Climate change behind Sindh floods!

A part of PWPGreen

Darks clouds hover during the monsoon season

Sindh province is located in the sub-tropical region of the world where summers are extremely hot while winters are mild. Located at 24.87°N 67.05°E, the province experiences south-west monsoon from July till August. Climatically, Sindh is divided into three climatic zones into Siro, Wichola and Lar. Siro mainly consists of upper parts of the province including Jacobabad. Wicholo consists of central parts of the province including Hyderabad while the Lar region is mostly based on the coastal parts of the province including Karachi.

In the year 2011, a total of six monsoon spells hit the province. The first spell in July was caused by an upper air cyclonic circulations while others in August and September were caused by severe dense low pressure systems. The floods of 2011 have been compared to the 2003 Sindh floods, in which severe rainfall continued for weeks.

Condition during monsoon season

  • Neutral ENSO

Most of the rainfall occurred during the neutral conditions while the last two spells occurred during weak La-Nina phase.

Background of Sindh floods

July and August - Rapid change of rainfall for Sindh

A total of sixteen districts were affected by the torrential rainfall in the province of Sindh, the rainfall that fell over the province was estimated to be over 37 million acres feet in just four months, these were the highest-ever recorded monsoon rains and the area had never seen such powerful level of precipitation since many years. During the first two months of monsoon season (July & August), anomalous behavior of precipitation was observed over Pakistan. In July, below normal (-72%) rain was recorded in Sindh.  The above normal monsoon activity was observed during August over the country, especially southern Sindh, where monthly rainfall was (+270%) above normal.

RAINFALL (Percentage Departure)

Region

July

August

Pakistan

-17.7

58.9

Khyber-PK

0.8

8.8

Punjab

1.2

16.6

Balochistan

-36.2

21.6

Sindh

-72.1

271.4

Monsoon season in Sindh generally starts in the from July till late August but during the monsoon season of 2011, precipitation started from late July and continued till mid-September. In 2010, the monsoon rainfall were 87% above normal in Pakistan and was highest since 1994 and ranked second highest during last 50 years of period. In 2011, the monsoon rainfall in Sindh was alone 270% above normal, which were the heaviest recorded during the period 1961-2011.

Before the start of torrential rainfall in Sindh, the province was under drought-like conditions especially in the monsoon month of July and with no major rainfall since last year’s (2010) rainy season that is twelve months.

Monsoon rainfall 2011 in Sindh

Following are the extreme rainfall that started from July till mid-September in Sindh. The rainfall quantity has been shared by PWP  follower Umair Dero;

  1. Mithi got 1332 mm (Maximum rainfall recorded 114 mm in 2004)
  2. Diplo got 1225 mm
  3. Islamkot got 1089 mm
  4. Nagar Parkar got 961 mm
  5. Mirpur Khas got 866.2 mm
  6. Umerkot got 729 mm
  7. Nawabshah got 650.4 mm
  8. Badin got 646.7 mm (Maximum rainfall recorded 121 mm in 1936)
  9. Chhor got 552 mm
  10. Dadu got 485.2 mm
  11. Karachi got 436.5 mm
  12. Padidan got 423.4 mm
  13. Hyderabad got 415.4 mm
  14. Thatta got 245 mm
  15. Jacobabad got 243.3 mm
  16. Larkana got 172.4 mm
  17. Rohri got 134.2 mm
  18. Sukkur got 103.0 mm
  19. Moen-jo-Daro got 101.1 mm

These torrential rainfall caused 434 deaths in the Sindh province with 8.9 million people affected. While 1.52 million homes were damaged and 6.79 million acres land damaged as well.

Monsoon changing pattern – Climate change to be blamed!

Monsoon performance in Pakistan since 2000

In the year in which northern Pakistan gets severe rainfall then it is observed that southern Pakistan would get less precipitation and vice-versa. One thing that is confirmed is that the climate change would cause the monsoon to behave erratic and it would become hard to forecast these mega winds, the monsoon precipitation level could drop in some areas while rise in other areas is expected and there could be a delay in the arrival of monsoon too. Over the years, different reports have been published by different sources that suggest that the Indian monsoon is under threat from climate change and it could change its pattern. The Indian monsoon is very vital for the economic growth of both the agricultural states of India as well as Pakistan. There had been a conflict between these reports as some suggest that monsoon would be more vigorous over northern Pakistan than southern Pakistan and vice-versa. Pakistan Weather Portal (PWP) will discuss both possibilities;

Severe monsoon over northern Pakistan

  • 21st century examples: 2001, 2004, 2005, 2008, 2010

According to the Pakistan’s Asian Development Bank (ADB), monsoon winds are likely to become frequent over northern  Pakistan thus leading to a repeat of 2010 floods, a UK-based climate change expert has also said similar things. Due to climate change there will be an exceptional change in the temperatures in Pakistan in the coming years but the province of Sindh would be less affected as compared to the other provinces of the country.

Severe monsoon over southern Pakistan

  • 21st century examples: 2003, 2006, 2007, 2011

Climate change will impact the monsoon pattern over the country that would cause the monsoon winds to shift more westwards closer to Indus basin, moving away from the Indian state of Rajasthan. In the next 20 to 30 years, severe monsoon rainfall are expected according to some scientific calculations in the southern parts of Pakistan. Due to rise of pollution, frequent cyclones are expected in the Arabian sea as well that is a cause of worry for the countries situated near the Arabian sea.

Pakistan Weather Portal (PWP) conducted a poll on December 27 and majority of the people believed that climate change is a threat to Pakistan. It was surprising to observe this because in the middle of 2011 a local newspaper published a poll that showed the most Pakistani do not believe that climate change is a threat to the country.

A cause of great worry or not?

Though it is not clear whether climate change is happening due to human activities or it is Earth’s natural cycle but we do  know that it is dangerous for human beings. Extreme weather events in Pakistan has become a yearly phenomenon in the country because past records have shown that frequency, intensity and magnitude of such events that includes floods, droughts, cyclones and earthquakes all have become frequent, a clear indication climate change is happening which is a cause of worry for the citizens of Pakistan. 

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