Comparison of current status of protective planting of species in the draw down zone of the Danjiang reservoir area, Henan province, China.

(Google translation with heavy editing)

As a water source of the middle reaches of the South-to-North Water Transfer Project, the area of the Danjiang reservoir, Hechuan County of Henan Province, has for many years had a low water level of between 150 and 157 meters. Government has invested in protecting the reservoir area by growing trees and grasses in the draw down area (fluctuation zone). Since September 2017, the water level began to rise reaching 167 meters - the highest water level in history, in March 2018

The level then retreated to 160 meters by the end of Apri 2018. The water level fell by 7 meters in these six months. Most of the trees and grasses planted in the draw down area were submerged, only the vetiver grass survived. Jiang Jianggong, chief of the Yangtze River Committee, after seeing the scene said : "I have worked in the Yangtze River Valley for 30 years. I haven't seen a plant in the upper and lower reaches that can survive more than 3 months flooding, this vetiver grass is resistant to six months of flooding".

	Figure 1: The drowning of trees on the left bank of the dock area of the old town of Luanchuan
	Figure 2: Drowning of trees on the right bank of the dock area of the old town of Luanchuan
	Figure 3: Drowned trees along the reservoir area
	Figure 4: Farm Road in Chengang Village, Xianghua Town, Luanchuan. The road was flooded by water. Grass on the right side of the road.
	Figure 5: May 12, 2018, Luanchuan County. 3 meters high dead tree killed by flood. In contrast the vetiver is alive.
	Figure 6: The water level began to rise in October 2017, East of Donggou, Shiqiao Village, Mawei Town, Luanchuan County The condition of vetiver in the falling zone.
	Figure 7: September 2017, Shibuya County Ma Rong. Vetiver in the draw down area
	Figure 8: The water level began to rise in October 2017, West of Donggou, Shiqiao Village, Mawei Town, Luanchuan County. The condition of vetiver in the draw down area
	Figure 9: The water level subsides and is flooded for six months. The vetiver color begins to change from yellow to green;
	Fig 10. The water level in Mid October 2012 Up, vetiver that is about to be submerged;
	Fig 11. Other aquatic plants after 6 months inumdation. everything has died, only vetiver has revived - brilliant!
	Figure 12: The water rises and falls, the vetiver hedges block the straw, garbage and domestic waste entering the reservoir;
	Figure 13: Erosion gullies caused by runoff, planting the vetiver hedges across the gully will stabilize the gullies and stop the sediment from entering the water course.
	Figure 14: November 2017, in Rengou Village, Mazi Town, Luanchuan County. The vetiver grass hedge effectively blocks the entry of pollutants into the reservoir;
	Figure 15: On April 27, 2018, the water receded, leaving dead trees and live vetiver.
	Figure 16: Vetiver grass after being flooded for six months on the east side of Donggou, Shiqiao Village, Maqi Town, Luanchuan County - a clear contrast of the various vegetation
	Figure 17: Various vegetation types after being flooded for 6 months. Vetiver in good condition, and protecting the draw down area
	Figure 18: The tree in the water of Kuwan is drowned, and the fragrant grass is alive.
	Figure 19: Comparison of drowning trees and drowning vetiver in the draw down area of the reservoir in May 2018