Illuminating human activities using the Night Light

Since the dawn of the mankind, humans have worked from dawn to dusk and rested after the sunset. But that has changed ever since the invention of the lightbulb by Thomas Edison.

Today our nights are getting brighter than ever and the reason is that we have lights everywhere. Our markets, billboards, roads, and homes are lit. Every place humans have inhabited has some sort of nightlights today.

Now thanks to the satellites, we can see and map these nightlights from the space. This data serves a variety of purposes including aiding disaster relief, analyzing power outages and even to map the estimates of global and regional emissions of carbon dioxide, etc.

Nightlights is an extremely useful dataset to be incorporated in your analysis if you want insights on external factors. The night-time value gives really rich, unique insights on population and economic development.

Images of the Earth during the night are processed to create this data and are freely available for anyone to download and process/analyze. In my last blog, I talked about how Google Earth Engine provides geospatial datasets without the need to download and pre-process it.

Using Earth Engine, I analyzed the freely available Nightlights datasets derived from Satellite images for fun and found some interesting patterns using them and thought I should share some of them.

Old Civilizations developed around rivers

Old civilizations were around rivers. The most likely reason for it could be that in those days humans depended the most on agriculture and these rivers made it possible to have it on a very large scale. As these civilizations died, new were born on their footprints.

So by looking at the pattern of the human settlement today, we can see how ancient civilizations developed. So let’s have a look at the three oldest civilizations on this planet.

Indus Valley Civilization

This river has so much historic importance that even the name ‘India’ comes from the river‘Indus’. Most of its basin is in Modern-day Pakistan and if you look at the Nightlights of Pakistan, you can see the presence of humans is around River Indus and its tributaries.

It resembles so much that you can draw the rivers on this map. Now have a look at the Indus River System to see the resemblance.

Ancient Egyptian Civilization

Modern-day Egypt is also at the same place as the Ancient Egyptian Civilization i.e. the Delta of River Nile. And the Nightlight dataset shows that the population of Egypt is concentrated around the river Nile and its Delta. Again there’s a similarity.

To see the likeness, have a look at the map of Egypt and the river Nile.

Mesopotamia Civilization

These rivers start from modern-day Turkey, move through Syria and flow into Iraq before they finally make it to the Persian Gulf. If you look at modern-day Iraq and Syria, you can see that their cities still have that pattern.

Now have a look at the maps of these two rivers to see the resemblance.

New Civilizations are popping at the coasts

As trade got popular, humans changed the trend and started settling around the seaports. We have recently seen cities like Dubai, Abu Dhabi, and Sharjah, etc. popup along the Coast of UAE. We are seeing the similar new development of Chabahar in Iran and Gawadar in Pakistan along their coasts. For Example, have a look at Australia

Australian cities are much younger as compared to the civilizations we talked about earlier and they represent the newer pattern of Human settlements. You can see that Australia is a vast dark land except for the cities that have popped along its coasts.

Tensions on borders are visible from the space

Another human activity that is visible from the space is tension on borders. We all know that India and Pakistan don’t get along well. And it can be seen from above.

The southern part of their border is visible because it is situated in sparsely populated deserts which makes it dark on both sides but the border is lit by floodlights as both sides monitor activity on the other side 24/7.

Another border that is visible from above for the same reasons is between North and South Koreas. And it is even more clear.

Another thing to see here is the huge difference in development. South Korea is so much more developed as compared to the North that you can see lively cities all over South Korea while in the North, the only place with some nightlights is the city of Pyongyang.

Economic Development

Nightlights can also be seen as a gauge of economic development. The cities start getting bigger and brighter with economic development. I was using the DMSP OSP nightlights dataset for the analysis and it is available from 1992 to 2013 so I tried to see how the world changed in that time and I could see that almost the whole world got brighter.

One of the two countries that showed maximum growth was South Korea. The above image is self-explanatory. During this time, their GDP went from $386.3 billion to $1.3 trillion and it can be seen from the space. But one country even outpaced South Korea.

Chinese GDP went from $426.9 Billion to $9.6 Trillion between 1992 and 2013 and this can be easily seen from the space. But another thing visible from the space is that all the development was in its eastern half while the western half remains pretty underdeveloped. Probably this is the reason why China is connecting its western half with Pakistan’s seaports, the Middle East and Europe through the Belt and Road initiative.

War plunged countries into darkness

War is hell. It is indifferent and shows you how fragile human life is. War plunges countries into darkness. It literally does and we can see that from the space. Between 1992 and 2013, two wars were started and I thought I should have a look at these.

The USA invaded Iraq in 2003 on the alleged possession of Weapons of Mass Destruction. So we can see that Iraq’s nights were brighter in 2002 (left) as compared to 2005 (right) which was during the war.

The Syrian Civil War started in March 2011 and it continues today. 2010 was the year before the fighting started in Syria and 2013 was the last year of which the dataset was available. In these three years, you can see that Syria plunged into darkness.

There’s a dark side of the light

So far I’ve only talked about light as a symbol of peace & prosperity but there’s another side of the story. Nightlights also cause some issues and there’s a reason why it is called ‘lightpollution’.

The migratory birds that travel in the night evolved to follow distant dim lights but now they get confused by city lights, they circle lit buildings and fall due to exhaustion. Due to nightlights, millions of birds die each year.

There are some species in the animal kingdom like the Dung Beetles that evolved to navigate using the Milkyway as a reference but nightlights make it invisible. Here is a visual representation of how it makes the Milkyway disappear.

There are some species in the animal kingdom like the Dung Beetles that evolved to navigate using the Milkyway as a reference but nightlights make it invisible. Here is a visual representation of how it makes the Milkyway disappear.

I can bet that some (if not most) of you have never seen the Milkyway like this and city lights are to blame. And BTW that’s me in the black jacket in the above photo.

Nightlights aren’t only bad for the environment. Even us humans have evolved to sleep when it is dark and wake up when its the day. So much light in the night tricks us into thinking it is still day and this causes insomnia and other health issues.