Assessing climate change impacts on alpine stream‐flow and vegetation water use: mining the linkages with subsurface hydrologic processes
Assessing climate change impacts on alpine stream‐flow and vegetation water use: mining the linkages with subsurface hydrologic processes
复制标题
评估气候变化对高山溪流和植被用水的影响：挖掘与地下水文过程的联系
DOI：
10.1002/hyp.7288
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发表时间：
2009
影响因子：
3.2
通讯作者：
C. Tague
中科院分区：
文献类型：
--
作者：
C. Tague
2009年1月23日接受2009年1月23日在政府间气候变化专门委员会（气专委）最近的报告中，研究最充分和已经观察到的气候变化影响是与融雪提前和积雪减少有关的季节性水流模式的变化，在欧洲阿尔卑斯山、喜马拉雅山、和北美西部（由Kundzewicz等人综述，2007年）。除了河流对变暖的反应外，高山生态系统也极易受到气温升高的影响（迪亚兹等人，2003年）。许多这些观测到的和预测的生态系统响应与水文过程有关，包括与早期融雪相关的水可用性和生长季节长度的变化，以及与蒸散的大气驱动因素变化相关的潜在水压力增加（巴内特等人，2005; Betts等人，2007; Bales等人，2006年）。有各种各样的科学研究举措，旨在提高对高山系统对气候变化的反应的理解和可预测性。山区研究倡议（http：//mri.scnatweb.ch/，Drexler，2008年）等组织组成了全球和区域研究网络。在美国，诸如西部山区综合气候研究联盟（CIRMOUNT）（迪亚兹等人，2008年）和包括西部山区研究倡议（http：//www.cfr. washington.edu/research.fme/wmi/，Baron等人，2006年）和最近资助的国家科学基金会（NSF）塞拉利昂临界区观测站旨在明确应对气候变化对山区环境的影响。其中大多数举措都与密集的现场监测站有关。因此，虽然这些研究的重点往往是评估气候变化的影响，但它们显然也是促进水文科学发展的机会。在高山环境中研究气候变化有几个特点，也许是独一无二的，在他们的水文分析支持。首先，积雪和融化（从径流或植被用水的角度来看，是一个关键的水文输入）在流域内跨多个尺度相对系统地变化（例如，Daly等人，2000年; Nolin和Daly，2006年）。气候变化研究也促使人们共同努力，在区域尺度上描绘高山环境中积雪和融化的时空模式（例如，Molotch等人，2004; Jain等人，2008;特鲁希略等人，2007年）。虽然仍然存在重大的不确定性，在高山地区观察到的雪的时空模式的实质性梯度可能解决更好的准确性（在大面积）比其他水文变量或其他地区的更微妙的梯度。积雪和融化的这些相对较强的梯度可能比其他水文变量（蒸散量、土壤湿度、非高山地区的降水量或未蓄水流域的水流）的梯度更容易测量。在许多高山地区，如美国西部，融雪也是主要的水输入。鉴于融雪在空间（通常与特定流域的海拔高度有关）和时间（
Received 19 January 2009 Accepted 23 January 2009 Within the most recent Intergovernmental Panel on Climate Change (IPCC) report, some of the most well-researched and already observable impacts of climate change are changes in seasonal stream-flow patterns associated with earlier snowmelt and the reduction in snow accumulation, as evidenced by studies in the European Alps, Himalayas, and western North America (reviewed by Kundzewicz et al., 2007). In addition to stream-flow responses to warming, alpine ecosystems are also highly vulnerable to warmer temperatures (Diaz et al., 2003). Many of these observed and projected ecosystem responses are linked to hydrologic processes, including changes in water availability and growing season length associated with earlier snowmelt and potential increased water stress associated with changes in atmospheric drivers of evapotranspiration (Barnett et al., 2005; Betts et al., 2007; Bales et al., 2006). There are a variety of science research initiatives directed towards improving the understanding and predictability of the responses of alpine systems to climate change. Organizations such as Mountain Research Initiative (MRI) (http://mri.scnatweb.ch/, Drexler, 2008) comprise global and regional networks of research. Within the USA, organizations such as Consortium for Integrated Climate Research in Western Mountains (CIRMOUNT) (Diaz et al., 2008) and projects including Western Mountain Research Initiative (WMI) (http://www.cfr. washington.edu/research.fme/wmi/, Baron et al., 2006) and the recently funded National Science Foundation (NSF) Sierra Critical Zone Observatory are designed to explicitly address climate change impacts in mountain environments. Most of these initiatives are linked to intensive field monitoring sites. Thus, while the focus of these studies is often the assessment of climate change impacts, they are also clearly opportunities to advance hydrologic science in general. Studying climate change in alpine environments has several features that are perhaps unique in their support of hydrologic analysis. Firstly, snow accumulation and melt (a key hydrologic input from a streamflow or vegetation water use perspective) vary relatively systematically within watersheds across multiple scales (e.g. Daly et al., 2000; Nolin and Daly, 2006). Climate change studies have also led to a concerted effort to characterize spatial-temporal patterns of snow accumulation and melt in alpine environments, at plot to regional scales (e.g. Molotch et al., 2004; Jain et al., 2008; Trujillo et al., 2007). While significant uncertainties remain, substantial gradients in spatial-temporal patterns of snow observed in alpine regions are perhaps resolved with better accuracy (over large areas) than more subtle gradients in other hydrologic variables or in other regions. These relatively strong gradients in snow accumulation and melt may be easier to measure than gradients in other hydrologic variables (evapotranspiration, soil moisture, precipitation in non-alpine regions or stream-flow in ungaged watersheds). In many alpine regions, such as the western USA, snowmelt is also the dominant water input. Given that snowmelt varies both in space (often with elevation in a particular watershed) and in time (with