Climate Change and Drought in Pakistan

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1 Climate Change and Drought in Pakistan Muhammad Munir Sheikh Global Change Impact Studies Centre (GCISC) Islamabad, Pakistan 5 th Meeting of the GEOSS Asian Water Cycle Initiative (AWCI) & International Coordination Group (ICG) December, 2009, Tokyo, Japan

2 Outline of the Study Location and physiographic features of Pakistan Aridity and desertification index maps to see areas susceptible to droughts Areasofremainingdryformorethan50%ofthetimetolocatethedrought vulnerable areas Drought patters in Pakistan and their classification Natural forcing phenomena like ENSO and NAO in the context of their effect on droughts and floods Hydrological drought in the context of variations in the IRS (Indus River System) flows Past and projected climate changes in temperature and precipitation and desertification trend over the country to see their implications Drought implications under climate change Damages caused by droughts and possible adaptation strategies to counteract their adverse impacts Drought Management Future Strategies

3 Pakistan s Location and Physiographic Features Pakistan is located approximately within the latitudinal and longitudinal extensions 24 N to37 N and61 E to76 E respectively The country is located in sub-tropics as well as in temperate region Physically it is the vast valley of mighty Indus River and its tributaries running through the whole country Northern mountains comprise parts of the Himalayan and Karakoram ranges with a small part of the Hindukush range. Pakistan has more glaciers than any other land outside north and south Poles and cover some 13,680 sq. km as glaciated area. Karakoram is the abode of sizable glaciers and as high as 37% of Karakoram area is under its glaciers against Himalayas 17% and Alps 22%. Vast expanses of Arabian Sea lie to the south of Pakistan Areas below approximately 31 N constitute deserts. Thar desert spans the border between India and Pakistan. Hamun-e-Mashkhel, some 87 km long and 35km wide is the largest desert found in Balochistan. The Dasht and Kharan deserts of Balochistan lie towards the western border of Pakistan with Iran.

4 Physiographic Map of Pakistan

5 Aridity Index Map of Pakistan ( )

6 Northern & Southern Parts of Pakistan in the context of their climates Northern half of the country above 31 N is semi arid to humid with a sub-humid belt running along the southern slopes of the sub-montane regions Southern half of Pakistan below 31 N is mostly arid to hyper arid The weighted precipitation in the southern half (~175mm) is one-third of the precipitation in the northern half (~600mm). The weighted rainfall in southern half is almost half of Pakistan s weighted precipitation( around 330 mm) Pakistan receives around 50% of the rainfall during monsoon (JJAS) season while about 30% is received in winter (DJFM) season a) Northern Pakistan b) Southern Pakistan

7 Desertification Criteria and Index for Pakistan Criterion used for defining a desert in Pakistan is that R<T/5, where R is annual precipitation in inches and T is annual average temperature (Desert Meteorology by Thomas T. Warner, 2004) Area below 31 N being arid and hyper arid fits well into the definition of a desert The highest desertification index is towards the western border of Pakistan with Iran having Dasht and Kharan deserts of Balochistan. Average annual rainfall in these deserts is less than 60 mm

8 Desertification Index Map of Pakistan

9 Desertification Trend ( )

10 Season-wise Drought Vulnerable areas ( ) Areas shown during different seasons on the average remain dry for more than 50% of the time and are termed as drought vulnerable during a particular season. DJFM AM JJAS ON

11 Droughts History and patterns in Pakistan Pakistan has a long history of droughts. The Punjab province experienced the worst droughts in 1899, 1920, 1935 and The North-West Frontier Province (NWFP) experienced the worst droughts in 1902 and 1951, while Sindh had its worst droughts in 1871, 1881, 1899, 1931, 1947 and 1999 Southern Pakistan and parts of Sindh and Balochistan faced the worst drought during the period which prolonged till 2002 in certain areas The media reports and actual records classify on the average a moderate and a severe drought when rainfall departures from normal are respectively <-25% and <-50% Droughts in Pakistan follow the same definitions as generally accepted, prolonged period with below average precipitation in case of Meteorological drought; water reserves in aquifers, lakes and reservoirs etc. fall below the statistical average (Hydrological drought) and insufficient moisture for average crop production in case of agricultural drought Provinces of Pakistan

