Loess Plateau, an arid and semi arid region in Northwest China, is well known for its most serious soil erosion in terms of sediment yield each year. Soil erosion, which is intensified by agricultural activities, is...Loess Plateau, an arid and semi arid region in Northwest China, is well known for its most serious soil erosion in terms of sediment yield each year. Soil erosion, which is intensified by agricultural activities, is the major factor influencing sustainable agriculture development in this region. It reduces productivity by removing nutrients and especially reducing water availability that is essential for crop production in the area. It also brings about off site costs by demanding more efforts for maintenance of banks and dams along Yellow River through raising the riverbed with sediment. Climate is capricious and extreme weather conditions occur frequently, which impairs normal agricultural production with erosion and also decrease of water availability. Extensive way of farming still dominates on the Loess Plateau, which cannot produce satisfying economic results and needs to be improved or altered. Conventional agricultural production pattern needs to be reconsidered for husbandry has not been granted its due position. Agriculture is the backbone of economy. Poor agricultural production impedes economic development and vice versa, backward economy also influences the advancement of agriculture. Besides a large population, education status of farmers is another threshold that requires being resolved for a sustainable agriculture. Although conventional agriculture has been practiced there for more than 5000 years, now it cannot meet the demand for food and fiber by the increasing population and some of its farming practices are contributing to environmental degradation directly or indirectly and can sustain no longer. Agriculture on Loess Plateau needs to find its own way of sustainability. To work toward a sustainable agriculture, chances and challenges both indwell on Loess Plateau.展开更多
针对东北黑土区长缓坡地形条件下坡面产汇流集中易加剧土壤侵蚀的问题,本研究基于GIS和SIMWE(SIMulated Water Erosion)模型,引入连通性指数和水深空间分布作为水文连通性与径流路径的衡量指标。通过量化不同典型水土保持措施对土壤入...针对东北黑土区长缓坡地形条件下坡面产汇流集中易加剧土壤侵蚀的问题,本研究基于GIS和SIMWE(SIMulated Water Erosion)模型,引入连通性指数和水深空间分布作为水文连通性与径流路径的衡量指标。通过量化不同典型水土保持措施对土壤入渗速率和地表曼宁糙率的影响,构建梯田数字高程模型(DEM)模拟表征地表微地形变化,以水文连通性和径流路径的空间响应为依据,分析不同典型水土保持措施的侵蚀阻控能力。结果表明:1)梯田措施能够有效降低坡面水文连通性并阻控径流路径;不同田坎形态下,水文连通性与径流路径的响应存在明显差异,径流路径的变化将改变坡面侵蚀-沉积空间分布特征,并导致局部侵蚀加剧;2)植物缓冲带与等高耕作等措施对坡面径流路径的阻控作用有限,植物缓冲带措施的水土保持效益更多体现在对泥沙输移的调控上;3)保护性耕作措施通过增大地表粗糙度,降低坡面水文连通性,从而改善坡面滞蓄径流的能力。本研究通过量化不同水土保持措施对水文连通性、径流路径及侵蚀-沉积空间分布的影响,可为黑土区水土保持措施优化配置提供理论参考。展开更多
文摘Loess Plateau, an arid and semi arid region in Northwest China, is well known for its most serious soil erosion in terms of sediment yield each year. Soil erosion, which is intensified by agricultural activities, is the major factor influencing sustainable agriculture development in this region. It reduces productivity by removing nutrients and especially reducing water availability that is essential for crop production in the area. It also brings about off site costs by demanding more efforts for maintenance of banks and dams along Yellow River through raising the riverbed with sediment. Climate is capricious and extreme weather conditions occur frequently, which impairs normal agricultural production with erosion and also decrease of water availability. Extensive way of farming still dominates on the Loess Plateau, which cannot produce satisfying economic results and needs to be improved or altered. Conventional agricultural production pattern needs to be reconsidered for husbandry has not been granted its due position. Agriculture is the backbone of economy. Poor agricultural production impedes economic development and vice versa, backward economy also influences the advancement of agriculture. Besides a large population, education status of farmers is another threshold that requires being resolved for a sustainable agriculture. Although conventional agriculture has been practiced there for more than 5000 years, now it cannot meet the demand for food and fiber by the increasing population and some of its farming practices are contributing to environmental degradation directly or indirectly and can sustain no longer. Agriculture on Loess Plateau needs to find its own way of sustainability. To work toward a sustainable agriculture, chances and challenges both indwell on Loess Plateau.
文摘针对东北黑土区长缓坡地形条件下坡面产汇流集中易加剧土壤侵蚀的问题,本研究基于GIS和SIMWE(SIMulated Water Erosion)模型,引入连通性指数和水深空间分布作为水文连通性与径流路径的衡量指标。通过量化不同典型水土保持措施对土壤入渗速率和地表曼宁糙率的影响,构建梯田数字高程模型(DEM)模拟表征地表微地形变化,以水文连通性和径流路径的空间响应为依据,分析不同典型水土保持措施的侵蚀阻控能力。结果表明:1)梯田措施能够有效降低坡面水文连通性并阻控径流路径;不同田坎形态下,水文连通性与径流路径的响应存在明显差异,径流路径的变化将改变坡面侵蚀-沉积空间分布特征,并导致局部侵蚀加剧;2)植物缓冲带与等高耕作等措施对坡面径流路径的阻控作用有限,植物缓冲带措施的水土保持效益更多体现在对泥沙输移的调控上;3)保护性耕作措施通过增大地表粗糙度,降低坡面水文连通性,从而改善坡面滞蓄径流的能力。本研究通过量化不同水土保持措施对水文连通性、径流路径及侵蚀-沉积空间分布的影响,可为黑土区水土保持措施优化配置提供理论参考。
