TED Talks2016.1.29---David Sedlak :避免災難性乾旱的4種方式

TED Talks2016.1.29---David Sedlak :避免災難性乾旱的4種方式
發佈日期：2016年1月29日
As the world's climate patterns continue to shift unpredictably, places where drinking water was once abundant may soon find reservoirs dry and groundwater aquifers depleted. In this talk, civil and environmental engineer David Sedlak shares four practical solutions to the ongoing urban water crisis. His goal: to shift our water supply towards new, local sources of water and create a system that is capable of withstanding any of the challenges climate change may throw at us in the coming years.
作为全球气候模式不断转变不可预测的，地方的饮用水，曾经充沛可能很快就会发现水库干和地下蓄水层的枯竭。在这次讲座中，土木和环境工程师David塞德拉克分享四项实用解决方案，以目前的城市用水危机。他的目标是：转变我们的供水对水新的本地资源，并创建一个系统，能够经受住任何的挑战，气候变化可能会在未来几年抛给我们。

0:07grandparents generation created an amazing system of canals and reservoirs 0:17that made it possible for people to live in places where there wasn't a lot of 0:21water for example during the Great Depression they created the Hoover Dam 0:26which in turn created Lake Mead and made it possible for the cities of Las Vegas 0:31and Phoenix and Los Angeles to provide water for people who lived in a really 0:35dry place in the 20th century we literally spent trillions of dollars 0:41building infrastructure to get water to our cities in terms of economic 0:45development it was a great investment but in the last decade we've seen the 0:51combined effects of climate change population growth and competition for 0:56water resources threaten these vital lifelines of Water Resources this figure

1:02shows you the change in the lake level of Lake me that happened in the last 1:06fifteen years you can see starting around the year 2000 the lake level 1:11started to drop and it was dropping at such a rate that it would have left the 1:15drinking water intakes for Las Vegas high and dry the city became so 1:19concerned about this that they recently constructed a new drinking water intake 1:25structure that they refer to as the third straw to pull water out of the 1:28greater depths the lake the challenges associated with providing water to a 1:34modern city are not restricted to the American Southwest in the year two 1:38thousand and seven the third largest city in Australia Brisbane came within 1:43six months of running out of water a similar traumas playing out today in Sao 1:48Paulo Brazil where the main reservoir for the city has gone from being 1:52completely folded in 2010 to being nearly empty today as the city 1:58approaches the 2016 Summer Olympics for those of us who were fortunate enough to

2:04live in one of the world's great cities we've never truly experience the effects 2:08of a catastrophic drought we like to complain about the Navy showers we have 2:13to take we like our neighbors to see our dirty cars in our brown lawns but we've 2:19never really facing 2:20prospect turning on the tap and having nothing come out and that's because when 2:26things have gotten bad in the past it's always been possible to expand a 2:30reservoir did a few more groundwater wells well in a time when all of the 2:35water resources are spoken for its not going to be possible to rely on this 2:40tried and true way of the priding ourselves of water now some people think 2:44that we're gonna solve the urban water problem by taking water from a rural 2:48neighbors but that's an approach that's fraught with political legal and social 2:54dangers and even if we succeed in grabbing the water from a rural 2:59neighbors were just transferring the problem to someone else and there's a

3:03good chance I'll come back and bite us in the form of higher food prices and 3:07damage to the aquatic ecosystems that already rely upon that water I think 3:12that there's a better way to solve our urban water crisis and i think thats to 3:16open up for new local sources of water that I like into faucets if we can make 3:22smart investments in these new sources of water in the coming years we can 3:27solve urban water problem and decrease the likelihood that will ever run across 3:32the effects of a catastrophic drought now he told me twenty years ago that a 3:38modern city could exist without a supply of imported water I probably would have 3:43dismissed use an unrealistic and uninformed reimer 3:47my own experiences working with some of the world's most water starts cities in 3:52the last decades have shown me that we have the technologies and the management 3:57skills to actually transition away from imported water and that's what I want to 4:01tell you about tonight the first source of local water supply that we need to

