The paper discussed theory and methodologies of soil erosion assessment and established an implementation process according to USLE factors combining with thematic paper maps and DEMs. Factors of USLE- R, K, S, L, P a...The paper discussed theory and methodologies of soil erosion assessment and established an implementation process according to USLE factors combining with thematic paper maps and DEMs. Factors of USLE- R, K, S, L, P and C were adapted to the test area, the Nihe Gou catchment in Chunhua County of Shaanxi Province, China. Afterwards the parameters of the USLE were evaluated individually and merged in order to calculate the amount of soil loss over the corresponding years, 1977 and 2003. In order to derive all necessary factors a TIN was generated out of a paper contour map. Furthermore, thematic paper maps and climate data completed the source of information for the implementation. The quantitative methodologies integrated with GIS were applied during the process. The verification of the result was performed comparing the real world situation at the test area with the resulting thematic maps. It shows these principles and methodologies were reasonable and feasible and can provide basis or reference for further areas of the Chinese Loess Plateau.展开更多
武汉市位于桐柏山大别山国家级水土流失预防区与幕阜山省级水土流失治理区之间,其土壤侵蚀问题对长江中游生态安全具有重要影响。基于2009—2018年武汉市蔡店、磨盘山、西湖流域、燕子山等4个水土保持监测站35个径流小区的观测数据(139...武汉市位于桐柏山大别山国家级水土流失预防区与幕阜山省级水土流失治理区之间,其土壤侵蚀问题对长江中游生态安全具有重要影响。基于2009—2018年武汉市蔡店、磨盘山、西湖流域、燕子山等4个水土保持监测站35个径流小区的观测数据(139组),定量分析了坡度、侵蚀性降水量、土地利用和水土保持措施对土壤侵蚀的影响,并借鉴USLE模型识别土壤侵蚀主导因子。结果表明,裸地小区的平均土壤侵蚀模数最高(2597.57 t km^(-2)a^(-1)),其次是经济林、草地和耕地小区且三者的侵蚀模数相差不大,土壤侵蚀模数与侵蚀性降雨量、坡度之间呈显著二元线性或幂函数关系;与天然植被小区相比,植物篱(草带、茶树、紫穗槐)及石坎梯田措施均显著降低了土壤侵蚀模数,其中植物篱措施的效果更优,且草带植物篱小区的侵蚀模数最低(46.13 t km^(-2)a^(-1));3个坡度等级(0—10°、10—20°、20—25°)小区平均侵蚀模数分别为892.07、911.15、2087.60 t km^(-2)a^(-1),表明坡度超过20°后土壤侵蚀严重加剧;武汉市土壤侵蚀的主导因子为水土保持措施、植被覆盖与管理因子。研究结果可为武汉市水土保持措施合理布设及侵蚀预报模型的完善提供依据,基于径流小区长期观测数据的土壤侵蚀定量研究值得进一步深入。展开更多
近几十年来,松嫩平原的生态环境严重恶化,荒漠化迅速发展,这与区域水土保持功能持续下降有关。本文应用生态学、经济学和生态环境科学等学科的有关理论,以TM/M OD IS/DEM数据为基础,应用3S技术建立了松嫩平原水土保持价值的复合计算模...近几十年来,松嫩平原的生态环境严重恶化,荒漠化迅速发展,这与区域水土保持功能持续下降有关。本文应用生态学、经济学和生态环境科学等学科的有关理论,以TM/M OD IS/DEM数据为基础,应用3S技术建立了松嫩平原水土保持价值的复合计算模型。计算表明,全区2001年水土保持总价值为662.63亿元,就单位面积的水土保持价值而言,林地最高,为173.59万元/km2,草地次之,为70.42万元/km2,耕地很低,为24.53万元/km2,难利用地仅为2.89万元/km2。水土保持价值分布的总趋势从东北向西南递减,从193.86万元/km2降至18.87万元/km2。研究指出,进行林地、草地建设是提高区域水土保持功能的关键,中、西部尤应加强水土保持工作。本文不仅解决了水土保持价值的量化问题,而且为绿色GDP的核算提供了基础数据。展开更多
This study aimed to assess the influence of conservation practices (P) and cover management (C) on soil loss reduction by determining it at the scale of landscape units in 16 systematically selected watersheds. Focusi...This study aimed to assess the influence of conservation practices (P) and cover management (C) on soil loss reduction by determining it at the scale of landscape units in 16 systematically selected watersheds. Focusing on major land management practices implemented through free community labor mobilization, the assessment combined remote sensing techniques, field observation, and expert as well as local knowledge. The results show an average net decrement of 39% ( ± 19%) in the P factor value and 8.9%( ± 21%) in the C factor value after implementation of land management practices. P factor value re-duction is linked to a high area coverage of level structures, while increases in the P factor value are associated with poor quality of structures, inappropriate practices, and wide spacing between structures on steep slopes. C factor value reduction is observed in non-arable shrub- and bushland with enriched area closure, whereas increased C factor values are associated with open access grasslands and untreated croplands. The overall change in P and C factor values resulted in a 42% ( ± 28%) relative soil loss re-duction. The demonstrated approach makes it possible to assess spatial and temporal dynamics in the P and C erosion factors and to estimate spatially disaggregated changes in the P and C factor values. This can help to improve parameterization of inputs for erosion modelling and to assess their relative soil loss effect. The approach provides valuable feedback on watershed planning processes and supports informed decisions regarding the appropriate selection of land management practices.展开更多
基金funded by the National Natural Science Foundation of China(40501031)the University Research Project(08080115),administrated by the Northwest A&F University of China.
