Water Worries – What Can Be Done?
Prior to Typhoon Morakot, Taiwan's agricultural land was bone dry. But the gods overcompensated with a massive deluge. What can the agricultural sector do to survive such extreme climatic variations?
Water Worries – What Can Be Done?By Yu-Jung Peng
From CommonWealth Magazine (vol. 428 )
Heading south on the Sun Yat-sen Freeway, in the wake of Typhoon Morakot both sides of the road on the stretch between Sinying and Matou in Tainan County are one big swamp. Flocks of ducks lounge around right on the road.
As the water recedes, the Matou freeway interchange becomes passable, yet the area in the immediate vicinity, Youcheli, which produces premium pomelos renowned for their sweetness that sell for NT$2000 per catty, remains submerged.
"An entire year of hard work just washed away," laments Chen Ming-ho, a distraught 73-year-old farmer as he stares at his grove of old pomelo trees.
Well before the traditional pomelo season around the Mid-Autumn Festival, a large batch of pomelos is floating in water. According to official Tainan County estimates, half of the pomelo crop was destroyed by the typhoon.
When it comes to unpredictable water, farmers have what can only be described as a love-hate relationship. After a particularly tame plum rain season this year, Chen Ming-ho anticipated that the pomelo harvest would be especially sweet. However, the torrential rains not only plunked a large percentage of the fruits in the water, but may cause the 20-year-old trees to rot from the roots up. Over the last three years, alternating droughts and floods have destroyed nearly one hundred of Chen's trees.
Proceeding deeper into Kaohsiung's Cishan area along the provincial highway, 20 hectares of banana fields alongside the New Ciwei Bridge, which was broken asunder under the load of surging water, have been submerged under two meters of driftwood and gravel. By his initial reckoning, Huang Shun-Cheng, section chief of the Kaohsiung County Agricultural Department, estimates that 200 hectares of agricultural land in Cishan have been swallowed up by the floodwaters.
Nearly the entire crop of bananas has been wiped out at Cishan, which supplies 40 percent of Taiwan's banana output, with losses estimated at NT$150 million. An estimated 3000 hectares of bananas around Taiwan have been damaged. The price of bananas is now expected to skyrocket as a consequence by 500 to 1000 percent, and to remain high for an entire year.
The deluge has swamped Taiwan's breadbasket, the Jianan Plain (running from Jiayi to Tainan), which accounts for nearly half the country's rice, fruit, animal husbandry, and aquaculture. The direct impact of the damage, estimated at NT$2.1 billion at present, will be felt in high food prices for the rest of the year.
The extremes in weather from floods to water shortage have become the most severe test of Taiwan's agriculture industry and food supply, which depend so directly on nature's bounty.
Water Conservation Makes Magnificent Muskmelons
It's not yet 9:00 a.m., and the August sun is already scorching the fields of Taibao, in Jiayi County.
The brawny production and marketing director Chen Chin-yi enters the greenhouse and switches on the automatic irrigation box, his thick fingers expertly twiddling the controls to reset the length of the automatic watering period from 45 seconds to one minute, keeping it at 21 times per day.
At the appropriate time the irrigation hoses buried under the soil turn on automatically, dripping precisely on the melons' roots, barely wasting a single drop on the leaves. Under the leaves lie the muskmelons, with their smooth emerald skin, plump shape and subtle fragrance. Highly profitable, they are also an environmentally friendly crop.
The village greenhouse, which seems to go on as far as the eye can see, is equipped with a water-saving irrigation system developed in Israel, a country that knows a thing or two about water shortages. As precise as the body's circulation system, it has helped Shennong Award winner Chen Chin-yi grow his Imperial Red variety of cherry tomatoes and premium muskmelons. He sells his muskmelons directly to the high-end supermarkets at Sogo and Taipei 101. When the pricing is good, they can fetch NT$250 per kilo, yielding a profit four to five times that of the average muskmelon.
The traditional method for growing muskmelons involves arranging the melons in rows with irrigation channels running between them, letting the water penetrate the soil from both sides. This rough method is notoriously water-intensive. Chen Chin-yi, who gave up a career in life insurance ten years ago to return to his roots as a commercial farmer, received a partial grant four years ago from the Chia-Nan Irrigation Association, installing the Israeli drip irrigation system at a cost of NT$150,000 per fen (a Taiwanese measurement of area equal to 9.93 square meters).
