South-North Water transfer project - Enviromental impacts of a major water supply shceme and associated distirbution networks

Question 1

What is it?

Answer 1

The South-North Water transfer project is a 62 billion dollar scheme intended to increase water security in China, it onvolves a network fo tunnels and canals that diverts 45 billion cubic metres of water evry year from the Yangtze river and its tributaries in the south to the yellow river in the nroth.

Question 2

Enviromental imapacts

Answer 2

• As part of the central route consturction the height of the existing Danjiangkou Dam on the Hanshui river was increased about 15 meters to allow more water to be stored in the resevoir, this flooded more land which destoryed habitats and reduced biodiversity in the area.
• Increased height also decreased the velocity of the river downstream and this has contrbuted to an increases in Algal blooms, thick blankets of algae on the water suface, which prevent light from penetrating below the surface. This causes plants in the river to die, resulting in oxygen shortages in the water and the death of organisms that rely on oxygen such as fish.
• The water can be polluted during the transfer, this can make it toxic for plants and animals, water treatment plants require large amounts of energy to operate, much of which comes from burning fossil fuesl, this relases greenhouse gasses GLOBAL IMPACT.

Question 3

Preducted enviromental impacts

Answer 3

• Decreased flow of speeds near the Yangtze delta may change which species thrive in the area, for example a popultion of water snails that carry the parasite which causes certain disease may increase, Schistosomiasis can kill other animals, including pigs and water buffalo.
• Reduced water flow in the Yangtze delta could lead to salt intrusion, where seawater mixes with river water futher upstrea, this could affect the delta ecoystem by killing freshwater spcies.
• Wetlands around the Yangtze delta could become dryer, drylands to the north could become wetter, this would affect habitats and change the species that live and thrive in these ecosystems.