David on Formosa

I came across this article in the Taipei Times today which noted that parts of central and southern Taiwan are yet to record any rainfall this year! The article mentions concerns about an imminent drought and then goes on to say,

The Ministry of Economic Affairs’ Water Resources Agency issued a warning on Tuesday about a water shortage.

Central Weather Bureau forecaster Daniel Wu (吳德榮) said the phenomenon was unusual, adding that last month the nation may have received among the lowest precipitation on record.

Information provided by the bureau showed that observation stations in Taichung, Chiayi, Tainan and Kaohsiung had not recorded rainfall for 49 consecutive days since last month.

What is surprising to me is that the article does not once mention climate change. While the conditions might be unusual, they should not be unexpected. A paper by Yu Pao-shan, Yang Tao-chang and Wu Chih-kang published in the Journal of Hydrology in 2002 investigated the impact of climate change on water resources in southern Taiwan. The study forecast increasing run off during the wet season (summer) with decreasing run off during the dry season (winter). This would lead to increasing challenges in storing water during the high run off period for use in the low run off period.

Another paper by H.H. Hsu and C.T. Chen published in Meteorology and Atmospheric Physics in 2002 examined observed and projected climate change in Taiwan. It notes that rainfall increased in northern Taiwan and decreased in southern Taiwan over the past 100 years. There is also a change in the seasonal pattern with more rain falling during the wetter months and less rain falling during the drier months.

The February 2009 edition of Taiwan Review focuses on the issue of water. One article notes that Taiwan faces a projected shortfall in water supply by 2021. Central and local governments are focusing on making better use of water through conservation and recycling in response. However, less than 20% of Taiwanese households are connected to sewerage systems which places on obvious limitation on the potential for water recycling. The article also notes that the price of water in Taiwan is too cheap which discourages recycling and conservation.

Taiwan’s steep mountainous terrain and rivers that have a short run to the sea pose enormous challenges for water management. Changes in rainfall patterns due to climate change further exacerbate these difficulties. The challenges for policy makers are enormous and they can’t afford to get it wrong.