Threshold hydrologic change across the intermittent-persistent snow transition

间歇性-持续积雪过渡期间的阈值水文变化

• 批准号: 1446870
• 负责人: Stephanie Kampf
• 金额: $ 26.81万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-03-01 至 2020-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1446870&HistoricalAwards=false
• 关键词: Threshold; hydrologic; change; across; intermittent

This project will develop a geographic synthesis of snow, streamflow, and soil moisture data across the western U.S. and the analyses will provide key information that can be used to identify areas most vulnerable to large hydrologic changes due to smaller snowpack accumulation. Datasets produced will be publicly available and this information can be incorporated into land and aquatic resource management, particularly in locations that lack hydrologic data. The project will train a PhD student and undergraduate research assistants, develop an interactive digital display for education outreach and student recruitment, and develop a hydrology class activity using soil moisture simulations. Loss of persistent winter snowpack impacts water resources in mountain and high latitude regions throughout the world, and the need to understand water resource vulnerability to snow loss is pressing. The central hypothesis guiding this research is that loss of a persistent snowpack triggers changes in both stream flow and soil moisture, but the magnitude of this change is greater in more arid climates. This project will document the geographic distribution of intermittent-persistent snow transitions in the western U.S. and examine how streamflow and soil moisture are affected by these transitions. Snow transitions will be mapped using both MODIS snow cover imagery and snow water equivalent data from SNOTEL sites. Indices of snow transitions will then be compared to streamflow and soil moisture data at both annual-decadal time scales and event-seasonal time scales. HYDRUS-1D simulations of soil moisture changes in response to varying scenarios of snow persistence will be developed for SNOTEL sites in two different climate regions to examine how process interactions between snow loss and hydrologic response vary with climate. The study synthesizes a top-down approach examining runoff and soil moisture changes across geographic gradients of snow persistence with a bottom-up process modeling approach examining how soil moisture responds to a transition from persistent to intermittent snow. The multi-scale approach will help in understanding how regional long-term patterns link with local conditions in individual seasons.

该项目将对美国西部的积雪、水流和土壤湿度数据进行地理综合，分析结果将提供关键信息，可用于识别由于积雪堆积较小而最容易遭受重大水文变化的地区。 生成的数据集将公开，这些信息可以纳入土地和水生资源管理，特别是在缺乏水文数据的地区。该项目将培训一名博士生和本科生研究助理，开发用于教育推广和学生招募的交互式数字显示器，并利用土壤湿度模拟开发水文学课程活动。 持续性冬季积雪的损失影响着世界各地山区和高纬度地区的水资源，迫切需要了解水资源对雪损失的脆弱性。指导这项研究的中心假设是，持续积雪的消失会引发溪流和土壤湿度的变化，但这种变化的幅度在更干旱的气候中更大。该项目将记录美国西部间歇性持续积雪转变的地理分布，并研究这些转变如何影响水流和土壤湿度。将使用 MODIS 积雪图像和 SNOTEL 站点的雪水等效数据来绘制积雪转变图。然后，将雪转变指数与年-十年时间尺度和事件-季节时间尺度的水流和土壤湿度数据进行比较。将为两个不同气候区域的 SNOTEL 站点开发响应不同积雪持续情况的土壤湿度变化的 HYDRUS-1D 模拟，以研究降雪量与水文响应之间的过程相互作用如何随气候变化。该研究综合了自上而下的方法和自下而上的过程建模方法，检查径流和土壤湿度在持续积雪的地理梯度上的变化，以及自下而上的过程建模方法，检查土壤湿度如何响应从持续性积雪到间歇性积雪的转变。多尺度方法将有助于了解区域长期模式如何与各个季节的当地条件联系起来。