ABSTRACT

This study is concerned with the physical impacts of flood-mitigation structures on ‘humanised’ and ‘natural’ floodplain ecosystems. The former constitute fertile, well drained and developed surfaces. The latter are mainly degraded wetland areas located in the backwater zones of wide, low-lying floodplains. Three rivers are investigated: the Hawkesbury–Nepean and the Macleay Rivers in New South Wales, Australia and the Durance River in southern France. Their floodplains, flood-mitigation works and floodplain ecosystems are analysed, together with site- and time-dependent differences in their floodplains, their exploitation and their degradation. Conservation of floodplains seeks to reverse wetland degradation, and to increase biodiversity and sustainability, as well as preserving developed floodplains. This study discusses gaps in our biophysical knowledge of ecosystems and the absence of ecological indicators of degradation. It also considers the lack of data on socio-economic values for what are unique, site- and time-specific, biophysical systems. Only when such inadequacies are addressed will the values of ecosystems be fully understood. Then cost-effective management might be possible. These knowledge gaps contribute to the many problems of floodplain management, which are likely to increase when the additional impacts of population increase and global warming become apparent.

摘要

本研究关注防洪结构对“人性化”和“自然”洪泛区生态系统的物理影响。前者构成肥沃、排水良好和发达的表面。后者主要是位于宽阔低洼洪泛区回水区的退化湿地。调查了三条河流：澳大利亚新南威尔士州的 Hawkesbury-Nepean 河和 Macleay 河以及法国南部的 Durance 河。分析了他们的洪泛区、防洪工程和洪泛区生态系统，以及洪泛区、开发和退化的地点和时间依赖性差异。洪泛区保护旨在扭转湿地退化，增加生物多样性和可持续性，以及保护已开发的洪泛区。本研究讨论了我们对生态系统的生物物理知识的空白以及缺乏生态退化指标。它还考虑到缺乏关于独特、特定地点和特定时间的生物物理系统的社会经济价值的数据。只有解决了这些不足之处，生态系统的价值才能得到充分理解。那么成本效益管理可能是可能的。这些知识差距导致了洪泛区管理的许多问题，当人口增加和全球变暖的额外影响变得明显时，这些问题可能会增加。只有解决了这些不足之处，生态系统的价值才能得到充分理解。那么成本效益管理可能是可能的。这些知识差距导致了洪泛区管理的许多问题，当人口增加和全球变暖的额外影响变得明显时，这些问题可能会增加。只有解决了这些不足之处，生态系统的价值才能得到充分理解。那么成本效益管理可能是可能的。这些知识差距导致了洪泛区管理的许多问题，当人口增加和全球变暖的额外影响变得明显时，这些问题可能会增加。