Climate change is becoming a serious issue nowadays.There are profound environmental,economic and political implications of global warming. Ecosystems,from mountains to oceans and from the poles to the tropics,are und...Climate change is becoming a serious issue nowadays.There are profound environmental,economic and political implications of global warming. Ecosystems,from mountains to oceans and from the poles to the tropics,are undergoing rapid change.The cost will be borne by all,but especially by the展开更多
If you drill a hole into the ground,in most places its bottom fills with water after a few days.The water appears even if no rain falls and no streams flow nearby.The water that seeps into the hole is part of the vast...If you drill a hole into the ground,in most places its bottom fills with water after a few days.The water appears even if no rain falls and no streams flow nearby.The water that seeps into the hole is part of the vast reservoir of subterranean ground water that saturates the Earth’s crust in a zone between a few meters and a few kilometers below the surface. Ground water is exploited by digging wells and pumping the water to the surface.It provides drinking water for more than half of the population of North America and is a major source of water for展开更多
Most of China's wetland areas are located in Sanjiang Plain (Three River Basin). It's area has 207×104 hm2 of wet and low-lying farmland, of which 59% is cropped. During 1970s and 1980s, the Chinese gover...Most of China's wetland areas are located in Sanjiang Plain (Three River Basin). It's area has 207×104 hm2 of wet and low-lying farmland, of which 59% is cropped. During 1970s and 1980s, the Chinese government organized intensive scientific research into potential changes to existing natural resources conditions for this farmland. The aim was to make the water resources regime beneficial to crop production. Arterial drainage, field drainage and appropriate sub-soil treatments were suggested. The Four Waters converting mechanism and the estimation of the Four Water converting amount in wet and low-lying farmland were discussed in the paper.展开更多
Most of China's wetland areas are located in the Sanjiang Plain.This area has 207×10 4 hm 2 of wet and low lying farmland,of which 59% is cropped.During the 1970s and 1980s,the Chinese government organize...Most of China's wetland areas are located in the Sanjiang Plain.This area has 207×10 4 hm 2 of wet and low lying farmland,of which 59% is cropped.During the 1970s and 1980s,the Chinese government organized intensive scientific research into potential changes to existing natural resources conditions for these farmlands.The aim was to change the water resources regime to one that was beneficial to crop production.Arterial drainage,field drainage and appropriate sub soil treatments were required.The relation between plant products industry and the Four Waters distribution,also the main measures of the Four Waters converting in wet and low lying farmland were discussed in the paper.展开更多
文摘Climate change is becoming a serious issue nowadays.There are profound environmental,economic and political implications of global warming. Ecosystems,from mountains to oceans and from the poles to the tropics,are undergoing rapid change.The cost will be borne by all,but especially by the
文摘If you drill a hole into the ground,in most places its bottom fills with water after a few days.The water appears even if no rain falls and no streams flow nearby.The water that seeps into the hole is part of the vast reservoir of subterranean ground water that saturates the Earth’s crust in a zone between a few meters and a few kilometers below the surface. Ground water is exploited by digging wells and pumping the water to the surface.It provides drinking water for more than half of the population of North America and is a major source of water for
文摘Most of China's wetland areas are located in Sanjiang Plain (Three River Basin). It's area has 207×104 hm2 of wet and low-lying farmland, of which 59% is cropped. During 1970s and 1980s, the Chinese government organized intensive scientific research into potential changes to existing natural resources conditions for this farmland. The aim was to make the water resources regime beneficial to crop production. Arterial drainage, field drainage and appropriate sub-soil treatments were suggested. The Four Waters converting mechanism and the estimation of the Four Water converting amount in wet and low-lying farmland were discussed in the paper.
文摘Most of China's wetland areas are located in the Sanjiang Plain.This area has 207×10 4 hm 2 of wet and low lying farmland,of which 59% is cropped.During the 1970s and 1980s,the Chinese government organized intensive scientific research into potential changes to existing natural resources conditions for these farmlands.The aim was to change the water resources regime to one that was beneficial to crop production.Arterial drainage,field drainage and appropriate sub soil treatments were required.The relation between plant products industry and the Four Waters distribution,also the main measures of the Four Waters converting in wet and low lying farmland were discussed in the paper.
