Global Assessment of Water Stress in Karst Regions in a Changing World

岩溶发育是由于碳酸盐岩的风化作用，导致地表和地下的水文流动和储存过程具有明显的非均质性。大约7%到12%的地球大陆被喀斯特地区覆盖，大约四分之一的全球人口完全或部分依赖于喀斯特含水层的饮用水。在未来的几十年里，气候模型预测世界上许多喀斯特地区的气温将大幅上升，降水将减少。尽管有这些预测，但只有很少的研究进行了量化气候变化对喀斯特水资源的影响。这主要是由于在现有的大规模模拟方法中缺乏数据和喀斯特过程的不充分表示。拟建的初级研究小组的目的是提供必要的数据和方法，首次在全球范围内评估当前和未来的喀斯特水资源可用性。为了应对这一挑战，有必要在以下方面进行新的研究：(1)理解并包括水文模型中的岩溶异质性；(2)将基于集水区的观测和模拟方法扩大到全球尺度；(3)将当前和未来的水资源可用性与全球的水需求进行比较。该项目将在分布于全球5个气候区的5个试验点（AU、D、ES、MX、UK）采用新的监测和分析方案，了解不同气候区的浅层地表过程岩溶异质性的影响。本文将利用新建立的集水区喀斯特系统观测数据库，应用喀斯特特征衰退分析来推断世界不同地区地下水储放过程的异质性。从同一数据库和全球径流数据库（GRDC）中，开发了一种将由此获得的认识整合到大尺度喀斯特水资源模拟模型中的新方法。新模型最终将用于(1)探索当前和未来喀斯特水资源的可用性，并与气候模拟模型相结合；(2)将其与水需求联系起来，以确定当前和未来对人们供水的威胁。

Karst develops due to the weathering of carbonate rock and results in significant surface and subsurface heterogeneity of hydrological flow and storage processes. About 7% to 12% of the Earths continental are is covered by karst regions, and approximately one quarter of the global population is completely or partially dependent on drinking water from karst aquifers. For the next decades, climate models predict a strong increase in temperature and a decrease of precipitation in many karst regions in the world. Despite these predictions, only few studies have been performed to quantify the impact of climate change on karst water resources. This is mainly due to a lack of data and inadequate representation of karst processes in existing large scale simulation approaches. The aim of the proposed junior research group is provide the necessary data and approaches to, for the very first time, assess present and future karst water resources availability at a global scale. To tackle this challenge, new research in (1) understanding and including karstic heterogeneity in hydrological models, (2) upscaling catchment based observations and simulation approaches to the global scale, and (3) comparing present and future water resources availability with water demand across the globe is necessary. The project will apply novel monitoring and analysis schemes at five test sites distributed in 5 climate regions over the world (AU, D, ES, MX, UK) to understand the effects of karstic heterogeneity of shallow surface processes in different climate regions. A newly established data base of catchment scale karst system observations will be used to apply a karst specific recession analysis to infer about the heterogeneity of groundwater storage and discharge processes in different regions in the world. From the same database and the global runoff database (GRDC), a new approach to integrate the hereby gained understanding into a large scale karst water resources simulation model will be developed. The new model will finally be used (1) to explore present and, coupled with climate simulation models, future karst water resources availability and (2) to relate it to water demands to identify present and future threats on peoples water supply.