4:07develop to solve our urban water problem will flow with the rainwater that falls 4:11on our cities one of the great tragedies of urban development is that as our 4:17cities grew we started covering all the surfaces with concrete and asphalt and 4:22when we did that we had to build storm sewers to get the water that fell on the 4:26city's out before could cause flooding and that's a waste of a vital water 4:30resource let me give you an example 4:33this figure here shows you the volume of water that could be collected the city 4:38of San Jose if they could harvest the storm water that fell within the city 4:42limits 4:43you can see from the intersection of the blue line and the black dotted line at 4:48its San Jose could just capture half of the water that fell within the city they 4:52have enough water to get them through an entire year now I know what some of your 4:57probably thinking the answer to our problem is to start building great big

5:02tanks and attach them to the downspouts of our roof gutters rainwater harvesting 5:06now that's an idea that might work in some places but if you live in a place 5:10where it mainly rains in the wintertime and most of the water demand is in the 5:14summertime it's not a very cost effective way to solve a water problem 5:18and if you experience the effects of a multi-year drought like california's 5:23currently experiencing you just can't build a rainwater tank that's big enough 5:26to solve your problem I think there's a lot more practical way to harvest the 5:31storm water and the rainwater that falls in our cities and that's to capture it 5:35and let it percolate into the ground after all many of our cities are sitting 5:40on top of a natural water storage system that could accommodate huge volumes of 5:44water for example historically los Angeles is obtained about a third of its 5:51water supply from a massive aquifer that underlies the San Fernando Valley now 5:56when you look at the water that comes off of your roof and runs off of your 5:59lawn and flows down the gutter you might say to yourself to have a drink that

6:04stuff well the answer is you don't want to drink it until it's been treated a 6:08little bit and so the challenge that we face in urban water harvesting is to 6:13capture the water clean the water and get it underground and that's exactly 6:18what the city of los Angeles is doing with the new project that they're 6:21building in Burbank California this figure here shows the storm water park 6:28that they're building by hooking a series of stormwater collection system 6:32or storm sewers and routing that water into an abandoned gravel quarry the 6:37water that's captured in the quarry then it slowly passed through a man-made 6:41wetland and then 6:43it goes into that ball field there and percolates into the ground 6:47recharging the drinking water aquifer the city and in the process of passing 6:51through the wetland and percolating through the ground the water encounters 6:55microbes that live on the surfaces of the plants in the surface of the soil 6:59and that purifies the water and the water still not clean enough to drink

7:04after its been through this natural treatment process the city can't read it 7:08again when they pump it back out of the groundwater aquifers before they deliver 7:11to people to drink the second tap that we need to open up to solve our urban 7:17water problem will flow with the waste water that comes out of our sewage 7:21treatment plants now many of you are probably familiar with the concept of 7:25recycled water you've probably seen signs like this that tell you the 7:29shrubbery and the highway median and the local golf courses being watered with 7:35water that used to be in a sewage treatment plant we've been doing this 7:39for a couple of decades now but we're learning from our experience is that 7:43this is that this approach is much more expensive than we expected it to be 7:46because once we build the first few water recycling systems close to the 7:51sewage treatment plant we have to build longer and longer pipe networks to get 7:55that water to where it needs to go and that becomes prohibitive in terms of 7:59cost what we're finding is that a much more cost effective and practical way of

8:04recycling wastewater is to turn treated wastewater into drinking water through a 8:09two-step process in the first step in this process we pressurize the water and 8:14passing through a reverse osmosis membrane a thin permeable plastic 8:19membrane that allows water molecules to pass through but traps and retains the 8:23salts the viruses and the organic chemicals that might be president of 8:27wastewater in the second step in the process we had a small amount of 8:32hydrogen peroxide and shine ultraviolet light on the water 8:36the ultraviolet light cleaves the hydrogen peroxide into two parts that 8:40are called hydroxyl radicals and these hydroxyl radicals are very potent forms 8:45of oxygen that breakdown most organic chemicals have to the water's been 8:51through this two-stage process it's safe to drink I know 8:55I've been studying recycled water using every measurement technique known to

