Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling FK9 4LA, UK; Institute of Surface-Earth System Science, Tianjin University, Tianjin 300072, China.
School of Geographical and Earth Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
Sci Total Environ. 2019 Jan 1;646:438-447. doi: 10.1016/j.scitotenv.2018.07.292. Epub 2018 Jul 21.
Human exposure to water contaminated with faeces is a leading cause of worldwide ill-health. Contaminated water can be transmitted rapidly in karst terrain as a result of the connectivity of surface and groundwater systems, high transmissivity of aquifers over large areas, and well-developed underground conduit systems. Faecal indicator organisms (FIOs) are the most widely-used indicator of faecal contamination and microbial water quality; however, the conceptualisation of FIO risk and associated sources, pathways, and survival dynamics of FIOs in karst landscapes requires a degree of modification from traditional conceptual models of FIO fate and transfer in non-karst systems. While a number of reviews have provided detailed accounts of the state-of-the-science concerning FIO dynamics in catchments, specific reference to the uniqueness of karst and its influence on FIO fate and transfer is a common omission. In response, we use a mixed methods approach of critical review combined with a quantitative survey of 372 residents of a typical karst catchment in the southwest China karst region (SWCKR) to identify emerging research needs in an area where much of the population lives in poverty and is groundwater dependent. We found that the key research needs are to understand: 1) overland and subsurface FIO export pathways in karst hydrology under varying flow conditions; 2) urban and agricultural sources and loading in mixed land-use paddy farming catchments; 3) FIO survival in paddy farming systems and environmental matrices in karst terrain; 4) sediment-FIO interactions and legacy risk in karst terrain; and 5) key needs for improved hydrological modelling and risk assessment in karst landscapes. Improved knowledge of these research themes will enable the development of evidence-based faecal contamination mitigation strategies for managing land and water resources in the SWCKR, which is highly vulnerable to climate change impacts on water supply and quality of water resources.
人类暴露于受粪便污染的水中是全球健康不良的主要原因。由于地表水和地下水系统的连通性、大面积含水层的高透水性以及发达的地下管道系统，受污染的水在喀斯特地形中可以迅速传播。粪便指示生物（FIO）是粪便污染和微生物水质最广泛使用的指示物；然而，FIO 风险的概念化以及相关的来源、途径和 FIO 在喀斯特景观中的生存动态需要对传统的非喀斯特系统中 FIO 命运和转移的概念模型进行一定程度的修改。虽然有许多评论提供了关于集水区中 FIO 动态的最新科学状态的详细说明，但具体参考喀斯特的独特性及其对 FIO 命运和转移的影响是常见的遗漏。作为回应，我们使用批判性评论的混合方法以及对中国西南喀斯特地区（SWCKR）典型喀斯特流域 372 名居民的定量调查，以确定在该地区存在的新兴研究需求，该地区大部分人口生活贫困，依赖地下水。我们发现，关键的研究需求是了解：1）在不同流量条件下，喀斯特水文学中的地表和地下 FIO 输出途径；2）混合土地利用稻田流域中的城市和农业来源及负荷；3）稻田系统和喀斯特地形环境基质中的 FIO 生存能力；4）喀斯特地形中的沉积物-FIO 相互作用和遗留风险；以及 5）改善喀斯特景观水文模型和风险评估的关键需求。对这些研究主题的深入了解将使人们能够制定基于证据的粪便污染缓解策略，以管理 SWCKR 的土地和水资源，因为 SWCKR 极易受到气候变化对水资源供应和水质的影响。
