The arid areas in China are mainly located in North China and NorthwestChina. The North China is the main region for food production. There is 31. 19% of the totalfarmland and 26. 01% of the total population, but only...The arid areas in China are mainly located in North China and NorthwestChina. The North China is the main region for food production. There is 31. 19% of the totalfarmland and 26. 01% of the total population, but only 6. 14% of the available water resources ofChina. Groundwater is over pumped (6. 53 X 10~9m^3 every year) in the regions of Beijing, Tianjin,and Hebei Province, so water supply could not meet the water demand there. The distribution of waterin Northwest China is uneven, some inland rivers and lakes are dried up, and desertification hasexpanded since river water in the upper and middle reaches is diverted for irrigation. Up to 2050,population will be up to 1. 6 X 10~9 in China, and industry will be developed fast, therefore 50% ofthe water supply will be used by industry and resident, and water for agriculture will be decreasedyear by year. In the coming 50 years, water demand for agriculture will be increased by 5. 6 x10^9m^3 in the Huanghe (Yellow) River valley, and by 1. 7 x 10~9m^3 in the Northwest China. It willbe impossible for the Huanghe River to meet the water demand, because it always dried up in the coldhalf year since 1984. To avoid water shortage of agriculture in the arid regions, it is necessaryto divert water from the Changjiang (Yangtze) River in the south of China, and to use waterefficiently. It is the best way to use drip irrigation in agriculture, recycle water in industry andresident use, and control water pollution. Otherwise water shortage in the arid regions willrestrict the development of agriculture in China.展开更多
The soil and water conservation practices of ecological restoration(ER),fish scale pit(FP),furrow and ridge tillage across the slope(FR),shrub strips(SS),and vegetation-covered ridge(VR)are characteristic of the Jixin...The soil and water conservation practices of ecological restoration(ER),fish scale pit(FP),furrow and ridge tillage across the slope(FR),shrub strips(SS),and vegetation-covered ridge(VR)are characteristic of the Jixing small watershed of the low mountain and hilly region of Jilin Province,Northeast China.This study aims to elucidate the effects of soil and water conservation practices on soil conditions after the short-term implementation of practices.Soil samples were collected from five soil and water conservation sites(ER,FP,FR,SS,and VR)and two controls(BL and CT)to investigate their properties.To evaluate the influence of soil and water conservation practices on soil quality,an integrated quantitative index,soil quality index(QI),was developed to compare the soil quality under the different soil and water conservation practices.The results show that not all soil and water conservation practices can improve the soil conditions and not all soil properties,especially soil organic carbon(SOC),can be recovered under soil and water conservation practice in short-term.Moreover,the QI in the five soil and water conservation practices and two controls was in the following order:ER>VR>BL>FR>CT>SS>FP.ER exhibited a higher soil quality value on a slope scale.In the low mountain and hilly region of Northeast China,ER is a better choice than the conversion of farmlands to planted grasslands and woodlands early in the soil and water conservation program.展开更多
The Three Gorges Reservoir, the world’s largest hydropower reservoir, receives a significant sediment yield from soil erosion. Sloping farmland is the main source, exacerbated by changes in land use from relocating t...The Three Gorges Reservoir, the world’s largest hydropower reservoir, receives a significant sediment yield from soil erosion. Sloping farmland is the main source, exacerbated by changes in land use from relocating the inhabitants, and from engineering projects related to dam construction. Related geo-hazards, including landsliding of valley-side slopes, will further increase the sediment yield to the completed reservoir. Integrated watershed management, begun extensively in 1989, has effectively controlled soil erosion and sediment delivery to date. What is described here as the Taipinxi Mode of integrated watershed management, based on its application in the 26.14 km2 watershed of that name in Yiling District, has been successful and is recommended for the entire region. The effects of this set of erosion-mitigation measures are assessed, using experienced formulas for soil and water conservation and information from remote sensing. The amount of soil erosion, and of sediment delivery to the reservoir were reduced by 43.75–45.94 × 106 t y-1, and by 12.25–12.86 × 106 t y-1, respectively, by 2005, by which time the project had been operative for 16 years.展开更多
