PROBLEM E: Are we heading towards a thirsty planet?

Will the world run out of clean water? According to the United Nations, 1.6 billion people (one quarter of the world‘s population) experience water scarcity. Water use has been growing at twice the rate of population over the last century. Humans require water resources for industrial, agricultural, and residential purposes. There are two primary causes for water scarcity: physical scarcity and economic scarcity. Physical scarcity is where there is inadequate water in a region to meet demand. Economic scarcity is where water exists but poor management and lack of infrastructure limits the availability of clean water. Many scientists see this water scarcity problem becoming exacerbated with climate change and population increase. The fact that water use is increasing at twice the rate of population suggests that there is another cause of scarcity – is it increasing rates of personal consumption, or increasing rates of industrial consumption, or increasing pollution which depletes the supply of fresh water, or what? **

Is it possible to provide clean fresh water to all? The supply of water must take into account the physical availability of water (e.g., natural water source, technological advances such as desalination plants or rainwater harvesting techniques). Understanding water availability is an inherently interdisciplinary problem. One must not only understand the environmental constraints on water supply, but also how social factors influence availability and distribution of clean water. For example, lack of adequate sanitation can cause a decrease in water quality. Human population increase also places increased burden on the water supply within a region. When analyzing issues of water scarcity, the following types of questions must be considered. How have humans historically exacerbated or alleviated water scarcity? What are the geological, topographical, and ecological reasons for water scarcity, and how can we accurately predict future water availability?

What is the potential for new or alternate sources of water (for example, desalinization plants, water harvesting techniques or undiscovered aquifers)?

What are the demographic and health related problems tied to water scarcity?

Problem Statement

The International Clean water Movement (ICM) wants your team to help them solve the world’s water problems. Can you help improve access to clean, fresh water?

Task 1: Develop a model that provides a measure of the ability of a region to provide clean water to meet the needs of its population. You may need to consider the dynamic nature of the factors that affect both supply and demand in your modeling process.

Task 2: Using the UN water scarcity map (http://www.unep.org/dewa/vitalwater/jpg/0222-waterstress-overuse-EN.jpg) pick one country or region where water is either heavily or moderately overloaded. Explain why and how water is scarce in that region. Make sure to explain both the social and environmental drivers by addressing physical and/or economic scarcity.

Task 3: In your chosen region from Task 2, use your model from Task 1 to show what the water situation will be in 15 years. How does this situation impact the lives of citizens of this region? Be sure to incorporate the environmental drivers’ effects on the model components.

Task 4: For your chosen region, design an intervention plan taking all the drivers of water scarcity into account. Any intervention plan will inevitably impact the surrounding areas, as well

as the entire water ecosystem. Discuss this impact and the overall strengths and weaknesses of the plan in this larger context. How does your plan mitigate water scarcity?

Task 5: Use the intervention you designed in Task 4 and your model to project water availability into the future. Can your chosen region become less susceptible to water scarcity?

Will water become a critical issue in the future?

If so, when will this scarcity occur?

Task 6: Write a 20-page report (the one-page summary sheet does not count in the 20 pages) that explains your model, water scarcity in your region with no intervention, your intervention, and the effect of your intervention on your region’s and the surrounding area’s water availability. Be sure to detail the strengths and weaknesses of your model. The ICM will use your report to help with its mission to produce plans to provide access to clean water for all citizens of the world. Good luck in your modeling work!

Possible Resources

An Overview of the State of the World’s Fresh and Marine Waters. 2nd Edition, 2008. (http://www.unep.org/dewa/vitalwater/index.html).

The World’s Water: Information on the World’s Freshwater Resources. (http://worldwater.org).

AQUASTAT. Food and Agriculture Organization of the United Nations. FAO Water Resources. (http://www.fao.org/nr/water/aquastat/water_res/index.stm).

The State of the World‘s Land and Water Resources for food and agriculture. 2011. (http://www.fao.org/docrep/017/i1688e/i1688e00.htm).

