In the beginning man used to be a hunter and forager. But slowly as time passed, the cultivation of food became a more preferred method of obtaining food and these hunters began to settle down. These settlements occurred around large rivers which had fertile land and abundant food resources. Man began to cultivate these lands, developing farmlands followed by the growth of agriculture began. As these small settlements grew in number, they formed cities which further grew to form civilizations. Many other activities developed and flourished under these civilizations such as craft, art and trade. The development in trade encouraged the farmers to grow surplus crops which helped to acquire new materials, objects and resources. But as man lent towards the need to have and grow through agriculture, doing so was not always possible. The geographical conditions and the weather were not always in their favour, the raw materials required to maintain the growing crops were scarce. These were some of the obstacles in their path. So to combat these problems the idea of irrigation came up. The large water body by which these people had settled began to play a very important role. The various uses of water and some initial practices around irrigation that are used currently have their roots set back thousands of years ago.
The following essay will go through how irrigation as an idea is developed in making various systems in ancient civilizations which helped them further their agricultural practices and make advancements in various areas. The canal system, the building of dams and reservoirs goes far back in history. The settlements around rivers were very advanced and laid out the foundation of the technology used today. These structures were built as an extension of the already existing natural reservoirs and inlets. The embankments along rivers were made to stop the flood water from destroying the crops. In some places, these embankments were extended to form small pols of water which could be later used for irrigation and once the water was used, the silt enriched land was used for irrigation. Many practices like this came up to support each different civilization.
In ancient Assyria, there was a shortage of water due to low rainfall and geographical conditions around them were not much supportive either.The harsh sun and the vast deserts are assumed to have been some of the reasons for the troubles faced in developing agriculture in this civilization. Though as the civilization grew, people found ways to collect more resources, large amounts of water was now made accessible and the fields were irrigated.
One of the first basic methods was making an inlet connecting the river to the fields (Kang,1972). The water would then flow where the paths were made, this method is referred to as gravity flow irrigation (Ratnagar, 1981). The irrigation method focused on containing water within the leeves or canals and later when the fields were to be irrigated the walls would be then diverted to the fields (Ratnagar, 1981). The only problem was that the water would dry up due to high temperature and the leftover salt would damage the fields (Kang, 1972). The damaged fields were also assumed to be a reason for the changing positions of the cities.
The Assyrians in their capitals created a system of canals to allow the river water to flow into the city and be used for irrigation and drinking purposes (Bagg, 2000). During some part of the year the rivers Euphrates and Tigris would flood the land and the crops would be destroyed and cause damage. In such times the canals were blocked so that the excess water could not enter the city and be stored for use in the dry season (Willcocks,1910). The population growth was also a factor in developing a more sophisticated canal system to connect the city and the river for water usage. Another reason for such sophisticated building of canals and dams was to grow surplus crops which could be later used in trade.
The extensive canal system that ran through the city transported water and in areas the same canal acted as a waterway, transporting goods (Goldfrank, Goodman, & Szasz, 1999).The canal system by 1800 BCE spread to 10,000 square miles (Goldfrank, Goodman, & Szasz, 1999). In lowland Mesopotamia, the method preferred to water the crops was surface irrigation (Bagg, 2000).
The tools such as Shaduf were used in Mesopotamia for irrigation purposes around 3000 BC. The south region of Mesopotamia faced the most water problems for which irrigation methods had to be improvised to produce crops in a better yield, sometimes shifting the crop, like barley which would grow better in salinized regions (Goldfrank, Goodman, & Szasz, 1999). Although the Assyrian empire is usually known for its conquests, there have been seen the remnants of hydraulic projects in texts and scripts which would support the assumed irrigation practices.
In ancient Egypt, rainfall was minimal and owing to its geographical location; the desert surrounded land, promoted water harvesting to nurture the crops. The Nile River hence was quite important for the people of Egypt. The river would flood over regular periods of time and enrich the soil around increasing it’s fertility. The use of artificial irrigation and its advancements had started in the late Pre-Dynastic periods (Mays, 2010).
The crops near the river could receive the water well, but as the irrigation systems developed, new mechanisms such as the shaduf, a form of lift irrigation, allowed the crops to be watered better especially during the summer (Mays, 2010). The shaduf consisted of a long tapering wooden pole whose end was fixed with a bag like structure connected through the ropes and could water the crops as far as 1.5 meters (Scholz, 2015)
The other mechanism through which the water was distributed in fields was the waterwheel or the ‘Noria’ . This device had a pulley system which was connected to a wheel. This wheel had small water compartments like buckets to collect water and would have worked according to the water flow of the river (Scholz, 2015).
The mention of canals and dikes is noted in some texts in the early Egyptian texts, around the bronze age and was commonly mentioned in the Middle Kingdom era (Westermann, 1919). These were connected to the river and lead into the city to irrigate fields, provide water for sanitation and drinking. There are also some remains found of what could have supposedly been a drainage system. Flood waters were harvested using basin irrigation along the Nile to allow more crop produce (Mays, 2010). King Menes was the first to undertake a large scale basin irrigation project (Mays, 2010).
