ENVIRONMENTAL PLANNING EVIDENCE · ANAMBRA STATE, NIGERIA

Anambra Erosion Prioritization Dashboard

441 validated zones

THE RESEARCH QUESTION

Where should efforts to control soil erosion begin in Anambra?

Soil erosion removes valuable soil and can carry loosened material into waterways. We studied where erosion and drainage conditions suggest that checking or planning conservation measures may be most useful.

Explore the priority map
01 · WHAT WE DID

Combined terrain, land cover, rainfall and drainage evidence to screen for erosion-related concerns.

02 · WHY WE DID IT

Help planners compare locations and decide where to investigate possible erosion-control measures first.

03 · WHAT WE FOUND

441 planning zones covering about 163.67 km² across Anambra, grouped into three relative priority levels.

04 · WHAT IT MEANS

These are places to investigate, not confirmed erosion damage, approved construction sites or guaranteed benefits.

Mapped planning zones 441 current map selection
Area in selected zones 163.67 km² for further investigation
Local government areas 21 represented in current selection
Illustrative conservation scenario 716,299 t/yr statewide modelled reduction · 3.396%; not a guaranteed result
Loading validated spatial assets…
Move over map for coordinates WGS 84 · longitude, latitude

Use with care

What this map cannot confirm

Project context

About this dashboard

Soil erosion can remove productive land and carry loose material toward streams and drainage networks. This study used mapped environmental conditions to identify and compare 441 areas that deserve closer attention across Anambra State. It is a first step for planning where to investigate possible solutions—not a survey of proven damage or a final engineering plan.

441validated priority zones
163.67 km²mapped intervention area
21LGAs represented
99.46%official LGA coverage

Methods in brief

  1. Soil-loss screening: baseline and conservation-scenario RUSLE surfaces estimate relative sheet-and-rill detachment.
  2. Connectivity: terrain and drainage relationships identify where detached material is more likely to connect to the drainage system.
  3. Delivery priority: erosion and connectivity evidence are integrated into relative sediment-delivery screening products.
  4. Intervention portfolio: contiguous priority cells are organized into sectors and three tiers using a 10 ha minimum mapping unit.
  5. LGA attribution: zones are assigned by maximum spatial overlap, with documented near-tie, boundary-mismatch and nearest-proxy rules.

How to read the map and priorities

Red, orange and teal areas show the three relative screening-priority tiers; Tier 1 is the first group for further investigation, followed by Tiers 2 and 3. The blue lines represent mapped drainage pathways and dashed lines show LGA boundaries. Tier and sector values support comparisons, not measured sediment yield, guaranteed annual soil loss, documented gully damage or construction-ready footprints. The modelled conservation reduction is only an illustrative scenario; field visits, community consultation and engineering verification must precede any intervention.

Boundary and attribution QA

All 441 zones have a primary LGA and valid P-code. The portfolio includes 65 cross-LGA zones, four near-tie assignments and three nearest-LGA proxy assignments retained with lower confidence.

Data and tools

RUSLE factors, terrain connectivity, primary drainage, intervention zones and administrative boundaries were processed in ArcGIS Pro 3.5 with ArcPy/Python. The web presentation uses MapLibre GL JS and OpenFreeMap.

Author

Gabriel Bahago Samuel

GIS Analyst · MECON Services Ltd., Jos, Nigeria