GrowingBlue: Water. Economics. Life. (http://growingblue.com).

World Resources Institute. www.wri.org.

**Note that the 2013 Mathematical Competition in Modeling (Problem B) and the 2009 High School Modeling Competition in Modeling (Problem A) were related to modeling different aspects of water scarcity.

Your ICM submission should consist of a 1 page Summary Sheet and your solution cannot exceed 20 pages for a maximum of 21 pages. Note: The appendix and references do not count toward the 20 page limit.

E: 将世界上跑出干净的水？依据联合国，1.6十亿人（四分之中的一个世界人口的）经验的水资源短缺。用水一直在增长，在人口上个世纪增长率的两倍。人类须要水的资源用于工业，农业和住宅用途。有两个基本的原因水资源短缺：物理稀缺性和经济匮乏。

物理稀缺性是有水的地方不足的区域，以满足需求。经济稀缺性就是存在水。但管理不善和缺乏基础设施限制了清洁水的供应。

很多科学家看到这种水资源短缺问题变得更加恶化与气候变化和人口增长。

水的使用越来越多，在人口增长率的两倍。这一事实表明。有稀缺性的还有一个原因 - 它是添加个人消费率，或添加工业消费率。或添加污染，消耗新奇水，或者是供应？ **

能否够提供清洁的食水就完了吗？供水必须考虑水的物理可用性（比如，天然水源，技术进步，如海水淡化厂或雨水收集技术）。了解水的供应是一种固有的跨学科的问题。

当中不仅要了解供水环境的制约。又受社会因素怎样影响可用性和干净的水分布。比如，缺乏足够的卫生设施会导致水质下降。

人类人口的添加也对地方的供水区域内负担添加。

在分析水资源短缺的问题，问题例如以下类型必须加以考虑。怎样有人类历史上加剧或缓解水资源短缺？什么是地质，地形和生态原因。水资源短缺，怎样才干准确地预測未来水的供应？什么是新的或备用水源（比如，海水淡化工厂，集水技术或未被发现的含水层）的潜力？什么是绑在水资源短缺的人口与健康有关的问题？

问题陈述

国际清洁水运动（ICM）希望你的团队，帮助他们解决全球水问题。

你能帮助改善获得清洁，新奇的水？

任务1：建立一个模型，它提供了一个地区提供清洁的水。以满足人民的须要的能力的度量。您可能须要考虑的影响在建模过程中供需双方面的因素的动态性。

任务2：使用联合国水资源短缺的地图（http://www.unep.org/dewa/vitalwater/jpg/0222- waterstress-过度-EN.jpg）选择一个国家或地区的水要么是严重或中度超载。

解释为何以及怎样缺水在该地区。确保通过解决物理和/或经济稀缺性来解释的社会和环境的驱动程序。

任务3：从任务2您所选择的地区。使用任务1中的模型表明缺水状况将在15年内是什么。请问这个情况影响该地区人民的生活水平？一定要结合对模型组件的环境司机的影响。

任务4：对于您所选择的地区。设计以水资源短缺的全部驱动程序在内的干估计划。

不论什么干估计划将不可避免地影响到周边地区，以及

作为整个水生生态系统。讨论此影响，并在此大背景中计划的总体优势和劣势。

请问你的计划，缓解水资源短缺？

任务5：使用在任务4设计的干预和你的模型来预測水供应到未来。你所选择的区域能够变得不那么easy缺水？将水成为未来的关键问题？假设是的话，什么时候才干稀缺性发生的呢？

任务6：写一个20页的报告（单页的汇总表并没有在20页计算），说明你的模型，缺水的地区，没有干预。您的干预。和你的干预对您所在地区的影响及周边地区的水供应。一定要具体模型的好处和短处。该ICM将使用您的报告，以帮助其使命，生产计划，提供清洁的水世界的全部公民。好运气在你的建模工作！

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