On a regional scale, TEEB estimates that the rainforest's role in avoiding siltation in hydro-power reservoirs is worth anything from $60m to $600m a year.A superior insurance policyTEEB puts the rainforest's contribution to South America's agricultural output, through regulating the continental water cycle, at $1 billion-3 billion.
Prime Minster Hun Sen of Cambodia alluded to potential development problems, saying: "We see the signs of such stress in erosion, siltation and changes in water currents.
Soil erosion, induced by forest denudation in the Artibonite valley, has resulted in severe siltation of the reservoir and has greatly reduced its agricultural and energy potential.
In addition, afforestation along the riverbanks would help in controlling siltation, erosion, agricultural runoffs containing pesticides and fertilizers, etc.
Compared to Phoenix's other heat and water woes, the demise of Arizona's forests may seem like a side issue, whose effects would be noticeable mainly in the siltation of reservoirs and the destabilization of the watersheds on which the city depends.
This had caused a negative impact in terms of reducing soil fertility, siltation in reservoirs, risk of flash or mud floods in lowlands (Diyabalanage et al. 2017).
The main purpose of the diversion was to divert water into the Hooghly River in order to limit siltation problems in the port of Calcutta.
Seepage loss is high in porous sandy soil and reduces gradually due to siltation in 1 or 2 years.
The subsequent effects observed in the sub-basin are natural resource use conflicts, poverty, low productivity, overcrowding, high siltation in rivers and lakes, degraded environment, decreased river flows, polluted water sources, etc.
