According to the locals, such vegetation generally stabilizes wells' edges and prevent siltation and wells collapsing.
In addition, in Mtumba and Mahoma Makulu areas, pierces of land around the wells were left uncultivated to protect the wells from drying up, erosion, siltation and, wells' collapsing.
A spry man in his 70's, he has witnessed many changes to the river, from a steady decline in water flow caused by drilling of nearby wells, to siltation of much of the stream bed.
Such studies have important applications in diverse fields such as civil and coastal engineering, sedimentology and environmental geology, where they can assist in flood control and the prevention of contaminant dispersal by wind and water, as well as the siltation of dams and harbours.
"The land around my SDWs is well-vegetated with trees and grasses and no cultivation is performed on/near the wells so as to protect it from drying, siltation and erosion" (personal communication with Mr. Jackson of Mtumba suburb).
This involves fundamental questions about the interplay of uplift, climate and denudation in mountain belts and transfer of sediments from the continents to the oceans as well as applied issues such as soil and gully erosion, reservoir siltation, and coastal protection.
A GIS-linked numerical model shows that the flood levels in the delta depend on the combined impacts of high river flows in the Mekong River, storm surges, sea level rise, and the likely, future siltation of the Mekong Estuary resulting from the construction of dams in China as well as many other dams proposed throughout the remaining river catchment.
Analysis of the inventory shows that sustainability and livelihood impact of the water harvesting schemes are threatened by siltation, leakage, insufficient run-off, poor water management and structural damages on the dam body as well as on irrigation infrastructure and spillway.
The high rate of awareness portended well for sustainability given water pans requires regular management to include periodic de-siltation.
However, increasing agriculture activities, shrimp farming and human settlement, uncontrolled deforestation, restricted fresh water supply from upstream due to the Farakka barrage, increasing river siltation, unscientific changes in land use, and climate change all still pose threats to the water quality of the river as well as to the whole mangrove ecosystem.
That means more flooding, more soil loss, more siltation, more trouble all round.
