Windhoek, Namibia

Making sense of imperfect data

All models are wrong, but some are useful.

— George Box

Most datasets are broken before anyone models them. Missing years. Failed sensors. Definitions that changed halfway through the record. Two sources that disagree and no note explaining why.

I build data pipelines, statistical models and decision tools that stay honest about that, methods that can be tested, traced and scrutinised, and results that say what the evidence can and cannot support. The domain has ranged across public finance, energy, climate and development programmes. The discipline is the same one each time.

Wilka Igulu — quantitative data analyst, Windhoek, Namibia

I'm a quantitative data analyst based in Windhoek, Namibia, with a background in applied mathematics and statistics. I work across the whole path from raw data to decision: building the pipeline, choosing the method, quantifying the uncertainty, and explaining the result to people who have to act on it.

My Honours research, published in Wind (MDPI), found that 70 spurious sensor records, 0.24% of the dataset, had inflated Namibia's 100-year extreme wind estimates by 35 to 45%. Quality control, not model choice, was the dominant source of error.

That finding shaped how I work. I check the data before I trust the model, I make uncertainty visible instead of hiding it behind a single number, and I build systems that stop rather than publish figures they cannot stand behind. The subject matter changes; the discipline does not.

35–45%
Overstatement traced to 0.24% of records. Peer-reviewed finding that quality control, not model selection, drove the error.
56
Data sources scored every month by an unattended Python pipeline, published as a citable dataset with a DOI.
4
Power BI pages on national accounts, inflation, electricity supply and project finance, on a warehouse that refuses to publish stale numbers.
80%
Honours mini-thesis, distinction The extreme-value analysis that became the published paper. BSc Honours Applied Statistics, NUST, 2026.

Tools

Languages Python (pandas, numpy, PyMC) · R · SQL · DAX
Data ETL pipeline design · star schema modelling · data quality frameworks · KoboToolbox
Analysis Applied statistics · extreme value theory · Bayesian methods · spatial analysis
Delivery Power BI · GitHub Actions · reproducible research workflows

Systems I built and run. Each one is live, automated, and documented end to end.

Economic analytics · BI · Power BI · Python · GitHub Actions Core data updates monthly

Namibia Economic, Energy, Climate Risk & Green Hydrogen Observatory

A four-page Power BI report on public debt, inflation, electricity supply, drought risk and the green hydrogen investment pipeline. A Python pipeline builds a star-schema warehouse, checks every run against a data-quality gate that fails closed, and refreshes source data on the first of each month. Every curated figure was audited against primary sources before publication, and several of my own numbers changed as a result.

Power BI · DAX Python Star schema GitHub Actions Data quality Public finance
Data infrastructure · Python · GitHub Actions · Zenodo Live — updates monthly

Namibia Station Monitor

An automated data-quality audit of 56 sources in a global public archive, scoring each one against a documented Data Quality Score (DQS v1.0) and republishing on the 1st of every month without supervision. Surfaced a concrete archive defect: one station present in ISD metadata since 1949 returns HTTP 404 in GHCND. Released as a citable dataset — Igulu (2026), DOI 10.5281/zenodo.21229782.

Python ETL automation GitHub Actions DQS v1.0 Zenodo Open data

Method development and peer-reviewed work on estimating risk when the record is incomplete.

Peer-reviewed research · Wind (MDPI), August 2026 Published

Modelling Wind Speed Extremes Using Extreme Value Theory: A Case Study for Namibia

Identified that quality control, not model choice, was the dominant source of error in national extreme-wind estimates. Removing 70 spurious records, 0.24% of observations, cut 100-year return levels by 35 to 45%. Produced the first station-level GPD return-level estimates with profile-likelihood uncertainty bounds for six Namibian stations.

doi.org/10.3390/wind6030040 ↗

EVT / GPD R Uncertainty quantification ArcGIS Pro
Methods research · v0.2 Active development

SACRF — Sparse-Adaptive Climate Risk Framework

A working framework for carrying observational uncertainty through to risk estimates when the underlying record is incomplete. It builds on the extreme-value work above, and asks a question that generalises well beyond climate: how should a model behave when you can measure how bad its inputs are?

Current focus: methodological development, empirical validation, reproducible implementation.

Bayesian EVT GPD / POT Uncertainty quantification Reproducibility
Applied research · Python · CMIP6 · PyMC In progress

Namibian Climate Risk Sandbox

An open, reproducible pipeline running from raw station records and CMIP6 projections through to a scenario-adjusted valuation for a real asset. A worked example of the full chain: ingest, bias-correct, model the tail, quantify uncertainty, convert to a number a decision-maker can use. Audit and bias-correction phases complete; extreme value and financial layers in build.

Python CMIP6 EVT PyMC Scenario analysis Open source
Map of Namibia showing dark shadow zones more than 100 km from the nearest long-record weather station, with 100 km coverage circles around each station and DFI infrastructure sites marked.
Namibia Weather Station Shadow Map: zones more than 100 km from the nearest WMO long-record station (dark wash) cover roughly 64% of the country. Coverage circles show each station's 100 km observation footprint; DFI infrastructure sites marked by category. Built in ArcGIS. Sources: WMO OSCAR/Surface, Natural Earth, NASA SRTM, Strohbach (2014).  Read the article →
June 2026

Why Namibia's weather stations are a development finance problem

Twenty long-record stations, 825,000 km², a shadow map covering 64% of the country. What that means for infrastructure lending in southern Africa.

Contact

Have something worth investigating?

I'm interested in problems where the numbers have to be right, data analysis, data engineering, quantitative modelling and business intelligence, in any sector.

If something here resonates, or you'd like to discuss a project, a research collaboration or an opportunity, get in touch.

Email me ↗