration()
{
return(Evapotranspiration.Select(x => x / (((double)Counts[Evapotranspiration.IndexOf(x)]) / 365.25 * 12.0)).ToList());
}
public double GetAnnualAvgEvapotranspiration()
{
return(Evapotranspiration.Sum() / ((float)Counts.Sum() / 365.25));
}
//public Evapotranspiration Calculate(string wundergroundKey, DateTime inputDate, string pws, double canopyReflectionCoefficient)
public Evapotranspiration Calculate(string wundergroundKey, DateTime inputDate, string pws, double canopyReflectionCoefficient)
{
var url = "http://api.wunderground.com/api/" + wundergroundKey + "/conditions/history_" + inputDate.ToString("yyyyMMdd") + "/q/pws:" + pws + ".json";
var wc = new WebClient();
string json = wc.DownloadString(url);
var serializer = new JavaScriptSerializer();
dynamic obj = serializer.DeserializeObject(json);
var maxTempF = ParseDouble(obj["history"]["dailysummary"][0]["maxtempi"]);
var minTempF = ParseDouble(obj["history"]["dailysummary"][0]["mintempi"]);
var solarRadiationReadings = new List <double>();
var observationsArray = (object[])obj["history"]["observations"];
for (var i = observationsArray.Length - 1; i >= 0; i--)
{
var observations = (Dictionary <string, object>)observationsArray[i];
var solarRadiationReading = ParseDouble(observations["solarradiation"].ToString());
solarRadiationReadings.Add(solarRadiationReading);
}
var meanSolarRadiationW = solarRadiationReadings.Average();
var avgWindSpeedMPH = ParseDouble(obj["history"]["dailysummary"][0]["meanwindspdi"]);
var elevationFt = ParseDouble(obj["current_observation"]["display_location"]["elevation"]) * 3.28084;
var maxHumidity = ParseDouble(obj["history"]["dailysummary"][0]["maxhumidity"]);
var minHumidity = ParseDouble(obj["history"]["dailysummary"][0]["minhumidity"]);
var latitudeDegrees = ParseDouble(obj["current_observation"]["display_location"]["latitude"]);
var longitudeDegrees = ParseDouble(obj["current_observation"]["display_location"]["longitude"]);
var maxTempC = FtoC(maxTempF);
var minTempC = FtoC(minTempF);
var elevationM = FttoM(elevationFt);
var julianDay = inputDate.DayOfYear;
// step 1, mean daily air temperature C
var meanDailyAirTemperatureC = new List <double> {
maxTempC, minTempC
}.Average();
// step 2, mean solar radiation MJ
var meanSolarRadiationMJ = MJtoW(meanSolarRadiationW);
// step 3, avg wind speed Ms at 2m
var avgWindSpeedMs = MPHtoMs(avgWindSpeedMPH);
// step 4, slope of saturation vapor pressure curve
var saturationVaporPressureCurveSlope = saturationVaporPressureCurveSlopeFn(meanDailyAirTemperatureC);
// step 5, atmospheric pressure
var atmosphericPressue = atmosphericPressueFn(elevationM);
// step 6, psycometric constant
var psychrometricConstant = psychrometricConstantFn(atmosphericPressue);
// step 7, delta term (DT)
var deltaTerm = deltaTermFn(saturationVaporPressureCurveSlope, psychrometricConstant, avgWindSpeedMs);
// step 8, psi term (PT)
var psiTerm = psiTermFn(saturationVaporPressureCurveSlope, psychrometricConstant, avgWindSpeedMs);
// step 9, temperature term (TT)
var temperatureTerm = temperatureTermFn(meanDailyAirTemperatureC, avgWindSpeedMs);
// step 10, mean saturation vapor pressure curve
var saturationVaporPressureMean = new List <double> {
saturationVaporFn(maxTempC), saturationVaporFn(minTempC)
}.Average();
// step 11, actual vapor pressure
var saturationVaporPressureActual = saturationVaporPressureActualFn(minTempC, maxTempC, minHumidity, maxHumidity);
// step 11.1, vapor pressure deficit
var saturationVaporPressureDeficit = saturationVaporPressureMean - saturationVaporPressureActual;
// step 12.1 relative sun earth difference
var relativeEarthSunDifference = relativeEarthSunDifferenceFn(julianDay);
// step 12.2 relative sun earth difference
var solarDeclination = solarDeclinationFn(julianDay);
// step 13 latitude radians
var latitudeRadians = DEGtoRAD(latitudeDegrees);
// step 14 sunset hour angle
var sunsetHourAngle = sunsetHourAngleFn(latitudeRadians, solarDeclination);
// step 15 extraterrestrial radiation
var extraterrestrialRadiation = extraterrestrialRadiationFn(relativeEarthSunDifference, sunsetHourAngle, latitudeRadians, solarDeclination);
// step 16 clear sky solar radiation
var clearSkySolarRadiation = clearSkySolarRadiationFn(elevationM, extraterrestrialRadiation);
// step 17 clear sky solar radiation
var netSolarRadiation = (1 - canopyReflectionCoefficient) * meanSolarRadiationMJ;
// step 18 Net outgoing long wave solar radiation
var netOutgoingLongWaveSolarRadiation = netOutgoingLongWaveSolarRadiationFn(minTempC, maxTempC, saturationVaporPressureActual, meanSolarRadiationMJ, clearSkySolarRadiation);
// step 19 net radiation
var netRadiation = netSolarRadiation - netOutgoingLongWaveSolarRadiation;
// step 19.1 net radiation ng in mm
var netRadiationMM = netRadiation * 0.408;
// step FS1 radiation term
var radiationTerm = deltaTerm * netRadiationMM;
// step FS2 wind term
var windTerm = psiTerm * temperatureTerm * (saturationVaporPressureMean - saturationVaporPressureActual);
// step Final, evapotranspiration value
var evapotranspirationMM = radiationTerm + windTerm;
var evapotranspirationIN = evapotranspirationMM * 0.0393701;
var evapoObject = new Evapotranspiration
{
AvgDailyAirTemperatureC = meanDailyAirTemperatureC,
AvgSolarRadiationMJ = meanSolarRadiationMJ,
AvgWindSpeedMs = avgWindSpeedMs,
SaturationVaporPressureCurveSlope = saturationVaporPressureCurveSlope,
AtmosphericPressue = atmosphericPressue,
PsychrometricConstant = psychrometricConstant,
DeltaTerm = deltaTerm,
PsiTerm = psiTerm,
TemperatureTerm = temperatureTerm,
SaturationVaporPressureAvg = saturationVaporPressureMean,
SaturationVaporPressureActual = saturationVaporPressureActual,
SaturationVaporPressureDeficit = saturationVaporPressureDeficit,
RelativeEarthSunDifference = relativeEarthSunDifference,
SolarDeclination = solarDeclination,
LatitudeRadians = latitudeRadians,
SunsetHourAngle = sunsetHourAngle,
ExtraterrestrialRadiation = extraterrestrialRadiation,
ClearSkySolarRadiation = clearSkySolarRadiation,
NetSolarRadiation = netSolarRadiation,
NetOutgoingLongWaveSolarRadiation = netOutgoingLongWaveSolarRadiation,
NetRadiation = netRadiation,
NetRadiationMM = netRadiationMM,
RadiationTerm = radiationTerm,
WindTerm = windTerm,
EvapotranspirationIN = evapotranspirationIN,
EvapotranspirationMM = evapotranspirationMM
};
return(evapoObject);
}