9:01modern science for the past 15 years we've detected some chemicals that can 9:06make it through the first step in the process but by the time we get to that 9:09second step the advanced oxidation process we rarely see any chemicals 9:14present and that's in stark contrast to the taken for granted water supplies we 9:19regularly drink all the time there's another way we can recycle water this is 9:24an engineer treatment wetland that we recently built on the Santa Ana River in 9:28southern california the treatment wetland receives water from a part of 9:33the Santa Ana River that in the summertime consists almost entirely of 9:36wastewater effluent from cities like Riverside and San Bernardino the water 9:41comes into our treatment wetland it's exposed to sunlight and algae and those 9:46break down the organic chemicals removed the nutrients and inactivate the 9:50waterborne pathogens the water gets put back in the Santa Ana River it flows 9:54down to Anaheim gets taken out at Anaheim and percolated into the ground 9:59and becomes a drinking water of the city of Anaheim completing the trip from the

10:03sewers of Riverside County to the drinking water supply of Orange County 10:08now you might think that this idea of drinking wastewater is some sort of 10:14futuristic fantasy or not commonly done well in california we already recycle 10:19about forty billion gallons a year of wastewater through the two-stage 10:23advanced treatment process I was telling you about that's enough water to be the 10:27supply of about a million people if it were their soul water supply the third 10:32tap that we need to open up will not be a taboo at all it'll be kind of a 10:37virtual tap water conservation that we managed to do and the place where we 10:42need to think about water conservation is outdoors because in California and 10:46other modern American cities about half of our water use happens outdoors in the 10:52current drought we've seen that it's possible to have our long survive in our 10:57plants survive with about half as much water so there's no need to start

11:01painting concrete green and putting an astroturf buying cactuses we can have 11:06California friendly landscaping 11:08with soil moisture detectors and smart irrigation controllers and have 11:12beautiful green landscapes in our cities the fourth and final water tap that we 11:18need to open up to solve our urban water problem will flow with desalinated 11:22seawater now I know what you probably heard people say about seawater 11:26desalination it's a great thing to do with you have lots of oil not a lot of 11:30water and you don't care about climate change 11:33seawater desalination energy-intensive no matter how you slice it but that 11:38characterization of seawater desalination is being a non-starter is 11:42hopelessly out of date we've made tremendous progress and seawater 11:45desalination in the past two decades this picture shows you the largest 11:51seawater desalination plant in the western hemisphere that's currently 11:55being built north of San Diego compared to the seawater desalination plant that 11:59was built in Santa Barbara twenty-five years ago this treatment plant will use

12:04about half the energy to produce a gallon of water but just because 12:08seawater desalination has become less energy-intensive doesn't mean we should 12:12start building D sell plants everywhere among the different choices we have it's 12:16probably the most energy-intensive and potentially environmentally damaging of 12:20the options to create a local water supply so there it is with these four 12:26sources of water we can move away from our reliance on imported water through 12:32reform in the way we landscape our services and our properties we can 12:36reduce outdoor water use by about 50% thereby increasing the water supply by 12:4125% we can recycle the water that makes it into the sewer thereby increasing our 12:46water supply by 40% and we can make up the difference through a combination of 12:51stormwater harvesting and seawater desalination so let's create a water 12:57supply that will be able to withstand anything any of the challenge that

13:02climate change throws at us in the coming years let's create a water supply 13:06that uses local sources in leaves more water in the environment for fish and 13:11for food let's create a water system that's consistent with our environmental 13:17values and let's do it for our children 13:20and our grandchildren and let's tell them this is the system that they have 13:25to take care of in the future cuz it's our last chance to create a new kind of 13:30water system thank you very much for attention

