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Posts by Yohan

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Interested in getting a short overview of the latest geospatial papers and datasets each week?

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๐˜๐—น;๐—ฑ๐—ฟ

1. nightlights can capture certain elements of consumption and production

2. the level of granularity when using nightlights really matters

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๐—ง๐—ต๐—ฒ ๐—ธ๐—ฒ๐˜† ๐˜๐—ฎ๐—ธ๐—ฒ๐—ฎ๐˜„๐—ฎ๐˜†:

The more you zoom in, the bigger these spatial mismatches between daytime and nighttime economic activity become.

11 months ago 0 0 1 0

This underrepresentation occurs even if:

โ€ข these areas generate a lot more economic activity (e.g. financial districts), compared to
โ€ข areas bustling with bars and restaurants

These nightlife areas tend to be overestimated in nightlights data.

11 months ago 0 0 1 0

As a result, it's likely that I:

โ€ข work during the day in one 500m2 pixel and
โ€ข spend money in a different pixel at night.

This implies that pixels with higher daytime economic activity will be systematically underrepresented in nightlights data.

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This creates a discrepancy between areas where economic activity is generated during the day (London) vs at night (Essex).

With nightlights we can zoom into areas as small as 500m2.

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In this example, the economic activity from my job in London doesn't get picked up by nightlights.

However, the places where I spend money at night in Essex, like restaurants, do light up and are visible from space.

11 months ago 0 0 1 0
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2. Spatial Mismatches

Imagine I work in London but live in Essex, an hour away.

My work (i.e. production) contributes to London's economy.

But when I spend time in Essex, like eating out at night, that's where my consumption mainly happens.

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The bottom line:

Nightlights can capture certain elements of consumption AND production.

So when doing an analysis using nightlights, we need to know the composition of production and consumption.

This is important to avoid double counting.

11 months ago 0 0 1 0
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See this image of the Pilbara region in Australia

Here we see:

1. lights generated from mines being lit up at night (i.e. production-based economic activity), AND

2. lights generated by mining staff who are eating out at night (e.g. consumption-based economic activity).

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But the reality is a bit more complex.

Nightlights can capture some production-related activities.

E.g. nighttime construction and nighttime mining.

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However, we need to be careful about double counting.

E.g. combining production values with income and consumption figures without accounting for overlaps could distort things.

Henderson et al., essentially view nightlights as a measure of nighttime consumption:

11 months ago 0 0 1 0

However, GDP is typically measured in three ways:

1. Adding up all of the consumption in an economy

2. Adding up all of the income earned in an economy

3. Adding up the value of all things produced in an economy

For an entire country, these should equal one another.

11 months ago 0 0 1 0
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1. Economic Activity

Itโ€™s vague to say nightlights capture โ€˜economic activityโ€™.

What ๐™š๐™ญ๐™–๐™˜๐™ฉ๐™ก๐™ฎ do we mean by economic activity?

The most popular paper on nightlights and economic activity is Henderson et al. (2012).

It uses nightlights as a proxy for real GDP growth.

11 months ago 0 0 1 0
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If you're using nightlights you need to know about two things:

1. What ๐™ฉ๐™ฎ๐™ฅ๐™š of economic activity it captures, and
2. ๐™Ž๐™ฅ๐™–๐™ฉ๐™ž๐™–๐™ก ๐™ข๐™ž๐™จ๐™ข๐™–๐™ฉ๐™˜๐™๐™š๐™จ

Here's the breakdown (in simple terms):

11 months ago 4 1 1 0
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Interested in getting a short overview of the latest geospatial papers and datasets each week?

Subscribe to the Spatial Edge newsletter: yohan.so

11 months ago 0 0 0 0

So: while AI is clearly going to play a massive role in geospatial analysis going forward, could it actually be overhyped?

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๐—ช๐—ต๐˜† ๐˜๐—ต๐—ถ๐˜€ ๐—ฎ๐—น๐—น ๐—บ๐—ฎ๐˜๐˜๐—ฒ๐—ฟ๐˜€

At the end of the day, autonomous GIS could make spatial analysis:

โ€ข More accessible to non-experts.
โ€ข Faster and more scalable.
โ€ข Capable of generating new insights.

It also forces GIScience to rethink education, ethics, and what it means to โ€œknowโ€ geography

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โ€ข Modeling: Automating complex analysis like disease spread or flood risk still requires human judgment.
โ€ข Trust and ethics: Who is responsible if a model makes a bad call? How do we ensure fairness?

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However, several big hurdles remain:

โ€ข LLMs lack of GIS-specific knowledge (e.g., projections, spatial joins).
โ€ข Skills gap: LLMs donโ€™t always know what tools to use or how to handle large files.
โ€ข Continuous learning: Most models canโ€™t improve themselves after deployment.

11 months ago 0 0 1 0
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โ€ข ๐—Ÿ๐—Ÿ๐— -๐—–๐—ฎ๐˜: Makes maps iteratively and improves them based on its own visual critique.
โ€ข ๐—š๐—œ๐—ฆ ๐—–๐—ผ๐—ฝ๐—ถ๐—น๐—ผ๐˜: Helps QGIS users do analysis more efficiently.

