Introduction to Lower Mekong Free-flowing River Assessment
The Lower Mekong Free-flowing River assessment has been conducted between January and September 2022 by WWF-US, WWF-Greater Mekong and Confluvio. The following describes the general steps of the assessment and the specific objectives and outcomes
Preparation and data review: The first step in conducting a Free-flowing river assessment (FRA) entails the review of existing (global) data and methodology, as well as a discussion with local groups, experts, and stakeholders of possible methods refinements and enhancements to better represent the local context.
Data processing: Simultaneously, a review of available data layers that could replace global data layers should be conducted with the help of regional experts. The data review is followed by data collection and subsequent data processing using Geographic Information Systems (GIS). The result of the data processing are various layers representing pressures on natural connectivity (dams, roads, urban areas, etc.). Next, the data sets collected and processed are translated to the river reach scale using the necessary data processing steps.
Model: Once the relevant datasets and indicators are in place (at the river reach scale), the FRA model, a set of python tools bundled in a Python Toolbox is used to calculate:
the Connectivity Status Index (CSI) of the river reaches, by combining the pressure variables,
the Free-flowing status (free-flowing or not), based on the CSI values and a threshold,
benchmarking statistics, which determine if the settings used to create the outcome is reasonable based on pre-defined benchmarking rivers,
an ArcMap document providing production-ready maps for various data layers
a series of statistics as Excel output
Refinements: The production of summary statistics and maps is typically followed by several cycles of refinement, based on stakeholder discussion, including local river experts.
A free-flowing river assessment should engage a variety of stakeholders into a discussion of the importance of free-flowing rivers and river connectivity, their benefit and their vulnerabilities to local pressures, such as fragmentation. Aside from this, the specific products of the assessment include:
High-resolution hydrographic framework including river networks and network metrics; flow direction maps; hydrologic connectivity information and attribute information. This framework can be reused for other assessments, for example for strategic environmental assessment of hydropower development options.
Free-flowing rivers map for the study area, including maps of underlying metrics (i.e., degree of fragmentation, degree of regulation, sediment loss, road and urban development, water abstraction from rivers, and connectivity status index).
Free-flowing status report, including statistical analysis of extent of free-flowing rivers (number, length, connectivity to ocean)
Adjusted Python tool: Although extensive modifications to the main toolbox are rarely required, some modification may be necessary in the template and configuration files to tailor the analysis for specific needs. In the case of the Lower Mekong basin assessment, the analysis was conducted at the scale of the entire Mekong Basin, and a few simple modifications of the source code were necessary to focus the maps and statistical analysis to only the area of interest - the lower Mekong basin. See this section for tool downloads.
To aid current and future FFR assessments, comprehensive documentation, guidance materials and training tools for understanding the FFR methodology as well as for implementing the approach at basin, national or regional scales will be developed and/or updated.
The training tools and materials will be developed in conjunction with applying the FFR methods in the Lower Mekong Basin in Vietnam and Cambodia as an additional case study. To allow current and future users to learn more about completed assessments, selected examples will be described and added as case studies to the training materials, more clearly explaining how to produce and use maps, results, and figures, among others.
Training tools
The results of this assessment were translated to an online interactive tool to explore the results in detail. The Lower Mekong Free-flowing River Atlas App provides data layers summarizing the six individual pressure indices, as well as the combined indices, including the Connectivity Status Index (CSI), the Free-flowing River status (FFR) and the Dominant pressure factors (DOM). The user can interact with the map interface by zooming and panning, by filtering layers based on their attributes, and by clicking on river reaches and dams to receive key statistics. The tool is accessible through this page or directly at https://free-flowing-lower-mekong.web.app/
Workshop
Our team participated in a Regional Joint Workshop termed 'Rivers of the Lower Mekong Region', supported and organized by USAID, Stockholm Environment Institute, World Wildlife Fund for Nature (WWF), and the Asian Disaster Preparedness Center (ADPC).
The goal of this workshop is to bring together stakeholders from across the region to build knowledge and technical capacities, aid the development of new networks and partnerships that support the sustainable development and use of the rivers, and support the inclusion of those most impacted and least consulted when it comes to the development of the Lower Mekong Region. Topics covered include learning about the importance of river connectivity and its threats, tools that can be used for river planning, guidance to address governance and transparency issues, and potential entry points for inclusion in decision-making and advocacy efforts for CSOs, INGOs, and research institutions.
At the workshop we introduce the Free-flowing rivers Initiative, provide an overview of the methodology, conduct a technical session to introduce a Toolbox for Geographic Information Systems (GIS).
This projects was realized with the generous support of the USAID Wonders of the Mekong project. The Wonders of the Mekong project conducts applied research, builds capacity, and develops outreach and communications products to highlight the economic, ecological, and cultural values of biodiversity and ecosystem services associated with the Lower Mekong River. The outputs and resulting products, developed as an integrated package, will lead to better protection of a vibrant and healthy Lower Mekong system.
Interview with Zeb Hogan lead investigator of the Wonders of the Mekong project
