The expansion of the Roman Republic made Rome surpass the concept of city-state and become a multi-ethnic, multi-religious, multi-lingual and multi-cultural country around the Mediterranean. In 27 BC, the Senate awarded Gaius Octavius the title of "Augustus", and the Roman Republic entered the imperial era.

During the reign of Emperor Trajan of Antoine Dynasty (98-65438 +065438 +07), the Roman Empire reached its peak, with unprecedented economic prosperity and the largest territory: Spain, Gaul and Britain in the west, the upper reaches of the Euphrates River in the east, North Africa in the south, the Rhine River and Danube River in the north, and the Mediterranean Sea became the inland sea of the empire.

At its peak, it controlled about 5 million square kilometers of land and was one of the largest monarchies in the ancient history of the world.

Extended data

"Why did the powerful Roman Empire decline" has always been a topic of interest to historians. There used to be a lot of research on political, military and social reasons. However, under the natural conditions of drought and water shortage in the Mediterranean at that time, the role of water resources in supporting the huge empire was a long-neglected aspect.

The latest research points out that population growth and urbanization make the imperial grain supply capacity close to the limit, and when climate change leads to reduced grain production and soaring transportation costs, the empire will inevitably decline.

Demody, an environmental scholar at Utrecht University in the Netherlands, led a research team composed of Dutch water writers and classical scholars from Stanford University, hoping to find out the relationship between Roman agricultural water management and grain trade and the rise and fall of the empire. Related research papers were published in the journal Hydrology and Earth System Science in February, 20 14.

The grain trade is actually the trade of water resources. Generally speaking, it takes 1000 ~ 2000 liters of water to irrigate one kilogram of grain. Therefore, the research team borrowed the concept of "virtual water", hoping to find out the source of water resources at that time and how to flow within the empire.

The researchers used the Rome World Geographic Information Network developed by Stanford University, which contains the trade and transportation routes within the empire for hundreds of years, as well as the cost information of transporting food by land, river and sea.

On this basis, they established a model to simulate the geological and hydrological information, temperature and precipitation conditions, so as to draw the geological and hydrological information map of ancient Rome, so as to observe the virtual water resources in various regions, as well as its flowing distance and cost.

The simulation results show that the agricultural system in Rome is highly dependent on natural environmental conditions and heavily dependent on water resources imported from other places. Romanesque buildings built all over the empire-excellent public drainage systems, large fountains, public bathrooms and toilets-are consuming the already stretched water resources, especially in Rome.

In the distribution of virtual water resources, Rome is the largest import area, and everyone in Rome can enjoy 1 100 liters of water on average every day.

It is also found that transportation cost is negatively related to temperature. In the Mediterranean region, the temperature rises, the grain output will increase, and the Roman Empire's competition for virtual water resources will decrease. Due to the unusually warm climate in Europe from 250 BC to 400 AD, the empire could always meet the food demand at a lower cost, and the arid areas could import food from other places.

However, the high degree of urbanization and huge population made the empire's adaptability to agricultural crop failure decline year by year. Once the climate changes greatly, agricultural production decreases and transportation costs soar, cities that rely too much on foreign water resources will easily collapse quickly.

When the Roman Empire fell into a 50-year civil war in the third century, it began to decline, and the warm period ended around 400 AD, when the Roman Empire was about to end.

People's Network-Water Resources and the Decline of Roman Empire

Baidu Encyclopedia-Roman Empire