11 months ago 0 0 1 0

๐—ช๐—ต๐—ฎ๐˜ ๐—–๐—ฎ๐—ป ๐—œ๐˜ ๐——๐—ผ ๐—ง๐—ผ๐—ฑ๐—ฎ๐˜†?

The authors provide working examples:

โ€ข ๐—Ÿ๐—Ÿ๐— -๐—™๐—ถ๐—ป๐—ฑ: Automatically finds and downloads the right geospatial data.
โ€ข ๐—Ÿ๐—Ÿ๐— -๐—š๐—ฒ๐—ผ: Runs a complete spatial analysisโ€”e.g., walkability around schoolsโ€”by creating code and visualizing results.

11 months ago 0 0 1 0
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๐—ฆ๐—ฐ๐—ฎ๐—น๐—ฒ๐˜€ ๐—ผ๐—ณ ๐—ข๐—ฝ๐—ฒ๐—ฟ๐—ฎ๐˜๐—ถ๐—ผ๐—ป

There are three technical scales:

1. Local: Runs on a single machine
2. Centralized: Uses cloud computing to handle larger tasks.
3. Infrastructure-scale: Distributed systems for massive analysis, possibly run by governments or research institutions.

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๐—›๐—ผ๐˜„ ๐—œ๐˜€ ๐—œ๐˜ ๐—•๐—ฒ๐—ถ๐—ป๐—ด ๐—•๐˜‚๐—ถ๐—น๐˜?

The core of an autonomous GIS is the โ€œdecision coreโ€. This is typically an LLM that:

โ€ข Reads your question.
โ€ข Plans a solution.
โ€ข Finds and cleans the data.
โ€ข Runs the analysis (e.g., in Python or GIS software).
โ€ข Presents results (maps, stats, reports).

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Most current prototypes are at Level 2.

I.e. they can follow instructions, create workflows, and run them, but need help getting the right data or interpreting results.

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๐—Ÿ๐—ฒ๐˜ƒ๐—ฒ๐—น ๐Ÿฎ: Generates and runs workflows, but still needs human-provided data.

๐—Ÿ๐—ฒ๐˜ƒ๐—ฒ๐—น ๐Ÿฏ: Selects and prepares its own data.

๐—Ÿ๐—ฒ๐˜ƒ๐—ฒ๐—น ๐Ÿฐ: Understands and refines results without help.

๐—Ÿ๐—ฒ๐˜ƒ๐—ฒ๐—น ๐Ÿฑ: Fully independent, learns from experience, and adapts over time.

11 months ago 0 0 1 0

๐—Ÿ๐—ฒ๐˜ƒ๐—ฒ๐—น๐˜€ ๐—ผ๐—ณ ๐—”๐˜‚๐˜๐—ผ๐—ป๐—ผ๐—บ๐˜†

Autonomous GIS can be built gradually. The authors define five levels:

๐—Ÿ๐—ฒ๐˜ƒ๐—ฒ๐—น ๐Ÿฌ: Everything is manual โ€“ traditional GIS.

๐—Ÿ๐—ฒ๐˜ƒ๐—ฒ๐—น ๐Ÿญ: Automates repetitive tasks, but a human sets them up.

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๐Ÿฏ. ๐—ฆ๐—ฒ๐—น๐—ณ-๐˜ƒ๐—ฒ๐—ฟ๐—ถ๐—ณ๐˜†๐—ถ๐—ป๐—ด โ€“ It checks its own work step by step and ensures results are reasonable.
๐Ÿฐ. ๐—ฆ๐—ฒ๐—น๐—ณ-๐—ผ๐—ฟ๐—ด๐—ฎ๐—ป๐—ถ๐˜‡๐—ถ๐—ป๐—ด โ€“ It manages time, data, compute power, and even collaborates with other agents.
๐Ÿฑ. ๐—ฆ๐—ฒ๐—น๐—ณ-๐—ด๐—ฟ๐—ผ๐˜„๐—ถ๐—ป๐—ด โ€“ It learns from experience and gets better.

11 months ago 0 0 1 0
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There are 5 goals for autonomous GIS:

๐Ÿญ. ๐—ฆ๐—ฒ๐—น๐—ณ-๐—ด๐—ฒ๐—ป๐—ฒ๐—ฟ๐—ฎ๐˜๐—ถ๐—ป๐—ด โ€“ It creates ideas, workflows, code, and insights on its own.
๐Ÿฎ. ๐—ฆ๐—ฒ๐—น๐—ณ-๐—ฒ๐˜…๐—ฒ๐—ฐ๐˜‚๐˜๐—ถ๐—ป๐—ด โ€“ It can run the tasks (e.g., calculating distances, drawing maps).

11 months ago 0 0 1 0
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The emergence of LLMs, has made this possible. These models can:

โ€ข Interpret instructions in natural language.
โ€ข Generate workflows and code.
โ€ข Work iteratively to refine outputs.

This opens the door to GIS reasons and adapts.

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