ZIMSEC O Level Geography Notes: River Processes: Stream bank cultivation
- Stream bank cultivation refers to the practice of growing or cultivation of crops near a wetland, stream or river.
- Sub-Saharan Africa has faced political, socio-economic problems in the recent times.
- These problems have been in brought about by erratic rainfall patterns in the region.
- In Zimbabwe, erratic rainfall patterns, lack of employment and poverty has led to the cultivation of stream banks.
- An example of areas that experience a lot of streambank cultivation are the peri-urban areas of Seke-Chitungwiza.
- Crops are grown mostly for domestic consumption although horticultural activities such as vegetable grown is sometimes carried out with most of the produce sold at local farmer’s markets.
- Stream bank cultivation results in siltation and the choking of rivers and dams.
- It also leads to eutrophication as fertilizers containing nitrates are washed into the rivers.
- It also leads to the disturbance of natural ecosystems.
- It results in the siltation and choking of rivers and dams.
- It leads to pollution as dangerous chemicals like mercury an cyanide are released into streams.
- The disturbances of ecosystems.
- Results in increased pollution and disturbances of ecosystems.
- Increased impervious surfaces result in increased overland flow, shorter lag time between a storm and a surge in discharge and increased incidences of flooding downstream.
- Sometimes river water is diverted through man made canals, dames and pipelines to supply water for irrigation, industrial and domestic use.
- The Pungwe Project in Mutare is an example.
- The result is decreased discharge and the formation of more deposition features.
- This may also lead to the shortage of water downstream.