0:07爷爷奶奶辈创造的运河和水库的惊人的系统 0:17使得有可能适合人类居住的地方，那里有没有很多 0:21水，例如在大萧条期间他们创造了胡佛水坝 0:26这反过来又创造了米德湖并有可能对拉斯维加斯的城市 0:31和菲尼克斯和洛杉矶为谁住在一个真正的人提供水 0:35在20世纪干燥的地方，我们从字面上花费数万亿美元 0:41基础设施建设得到水，我们的城市在经济方面 0:45发展这是一个伟大的投资，但在过去十年里，我们已经看到了 0:51气候变化的人口增长和竞争的综合效应 0:56水资源威胁水资源这一数字的这些重要的生命线

1:02显示您在我湖的湖面水平，在过去发生的变化 1:06 15年，你可以看到周围的2000年湖泊水位开始 1:11开始下降，它是在这样的速度，这将已经离开滴 1:15饮用水取​​水口拉斯维加斯高，干燥的城市变得如此 1:19关心这个，他们刚刚建成的新的饮用水取水口 1:25他们称之为第三稻草结构拉水出的 1:28更大深度的湖泊，一个提供水相关的挑战 1:34现代化的城市并不仅限于美国西南部的一年两 1:38一千七百在澳大利亚布里斯班的第三大城市来到内 1:43 6个月用完水类似的创伤，今天发挥出骚 1:48巴西圣保罗的地方为城市的主要水库已经从去 1:52在2010年完全折叠到是几乎空今天的城市 1:58接近2016年夏季奥运会对于我们这些谁是幸运地

2:04生活在世界上最伟大的城市之一，我们从来没有真正体验到效果 2:08灾难性的干旱，我们喜欢抱怨，我们有海军阵雨 2:13拿我们喜欢我们的邻居看到我们污染的汽车在我们的褐色的草坪，但我们已经 2:19从来没有真正面对 2:20水龙头前景转向并没有什么出来，这是因为当 2:26事情变得糟糕，在过去它一直能扩大 2:30在藏时间做了几个地下水井以及当所有的 2:35水资源说话了其不会成为可能依靠这个 2:40尝试和标榜的水我们自己的正确的方法现在有些人认为 2:44那我们要通过从农村取水解决城市用水问题 2:48邻居，这是一个方法，就是充满了政治法律和社会 2:54危险，即使我们从农村抓水成功 2:59邻居们只是问题转移给别人，有一个

3:03很好的机会，我会回来咬我们在食品价格上涨的形式和 3:07损害了水生生态系统已经依赖于水，我认为 3:12有一个更好的办法来解决我们的城市用水危机，我认为是要 3:16开辟水新的本地源，我喜欢到水龙头，如果我们能够使 3:22在水这些新来源明智的投资，在未来几年，我们可以 3:27解决城市供水问题，并减少了将永远运行对面的可能性 3:32一个灾难性的干旱影响，现在他跟我说二十年前，一个 3:38现代城市可能存在没有进口水的供应，我可能会 3:43驳回使用不现实的，也是无知的雷默 3:47我与一些世界上最缺水的工作自己的经历开始于城市 3:52在过去几十年已经证明我说，我们有技术和管理 3:57技能实际进口水过渡路程，这就是我想

4:01告诉你今晚当地水源的第一来源，我们需要 4:07发展来解决我们的城市供水问题将落在雨水流 4:11在我们的城市的城市发展的大悲剧之一是，作为我们 4:17城市的成长，我们开始与覆盖混凝土和沥青，所有的表面 4:22当我们这样做，我们必须建设雨水管道来获取落在水 4:26前全市出可能导致洪水泛滥，这是一个重要的水浪费 4:30资源让我给你一个例子 4:33这里本图显示了可收集城市的水的体积 4:38圣何塞的，如果他们能收获雨水，城市内下跌 4:42范围 4:43您可以从蓝线的交叉点和黑点线在看 4:48其圣荷西可能只是抓住一半，在全市范围内下跌的水，他们 4:52有足够的水经过了整整一年，让他们现在我知道你的一些 4:57大概思路回答我们的问题是，开始建设新的伟大大

