Implications of Vegetation Dynamics for Semi-Arid Hydrology: A Basis for Predicting Climate Impacts on Water Resources

植被动态对半干旱水文的影响：预测气候对水资源影响的基础

• 批准号: 0838301
• 负责人: John Albertson
• 金额: $ 39.7万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2012-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0838301&HistoricalAwards=false
• 关键词: Implications; Vegetation; Dynamics; Semi; Arid

Implications of Vegetation Dynamics for Semi-Arid Hydrology: A Basis for Predicting Climate Impacts on Water ResourcesPI: John D. Albertson, Duke UniversityCollaborator: Nicola Montaldo, University of Cagliari, ItalyAbstract:This project addresses the coupled eco-hydrologic dynamics of semi-arid Mediterranean watersheds, where the surface drinking-water reservoirs depend almost exclusively on overland flow in the rainy season and where the vegetation growth is water limited. The motivation centers on the observed and projected decreases in winter rainfall, stemming from shifts in large-scale atmospheric circulation patterns. Presently, the ability to predict future hydrologic behavior of these systems is limited by gaps in understanding of how changes in the vegetation cover interact with precipitation dynamics to control the hydrological response. The proposed research will test a set of five focused hypotheses in a Sardinian study basin that is already instrumented and broadly representative of semi-arid Mediterranean watersheds. This project builds on experimental and modeling studies that the PI and Italian collaborator have been conducting for the past several years on Sardinia, the second largest island in the Mediterranean. This project would add overland flow experiments to capture the effect of variable grass cover and rainfall intensity on infiltration and runoff generation. Analysis will be conducted over three overlapping time periods, representing: 1) the intensive field experiment record (~ 5+ years), 2) the satellite record (~ 20+ years), and 3) the streamflow and precipitation record (~ 80 years). Analysis will include possible tradeoffs between infiltration and evapotranspiration. Intellectual Merit: This project is designed to reveal how change and variability in seasonal precipitation patterns excite vegetation dynamics and how these changes in turn impact the hydrological budget of semi-arid watersheds. The tools developed will enable rigorous prediction of the response of eco-hydrological systems to climate forcing. The connection of the results to the large-scale circulation indices is expected to lead to improved predictability at the seasonal time scale. Furthermore, the broad prevalence of Mediterranean climates (e.g. California) simplifies the transferability of the approach and findings.Broader Impacts: The results of the proposed activity will provide direct support for planning water resources needs in the face of systematic changes in Mediterranean precipitation regimes. The undergraduate and Ph.D. students trained on this project will experience broad and meaningful interdisciplinary research experience, including collaborative periods abroad. Preliminary efforts were funded by Duke start-up support to the PI. Duke will provide funding (Pratt Fellowship) for summer support of the undergraduate student researcher.

植被动态对半干旱水文的影响：预测气候对水资源影响的基础PI：John D. Albertson，杜克大学合作者：Nicola Montaldo，卡利亚里大学，意大利摘要：该项目解决了半干旱地中海流域的耦合生态水文动态，其中地表饮用水水库几乎完全依赖于 雨季的地表径流以及植被生长受水限制的地区。 其动机集中在由于大规模大气环流模式的变化而观测到和预计的冬季降雨量减少。 目前，预测这些系统未来水文行为的能力受到对植被覆盖变化如何与降水动态相互作用以控制水文响应的理解差距的限制。拟议的研究将在撒丁岛研究盆地测试一组五个重点假设，该盆地已经安装了仪器，广泛代表半干旱地中海流域。 该项目建立在过去几年中 PI 和意大利合作者在地中海第二大岛屿撒丁岛进行的实验和建模研究的基础上。 该项目将增加地表水流实验，以捕捉变化的草地覆盖和降雨强度对渗透和径流产生的影响。分析将在三个重叠的时间段内进行，分别代表：1）密集的现场实验记录（〜5年以上），2）卫星记录（〜20年以上），以及3）径流和降水记录（〜80年）。 分析将包括渗透和蒸散之间可能的权衡。 智力价值：该项目旨在揭示季节性降水模式的变化和变异如何激发植被动态，以及这些变化反过来如何影响半干旱流域的水文预算。 开发的工具将能够严格预测生态水文系统对气候强迫的响应。 结果与大规模流通指数的联系预计将提高季节性时间尺度的可预测性。此外，地中海气候的广泛流行（例如加利福尼亚州）简化了方法和研究结果的可移植性。更广泛的影响：拟议活动的结果将为规划水资源需求提供直接支持，以应对地中海降水状况的系统性变化。 本科生和博士生。接受该项目培训的学生将体验广泛且有意义的跨学科研究经验，包括国外的合作期。 初步工作由杜克大学对 PI 的启动支持资助。 杜克大学将为本科生研究员的暑期支持提供资金（普拉特奖学金）。