* Unpopular government faces another test
* Families flee flood-hit areas
* Vital agriculture sector hit (Adds details, quotes)
By Hamid Shaikh
HYDERABAD, Pakistan, Sept 12 (Reuters) - Pakistan's cash-strapped government, still struggling to help victims of last year's devastating floods, face another major test as monsoon rains sweep across Sindh province in the south.
Flooding has already killed about 200 people, destroyed or damaged nearly one million houses and flooded 4.2 million acres since late August , according to the United Nations Office for the Coordination of Humanitarian Affairs (OCHA).
Prospects for further flood damage would put Pakistan's unpopular government, already battling Taliban militants, allegations of widespread corruption and public anger over power cuts, under immense pressure.
"The situation in Sindh is already serious and there will be more flooding and more problems because of these rains," said meteorology department official Arif Mehmood.
"We have alerted all relevant government agencies dealing with the flood situation."
Zafar Qadir, chairman of the National Disaster Management Authority, said Pakistan was facing a fresh crisis "of great magnitude".
Pakistan's military, which has ruled the country for more than half of its history, took charge of rescue and relief operations during last year's floods, while the government was seen as slow and ineffective.
Still, more than a year later, over 800,000 families remain without permanent shelter, according to aid group Oxfam, and more than a million people need food assistance.
Pakistan may also have lost up to two million cotton bales, or about 13 percent of its estimated crop, due to heavy monsoon rains during harvesting in major producing region Sindh, government and industry officials said. The United Nations said 1.6 million acres of crops had been affected by floods.
"The water flow to the sea is very slow. The drainage system has choked...the agriculture system could not stand the water pressure. So the devastation became immense," said Qadir.
WEAK ECONOMY
Monsoon rains sweep the subcontinent from June to September and are crucial for agriculture in the region.
The South Asian nation, which relies heavily on foreign aid and an IMF emergency loan package, cannot afford heavy losses in the agriculture sector, a pillar of the economy.
Last year, the cotton output fell to 11.70 million bales against a target of 14 million bales due to 2010's floods.
The losses in the cotton crop were among the reasons Pakistan's economic growth that year slipped to 2.4 percent from the original target of 4.5 percent.
Prime Minister Yusuf Raza Gilani has already appealed for international help to cope with the latest floods.
The 2010 floods killed about 2,000 people and made 11 million homeless in one of the country's worst natural disasters.
One-fifth of Pakistan was then submerged in water -- an area the size of Italy -- and the government faced ${esc.dollar}10 billion in damage to infrastructure, irrigation systems, bridges, houses and roads.
Aid workers expressed fears over possible outbreaks of diseases linked to the new floods, especially among children.
"The biggest issue is that they will drink water from anywhere, so water-borne diseases are a threat, especially diarrhoea and cholera," Sami Malik, a spokesman for the United Nations Children's Fund, told Reuters by telephone from flood-affected areas.
"An adult might not drink water if it's dirty. But a child, if he's thirsty, would just drink it." (Reporting by Zeeshan Haider and Qasim Nauman in Islamabad and Sahar Ahmed in Karachi; Writing by Michael Georgy; Editing by Nick Macfie)
Our Standards: The Thomson Reuters Trust Principles.
