evapor-trans2-komplit
Post on 08-Apr-2018
218 Views
Preview:
TRANSCRIPT
-
8/7/2019 Evapor-trans2-komplit
1/38
E V A P O R A S I
Oleh : Emilya Nurjani
-
8/7/2019 Evapor-trans2-komplit
2/38
-
8/7/2019 Evapor-trans2-komplit
3/38
-
8/7/2019 Evapor-trans2-komplit
4/38
Hampir 80% berasal dari laut,sisanya 20% berasal daridaratan dan vegetasi.
Most evaporated water exists asa gas outside of clouds and
evaporation is more intense inthe presence of warmertemperatures.
Evaporasi dan Evapotranspirasi
-
8/7/2019 Evapor-trans2-komplit
5/38
-
8/7/2019 Evapor-trans2-komplit
6/38
FAKTOR YANG
BERPENGARUH
-
8/7/2019 Evapor-trans2-komplit
7/38
-
8/7/2019 Evapor-trans2-komplit
8/38
PARAMETERCUACA
FAKTORTANAMAN
KONDISI LINGKUNGANDAN
PENGELOAAN
-
8/7/2019 Evapor-trans2-komplit
9/38
PARAMETER CUACA
-
8/7/2019 Evapor-trans2-komplit
10/38
RADIASI MATAHARI
Sumber utama energi bumienergi (terpancar 56 x 1026
kalori, sampai di bumi hanya5 x 10-10)
Radiasi gelombang pendek
(< 3 m) : matahari, radiasigelombang panjang
( > 3 m) : bumi
-
8/7/2019 Evapor-trans2-komplit
11/38
-
8/7/2019 Evapor-trans2-komplit
12/38
insolasi
-
8/7/2019 Evapor-trans2-komplit
13/38
-
8/7/2019 Evapor-trans2-komplit
14/38
-
8/7/2019 Evapor-trans2-komplit
15/38
Annual variation in extraterrestrial radiation (Ra)
at the equator, 20 and 40 north and south
-
8/7/2019 Evapor-trans2-komplit
16/38
Annual variation of the daylight hours (N)
at the equator, 20 and 40 north and south
-
8/7/2019 Evapor-trans2-komplit
17/38
SUHU
Temperature is a measure of the
level of sensible heat of matter(solid, liquid, gas)
-
8/7/2019 Evapor-trans2-komplit
18/38
ALAT UKUR SUHU
-
8/7/2019 Evapor-trans2-komplit
19/38
-
8/7/2019 Evapor-trans2-komplit
20/38
-
8/7/2019 Evapor-trans2-komplit
21/38
BEBERAPA PERSAMAANThe relative humidity (RH) expresses the degree of saturation of theair as a ratio of the actual (ea) to the saturation (e(T)) vapourpressure at the same temperature (T):
As saturation vapour pressure is related to air temperature, it canbe calculated from the air temperature. The relationship isexpressed by:
wheree(T) saturation vapour pressure at the air temperature T [kPa],T air temperature [C],exp[..] 2.7183 (base of natural logarithm) raised to the power [..].
-
8/7/2019 Evapor-trans2-komplit
22/38
Saturation vapour pressure shown as afunction of temperature: e(T) curve
-
8/7/2019 Evapor-trans2-komplit
23/38
Variation of the relative humidity over 24 hours for
a constant actual vapour pressure of 2.4 kPa
-
8/7/2019 Evapor-trans2-komplit
24/38
ANGIN
-
8/7/2019 Evapor-trans2-komplit
25/38
Airrisesoverwarm areasandsinks
overcold areas
Airrises inwarm
regions where
pressureislow
(convection)
eg the tropics
Airdescends incold
areas where
pressureishigh
(subsidence)
eg the poles
-
8/7/2019 Evapor-trans2-komplit
26/38
-
8/7/2019 Evapor-trans2-komplit
27/38
effect of wind speed on evapotranspiration in
hot-dry and humid-warm weather conditions
-
8/7/2019 Evapor-trans2-komplit
28/38
-
8/7/2019 Evapor-trans2-komplit
29/38
-
8/7/2019 Evapor-trans2-komplit
30/38
-
8/7/2019 Evapor-trans2-komplit
31/38
-
8/7/2019 Evapor-trans2-komplit
32/38
PerhitunganE
vapotranspirasi
-
8/7/2019 Evapor-trans2-komplit
33/38
Gambaran Perhitungan Evapotranspirasi
-
8/7/2019 Evapor-trans2-komplit
34/38
BerdasarkannilaiEToFAO Penman-Monteith
equation
The FAOPenman-Monteith method isrecommended as the method fordetermining reference ETo. The FAOPenman-Monteith method requiresradiation, air temperature, airhumidity and wind speed data.
The Penman-Monteith form of thecombination equation is:
where Rn is the net radiation, G is thesoil heat flux, (es - ea) represents thevapour pressure deficit of the air, r ais the mean air density at constantpressure, cp is the specific heat of theair, D represents the slope of thesaturation vapour pressuretemperature relationship, g is thepsychrometric constant, and rs and raare the (bulk) surface andaerodynamic resistances.
-
8/7/2019 Evapor-trans2-komplit
35/38
Berdasarkan data meteorologi
ETo = 0.0023(Tmean + 17.8)(Tmax - Tmin)0.5 Ra
-
8/7/2019 Evapor-trans2-komplit
36/38
DeterminasinilaiET0
ETo = referenceevapotranspiration [mmday-1],Rn = net radiationat the crop surface [MJ m-2 day-1],G = soil heat fluxdensity [MJ m-2 day-1],T = air temperatureat 2 m height [C],
u2 = windspeedat 2 m height [ms-1],es = saturationvapourpressure [kPa],ea = actualvapourpressure [kPa],es- ea = saturationvapourpressuredeficit [kPa],D = slopevapourpressure curve [kPa C-1],g = psychrometric constant [kPa C-1].
-
8/7/2019 Evapor-trans2-komplit
37/38
ETobeberapa tipeiklim (mm/hari)
Region Suhu rata-rata harian (oC)
Dingin(~10)
Sedang(20)
Panas(>30)
Tropik dan SubtropikHumid dan sub-humid
2-3 3-5 5-7
Arid dan semi-arid 2-4 4-6 6-8
Temperate
Humid dan sub-humid
1-2 2-4 4-7
Arid dan semi-arid 1-3 4-7 6-9
-
8/7/2019 Evapor-trans2-komplit
38/38
top related