Saturday, December 15, 2012

TYPICAL RAIN 15 Disember 2012

Dicember is North East Monsoon season normally drier month in Kedah. Rain normally spill over from east coast of Peninsular. Putrajaya is reported to be misty from one of  facebook  friend.It is probably changing rain front line abnormally move inland. Kedah may experience the same for the year.

 Today15 December 2012 two days before 2 days  gave accumulated rain 40mm. The day before that jus 1mm.
Today ,15
4.29 p.m :First half minute it drizzel than it increased in intensity for the next ten minute. Run off flow steadily increased.(high intensity rainfall lasted for 11 mins)
4.44 p.m : It changes to driszzel (lasted for 4minutes)
4.48 p.m : It increased to moderate intensity for 3 minutes
4..56 p.m :intensity change to moderate dirzzel
5.02 p.m : drizzel (3minutes)
5.15 p.m : run off still runing
5.35 p.m : no more run off

10 minutes high intensity rain gave runn off on  roadside

Run off

Run off with silt load
Run off with silt load

Rain Subsides and run off cease

Tank rises more than 6 inches due 40mm rain for half an hour
In a standar USLE run off plot would result at least 180litre
 run off considering some percentage of infliteration seepage.
Actual volume of water would have been 250 litres

All reserve tank refilled 

Dark cloud remain ,it givas drizzel  finally 12 hours period yield total 48mm rain. Run of zinc is 64 feet length  thus have to make some correction to standard length.

After the rain total rainfall was checked . Total amount for about  45 minutes amounting to 45 mm. Most probably 50% were result of first 10 minutes.Half an hour after the first rain new drizzel comes probably gave few millimeter more.By nightfall no more rain.

Rain probably continued throught the late night but not not aware  measurement seem to increased to total 48mm (4.29p.m-7.00am 15 Dec 2012). 16 Dec 2012 Morning however bright. It look evening to day will give some more rain.It really gives 45mm rain.The intensity pattern is the same. 17 Dec Morning Cloudy b
ut no rain in the evening and it brightens as day ends.
Half of it eveporated on the next sunny day and the other half on next day.

Wilting Point No No rain  for a week water reserve depleted
Earlier December saturated irrigation (2.5 liters) survive well in 10 days without irrigation  in present of rain

Saturated Bottle has 60% water(2.5 liters) lasted for 3 days 4 days deficit  permenent wilting point for lower leaves
Flood irrigation survive well and better than saturated irrigation for ten days with additional rain

Flood Irrigation much more deficit withoutrain compare to ten days with rain earlier

Flooding irrigation deficit after 3 days kill sahllow rooted young plant bigger  plant  minimally survived in January

Compare to flooding irrigation minor deficit after 10 days  with supplement rain in December

With Rain 10 day without watering survive well

January is Dry month for Kedah there is no rain from 13 Jan to 18 January 2013 untill 22th where there is 0.1mm rain. Heavier rain only came on 24th where the is 3 minute shower followed by 13minute drizell. Rain continues at midnight till morning. However total rain just 25 mm.Evepotranspiration for next two day everporated almost all the as eveporation is about 12mm per day unless the water is collected in resourvour or tank where surface eveporation is reduced due two smaller surface area.
Brunei's climate is hot and humid. Average annual rainfall is about 2500mm along the coast and over 4000mm in the jungle-cloaked hills of the interior.Average annual rainfall is 2873.9 The wettest months are October, November and December, when average rainfall is over 300mm, while the driest are February and March, when average rainfall is about 130mm. November has the most rainy days, while February and March have the fewest.

Most of Agriculture Develepment area nearer the coast just average annual rainfall peobably around 3000mm however rain intensity is more important than average annual rainfall in factor that causes erosion.Thus using higher value will take into consideration of annomaly which causes flood in 20 Jan 2009 with 148.8 mm rain in 24 hour other major flood in 1962,1999(Temburong) and 2009(Muara and Tutong).

Rainfall factor in culculation of Erosion is R value :R=(9.28Pmm-8838.15)/100      joules/m2     : P (2873.9mm maximum 4000mm) is annual rainfall in mm. Therefor R for Brunei is = 178.3164 maximum will be 282.885



A    =    average annual soil loss in the project or farm area. 
                        R    =    rainfall erosivity index
                        K    =    soil erodibility factor
                        L    =    topographic factor, L for slope length
                        S    =    topographic factor, S for percent slope
                        C    =    a cropping-management factor
                        P    =    conservation practice factor

R=(9.28Pmm-8838.15)/100      joules/m2     : P is annual rainfall in mm

L=(l  meter/22.13 meter) 0.5

S   =     (65.4 sin2 θ + 45.56 sin θ + 0.065) where θ is the field slope in degrees

K=0.1317{2.1M to power 1.14 (1/1000)(12-OM)+3.25(S-2)+2.5(P-3)/100

K          =          0.1317[ 2.1M1.14(10-4)(12-OM) + 3.25(S – 2) + 2.5(P – 3)]/100

Where   K         is  the soil erodibility index (for the United States region)
M        is the product of (% silt + % very fine sand)(%silt + %very fine sand + %sand)
 or   (% silt + % very fine sand)(100-Clay)
OM     is the percent of organic matter
       is the soil structure value
       is the profile hydraulic permeability value  


1 VFine Crumb < 1mm
1 V fine Granular <1mm
2 Fine Crumb<2
2  fine Granular <2
3 Medium Crumb <5
3  Medium Granular <5
3 V fine SAB/AB<5
3 FineSAB/AB<10
2 Medium SAB<20
2 Coarse SAB<50
2 Prismatic
2 Platy
2 Massive


1     Rudua Excessively Drain
2     Tok Yong Well Drain
2     Cempaka Somewhat Imperfect
3     Lating Imperfect
4     Tepus Somewhat Imperfect
5     Poor
6     Binjai Very Poor

         M Field Test

                   M= (% silt + % very fine sand)(100-Clay)

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