There small earthen canals created on the banks of the Nile and these lead to the naturally formed basins around that area. The water would replenish the soil and the excess amount was allowed to be passed in the city though another set of canals (Mays, 2010). Other than this, the Egyptians even went as far as constructing a dam to harvest water.
At some point the water in the Nile had declined and water needed to be brought into the city for various purposes. The Lake Moeris became a source of water for the people. The level of the lake bed was below sea level and the depression used to store flood waters naturally. So with the further introduction of canals the water was diverted towards the fields (Mays, 2010). It is assumed that a large wall like structure similar to that of a dam was built around it to restrict any unnecessary water flow and collect water for usage (Westermann, 1919).
The Faiyum Depression was another important place from which the Egyptians were able to harvest water. The depression naturally collected floodwater from the Nile. It was later modified to increase its depth and provide water to irrigate the fields (Mays, 2010). The Bahr Yusef was a naturally built canal which was also used to divert water to man made canals leading to fields.
The various developments the irrigation techniques that the people made were simply due to the fact that they wanted to use the produce for other purposes and also to make use of the vast river they had settled around. Since inside the city, the number of people was large these practices ensured their well being and allowed some power to be generated for the rulers as well as flourishing many different activities and occupations.
Indus Valley Civilization
In another civilization, the veil of mystery shrouds the practices it must have had. The Indus Valley civilization, though lasted for a shorter time period than both of the above civilizations, was more complex and differed in various aspects including possibly irrigation.
The residents of Indus Valley did not make similar canals as the above civilizations. This is assumed since the side effects of large scale irrigation were salination of the land and changing positions of the settlements. None of these conditions seem to have been fulfilled (McIntosh, 2008). Though there are remnants of wells and reservoirs in the cities, there are not many similarities in the irrigation systems. The rivers did not have water throughout the year but there was an abundance of groundwater which was seen in the form of large number of wells. The people tended to have public and private wells which would be used for irrigation as well as for accessing the drinking water. The wells were dug to the level from which water could be easily drawn out and these wells were later replenished through the rainwater seeping into the ground. There is assumed to have been a pulley system through which the water was drawn out from the wells. These wells were an important source of irrigation during winter when the water became scarce in some regions (Ratnagar, 1981).
Some standing water bodies were also assumed to have been providing water. But as the water became harder to supply to the fields, small inlets or cuts in the bank of the river known as ‘Chhars’ were made to provide water to the far fields (Ratnagar,1981). There were even remains seen in the cities of Lahore for wheels which could have been used for irrigation of fields (Ratnagar, 1981). The use of a shaduf like mechanism using gears is also assumed to have been used by the people after finding drawings on the remains of pottery. Other than this small scale irrigation was prominently used in highland regions and small ‘Bandhs’ or dams as well as Gabarband were made to store and use water (McIntosh, 2008). Lift irrigation was also observed in the areas near Lake Manchchhar (Ratnagar, 1981). Though these devices were used, some regions of the Indus Valley Civilization had access to tributaries and small rivulets and not the river itself. In these areas, the water bodies at irregular intervals would face depletion due to irregular rainfall. After some time the farmers would go back to using wells for irrigation since digging the ground and acquiring water was easier. Oxens were also used to draw water if manual labour was not enough (Ratnagar, 1981).
The people of this civilization were quite advanced in town planning. Due to this aspect the irrigation method was well built but so was the sewage system of the city. There were proper gutters and paved paths through which the waste of the city was dumped. There were even large baths where water was collected for public use, the biggest one discovered till now is the Great Bath of Mohenjo Daro. The city of Dholavira, one of the major sites in Harappan Civilization, has 16 large reservoirs built with steps to allow people to store water and use it when needed (McIntosh, 2008). The reservoirs here were built with good workmanship from burned bricks and bitumen for waterproofing (McIntosh, 2008). These reservoirs were one of the key points in the Indus Valley Civilization as they showed how the workmanship of the people was alongside providing an explanation for the foundation of some of the world’s most complex technologies.
The various methods of irrigation were developed since there was an idea of using the water as a medium of supporting crops to meet the growing population and trade where the surplus grains could be sold. Many animals kept by the people were also fed particular grains which needed to be grown all year round and the stored water could be used to grow them. These methods developed according to the conditions of the land, the way the people lived and the area where they irrigated. The flat plains near the river banks were not the only place where crops were grown, the inside of the city also housed some fields. The development of irrigation systems was done to provide these fields with water and also to save the crops on the banks from flood waters. The Mesopotamians, Egyptians and Harappans all civilizations happened over different periods of time, yet all of them had a very detailed canal construction to irrigate their fields and provide water for other purposes. The Harappans and Egyptians also had a common structure used for storing water, Reservoirs. Both these civilizations used to collect large amounts of water to provide the fields with water as well as for sanitation and drinking purposes. The building of these structures during the later stages of the civilizations is also a marker to show the advancement the people made as the need for the agricultural produce increased. There are many tools which have been used to irrigate the fields such as the water wheel and shaduf whose advanced versions are also seen today. This development has led man to develop machinery like motors and pumps. There are also advancements in the machinery and scale of large structures like dams and reservoirs. The advancement in the field of irrigation, the idea of building such well thought structures for the better living and survival of the people was done thousands of years back. The same ideology has now carried forward in the present with a better output.
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