| 项目编号: | 1344552
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| 项目名称: | Collaborative Research: Hillslope hydrology under glass: Controlled experimental testing of hillslope-scale hydrologic transport theories at Biosphere2 |
| 作者: | Peter Troch
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| 承担单位: | University of Arizona
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| 批准年: | 2013
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| 开始日期: | 2014-03-01
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| 结束日期: | 2018-02-28
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| 资助金额: | USD315809
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| 资助来源: | US-NSF
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| 项目类别: | Continuing grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Geosciences - Earth Sciences
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| 英文关键词: | transport
; age function
; hillslope
; landscape
; project
; modeling transport
; biosphere2
; theory
; watershed-scale transport
; hillslope structure
; operational theory
; m2 artificial hillslope
; solute transport
; new theory
; hillslope scale
; transport phenomenon
; transport process
; flow
; research facility
|
| 英文摘要: | The transport of solutes through hillslopes and watersheds is difficult to predict due to the complexity of the landscape and the processes controlling flow and transport. The current approaches use process descriptions derived from observations at small scales to make predictions at much larger scales, using effective values of the scale dependent parameters. However, this paradigm is known to be flawed, as in many cases the parameters cannot be measured or predicted easily. Increasingly frequent calls have been made for new theories that better link large-scale predictions to observable properties of the landscape. A new theoretical framework has recently been developed to represent solute transport at hillslope and watershed scales. However the framework is incomplete as a key element, the "age functions", is not specified from theory and must be investigated empirically. These functions characterize how the water leaving the system is selected from the distribution of water of different ages within the system. If these age functions could be parameterized from available landscape data, this framework would provide a rigorous alternative for modeling transport at hillslope and watershed scales that circumvents some of the scale-related challenges other methods face. This project will use the new Landscape Evolution Observatory (LEO) research facility at Biosphere2 to directly observe the shape of these age functions at a hillslope scale using a novel set of tracer experiments. This facility can be used to create precisely controlled and replicated flow and transport phenomena in three 330 m2 artificial hillslopes, and observe them with an unprecedented spatial and temporal resolution with over 1,500 sensors and 500 soil water samplers. A carefully designed sequence of experiments using stable water isotope tracers will be used to directly measure these age functions and relate their properties to the structure of flow paths using a novel experimental procedure entitled PERTH (PERiodic Tracer Hierarchy), developed specifically for this purpose. This project has four goals: 1) to make direct measurements of the age function in the LEO; 2) to use an integrated modeling approach to understand the relationship between the age function and underlying hillslope structure, and generalize the empirical findings to a broader class of landscape units 3) to test a series of hypotheses about the controls on the age function that pave the way towards an operational theory; and 4) to propose and test functional forms of the age functions that can be encoded in operational models of watershed-scale transport.
Scientists, managers and policy-makers need tools to predict the movement of solutes through the landscape at large spatial scales, such as the movement of nitrogen from fertilizer distributed across agricultural watersheds into streams. Current state-of-the-art models are not able to capture many of the features of this transport, because the parameters they rely on cannot be measured at sufficiently fine detail in the landscape. This project will advance a new approach to modeling transport that does not rely on these fine-scale parameters, but instead makes predictions directly at the scale of hillslopes. This theory is more general than the models typically used for large-scale predictions, which rely on restrictive assumptions about the transport processes, or do not adequately account for the effect on transport of changes in flow through the landscape across storms, seasons and under climate change. This project will train two PhD students and several undergraduate students in new methods for hydrologic experimentation and environmental modeling. Furthermore, Biosphere2 is a hub of science education with 100,000 people visiting the facility each year, and this work will form part of the facility?s educational program. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/97271
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| Appears in Collections: | 影响、适应和脆弱性
气候减缓与适应
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| Recommended Citation: | |
Peter Troch. Collaborative Research: Hillslope hydrology under glass: Controlled experimental testing of hillslope-scale hydrologic transport theories at Biosphere2. 2013-01-01.
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