Abstract By comparison of volumes and 137Cs contents of the deposited sediments before and after 1993, changes of specific sediment yields and relative sediment contributions from the gully area and from the inter gul...Abstract By comparison of volumes and 137Cs contents of the deposited sediments before and after 1993, changes of specific sediment yields and relative sediment contributions from the gully area and from the inter gully area after closing cultivation on the later area on a small catchment of Zhaojia Gully, in the Rolling Loess Plateau, are analyzed in this paper. Closing cultivation in a large scale has not resulted in decrease but increase of specific sediment yield of the catchment, in sharp decrease of the sediment yield and the relative sediment contribution of the inter-gully area, and in increase of the sediment yield and the contribution of the gully area, for a short term. The mean specific sediment yield of 29650 t km-2 a-1 of 1994—1996 in the catchment was 2.2 times the average value of 13413 t km-2 a-1 for a long term. The specific sediment yield of the inter-gully area decreased from the 14335 t km-2 a-1 in 1994 to 7034 t km-2 a-1 in 1995 and 3517 t km-2 a-1 in 1996, while the yield of the gully area varied between 44944 and 62136 t km-2 a-1 during the period of 1994—1996 which was much greater than the value of 21118 t km-2 a-1 before 1993. The relative sediment contribution from the inter-gully area decreased from 23% in 1994 to 15% in 1995 and 6% in 1996, while the contribution from the gully area increased from 77% in 1994 to 85% in 1995 and 94% in 1996. It is suggested that compacting of ploughed soils resulted in increasing of the erosion resistance but in decreasing of the precipitation infiltration, therefore, the soil erosion reduced but the runoff amount increased on the inter-gully area. Increase of delivering runoff from the inter-gully area to the gully area should result in activeness of gully erosion and mass movements, consequently, in increase of the total sediment yield from the catchment.展开更多
实施乡村振兴战略,是党的十九大以来作出的重大决策部署。乡村振兴,关键是产业振兴。乡村国土地域系统及其产业组成要素之间的协调性决定了乡村持续振兴的能力。我国陇东地区乡村在长期的农业生产及城镇化发展中产业—空间矛盾尤为显著...实施乡村振兴战略,是党的十九大以来作出的重大决策部署。乡村振兴,关键是产业振兴。乡村国土地域系统及其产业组成要素之间的协调性决定了乡村持续振兴的能力。我国陇东地区乡村在长期的农业生产及城镇化发展中产业—空间矛盾尤为显著,迫切需要国土空间规划背景下的乡村产业—空间量化分类的探索性研究,客观反映乡村的发展程度,科学把握乡村发展差异和特点。本文充分剖析了国家与地区相关政策,进而通过分析该地区的产业-空间问题,基于“人地关系”协调理论构建“产村互动”耦合发展模型,以具备典型特征的陇东黄土高原沟壑区显胜乡村庄为研究对象,从产业与空间两大系统确定了19个评价因子,通过对评价因子进行赋值计算、运用地理信息系统(Geographic Information System,GIS)软件等手段,评价探析其产业—空间耦合互动的时空演变规律及内在机制,在规划响应方面得出如下启示:以科学评价现状为基础,分类引导乡村产业空间振兴;以统筹空间布局为核心,打造镇村一体发展新单元;以加强生态修复为策略,同步经济效益与空间效应;以延续历史文脉为补充,实现文化引领三产深度融合。展开更多
黄土高原生态环境恶劣,水土流失严重。选择退耕还林(草)程度非常显著的陕北吴旗县所在北洛河上游为研究区,探讨黄土高原丘陵沟壑区水土流失治理及大幅度退耕背景下流域水、沙等生态要素的演变规律,分析人类活动的影响贡献程度,为黄土高...黄土高原生态环境恶劣,水土流失严重。选择退耕还林(草)程度非常显著的陕北吴旗县所在北洛河上游为研究区,探讨黄土高原丘陵沟壑区水土流失治理及大幅度退耕背景下流域水、沙等生态要素的演变规律,分析人类活动的影响贡献程度,为黄土高原生态治理及环境效应分析提供理论依据。结果表明:在1963—2009年期间年降雨量没有显著变化背景下,同时期流域年径流量和年输沙量均呈现极显著减少趋势,年均减少率分别为0.28 mm/a和180 t km-2a-1,其突变时间均发生在1979和2002年,具有很好的同步性。与1979年前相比,20世纪70—80年代水土流失综合治理以及1999年后退耕还林(草)的事件背景,使汛期和平水期径流量逐时段减少,而枯水期径流量反而持续增加。输沙量呈持续性大幅度减少态势,且其减少程度远大于径流量的变化程度。水土流失综合治理和退耕还林(草)工程实施等人类活动,对流域径流量减少的影响贡献程度分别为38.2%和51.4%,对输沙量减少的影响程度分别为74.7%和86.7%。研究结果提示,黄土高原生态环境的大幅度改善在区域尺度上已经表现出一定程度上削洪补枯的水文效应特征,以及林草措施减水更减沙的良好生物治理效果。展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant No.40271015)MST(Grant No.2001CCB00100)+2 种基金CAS(Grant Nos.KZCX3 SW-330 and KZCX3-SW-422)IAEA(12322/RO)State Key Laboratory of Soil Erosion and Dry Land Farming on the Loess Plateau(10501-109).
