[미국] 캔자스공대, 물 가용량 및 분배량 예측 위한 모델 개발

인간 활동에 의해 주도되는 기후 변화는 향후 수십 년 동안 캔자스의 기온과 강우량을 변화시킬 것이다. 그러나 변화의 시기와 심각성에 대한 예측은 정확하지 않다.

현재, 캔자스공대 연구진은 캔자스물사무국(Kansas Water Office, KWO)과 함께 물 분배 관리가 중요한 자원의 공급과 수요를 더 잘 예측할 수 있도록 주의 미래 기후에 대한 불확실성을 설명하는 모델을 개발하고 있다.

연구는 물부족에 대한 최악의 시나리오로 캔자스의 1950년대 가뭄 연도의 데이터에 의존하는 KWO가 사용하는 모델을 확장하는 것이다.  이 프로젝트는 미 연방국토개발국의 9만8천 달러의 워터스마트 보조금과 캔자스물사무국과 캔자스공대의 추가 자금에 의해 지원된다.

조슈아 라우디(Joshua Roundy) 캔자스공대 토목, 환경 및 건축 공학 부교수 "이 프로젝트는 캔자스 워터 오피스와 협력하여 주의 수문학적 모델링과 기후 예보를 발전시켰다"고 말했다. 그는 "지금, 그들은 1950년대의 가뭄 기간을 가지고 그들의 모델을 살펴본 다음, '우리는 도시가 이 정도의 물을 사용하도록 허용할 수 있다'고 말하는 근거로 사용할 수 있다. 하지만 불확실성과 함께, 다른 시나리오를 고려하고 미래의 기후와 그것이 주 전체의 증발과 흐름에 어떻게 영향을 미칠지 기대하는 것이 도움이 된다. 그래서 우리는 기후 모델을 사용하여 물 예측 내의 불확실성 추정치를 개선하기 위해 이 제안을 함께 작업했다"고 말했다.

새로운 모델링 작업은 6개의 강 분지, 21개의 저수지, 51개의 유입 및 163개의 소모성 물 사용원을 포함하는 캔자스 주의 중부와 동부 지역에 초점을 맞출 것이다.

리차드 로켈(Richard Rockel) 캔자스물사무국 수자원플래너는 "캔자스 워터 오피스는 캔자스 주의 향후 수도 공급 계획에 기후 변화를 통합하기 위한 더 많은 도구와 자원을 개발하면서 캔자스공대와 함께 이 워터스마트 보조금 프로젝트를 진행하기를 기대하고 있다"면서 "이 프로젝트는 국가가 직면하고 있는 지역적인 물 공급 문제에 적용되는 기후 변동성에 대한 보다 포괄적인 분석을 가능하게 할 것"이라고 말했다.

라우디와 그의 연구팀은 향후 몇 년 동안 캔자스주의 물의 가용성이 기후 불확실성의 영향을 받을 수 있는 방법을 예측하기 위해 세계 기후 연구 프로그램의 결합 모델 상호 비교 프로젝트 5단계(CMIP5)를 사용할 것이다. CMIP5 모델은 여러 방출 시나리오를 비교하고 육지, 해양 및 대기 사이의 주요 피드백과 결합한다.

CMIP5 모델을 캔자스의 과거 기후 데이터와 결합하면 연구팀은 수문학적 모델링을 사용하여 기후 불확실성으로 인한 유량 및 증발의 불확실성을 추정한 다음 새로운 유량 및 증발 입력을 고려하여 기존 KWO 물 할당 모델을 수정할 것이다.

마지막으로, 캔자스공대 그룹은 베이지안 확률론적 프레임워크를 사용하여 기후 변화로 인한 미래 물 할당의 가변성을 정량화할 것이다. 라우디 부교수에 따르면, 기후에 대한 새로운 데이터가 등장함에 따라, 한국기후기구는 업데이트된 예측 능력을 위해 그것을 모델에 적용할 수 있을 것이다.

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RESEARCHERS TO DEVELOP NEW MODELS FOR FORECASTING WATER AVAILABILITY AND ALLOCATION IN KANSAS

LAWRENCE — Climate change, driven by human activity, will alter temperatures and rainfall in Kansas in the coming decades. But predictions about the timing and severity of the shift remain inexact.

Now, researchers at the University of Kansas School of Engineering are teaming up with the Kansas Water Office to create models accounting for uncertainty about the state’s future climate so officials who allocate water can better forecast supply and demand of the vital resource.

