穀物基因改造技術也沒用全球資源分配不均，使得非洲等落後國家可利用的水資源相當有限。這個現象更常常引發農業困境，衍生飢荒問題。先進國家為了解決這情形，運用生物科技發明穀物基因改良技術，希望能改善非洲糧食問題，但是有學者認為這未必是對的方法。

「國際食糧農業協會」﹙Food and Agriculture Organization﹚總幹事雅克．迪烏夫認為，在非洲，如果要改善衰弱的農業，最重要是優先解決灌溉和造路問題，而不是期望生物科技能在這片土地上發揮效用。同時，他也在「美洲開發銀行」（Inter-American Development Bank）發表一場演說中明確指出，非洲農業發展上面臨的首要問題是水，其次才是鄉村公共建設和道路問題。

基因改造農業技術不僅影響貧窮國家，先進國家關於此議題也有爭議；美國布希政府一直認為，歐盟的禁令會妨礙其他國家接受基因改造的利益，尤其是飽受飢荒之苦的非洲。布希政府向「世界貿易組織」（WTO）提起控訴，申訴歐盟生技產品延期償付是非法的貿易阻攔，使得美國農夫損失上百萬，同時，布希總統也在一場演講中說到，歐洲政府應該一起加入推廣基因改造而不是阻礙，最好的原因是可解決非洲飢餓問題。

但是雅克迪烏夫談論此問題時認為，非洲一直有糧食短缺需要靠國外農業技術幫忙，是因為在撒哈拉沙漠底下只使用1.6％可用水，因此合理認為應該還可以取得水並且有發展機會。

雖然「國際食糧農業協會」認為生物科技是一種改善農業和糧食不足的問題，但是迪烏夫表示，非洲許多國家甚至不能夠擅用40年的種植技術，最大的原因是他們沒能力利用水資源。

最近聯合國有一份報告發現，撒哈拉沙漠附近城市的貧民中，只有31％的人家中有水可用。

現在，非洲坦尚尼亞這個國家也出現了私人企業做販賣水的事業。受坦尚尼亞政府委託的「市民用水服務公司」（City Water Services），已經在今年8月正式開始營業。

只是，並非所有「市民用水服務公司」的顧客都可以盡情享用安全的飲用水。事實上，大部分作此消費的民眾還是只有定量配給的份。10萬名消費者中，只有30％的人可以天天享用安全無虞的水。該公司表示，這也是沒辦法的事，因為管線還沒有鋪設完畢。

水源緊張（water stress）的現象在非洲實在是太普遍了。當世界貧富差距問題受人討論之際，水資源分配的問題也該獲得正視。窮到連水都沒得喝、沒得用，非洲民眾面臨的貧窮更讓人感到可怕。下次，當你在飲用一罐七、八十塊台幣的礦泉水時，別忘了這個故事。From first light, the whistles and squawks of Dar es Salaam's water sellers echo around the streets of a city where only a fraction of the population has access to clean, safe water.

Tanzania's commercial capital is a humid, sweltering coastal city of around 3 million in one of the world's poorest countries.

More than half its people survive on less than $1 a day. Most cannot turn on a tap to wash or pour a drink and instead rely on water sellers.

They often they risk their health in the process -- cholera has killed almost thirty people in Dar es Salaam over the last two months, according to official figures.

In a bid to modernize the city's water services, the Tanzanian government appointed a private company, City Water Services, to run the formerly state-run operations in August.

Other governments will be keeping a close eye on how the British-German-Tanzanian venture tackles the crippling water problems common to many African cities.

A recent U.N. report found that only 31 percent of poor people in sub-Saharan cities had access to water in their homes.

In Dar es Salaam, the water supply network was last upgraded almost 30 years ago. The city's population has boomed since then, and the United Nations now puts its growth rate at around 8 percent -- one of the highest in the continent.

Water rationing is currently in force across large parts of the sprawling city.

Only about 30 percent of 100,000 registered City Water customers receive water seven days a week, 20 percent get water for three days or less than three days a week, and the rest get none from the water pipes at all, the company estimates.

City Water chief executive Mike O'Leary says he is under no illusions about the scale of the task ahead.

