Have you ever moved to a new place? Whether it may be a new school, a new house, or a new city or country, many centuries ago, people had to move to a different environment because of conditions that allowed their old home to become destroyed. Many historians are uncovering old homes that have been hidden under geographical circumstances. They are also trying to find the cause of why these people had to leave their beloved homes for a new place. Let’s discover certain places which people had to leave because of changes in climate, geography, and natural resources.

The oldest known civilization, Mesopotamia, has gone through a lot of changes during its reign of power. "The Cradle of Civilization" is situated in West Asia, next to the Tigris-Euphrates river system. There was very little possibility of rain in Mesopotamia, with only 12 inches or less annually. Fertile land for grain production, the Tigris and Euphrates river systems provided fertile land. Farmers began to rely on irrigation instead of waiting for rain to fall. As a result, various towns grew up along the river, resulting in the creation of Mesopotamian cities. 

According to historieshistories.com, "You might think living in ancient Mesopotamia, surrounded by deserts and mountains, would be an awful place to live. The Tigris and Euphrates rivers, however, provided early settlers in Mesopotamia with all they needed to survive and prosper. The rivers provided water for drinking, bathing, and irrigating crops. The rivers also provided an abundance of fish and water birds, such as ducks and geese, for eating. The mud along the banks of the rivers provided clay for pottery and materials for brick making. Due to the resources provided by the Tigris and Euphrates rivers, the Mesopotamians were able to develop agriculture, which led to a food surplus, permanent mud-brick dwellings, and specialized workers. Together, those three things led to a more complex society and the birth of civilization."

Because of the Tigris and Euphrates rivers, civilization began to grow around the two rivers. This meant that during that early period of time, the people living there were dependent on those rivers to provide a sustainable source of life. There was an abundance of food and water available for them. 

You might be thinking, "So, what happened that affected people’s lives?" The annual flooding of the rivers in ancient times was unpredictable, and it might have ruined crops or caused a drought that would have dried them all up. Irrigation channels delivered water from rivers to farms by 6,000 BCE, where workmen unclogged canals and built dams to keep flood water at bay. Melting snow from the high peaks of the northern Zagros Mountains and the Armenian Highlands aids this irrigation. Irrigation's utility is contingent on the ability to organize sufficient labor for canal building and maintenance, which has aided the growth of urban settlements and centralized political authority since the dawn of time. 

This is a great example that shows how a natural disaster effects on people lives . Because of the annual flooding of the rivers, it caused the settlements there to come up with plans that would benefit the future of civilization. They built irrigation systems that would allow the annual flooding to subside and all the extra water would flow into the soil of plants and other crops. As a result, the annual flooding, which was once a big worry for the livelihoods of people, turned into something that would benefit them.

Another civilization to point out, Ancient China, also had major environmental events that affected people's lives greatly. Ancient China is known for its two large rivers, the Yellow River and the Yangtze River. These rivers provided a lot of vegetation and agricultural resources for the farmers. According to Newsela, it's not unexpected that a country the size of China has such a diverse geography, climate, and vegetation. Fertile plains have been developed in the east by China's big rivers. For thousands of years, this area has been populated and farmed. It was the home of all the major dynasties and their capitals.

Based on Newsela, nothing compares to the devastation of the August 19, 1931 floods. In just one day, the Yangtze River climbed an incredible 53 feet. The ensuing flood was one of the most devastating in history. Monsoon rains, high snowmelt, and unexpected rainfall all contributed to the flooding. They bombarded vast swaths of southern China. The Yangtze received all of this water. For hundreds of miles, the river swelled and burst its banks. It was a disaster. 24 million people were forced to flee their homes. More than 140,000 people died as a result of the flood. An area the size of Oklahoma was inundated, and Nanjing, China's southern capital, was waterlogged for six weeks. This is a very recent example of the great floods in China. Emperors centuries ago attempted to manage the environment's ups and downs. Natural cycles, on the other hand, have had a significant impact on the foundations of Chinese and East Asian civilizations. River activity has become a metaphor for the ever-changing nature of natural forces.