文摘The paper discussed theory and methodologies of soil erosion assessment and established an implementation process according to USLE factors combining with thematic paper maps and DEMs. Factors of USLE- R, K, S, L, P and C were adapted to the test area, the Nihe Gou catchment in Chunhua County of Shaanxi Province, China. Afterwards the parameters of the USLE were evaluated individually and merged in order to calculate the amount of soil loss over the corresponding years, 1977 and 2003. In order to derive all necessary factors a TIN was generated out of a paper contour map. Furthermore, thematic paper maps and climate data completed the source of information for the implementation. The quantitative methodologies integrated with GIS were applied during the process. The verification of the result was performed comparing the real world situation at the test area with the resulting thematic maps. It shows these principles and methodologies were reasonable and feasible and can provide basis or reference for further areas of the Chinese Loess Plateau.
文摘武汉市位于桐柏山大别山国家级水土流失预防区与幕阜山省级水土流失治理区之间,其土壤侵蚀问题对长江中游生态安全具有重要影响。基于2009—2018年武汉市蔡店、磨盘山、西湖流域、燕子山等4个水土保持监测站35个径流小区的观测数据(139组),定量分析了坡度、侵蚀性降水量、土地利用和水土保持措施对土壤侵蚀的影响,并借鉴USLE模型识别土壤侵蚀主导因子。结果表明,裸地小区的平均土壤侵蚀模数最高(2597.57 t km^(-2)a^(-1)),其次是经济林、草地和耕地小区且三者的侵蚀模数相差不大,土壤侵蚀模数与侵蚀性降雨量、坡度之间呈显著二元线性或幂函数关系;与天然植被小区相比,植物篱(草带、茶树、紫穗槐)及石坎梯田措施均显著降低了土壤侵蚀模数,其中植物篱措施的效果更优,且草带植物篱小区的侵蚀模数最低(46.13 t km^(-2)a^(-1));3个坡度等级(0—10°、10—20°、20—25°)小区平均侵蚀模数分别为892.07、911.15、2087.60 t km^(-2)a^(-1),表明坡度超过20°后土壤侵蚀严重加剧;武汉市土壤侵蚀的主导因子为水土保持措施、植被覆盖与管理因子。研究结果可为武汉市水土保持措施合理布设及侵蚀预报模型的完善提供依据,基于径流小区长期观测数据的土壤侵蚀定量研究值得进一步深入。
文摘近几十年来,松嫩平原的生态环境严重恶化,荒漠化迅速发展,这与区域水土保持功能持续下降有关。本文应用生态学、经济学和生态环境科学等学科的有关理论,以TM/M OD IS/DEM数据为基础,应用3S技术建立了松嫩平原水土保持价值的复合计算模型。计算表明,全区2001年水土保持总价值为662.63亿元,就单位面积的水土保持价值而言,林地最高,为173.59万元/km2,草地次之,为70.42万元/km2,耕地很低,为24.53万元/km2,难利用地仅为2.89万元/km2。水土保持价值分布的总趋势从东北向西南递减,从193.86万元/km2降至18.87万元/km2。研究指出,进行林地、草地建设是提高区域水土保持功能的关键,中、西部尤应加强水土保持工作。本文不仅解决了水土保持价值的量化问题,而且为绿色GDP的核算提供了基础数据。
文摘This study aimed to assess the influence of conservation practices (P) and cover management (C) on soil loss reduction by determining it at the scale of landscape units in 16 systematically selected watersheds. Focusing on major land management practices implemented through free community labor mobilization, the assessment combined remote sensing techniques, field observation, and expert as well as local knowledge. The results show an average net decrement of 39% ( ± 19%) in the P factor value and 8.9%( ± 21%) in the C factor value after implementation of land management practices. P factor value re-duction is linked to a high area coverage of level structures, while increases in the P factor value are associated with poor quality of structures, inappropriate practices, and wide spacing between structures on steep slopes. C factor value reduction is observed in non-arable shrub- and bushland with enriched area closure, whereas increased C factor values are associated with open access grasslands and untreated croplands. The overall change in P and C factor values resulted in a 42% ( ± 28%) relative soil loss re-duction. The demonstrated approach makes it possible to assess spatial and temporal dynamics in the P and C erosion factors and to estimate spatially disaggregated changes in the P and C factor values. This can help to improve parameterization of inputs for erosion modelling and to assess their relative soil loss effect. The approach provides valuable feedback on watershed planning processes and supports informed decisions regarding the appropriate selection of land management practices.