"The scope of the work involved is enormous and it will not be possible to resolve all problems immediately," he told Reuters. "But certainly, there will be some improvement in the supply to some areas over the next few months."

Foremost among the challenges are thousands of illegal connections to the supply network -- many by unscrupulous water vendors who then supply homes and businesses at a vast profit.

"A 20 liter (four gallons) jerry can from one of these sellers costs 100 Tanzania shilling ($0.1) or more," said Ali Rajab, buying vegetables at the city's heaving Kariakoo market under a blazing midday sun. "It is much too much."

City Water says the "street price" is more than 10 times what they charge through the pipes.

Most of Dar es Salaam's water comes from three treatment plants. City Water says 60 percent is lost through leaks, unmetered excessive usage and straightforward theft.

It plans to tackle illegal connections, which increase wastage through leaks and risk contaminating the rest of the supply, through a six-month amnesty.

Removing illegal connections is a sensitive business. It is not just market gardeners, or small-scale entrepreneurs, who are diverting water illegally.

Since starting its operations, City Water says many people have told it certain individuals are charging significant sums to arrange water supply connections.

"We can also show you places where the tampering on our network has been done by people who are not short on resources," O'Leary said.

Others accuse those with vested interests in the status quo of deliberately sabotaging the distribution system.

"When the water flows in the pipes once in a month, it reaches only a few houses as the piping has been destroyed deliberately by those who benefit because of this consistent problem," one resident wrote to The Guardian newspaper.

Countries with less than 4,600 quarts of water available per person, per day, including agricultural and industrial usage, are said to be in "water stress," according to the U.N.

By 2025, the share of the world's population living in water-stressed areas will increase to 35 percent, or about 2.8 billion people. If Tanzania's population grows at a medium or fast rate, the U.N. says, it will have joined the list by then.

The private sector can modernize outdated networks in the developing world, but it must be effectively regulated by governments, the U.N. says.

「世界水之週」（World Water Week）在今年的8月10日至16日於瑞典斯得哥摩爾舉行。總共有1千2百位專家學者出席討論全球水資源問題，與會者還包括來自各國的政府官員、科學家、貿易家、以及許多非政府組織機構，他們在這個跨國際論壇上討論水資源分配、天然災害、人口與糧食供給等問題。

今年的議題鎖定在8個焦點，其中也談到歐盟每年在非洲投資1.5兆歐元的水工程計劃，使許多非洲的國營用水企業轉變成一種「多國聯合民營化」的型態（如坦桑尼亞的City Water Services民營公司）。然而，民營化也在許多非洲國家引發一連串的問題。就像「世界銀行」（World Bank）今年在迦納提出的「水資源是可販賣財產，還是應該免費提供給貧困民眾的天然資源」問題，日後都可能成為國際會議所關注的議題。雖然如此，歐盟主要還是希望，能透過「歐盟供水方案」（EU Water Initiative）的實施，在2015年以前，幫助4億居住在偏遠地區的非洲人口，使他們能夠享用乾淨的飲用水與衛生的環境。

今年同時也是聯合國的國際淡水年（United Nations International Year of Freshwater），關於淡水的使用問題，也是今年斯得哥摩爾集會所要討論的重頭戲。德國慕尼黑大學的教授威得洛（Peter A. Wilderer）是今年「斯得哥摩爾水獎」（Stockholm Water prize）得主，他認為，西方世界的水資源回收技術未必適合非洲地區，而非洲飲用水的問題應依照各地不同風土民情，尋求個別解決之道。例如，在肯亞首都奈洛比，政府每年發出4千張販水執照，但大多數的水販使用的水源不明，於是造成了浪費，毀壞的供水系統使得當地40％的水不知去向。

提供安全飲用水和下水道設施（sanitation）也可以省下健康衛生預算，以飲用水為傳染途徑的疾病患者減少與流行病預防能力的提升，將使醫院空出些病床。

威得洛教授從事水資源回收研究有數十年，同時將回收水的原理，運用在歐洲某家航空公司一款巨無霸豪華客機的設計上。而埃及政府也因實行一套水資源回收的政策，將處理過的用水拿來灌溉森林，減少水資源的浪費，進而增加國家的收入。根據以上的實例，科學家們討論出一個結論，只要水資源能夠確實地以適當的量使用在對的地方，水資源供需平衡的美夢是能夠實現的。

Simple innovations such as recycling household water and fixing leaky pipes would bring safe drinking water to hundreds of millions of people lacking it today, politicians and scientists said yesterday.

