Decade × Theme Heatmap

A temporal overview of how key mining themes surface, recede, and reappear across decades of Nigerian newspaper reporting.

Longue durée Temporal clustering Environmental memory

1. What this heatmap shows

Each column represents a decade (for example, 1940s, 1970s, 2010s). Each row represents a thematic cluster (such as Environmental Memory, Labour & Disability, Community Resistance).

The colour intensity of each cell reflects how many articles in that decade are tagged with that theme. Darker cells indicate heavier coverage or stronger discursive presence.

2. How to use this as a researcher

Locate turning points: Identify decades where environmental memory or accidents & safety suddenly intensify. These may align with mine openings/closures, disasters, wars, or regulatory shifts.
Trace thematic arcs: Follow a single row (for example, Labour & Disability) across all decades to see if it is consistently present, gradually building, or only erupting in crisis moments.
Compare themes within a decade: Scan down a column (for example, the 1980s) to understand which themes dominated public discourse at that time.
Identify silences and afterlives: Gaps or pale cells may suggest long periods where certain harms were under-reported, even if they were ongoing on the ground.

3. Interaction guide

Hover over each cell to see: theme, decade, and exact article count.
Use the zoom tools (magnifying glass icons in the Plotly toolbar) if you have many decades or themes and need to focus on a subset.
Download the figure as a PNG using the camera icon for use in slides, articles, or teaching.

4. Building historical arguments from the heatmap

          Suggested workflow: Use the heatmap to articulate a
          periodisation of concern. For instance, you might argue that
          environmental memory only becomes a visible category of public debate
          after the closure of certain mines, or that labour & disability
          is most intensely discussed during wartime mobilisation and structural adjustment.
          The figure does not replace close reading; it helps you decide where to linger.
        

5. Data & method (short note)

The underlying matrix aggregates article counts by decade of publication and theme. Decades are derived from publication year (for example, 1938 → “1930s”), and themes come from your text-analysis pipeline and manual coding around issues such as environmental harm, eco-technological disability, community resistance, and governance.

6. How to cite this visualisation

Suggested citation (example):
“Media Mining Memory: Decade × Theme Heatmap,” Reports on Mining in Nigeria (digital project), accessed [date], GitHub Pages / project URL.

Interactive decade–theme heatmap

Compare how different mining-related themes wax and wane across decades. Hover for counts, zoom into particular time slices, and export for analysis or teaching.