Their work will expand models used by KWO that depend on data from 1950s drought years in Kansas as a worst-case scenario for water scarcity. The project is supported by a $98,000 WaterSmart Grant from the Department of the Interior’s Bureau of Reclamation and additional funds from the Kansas Water Office and KU.

Joshua Roundy, University of Kansas professor“This project is a collaboration with the Kansas Water Office to advance hydrological modeling and climate forecasting for the state,” said Joshua Roundy, associate professor of civil, environmental & architectural engineering at KU, who is leading the effort. “Now, they take the 1950s drought period and run it through their model, and then use that as a basis to say, ‘We can allow cities to take this much water.’ But with the uncertainties involved in that, wouldn’t it be helpful to consider different scenarios and look forward to the future climate and how that’s going to impact evaporation and streamflow throughout the state? So, we worked together on this proposal to improve uncertainty estimates within water forecasting using climate models to create new scenarios for their water allocations.”

Computer plot of streamflow in KansasThe new modeling effort will focus on central and eastern sections of Kansas that depend on surface water, incorporating six river basins, 21 reservoirs, 51 inflows and 163 sources of consumptive water use.

“The Kansas Water Office is looking forward to working with the University of Kansas on this WaterSmart grant project, developing more tools and resources to incorporate climate variability to future water supply planning for the state of Kansas,” said Richard Rockel, KWO water resource planner. “This project will allow for a more comprehensive analysis of climate variability as applied to regional water supply issues the state is facing.”

Roundy and his team will use the Coupled Model Intercomparison Project phase 5 (CMIP5) from the World Climate Research Programme to forecast how Kansas water availability could be affected by climate uncertainties in the coming years. The CMIP5 models compare multiple emission scenarios and combine them with key feedbacks among the land, ocean and atmosphere.

“It’s a global organization, a whole bunch of modeling groups that run model experiments and compile all that data together, so you have a variety of estimates of what future climate might be like,” Roundy said. “A lot of the models are showing for most of the state maybe a small decrease in precipitation overall. When you break that down seasonally, we’re actually seeing more extreme precipitation in the wetter periods like spring times, but then you’re also getting drier fall and winter times — so they’ll have an averaging effect that overall, there’s not much change.”

Coupling the CMIP5 models with historical climate data for Kansas, Roundy and his team will use hydrologic modeling to estimate the uncertainty in streamflow and evaporation due to climate uncertainty, then modify the existing KWO water-allocation model to account for the new streamflow and evaporation inputs.

Finally, the KU group will quantify variability in future water allocations due to climate change using a Bayesian probabilistic framework. In other words, according to Roundy, as new data about climate emerges, the KWO will be able to plug it into the models for updated forecasting ability.

“We hope to help them define these probabilities based on historical and projected scenarios we create and then we can update those probabilities as we get new information that comes in,” he said. “For instance, we’re going to start by looking at the CIMP5 version of the client models. But then we’ll look at what happens if we use the latest version, which is CIMP6, and see how those probabilities would update.”

The KU researcher said managing water supplies could be more challenging due to forecasted periods of increased drought but also periods of increased floods.

“That’s going to be something that could strain the water resources, strain the reservoir systems, and the Kansas Water Office is definitely interested in trying to understand it,” Roundy said. “We’re asking, ‘OK, how could this potentially change?’ If we construct scenarios based off these climate models of how the seasonality may change — how we may get more precipitation in some periods, but then less in others — they can run those through their models to make good decisions and say, ‘OK, this is what we might see.’ That’s why we say it’s ‘uncertainty,’ because we might not be completely correct in our estimates, but our work could offer a better level of risk assessment for the state’s water supply.”

In addition to helping the KWO improve their forecasting to account for uncertainty stemming from climate change, the work will fund a KU graduate student for two years to focus on the models.

Roundy said his group’s work could result in an academic paper intended to show other states and regions an approach for forecasting in future water supplies. But his real objective is to help the state of Kansas thrive as climate change raises questions about water availability.

“This is about creating tools for decision-makers to make better decisions,” he said. “It’s great to be able to work with the state and really show the benefit of research at KU and how it is helping state entities improve their systems. Our main goal is to make sure things are going to be sustainable and we have sustainable growth in terms of water availability within cities going forward.”

[출처 = 캔자스공과대학교(Researchers to develop new models for forecasting water availability and allocation in Kansas | The University of Kansas (ku.edu)) / 2021년 11월 11일자 보도자료]