文摘The arid areas in China are mainly located in North China and NorthwestChina. The North China is the main region for food production. There is 31. 19% of the totalfarmland and 26. 01% of the total population, but only 6. 14% of the available water resources ofChina. Groundwater is over pumped (6. 53 X 10~9m^3 every year) in the regions of Beijing, Tianjin,and Hebei Province, so water supply could not meet the water demand there. The distribution of waterin Northwest China is uneven, some inland rivers and lakes are dried up, and desertification hasexpanded since river water in the upper and middle reaches is diverted for irrigation. Up to 2050,population will be up to 1. 6 X 10~9 in China, and industry will be developed fast, therefore 50% ofthe water supply will be used by industry and resident, and water for agriculture will be decreasedyear by year. In the coming 50 years, water demand for agriculture will be increased by 5. 6 x10^9m^3 in the Huanghe (Yellow) River valley, and by 1. 7 x 10~9m^3 in the Northwest China. It willbe impossible for the Huanghe River to meet the water demand, because it always dried up in the coldhalf year since 1984. To avoid water shortage of agriculture in the arid regions, it is necessaryto divert water from the Changjiang (Yangtze) River in the south of China, and to use waterefficiently. It is the best way to use drip irrigation in agriculture, recycle water in industry andresident use, and control water pollution. Otherwise water shortage in the arid regions willrestrict the development of agriculture in China.
基金Under the auspices of Foundation of State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau(No.10501-1210)National Natural Science Foundation of China(No.31101606)+1 种基金Basic Scientific Research Operating Expenses of Jilin University(No.200903377)National Key Projects in National Science&Technology Program during the 12th Five-Year Plan Period of China(No.2011BAD16B10-3,2012BAD04B02-3)
文摘The soil and water conservation practices of ecological restoration(ER),fish scale pit(FP),furrow and ridge tillage across the slope(FR),shrub strips(SS),and vegetation-covered ridge(VR)are characteristic of the Jixing small watershed of the low mountain and hilly region of Jilin Province,Northeast China.This study aims to elucidate the effects of soil and water conservation practices on soil conditions after the short-term implementation of practices.Soil samples were collected from five soil and water conservation sites(ER,FP,FR,SS,and VR)and two controls(BL and CT)to investigate their properties.To evaluate the influence of soil and water conservation practices on soil quality,an integrated quantitative index,soil quality index(QI),was developed to compare the soil quality under the different soil and water conservation practices.The results show that not all soil and water conservation practices can improve the soil conditions and not all soil properties,especially soil organic carbon(SOC),can be recovered under soil and water conservation practice in short-term.Moreover,the QI in the five soil and water conservation practices and two controls was in the following order:ER>VR>BL>FR>CT>SS>FP.ER exhibited a higher soil quality value on a slope scale.In the low mountain and hilly region of Northeast China,ER is a better choice than the conversion of farmlands to planted grasslands and woodlands early in the soil and water conservation program.
基金State Key Project of 2006BAC10B04, ChinaCAS Knowledge Innovation Project of KZCX2-YW-302
文摘The Three Gorges Reservoir, the world’s largest hydropower reservoir, receives a significant sediment yield from soil erosion. Sloping farmland is the main source, exacerbated by changes in land use from relocating the inhabitants, and from engineering projects related to dam construction. Related geo-hazards, including landsliding of valley-side slopes, will further increase the sediment yield to the completed reservoir. Integrated watershed management, begun extensively in 1989, has effectively controlled soil erosion and sediment delivery to date. What is described here as the Taipinxi Mode of integrated watershed management, based on its application in the 26.14 km2 watershed of that name in Yiling District, has been successful and is recommended for the entire region. The effects of this set of erosion-mitigation measures are assessed, using experienced formulas for soil and water conservation and information from remote sensing. The amount of soil erosion, and of sediment delivery to the reservoir were reduced by 43.75–45.94 × 106 t y-1, and by 12.25–12.86 × 106 t y-1, respectively, by 2005, by which time the project had been operative for 16 years.
