The early Mesopotamian countryside experienced repeated conflicts overland and water due to several factors. These factors include the geography of the region, the agricultural practices of the people, the lack of natural resources, and the presence of various rival city-states.

Geography:
- Mesopotamia, located between the Tigris and Euphrates rivers, had a flat and fertile landscape conducive to agriculture.
- However, the rivers periodically flooded, causing changes in the course of the rivers and the destruction of farmland.
- The lack of natural barriers and the easy access to waterways made it vulnerable to invasions and conflicts.

Agricultural Practices:
- The people of Mesopotamia heavily relied on agriculture for their livelihood.
- They developed an extensive irrigation system to manage water supply for their crops.
- This created competition for limited water resources, leading to conflicts between neighboring communities over access to water.

Lack of Natural Resources:
- Mesopotamia lacked many natural resources, such as timber and stone, which were necessary for construction and trade.
- This scarcity led to conflicts over control of these resources, as city-states would invade and conquer neighboring territories to gain access to these valuable commodities.

Rival City-States:
- Mesopotamia was home to several independent city-states, each with its own government and ruling elite.
- These city-states often engaged in conflicts with one another to expand their territories and increase their wealth and power.
- The constant competition and rivalry between these city-states led to frequent conflicts overland and water.

Conclusion:
In conclusion, the early Mesopotamian countryside experienced repeated conflicts overland and water due to the geography of the region, the agricultural practices of the people, the lack of natural resources, and the presence of rival city-states. The flat and fertile landscape, combined with the periodic flooding of the rivers, created competition for limited water resources. Additionally, the scarcity of natural resources and the desire for territorial expansion led to conflicts between city-states. These factors contributed to the repeated conflicts in the region during this period.