Department of Environmental Sciences, University of Basel, Klingelbergstr. 27, 4056 Basel, Switzerland.
J Environ Manage. 2011 Feb;92(2):275-83. doi: 10.1016/j.jenvman.2009.08.023. Epub 2009 Nov 11.
The Gallocanta Basin represents an environment highly sensitive to climate change. Over the past 60 years, the Laguna de Gallocanta, an ephemeral lake situated in the closed Gallocanta basin, experienced a sequence of wet and dry phases. The lake and its surrounding wetlands are one of only a few bird sanctuaries left in NE-Spain for grey cranes on their annual migration from Scandinavia to northern Africa. Understanding the impact of climate change on basin hydrology is therefore of utmost importance for the appropriate management of the bird sanctuary. Changes in lake level are only weakly linked to annual rainfall, with reaction times between hours and months after rainfall. Both the total amount of rainfall over the reaction period, as well as individual extreme events, affect lake level. In this study the characteristics and frequencies of daily, event, monthly and bi-monthly rainfall over the past 60 years were analysed. The results revealed a clear link between increased frequencies of high magnitude rainfall and phases of water filling in the Laguna de Gallocanta. In the middle of the 20th century, the absolute amount of rainfall appears to have been more important for lake level, while more recently the frequency of high magnitude rainfall has emerged as the dominant variable. In the Gallocanta Basin, climate change and the distinct and continuing land use change since Spain joined the EU in 1986 have created an environment that is in a more or less constant state of transition. This highlights two challenges faced by hydrologists and climatologists involved in developing water management tools for the Gallocanta Basin in particular, but also other areas with sensitive and rapidly changing environments. Hydrologists have to understand the processes and the spatial and temporal patterns of surface-climate interaction in a watershed to assess the impact of climate change on its hydrology. Climatologists, on the other hand, have to develop climate models which provide the appropriate output data, such as reliable information on rainfall characteristics relevant for environmental management.
加罗坎塔盆地是一个对气候变化高度敏感的环境。在过去的 60 年里，加罗坎塔封闭盆地中的一个短暂湖泊拉古纳德加罗坎塔经历了一系列干湿阶段。该湖及其周围湿地是西班牙东北部仅存的几个候鸟保护区之一，是灰鹤从斯堪的纳维亚半岛迁徙到北非的年度迁徙路线上的鸟类保护区。因此，了解气候变化对盆地水文的影响对于候鸟保护区的适当管理至关重要。湖泊水位的变化与年降雨量的关系较弱，降雨后数小时到数月之间存在反应时间。在反应期内的总降雨量以及个别极端事件都会影响湖泊水位。本研究分析了过去 60 年中每日、事件、每月和双月降雨量的特征和频率。结果表明，高降雨量频率的增加与拉古纳德加罗坎塔的充水阶段之间存在明显的联系。在 20 世纪中叶，降雨量的绝对量似乎对湖泊水位更为重要，而最近，高降雨量频率已成为主导变量。在加罗坎塔盆地，气候变化和自 1986 年西班牙加入欧盟以来明显且持续的土地利用变化，创造了一个或多或少处于持续过渡状态的环境。这凸显了参与开发加罗坎塔流域特别是其他具有敏感和快速变化环境的流域水资源管理工具的水文学家和气候学家所面临的两个挑战。水文学家必须了解流域地表水-气候相互作用的过程和时空模式，以评估气候变化对其水文的影响。另一方面，气候学家必须开发气候模型，提供适当的输出数据，例如与环境管理相关的可靠降雨特征信息。