According to ScientificAmerican, famine struck China during the Tang dynasty's reign in the late ninth century, caused by a bad harvest brought on by drought. The dynasty fell apart in A.D. 907, after nearly three centuries of power, when its emperor, Ai, was ousted and the empire was partitioned. Climate change may have been one of the reasons for the downfall, according to an atmospheric record preserved in a stalagmite.

"We believe climate had a significant influence on Chinese history," says University of Minnesota paleoclimatologist Hai Cheng, who was part of the research team that gathered and evaluated the stalagmite from Wanxiang Cave in Gansu Province, northwest China. The stalagmite, for example, demonstrates that the Asian monsoon's vital remains weakened during the downfalls of the Tang, Yuan, and Ming dynasties over the past 1,810 years.

The 4.6-inch (11.7-centimeter) long stalagmite, made of calcium carbonate leached from dripping water, retains a record of rainfall in this location, which is on the fringe of the Asian monsoon's influence. The researchers explain today in Science that when the monsoon is mild, the region receives less rainfall and when it is strong, the region receives more. When compared to Chinese historical records, these times of heavy and weak rainfall correspond to periods of imperial upheaval or prosperity, such as the Northern Song Dynasty's expansion—a time of rich harvests. Furthermore, the stalagmite record corresponds to glacier retreat in the Alps, sediment records from Lake Huguang Maar in southern China, and droughts across Barbados and Southern France. In fact, the Tang Dynasty's demise corresponds with that of the Mayan civilization's, both due to severe drought.

"We have demonstrated that the cave record correlates well with many other records, including the Little Ice Age in Europe, temperature changes across the Northern Hemisphere, and major solar variability," Cheng notes. In the past, variations in the sun's intensity seemed to be the most important factor in influencing the strength of the Asian monsoon. The data over the last 50 years, on the other hand, shows that the power of the rain is determined by man-made pollution and greenhouse gases.

"It is likely that the current global warming trend or anthropogenic forcing will be accompanied by a weakening trend of the Asian summer monsoons, especially in northwestern China," Cheng says. That may explain why China's current rulers are so eager to address man-made climate change.

Last but not least, Ancient India is another country that also had many devastating geographical changes that forced citizens to move places. "Weakened monsoons and reduced run-off from the mountains tamed the wild Indus and its Himalayan tributaries enough to enable agriculture along their valleys. During the early and mature phases of the Harappan civilization, settlements bloomed along the Indus, from the coast to the hills fronting the Himalayas and along the most likely course of the mythical River Sarasvati, in what is now a waterless region, part of the Thar Desert. With continued aridification, the population moved eastward toward the Ganges basin, where summer monsoon rains remained reliable and winter monsoon rains increased, marking a shift toward small farming communities and the decline of cities during late Harappan times." -Woods Hole Oceanographic Institution (WHOI)

To summarize what WHOI was announcing, the Ancient Indus Valley civilizations ended as a result of fewer monsoons and the agriculture started to dry up, meaning that the civilizations had to migrate north, as the rain in the Himalayas was able to sustain the growth of agriculture. Studies say that they weren’t exactly able to define whether or not the change took time or was at an exact point in a timeline.

Other scholars, such as LumenLearning, suggest that Harappan society's demise was caused by climate change. The main driver of climate change was the drying of the Saraswati river, which began around 1900 BCE. Due to a river's changing flow, climate change could have resulted in deforestation, flooding, or droughts. Another terrible change may have been eastward-moving monsoons. The Indus River Valley's monsoons promoted the growth of agricultural surpluses, which supported the construction of towns like Harappa. The environment had become cooler and drier by 1800 BCE, and a tectonic event may have caused the Ghaggar Hakra river system to be shifted into the Ganges Plain. People began to rely on seasonal monsoons rather than irrigation, and the water supply dried up as the monsoon drifted eastward. Trade with Egypt and Mesopotamia declined as a result of the reduced output of products. This is another reason why the Harappan cities of the Indus Valley were abandoned.

In conclusion, the changes in geography, climate, and natural resources have greatly affected the way people live. Certain examples included within this text were the extreme floods of China’s Yangtze and Yellow River, Mesopotamia’s untypical floods and droughts, as well as India’s Indus Valley’s monsoons. As a result, many citizens had to move to another place that would provide them with all the goods and resources they needed to survive.