我们严重低估了世界的水通道危机必威官网手机版

In开普敦，南非，以及Chennai, India, "Day Zero" events where cities run out of water have drawn global media attention. But while these catastrophes seem like rare, temporary crises caused by droughts or mismanagement, life without ample water is actually a daily reality for millions of people, even in cities with abundant supply.

世界资源报告中的新论文，负担不起且不可动荡：重新思考全球南方的城市水通道必威官网手机版, finds that nearly half the population in 15 major cities in the global south lacks access to public piped water systems, with access lowest in sub-Saharan Africa and South Asia. For these households without public piped water, water from other sources is either too expensive or too unsafe.

Even access to a public tap does not guarantee safe and reliable water: About 1 billion people receive piped water fewer than 24 hours each day, some of whom have access to water only a few hours a week. The more intermittent the service, the more likely water is contaminated.

We're Underestimating the Water Crisis—Especially in Lower-Income Cities

例如，在尼日利亚拉各斯，有16个邻近的家庭共享一个单根物件，每周三天有水 -if他们的房东每月向城市付款。如果没有，将切断服务，家庭必须长期排队等待从过度提取的钻孔或购买昂贵的瓶装或囊泡水中的水。两项选项都不能保证安全或负担得起的饮用水。

Lack of water service takes a major toll. When water is not accessible—because it is not available or because it is too expensive—households are forced to make tough decisions. They will sacrifice their health and time to self-provide "free" (but likely unsafe) ground and surface water, or they will buy expensive water—requiring cutbacks on food, electricity, education, health care and other household expenditures.

Widely used global indicators used to monitor the UN's Millennium Development Goals (MDGs) and Sustainable Development Goals (SDGs) fail to capture these everyday realities. For example, one statistic from UNICEF and the World Health Organization (WHO) states that 90% of the world's population used "improved drinking water sources" in 2015. But this measure fails to offer the full picture of challenges for urban residents in the global south. "Improved" includes a variety of sources, including water from boreholes and wells, where ground water quality is vulnerable to contamination in dense urban areas. It also does not give any indication whether water is always reliably available or if it's affordable. These are barriers that need to be overcome, and that should be reflected in global assessments of water access.

消水危机的解剖结构

考虑到成本，质量和其他因素，我们对全球南方15个城市的分析更为整体。

在城市中获得公共水域水的差异很大。在拉丁美洲城市中，它更为常见，但在撒哈拉以南非洲城市不到四分之一的场所可用。对于大多数家庭来说，管道水上的水是最便宜的选择，但是在所有分析的15个城市中，几乎所有家庭中几乎一半都没有接受。

And just because residences are connected to city pipes doesn't mean water is always available. In 12 of the 15 cities analyzed, households did not receive continuous water service. In two informal neighborhoods in Karachi and Bengaluru, water service was as low as 2 to 3 hours per day for 2 days of the week. Aside from being inconvenient, this is dangerous—when water service isn't continuous, contamination is more likely.

这是一个昂贵的损失。如果没有公共管道的水，居民为从油轮或供应商那里获取水支付了几倍，在孟买，他们支付的私人用水费用是公共水费用的52倍。谁建议家庭在水和卫生设施上花费不超过其月收入的3-5％。在某些城市，即使公共水是最负担得起的来源，对于低收入家庭来说，它仍然太昂贵了。

事实是，即使对于没有身体短缺问题的必威官网手机版城市，全球南部城市中的水的通量也不相等。

越来越有水的未来

当家庭无法获得最少的水以确保健康和福祉时，城市及其居民的环境和经济生产力将首次受到损害。在某些情况下，这已经导致紧急全市危机。雅加达缺乏足够的公共水网络，导致不受管制的井的收集过度；现在，随着海平面上升和沿海洪水的战斗，整个城市正在下沉。专家警告说可能是到2040年水下。

随着城市化的快速化，缺水的增加以及水基础设施的普遍投资不足，更多的城市将发现自己处于危机模式。到2030年，45个城市根据人口超过300万的人口可能会遇到高水压。WRI的渡槽工具。南亚和非洲增长最快的城市（到2050年将增加15亿居民）的水服务差距最大。对水的需求只会在城市中增长，随着农业和工业的水需求不断增长的紧张局势。

在越来越多的水限制的未来中，城市必须在管理水中扮演新角色。他们必须确保有足够的水，和所有人负担得起。不断增长的城市必须优先考虑水必威官网手机版前灾难。

What Can Cities Do to Avert Day Zero?

证据表明，使公共水更可靠和负担得起是前进的最佳途径。城市应扩大公共管道水网络，同时解决间歇性水服务的特定背景原因。对于某些城市，这可能意味着修复旧基础设施中的重大泄漏。对于其他人来说，它可能涉及更好的来源保护，这将需要除了城市管辖范围之外的分水岭协调。

Cities must also make water affordable for low-income residents. Decades of attempts to increase the private sector's role and govern water as a private good have not improved access. Cities in Chile and Colombia have had success in improving access for low-income households by providing direct subsidies. In South Africa, cities provide a monthly allowance of water for free, a policy that stemmed from the national government's declaration of water as a human right. Upgrading informal settlements—which houseone in three urban dwellers在全球南部，优先考虑改善水和卫生基础设施而不是搬迁它们，它比其他任何方法都改善了更多的低收入家庭的水通道。必威官网手机版

今天我们有更好的城市水风险的数据和知识，国际组织正在重新定位自己，以更好地监控水质和负担能力。但是，城市和水公用事业需要在政治和财务上承诺以供水公平。必威官网手机版我们需要从根本上认识到，公平获得安全，可靠和负担得起的水是每个人生活，移动和繁荣所必需的人类权利。