Dams trap sediments and nutrients, leading to increased nutrient concentrations downstream, promoting excessive algal growth and eutrophication.

Dams slow down the flow of water, allowing it to absorb more heat from the sun, resulting in elevated water temperatures downstream.

Irrigation projects can lead to increased salinity, reduced biodiversity, and groundwater depletion, but they do not generally improve water quality.

Dams can block fish migration routes, destroy spawning grounds, increase predation, and reduce food availability, leading to a decline in fish populations downstream.

Dams trap sediment, reducing the sediment load of downstream water, which can lead to channel erosion and loss of habitat.

Excessive fertilizer use, poor drainage systems, and evaporation from reservoirs can all contribute to increased salinity in water bodies downstream of irrigation projects.

Dams and irrigation projects can provide flood control, improve water supply, and generate hydropower, but they do not generally increase biodiversity.

Dams can reduce dissolved oxygen levels downstream by releasing cold, oxygen-poor water from the bottom of reservoirs.

Reduced water flow, increased water temperature, and sediment deposition can all contribute to the loss of riparian vegetation downstream of dams.

Dams can have negative impacts on downstream water quality, such as increased sediment load, elevated water temperature, and reduced dissolved oxygen levels, but they do not generally improve water quality.

Irrigation projects can raise the groundwater table by adding water to the soil, which can lead to waterlogging and salinization.

Excessive fertilizer use, poor drainage systems, and evaporation from reservoirs can all contribute to increased nutrient levels in water bodies downstream of irrigation projects.

Irrigation projects can provide increased agricultural production, improved food security, and reduced poverty, but they do not generally increase biodiversity.

Dams can increase flow variability downstream by releasing water during periods of high demand and storing water during periods of low demand.

Irrigation projects can lead to loss of spawning grounds, increased predation, and reduced food availability, all of which can contribute to the decline in fish populations downstream.