Chen Wu-sung, director of the Chia-Nan Irrigation Association's Technology and Promotion Center, relates that the drip irrigation system saves at least half the water used by conventional irrigation.
"An even greater benefit is being able to control the growth," adds Chen. Irrigating the roots directly helps reduce the risks of the leaves, fruit and flowers contracting illnesses from excessive wetness during the growth process. In addition, it allows for liquid fertilizer to be added to the drip irrigation system. The pinpoint precision greatly reduces fertilizer costs, and allows the farmer to retain the soil rather than replacing the over-fertilized soil each year, as is common practice.
Few melons fall from the vines, their shape is uniform, and their taste is very sweet, naturally fetching significantly higher prices.
Water-conserving Field Laboratory
Average rainfall in Israel, a state three-quarters the area of Taiwan, is around 700 millimeters a year (just 30 mm. in the southern desert region), only one-third the amount of sub-tropical Taiwan.
In its desperate need for water, Israel has developed advanced agricultural irrigation systems. As much as 80 percent of its agricultural land uses automatic irrigation and fertilization systems, and nearly 40 percent of the irrigation water uses recycled treated water.
The Israeli IrriWise automatic irrigation system introduced by the Council of Agriculture is currently being used on an experimental basis by the Chia-Nan Irrigation Association's Technology and Promotion Center.
The space between the rows of guavas and mangos at the Technology and Promotion Center's experimental field is dotted with moisture-monitoring instruments placed at varying depths in the soil, which report data through a wireless system to a solar-powered main station near the fields, equipped with a secure smart card access mechanism.
Professor Kuo Sheng-feng of the Department of Resource Environment at Leader University explains that this irrigation system compiles water and soil readings with biological crop data into a remote computer, which enables control over the fields from a remote control room. For instance, when the soil moisture drops below the set level, it automatically turns on the irrigation system, shutting it back off when the desired level is reached, and facilitating control over crop quality.
Old-fashioned Irrigation, Modern Management
Agriculture accounts for around 70 percent of all water usage on Taiwan – a typical water usage ratio for anywhere in the world. Most of the agricultural water is devoted to irrigation. Chen Shen Hsien, director general of the Ministry of Economic Affairs' Water Resources Agency, relates that although irrigation water helps supplement ground water supplies and maintain ecological balance, current methods are too scattershot and have plenty of room for improvement.
In order to improve the efficiency of Taiwan's irrigation water usage, in addition to altering dry field irrigation methods, management of the agricultural field water resources system that feeds 460,000 hectares of fields around the island is especially critical.
The Chia-Nan Irrigation Association is Taiwan's largest such organization, with 600 staff overseeing management of 75,000 hectares (an area 2.7 times the size of Taipei City) in Jiayi and Tainan counties. The irrigation channels are long enough to stretch from one tip of the island to the other 25 times.
In comparison to other regions not affected by water shortages, the Jianan region has an average 900-percent gap in water supply between its wet and dry seasons. With 80 percent of its rainfall coming between May and September, water resource distribution is severely uneven. Consequently, the water resource monitoring system and regional irrigation management have long been the lifeblood of Jianan area agricultural production.
The Chia-Nan Irrigation Association began setting up its automatic monitoring and reporting system 15 years ago, using electronic instruments to measure the ingress and egress of water at 85 monitoring points and work stations.
The importance of this management system can be expected to rise as droughts increase in frequency. Huang Che-jen, head of the Syuejia Township Irrigation Station in Taiwan County, recalls how this system's equitable distribution mechanism, using monitoring and alternate flow regulation, helped minimize conflicts and the theft of water resources during the severe water shortage of 2002.
Back in the era of Japanese colonial rule over Taiwan, civil engineer Hatta Yoichi designed the Jianan canal system and the Wushantou Reservoir, lifting the Jianan Plain out of its long-term suffering from water shortages to transform it into the fertile breadbasket of Taiwan. As the extremes between drought and flood periods intensify in the future, water management poses a critical challenge to Taiwanese agriculture.
Translated from the Chinese by David Toman
Chinese Version: 旱澇劇變 農民該拿水怎麼辦？