More than 1.2 billion people lack access to clean water, according to the United Nations, and 12 million die of diseases caused by poor water quality each year, said speakers at World Water Week, an annual gathering of some 1,200 water experts from 100 countries.

A U.N. action plan aims to halve the number of people lacking access to clean drinking water and tolerable sanitary conditions by 2015, but little progress has been made so far.

"There are people in the semi-arid and arid areas who still have to walk about 10 hours looking for water. That situation is totally unacceptable," Martha Karua, Kenya's minister of water resources, told Reuters.

"Kenya is a water-scarce country, but I believe that with efficient management of our water resources we can use the available water resources for the benefit of everybody and to cover all our needs," Karua said in an interview.

She said rebuilding Nairobi's crumbling water infrastructure with leaking pipes would cost over $80 billion, but much also needed to be done to eradicate corruption and misuse.

"In Nairobi around 40 percent of the water is unaccounted for," Karua said.

"It is estimated that there are around 4,000 water vendors licensed by the Nairobi City Council. What is amazing is that very few of these have any known water source which means basically that we are licensing people to vandalize the system."

Providing safe drinking water and sanitation would also save money from health budgets by freeing hospital beds from those suffering from water-borne diseases and prevent epidemics.

"SARS developed in an area where there was virtually no sanitation available and no safe drinking water, and it affected both the people there but also people living in Canada and the world economy," said Peter Wilderer, professor at the Technical University of Munich.

Wilderer has studied recycling household water and said the technical innovations to cut water use dramatically are already there.

"This is not an academic exercise. Many large industrial firms have realized this is the market of the future," he said.

加拿大境內河流湖泊無數，向來以豐富的水資源聞名，其淡水資源佔全球的20％，然而，去年加拿大自然資源部的報告指出，受全球溫室效應影響，加拿大的水資源在接下來的一百年將遭到極為嚴重破壞，水力發電功效將減弱，湖泊的水位也會下降，甚至帶來更嚴重的乾旱現象。

氣候因素在水循環中有著重要角色，加拿大自然資源部所提出的報告詳述了氣候變遷將使得水資源的供應急遽下降，進而在農業發展、供應食物、人體健康、生態保育各方面產生負面效果。此外，加拿大南部在過去的30至50年間，河流每年平均流水量大幅減少，尤其在夏季用水量高峰期8月及9月最為明顯，如果這個情形持續進行，會使得許多原本乾旱現象就很明顯的地區，其水資源短缺更加嚴重。

在水文現象方面，全球氣溫上升引發一些「極端事件」的發生，如氣候變遷所導致不尋常的大洪水量，將可能成為危害加拿大人最嚴重的一次。而暖冬現象也造成加拿大高緯度地區的冰山融化，造成冬季洪水現象，甚至影響許多地區的觀光產業。

除此之外，隨著這些氣候變遷帶來的極端現象，加拿大水資源的品質也會大打折扣，大流量的洪水增加了水的混濁度，也把污染物沖刷到水循環系統中，而低水位將使得污染物的集中程度更高。

由於水資源豐富，加拿大2／3的總發電量都是依賴水力發電。但由於氣候變遷帶來水量不足的問題，電力的產出量也因此大打折扣，夏季溫室效應更大大影響用電需求量，其氣溫節節上升，使得用電需求量的壓力大增。而美國藉著夏季用電量需求大增的藉口，要求加拿大輸出更多水力發電，對視水資源為珍寶的加拿大而言，無疑是另一大威脅。

水是加拿大珍貴的資源，也以其供應大量電力，然而，世界大壩委員會(World Commission on Dams)曾指出，因應水力發電所建立的蓄水大壩卻可能釋放出溫室效應氣體，讓加拿大水資源危機陷入一惡性循環當中。