Methods, assumptions and conventions

A.1 Scope and approach

This paper is a desk study prepared in September and October 2026. It draws on four kinds of evidence:

1. Primary legal texts. Cameroonian laws, decrees and orders were read in their published versions, mainly through the FAO’s FAOLEX database and ministry websites. International standards were read in the issuing bodies’ own publications.
2. Published science and official data. These include hydrological monographs, peer-reviewed studies of the Kribi coast, the national Demographic and Health Survey, protected-area decrees and the UNESCO Tentative List.
3. Reanalysis and open geodata. Modelled climate, wind and air quality data come from ERA5 and CAMS. Settlements, watercourses, coastline and protected-area outlines come from OpenStreetMap, and country outlines from Natural Earth.
4. The public record and Cameroon Steel’s planning basis. These are press reports of the project’s public milestones, and the company’s planning model of 10 October 2026 for planned capacities and benchmark-based estimates.

No field survey has yet been carried out for the steel site area. All site-specific predictions are deferred to the environmental and social impact assessment (Chapter 11). Secondary sources such as press articles are used only where no primary source was available, and are identified as such in Annex C. Where sources conflict, the paper states the range, the source preferred and the reason.

A.2 Distances and maps

Distances to receptors were measured from public geodata to the centre of a generalised indicative area within the Mboro sector of the industrial-port zone (9.90° E, 2.72° N, the centre of the indicative area shown on Cameroon Steel’s public website). They were not measured to a surveyed site boundary. The geodata are OpenStreetMap features queried through the Overpass API on 10 October 2026 (extract base 24 July 2026), and the boundary points published in the marine park’s creation decree [E11][B01]. Up to 10 km, each distance is given as a whole-kilometre band (for example 3 to 4 km); beyond 10 km it is rounded to the nearest kilometre. Every receptor distance quoted in the paper comes from Annex D, Table D.1. OpenStreetMap is crowd-sourced. It is incomplete for small streams and buildings, and its protected-area outlines can differ from the legal boundaries. The assessment will replace these distances with surveyed values and with boundaries checked against the World Database on Protected Areas and the decrees.

The regional map (Figure 1.1) shows the steel complex as a hatched circle 1.5 km in radius around the centre of the indicative area, the same indicative area as on Cameroon Steel’s public website. The circle is a generalised marker of the indicative location, not the site boundary. Satellite surface models give elevations of roughly 50 to 120 m across the wider area; allowing for the tree canopy they include, we estimate the ground at about 40 to 100 m above sea level (rounded; to be confirmed by survey) [E17].

A.3 Climate and air quality data

Rainfall statistics come from the homogenised Kribi station record for 1937 to 1976, as published by Olivry [E01]. This record includes the monthly means and the Pearson III fit of one-day extremes over 33 years. WMO climate normals for 1981 to 2010 [E09] and the ERA5 reanalysis [E04] were used as cross-checks. Reanalysis was not used for extremes, because it underestimates point rainfall maxima. Wind frequencies come from hourly ERA5 data for 2011 to 2020 [E04], cross-checked against the port authority’s observations [E07]. Background air quality comes from the CAMS global reanalysis for 2024 to 2025 [E05]. All reanalysis values are labelled "modelled". They are used to frame the questions and the objectives, never as substitutes for measurement.

A.4 Planning estimates for the steel complex

Planned capacities, water demand, residues, electricity use, greenhouse gas emissions and traffic come from Cameroon Steel’s planning model, edition of 10 October 2026 [X03]. The model multiplies planned capacities by benchmark intensities from the IFC EHS Guidelines, worldsteel and standard industry practice. The capacities are 0.3 Mtpa of finished products in Phase 1, 0.5 Mtpa after Phase 2 and 1.0 Mtpa at full design. Its outputs are indicative planning values. They are not engineering design values or measurements, and they will be replaced by the design basis in the assessment. Table A.1 lists the main assumptions and their ranges.

Table A.1 Main assumptions of the planning model, with ranges

Source: Cameroon Steel planning model, edition of 10 October 2026 [X03], with benchmark sources as cited.

Derived values in the text are calculated from these assumptions. They are:

• Scope 1 and 2 emissions of about 97,000, 163,000 and 328,000 tCO₂e a year by phase;
• residues of about 55,000, 92,000 and 185,000 t a year;
• fresh water of about 0.6, 1.0 and 2.0 million m³ a year;
• about 74, 123 and 245 truck loads a day.

They are rounded, and their uncertainty follows from the ranges above. For example, using the full range of slag intensity changes the full-capacity slag estimate from about 117,000 to about 191,000 t a year. Water shares of river low flow divide the average daily make-up, on a 365-day basis, by the median low flow of the Lobé (8.35 m³/s) or the 10-year low flow of the Kienké (4.68 m³/s) [E01].

A.5 Critical habitat screening

The screening in Figure 7.1 is qualitative. For each feature it rates each IFC criterion as unlikely, possible, candidate or likely. The rating reflects whether species or ecosystems meeting that criterion are known or expected to occur in the feature, according to the desk sources [G02][B08][B06]. It is not a critical habitat assessment. Such an assessment requires survey data, an IBAT screening and the definition of an ecologically appropriate area of analysis for each feature, and these are listed in Chapter 11.

A.6 Status labels

Every figure carries a status label, and every planning value in the text is identified as planned or indicative.

• Sourced: published data used as published, from the source cited.
• Derived: calculated by Cameroon Steel from sourced inputs, with the method stated.
• Assumed: a planning assumption or indicative sequence, with its range where relevant.
• Illustrative: a diagram or a generated visualisation. Generated images are not photographs of the project or its site.

A.7 Conventions

Units follow the International System, with tonnes (t), million tonnes per annum (Mtpa) and normal cubic metres (Nm³) at 273 K and 101.3 kPa, dry. Currency amounts are in CFA francs (FCFA), pegged at 655.957 FCFA to the euro. Dates are given in full. The paper uses British English. Legal instruments are cited by their French titles, with English explanations on first use. Documents published by the Port Autonome de Kribi are cited by title and date, without web links.