5:02坦克和它们连接到我们的屋顶水槽收集雨水的落水管 5:06现在这可能在一些地方工作的想法，但如果你住的地方 5:10它主要是在下雨的冬天，最需水的是在 5:14夏季这不是解决水的问题非常经济有效的方法 5:18并且如果遇到一个多年的干旱像加州的影响 5:23目前遇到你就不能建立一个雨水箱这就足够大 5:26解决你的问题我觉得有收获了很多实用的方法 5:31雨水和落在我们的城市，这就是捕捉到它的雨水 5:35并让它渗透到地面毕竟我们的很多城市都坐 5:40在一个可以容纳海量天然储水系统之上 5:44历史洛杉矶是约三分之一得到的水，例如其 5:51从现在underlies圣费尔南多谷的大规模蓄水层供水 5:56当你看那个脱落的屋顶，并运行了水的 5:59草坪和流下来你可能会说自己阴沟里有饮料，

6:04东西好答案是你不想喝它，直到它被视为一个 6:08点点这样的挑战，我们在城市集水面临的是 6:13捕捉水的清洁水，并得到它的地下而这正是 6:18什么洛杉矶的城市新项目，他们是在做 6:21建筑在加利福尼亚州伯班克这个数字在这里显示了风暴水上乐园 6:28他们正在通过钩住了一系列的雨水收集系统建设 6:32或雨水管道和布线池水成一个废弃的砂石采石场 6:37该公司在采石场拍摄的水，然后它慢慢地通过人为传递 6:41湿地再 6:43它进入了球场那里和渗滤到地面 6:47充电饮用水含水层的城市，在传球的过程 6:51通过湿地，并通过地面渗透水接触 6:55该植物的表面上生活在土壤表面的微生物 6:59和用于净化水和水仍然不够干净饮

7:04其过这种自然的工艺处理后的城市无法阅读 7:08再次，当他们抽回来了地下水层的他们提供前 7:11人喝，我们需要开拓，以解决我们城市的第二次敲击 7:17水的问题将与来自我们的污水废水流 7:21处理厂现在你们很多人可能熟悉的概念 7:25循环水，你可能已经看到了这样的迹象告诉你 7:29灌木林和公路位数和当地的高尔夫球场正在与浇灌 7:35所用的水是我们一直在做这个污水处理厂 7:39了几十年的，但现在我们正在学习从我们的经验是， 7:43这是这种方法是更昂贵的比我们预期它是 7:46因为一旦我们建立接近前几个循环用水系统 7:51污水处理厂，我们必须建立越来越长的管网来获得 7:55水到需要的地方去，在这方面会让人望而却步 7:59成本就是我们发现的是一个更具成本效益和实用的方法

8:04回收的废水是把处理过的废水变成通过饮用水 8:09在这个过程中的第一步骤两个步骤的过程，我们加压水和 8:14穿过反渗透膜的薄透性塑料 8:19膜，使水分子通过，但陷阱和保留 8:23盐病毒可能是总统的有机化工原料 8:27废水中的过程中的第二步骤中，我们有少量 8:32过氧化氢和紫外光去照射在水面上 8:36紫外线裂解的过氧化氢为两部分即 8:40被称为羟基自由基和这些羟基自由基是非常有效的形式 8:45氧气击穿大多数有机化工原料有水的过 8:51通过此两阶段的过程是安全饮用我知道 8:55我一直在研究用家喻户晓的测量技术，再生水