12 Natural Forcing Phenomena (ENSO & NAO) affecting Rainfall Variability during JJAS

13 Natural Forcing Phenomena (ENSO & NAO) affecting Rainfall Variability during DJFM

14 Droughts and Floods and their linkage to ENSO and NAO Indices El Nino years are generally seen to relate to deficient rains in the country leading to drought conditions whereas La Nina years behave the other way round and bring excess rains The media reports and actual record support that the deficient rains during El Nino years in general, caused drought condition in the country Positive NAOI values generally bring above normal rains during winter and negative values the deficient rains At times La Nina conditions negate the drought conditions in northern half of Pakistan during winter (DJFM) as for example the case in 1998 when there was drought in the southern parts of the country

15 Indus River System and its tributaries

16 Distribution of Water in Main Rivers of Pakistan % of IRS Inflows % Seasonal Distribution Summer (Apr-Sep) Winter (Oct-Mar) Dominant Source in Summer Indus Snow/Glacial melt Chenab Jhelum Snow/Glacial melt + Monsoon Mainly Snow melt + Monsoon Kabul Snow/Glacial melt Others 5 Dominant Source in Winter Winter Rainfall + Base flow Winter Rainfall + Base flow Winter Rainfall + Base flow Winter Rainfall + Base flow

17 Variation in River Flows and implications during low-flow years The average annual river flows are about 141 maf (174 bcm) at RIM (River Inflow Monitoring) stations varying from 97 maf in a lowflow year (2002), the drought year to 172 maf in a high flow-year (1992), a worst flood year Some 82% of water inflows are during the Kharif period (i.e. the summer months: April-September) about 18% in the Rabi period (i.e. the winter months: October-March) The average flow to the sea ( i.e. flow below Kotri) is about 35 maf (average for to period) with the minimum flow as low as 0.8 maf (in , the drought period and the maximum flow as high as 92 maf (in ), the flood period. (GoP-MoW&P 2005) One of the most feared effects of climate change on Pakistan is the likelihood of increased frequency of occurrence and severity of extreme weather events as was witnessed during the last decade of the previous century and thereafter

18 Observed Trends in Temperature and Precipitation Temperature The area averaged mean annual temperature over Pakistan increased by 0.57C (in agreement with the global trend) over the period The 48-year period recorded a slope of mean annual temperature as 0.24C per decade as compared to 0.06 per decade during reflecting much increased rate of warming in recent years (again in agreement with the global trend) Summer (April-May) temperatures (both mean and maximum) increased in all parts of Pakistan during During the same period, Balochistan Plateau, located in southern half of the country, was seen warmer in all the seasons. Monsoon (June-September) temperatures (both mean and maximum) dropped throughout Pakistan during except in Balochistan Plateau During , the Greater Himalayan region (the abode of sizeable glaciers feeding the Indus River System) had a warming trend on annual basis as well as in all seasons except monsoon season

19 Observed Trends in Temperature and Precipitation Precipitation The area averaged mean annual precipitation over Pakistan increased by 25% during the previous century Monsoon precipitation increased elsewhere except in coastal regions (where there was a significant drop) and the Western Balochistan Plateau during During the above period, the winter rains decreased by 13-20% in Sindh and western Balochistan. It may be seen that the Sindh province is particularly vulnerable to drought and remains dry for more than 50% of the time

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21 Projected Changes in Average Precipitation of Northern and Southern Pakistan 16 Series1 Northern Pakistan Series2 Southern Pakistan (Coarse Resolution Results) Precipitation chnage (%) (Corresponding to IPCC A2 Scenario) Based on Ensemble of 13 GCMs s 2020s 2050s 2080s Periods (Corresponding to IPCC A1B Scenario) Based on Ensemble of 17 GCMs

