Implementing Ecosystem Natural Capital Accounting on the Rhone Watershed: A Proof-of-Concept

This doctoral thesis applies the Ecosystem Natural Capital Accounting (ENCA) methodology to the Rhone watershed, serving as a proof-of-concept. The Rhone watershed, a significant river system in Europe, presents a complex and diverse environment, making it an ideal candidate for demonstrating the applicability and utility of ENCA. By focusing on this specific geographical area, the research aims to illustrate how ENCA can be implemented to assess the health and status of a major natural resource system. The choice of the Rhone watershed allows for the examination of various ecosystem services, resource management challenges, and the potential impacts of human activities on natural capital within a defined hydrological and administrative boundary.

The ENCA methodology, as developed and applied in this research, is built upon several key principles. It involves defining statistical accounting units, analyzing land cover stocks and flows, and developing synthetic indicators related to ecosystem functions and integrity. The framework aims to calculate the 'ecological potential' of a given area, which represents its capacity to provide ecosystem services. This potential is then used to measure ecosystem degradation, stability, or enhancement. The accounting diagnosis is complemented by a spatial description of observed changes, providing a clearer understanding of their relevance and impact. ENCA seeks to integrate with existing national accounting systems, offering a more comprehensive picture of national wealth that includes natural capital alongside produced capital.

Chapter 4 focuses on the Ecosystem Water Account for the Rhone river catchment. This section elaborates on the principles of water environmental accounts and the specific features of ENCA Water and Rivers accounts. It outlines the system analysis behind the accounts, defining statistical units for accounting, including hydrological units and other land zonings. The chapter also addresses units for soil water and groundwater accounting. The making of ENCA Water and Rivers accounts for the Rhone involves a detailed water accounting framework and specifies the data requirements. The methodology for calculating river quality and status is presented, including principles of river water quality accounting and considerations for implementation. The results section provides an account of river quality and status, contextualizing the work and detailing the 'Ecological Status' of rivers, with data extracted to hydrological units and average ecological status values calculated by river class and hydrological unit.

The research demonstrates that implementing ENCA on the Rhone watershed provides a robust tool for understanding the state of natural capital and its degradation. The developed indicators and accounts for carbon, water, and ecosystem infrastructure offer valuable insights into the complex interactions within the watershed. The findings highlight the potential for ecological debts arising from unsustainable resource use and underscore the importance of integrating ecological considerations into policy-making. The ENCA tool is designed to assist territorial entities in making informed decisions regarding the management of strategic renewable resources. In the context of a changing global order, with significant geopolitical issues related to security, food, and energy sovereignty, and their links to public health, such tools are indispensable for fostering resilience and sustainability.