9:01现代科学在过去的15年中，我们已经发现了一些化学物质，可 9:06使它通过在过程的第一个步骤，而是由时间我们获得该 9:09第二步，高级氧化过程中，我们很少看到任何化学物质 9:14目前，这就是形成鲜明对比的是理所当然的供水，我们 9:19经常喝所有有可以回收的水，这是另一种方式的时候 9:24我们最近建立在圣安娜河工程师处理湿地 9:28南加州治疗湿地收到一部分水 9:33圣安娜河在夏季几乎全部的 9:36从滨江喜欢和圣贝纳迪诺水的城市废水排放 9:41进入我们的湿地处理它暴露在阳光和藻类以及 9:46分解去除营养成分的有机化工原料和灭活 9:50水生病原体的水被放回到圣安娜河它流 9:54到阿纳海姆被取出，在阿纳海姆和渗出到地面 9:59并成为城市阿纳海姆的完成从行程饮用水

10:03河滨县的下水道奥兰治县的饮用水供应 10:08现在你可能会认为这种想法喝污水是某种 10:14未来的幻想或不常用的加州做得很好，我们已经回收 10:19一年废水约四十十亿加仑的通过两阶段 10:23先进的处理工艺，我告诉你 - 这就是足够的水是 10:27大约100万人供应好像它是自己的灵魂供水第三 10:32自来水，我们需要开辟不会是一个忌讳在所有这将是形式的 10:37我们设法做虚拟自来水保护和地方，我们 10:42需要考虑节约用水是在户外，因为在加利福尼亚州和 10:46我们用水的一半等现代美国城市户外发生在 10:52我们已经看到，它可能当前旱情有我们在长期存活我们 10:57植物存活大约一半的水，所以没有必要启动

11:01具体画绿，把一个人工草皮购买仙人掌我们可以有 11:06加州友好园林绿化 11:08与土壤湿度探测器和智能灌溉控制器，并有 11:12美丽的绿色景观在我们的城市的第四个也是最后水龙头我们 11:18需要开拓，以解决我们的城市供水问题将用脱盐流 11:22海水现在我知道你可能听说过什么人说的海水 11:26海水淡化是做与你有大量的油不是很多的一件大事 11:30水，你不关心气候变化 11:33海水淡化能源密集型的，无论你如何切它但 11:38海水淡化的表征是一个非起动器 11:42无可救药地过时了，我们已经取得了巨大的进步和海水 11:45海水淡化在过去的二十年里这个图片显示你最大 11:51在西半球这是目前海水淡化厂 11:55正在建北圣地亚哥相比，海水淡化厂的 11:59始建于圣巴巴拉25年前的这个处理厂将采用

12:04大约一半的能量来产生一加仑的水，但仅仅是因为 12:08海水淡化已经成为能源密集度较低并不意味着我们应该 12:12启动D栋出售工厂遍地开花不同的选择中，我们有很 12:16可能是最耗能的和潜在的破坏环境的 12:20选项​​来创建本地供水因此它与这四个 12:26水的来源，我们可以从我们依赖进口水通过搬走 12:32改革的方式，我们的景观我们的服务和我们的物业，我们可以 12:36减少室外用水约50％，从而通过增加供水 12:41 25％，我们可以回收，使得它排入下水道从而提高了我们的水 12:46供水40％，我们可以补差价，通过组合 12:51雨水收集和海水淡化所以让我们创建一个水 12:57供应，这将能承受任何任何挑战的那

13:02气候变化在未来几年内将抛出在我们让我们创建一个供水 13:06使用叶更多的水分本地源在环境中的鱼类和 13:11食物让我们创建一个水系统，这是我们一贯的环保 13:17价值观，让我们做它为我们的孩子 13:20和我们的子孙后代，让我们告诉他们，这是他们对系统 13:25照顾在未来的Cuz这是我们最后的机会来创造一种新的 13:30水系统非常感谢你的关注