文摘Abstract By comparison of volumes and 137Cs contents of the deposited sediments before and after 1993, changes of specific sediment yields and relative sediment contributions from the gully area and from the inter gully area after closing cultivation on the later area on a small catchment of Zhaojia Gully, in the Rolling Loess Plateau, are analyzed in this paper. Closing cultivation in a large scale has not resulted in decrease but increase of specific sediment yield of the catchment, in sharp decrease of the sediment yield and the relative sediment contribution of the inter-gully area, and in increase of the sediment yield and the contribution of the gully area, for a short term. The mean specific sediment yield of 29650 t km-2 a-1 of 1994—1996 in the catchment was 2.2 times the average value of 13413 t km-2 a-1 for a long term. The specific sediment yield of the inter-gully area decreased from the 14335 t km-2 a-1 in 1994 to 7034 t km-2 a-1 in 1995 and 3517 t km-2 a-1 in 1996, while the yield of the gully area varied between 44944 and 62136 t km-2 a-1 during the period of 1994—1996 which was much greater than the value of 21118 t km-2 a-1 before 1993. The relative sediment contribution from the inter-gully area decreased from 23% in 1994 to 15% in 1995 and 6% in 1996, while the contribution from the gully area increased from 77% in 1994 to 85% in 1995 and 94% in 1996. It is suggested that compacting of ploughed soils resulted in increasing of the erosion resistance but in decreasing of the precipitation infiltration, therefore, the soil erosion reduced but the runoff amount increased on the inter-gully area. Increase of delivering runoff from the inter-gully area to the gully area should result in activeness of gully erosion and mass movements, consequently, in increase of the total sediment yield from the catchment.
文摘实施乡村振兴战略,是党的十九大以来作出的重大决策部署。乡村振兴,关键是产业振兴。乡村国土地域系统及其产业组成要素之间的协调性决定了乡村持续振兴的能力。我国陇东地区乡村在长期的农业生产及城镇化发展中产业—空间矛盾尤为显著,迫切需要国土空间规划背景下的乡村产业—空间量化分类的探索性研究,客观反映乡村的发展程度,科学把握乡村发展差异和特点。本文充分剖析了国家与地区相关政策,进而通过分析该地区的产业-空间问题,基于“人地关系”协调理论构建“产村互动”耦合发展模型,以具备典型特征的陇东黄土高原沟壑区显胜乡村庄为研究对象,从产业与空间两大系统确定了19个评价因子,通过对评价因子进行赋值计算、运用地理信息系统(Geographic Information System,GIS)软件等手段,评价探析其产业—空间耦合互动的时空演变规律及内在机制,在规划响应方面得出如下启示:以科学评价现状为基础,分类引导乡村产业空间振兴;以统筹空间布局为核心,打造镇村一体发展新单元;以加强生态修复为策略,同步经济效益与空间效应;以延续历史文脉为补充,实现文化引领三产深度融合。
文摘黄土高原生态环境恶劣,水土流失严重。选择退耕还林(草)程度非常显著的陕北吴旗县所在北洛河上游为研究区,探讨黄土高原丘陵沟壑区水土流失治理及大幅度退耕背景下流域水、沙等生态要素的演变规律,分析人类活动的影响贡献程度,为黄土高原生态治理及环境效应分析提供理论依据。结果表明:在1963—2009年期间年降雨量没有显著变化背景下,同时期流域年径流量和年输沙量均呈现极显著减少趋势,年均减少率分别为0.28 mm/a和180 t km-2a-1,其突变时间均发生在1979和2002年,具有很好的同步性。与1979年前相比,20世纪70—80年代水土流失综合治理以及1999年后退耕还林(草)的事件背景,使汛期和平水期径流量逐时段减少,而枯水期径流量反而持续增加。输沙量呈持续性大幅度减少态势,且其减少程度远大于径流量的变化程度。水土流失综合治理和退耕还林(草)工程实施等人类活动,对流域径流量减少的影响贡献程度分别为38.2%和51.4%,对输沙量减少的影响程度分别为74.7%和86.7%。研究结果提示,黄土高原生态环境的大幅度改善在区域尺度上已经表现出一定程度上削洪补枯的水文效应特征,以及林草措施减水更减沙的良好生物治理效果。
