Upload
lekhanh
View
225
Download
3
Embed Size (px)
Citation preview
Conserving Water: Mountain Forests ghold the Key for SAARC Region
Ajay Kumar Lalj y
30.05.2012aklal87@gmail [email protected]
WaterWater
Precious and vital National AssetPrime Natural ResourceEssential for existence of all Lives
Ch llChallenges
A il bilit t S itAvailability yet ScarcityRecharging yet DepletionHuge Investments yet Diminishing ResultsHuge Investments yet Diminishing Results
SAARC REGION WATER AVAILABILITY
Country Renewable water
Per Capita Agriculture Inputs water
Remarks
resourcesp
Km3 M3 M3/ha
Afghanistan NA NA NAg a staBangladeshBhutanIndia
1211951897
8232420351670
899925003289
MaldivesNepalPakistan
NA210223
NA74471353
NA40437407
Sri Lanka 50 2372 6283
World Average 8210 m3 per capitaWorld total Renewable Sources 54228 km3
Where lies the key ???
Not in dams/surface storages
but
in plantsin plants
Hydrological Services by PlantsSurface Run Off Reduction
Water Table Change
Mitigating Floodsg g
Maintaining Rainfall Patterns
Reducing soil erosion
Scientifically established Facts through Research
Plantations/forests reduce run off by 28 to 30%.
Plantations / forests reduce peak discharge by as high as 72%.
Plantations / forests increase infiltration by almost 3 times.3
(FRI, India, Forest Influences Publication Series)
Rational Equation
Q=CIA/360
Infiltration:
Open 1.40 cm per hour - Cultivated land
5 30 h i d l t ti5.30 cm per hour - mixed plantation
3 0 cm per hour - grass land3.0 cm per hour grass land
Interception by plantations
(Stemflow) (throughfall) (interception)
P roxburgii 3 6% 74 3% 22 1%P. roxburgii 3.6% 74.3% 22.1%
T.grandis 6.0 % 73.2 % 20.8 %
S. robusta 7.2 % 54.6 % 38.2 %
A. Catechu 4.2 % 67.3 % 28.5 %
SAARC REGION AND FORESTS
Country Area (000sq
Population ( million)
Forest Area(million ha)
% Forest Area
Remarks
km)
AfghanistanBangladesh
652.2147.6
26152
N A2.58
NA17.49g
BhutanIndiaMaldives
38.43287.20 298
0.6712150 29
17.59 69.09 0 001
72.521.13Maldives
NepalPakistanS i L k
0.298147.179665 6
0.2923.115319 4
0.0015.5 3.9 1 94
3375.128 2Sri Lanka 65.6 19.4 1.94 28.2
Water Table
Discharge reduction average 30%water saved = 120 x 0 55 x 0 3water saved = 120 x 0.55 x 0.3
= 19.75 cmF f 100 h 197500 3For an area of 100 ha = 197500 m3
If 20% is recharging the aquifer to be reusedDrinking water requirement fulfilled
= 0.2 X197500 / (0.05 x 365)= 2164 persons.
Small watershed afforestation reduces run off by 28% and peak by y p y73 %
( Study by Dr. H N Mathur CSWRI 1978)
GW Recharge ( An Illustration)
Indian Haryana state GW level depletion0.20 to 0.3 m per year
Plantations save 28% run off (average)
GW Recharge = 1.30 X 0.5 X 0.28 = 0.18 m every year
Automatic natural recharge
Irrigation Scenario (Indian Context)g ( )Irrigation potential addition
Average Cost of providing water to one ha of land during 7thAverage Cost of providing water to one ha of land during 7Plan = 4.24 lakh Rs.
(BB Bohra Irrigation of Nation Report Aug. 96)
Afforestation by same expenditure = 20 haVolume of water saved = 197500 x 20/100 = 39500 cu mVolume of water saved 197500 x 20/100 39500 cu m
If half can be reused for irrigationWater requirement of wheat = 0.4 x 100 x 100
= 4000 m3/haPaddy = 1.2 x 100 x 100
= 12000 m3/ha= 12000 m3/haSo, 1 ha, 2 crops potential created by spending 4.27 lakh Rs.
Reducing Soil Erosiong
Reduced by 38 5% (TERI G I di 2047)Reduced by 38.5% (TERI Green India 2047)
In Moderately eroded area ( erosion 7 t/ha/yr)In Moderately eroded area ( erosion 7 t/ha/yr)Erosion reduction = 0.38 x 7 = 2.6 t/ha/yrT t l t il d f 100 h 260 t /Total top soil saved for 100 ha =260 t / yearPrice = 57 000 Rs.
SedimentationSedimentation
A Case in PointA Case in PointBhakra Nangal
Catchments 56876 sq. kmq
Annual Rate of Siltation
Assumed 6 43 t/haAssumed 6.43 t/ha
Observed 9.21 t/ha
D i Lif d d f 99 t 61Design Life reduced from 99 years to 61 years
Th k YThank You