22 Projected Temperature Changes in 2080s, T ( C) by GCM Ensemble for A2 Scenario Pakistan Northern Pakistan Southern Pakistan Annual 4.38 ± ± ± 0.18 Summer 4.13 ± ± ± 0.26 Winter 4.47 ± ± ± 0.18 Temperature increases in both summer and winter are higher in Northern Pakistan than in Southern Pakistan Temperature increases in Northern and Southern Pakistan are higher in winter than in summer

23 Projected Precipitation Changes in 2080s, P (%) by GCM Ensemble for A2 Scenario Pakistan Northern Pakistan Southern Pakistan Annual 3.48 ± ± ± 9.46 Summer ± ± ± Winter ± ± ± 9.05 The rather large errors make it difficult to draw any definite conclusions about change in precipitation with time There is, however, some indication of precipitation increase in summer and precipitation decrease in winter in the Southern Pakistan

24 Damages caused by drought Agricultural growth suffered a severe setback during as a result of the drought. While major crops (wheat, cotton and rice) registered a negative growth of almost 10%, the overall agriculture recorded a negative growth of 2.6% during The performance of minor crops (cereals, vegetables, fruits, condiments, oil seeds, fodder and others) was also affected by the prevalent long dry spell. The drought persisted throughout , resulting in water shortage of up to 51% of normal supplies as against 40% of the previous year The total flows of water in major rivers also declined to 109 bcm against an average of 162 bcm. The rainfall has also been below normal Drought occurred during the period in Pakistan affected over 3.3 million people, including thousands who became refugees and hundreds who died of thirst and starvation, and about 30 million livestock, including over 2 million died (GoP- MoEnv 2003) The droughts have a great affect on the country s economy. The State Bank of Pakistan calculated the effect of the drought to the tune of $ 927 million in the third quarter of the fiscal year. The anticipated GDP growth rate of 4.5% could not be achieved, rather, the GDP growth rate declined to less than 3% resulting in stagnation of the per capita income (Annual Report, State Bank of Pakistan, )

25 Drought Implications under Climate change More than 92% of water is consumed by irrigated agriculture, direct implicationofdroughtyearsonirrigatedagricultureandonrainfed areas affect adversely on the economy of the country as 22% of GDP is contributed by this sector 44% of labour is engaged in the agriculture sector which too gets adversely affected during the drought years The past and projected temperature and precipitation trends, in particular in the southern half of Pakistan, the drought susceptible region, the likelihood of enhanced desertification and consequently more and severe droughts may occur The variability in monsoon rains and their changing distribution over the country may enhance the variability in the river flows Erratic and uncertain rainfall patterns under climate change may cause drought conditions in the rain fed agricultural areas, about 16% of the total cultivated area

26 Drought Implications under Climate change Contd.. Intrusion of saline sea water into Indus deltaic region during the low flows will affect coastal ecosystems and decline in water quality for agriculture. The situation may further aggravate on account of sea level rise due to melting of glaciers due to general warming up of the HKH glaciated region under climate change Pressure on the ground water extraction, in particular, in the deltaic and coastal areas may cause the ground subsidence rates to increase and consequently allow more sea water to intrude in the deltaic region The rangelands cover almost a third of Pakistan s total area and support two third of the entire population of sheep and goats and over half of cattle population and provide livelihood to millions of herders and pastoralists. There are particularly vulnerable to the impacts of climate changes as the capacity for adaptation to these impoverished regionsisverylow

27 Mini dams and rain water harvesting techniques need to be developed in the drought vulnerable regions to help sustain the rangelands and livelihood of the people in the rain fed areas Drought Management - Future Strategies The strategy calls for the use of improved irrigation methods and practices, development of crops with high yields and lower water consumption, and use of water saving techniques etc. It is envisaged that drought-tolerant and water-use efficient crop varieties may be developed using the biotechnological techniques Enough water needs to be allocated to ensure minimum environmental river flows down stream Kotri. This is possible only through the construction of large dams upstream on the Indus rivers The extent of sea water intrusion in the deltaic region needs to be reliably assessed through data on the sediment and water discharges from Indus river into the Arabian Sea Ground water extraction needs to be regulated in the deltaic and coastal areas to lessen the ground subsidence rates to allow reduced sea water intrusion during drought years

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