Taking Lanjiabao,Shaanxi as an example,the land renovation methods for areas with severe drought,water loss and soil erosion were discussed from the planning and design of land leveling,irrigation and drainage enginee...Taking Lanjiabao,Shaanxi as an example,the land renovation methods for areas with severe drought,water loss and soil erosion were discussed from the planning and design of land leveling,irrigation and drainage engineering,field road engineering,soil and water conservation and other aspects to fundamentally improve the production conditions of local agriculture,thereby effectively inhibiting soil erosion,reducing the impact of wind and sand,greatly enhancing the ability to withstand natural disasters,improving the natural productivity of farmland,and enhancing adjustment capacity. The planning and design of this case project can provide reference for land renovation activities in similar areas.展开更多
A number of very serious drough disasters occurred in many regions of Aftica during past 30 years. It is commonly considered that they are among the most serious disasters after the World War II. The basic situation o...A number of very serious drough disasters occurred in many regions of Aftica during past 30 years. It is commonly considered that they are among the most serious disasters after the World War II. The basic situation of the droughs and drough disasters are introduced briefly, and the main causes resulting 1i drought disasters are analysed in the paper. The lack of rainfall is one of the factors producing the drough disasters in Africa, but it is not the real one. From environmental viewpoints, the drough disasters in Africa resulted from unsuitable land use and management by man, and in essence they are the results of man-made environmental disturbance. Finally, the strategy for preventing drought disasters in Africa is suggested.展开更多
The article discusses the effective use of degraded foothill lands of the Kamashy district of the Kashkadarya region of Uzbekistan. Sustainable land use in the arid lands of the foothill zone, due to water conservatio...The article discusses the effective use of degraded foothill lands of the Kamashy district of the Kashkadarya region of Uzbekistan. Sustainable land use in the arid lands of the foothill zone, due to water conservation, growing seedlings of nut and fruit trees, growing fodder crops in row spacing, allows local livestock breeders to create a rational model of agroforestry system of land use. The organization and development of agroforestry will ensure sustainable land use, create additional jobs, increase household incomes and improve the standard of living of the population.展开更多
ERA5-Land再分析产品作为全球重要的地表要素数据,其在干旱监测中的误差评估对进一步提升干旱预警能力和降低灾害风险具有重要意义。利用1981—2020年国家气象信息中心逐日降水格网数据,结合标准化降水指数(Standardized Precipitation ...ERA5-Land再分析产品作为全球重要的地表要素数据,其在干旱监测中的误差评估对进一步提升干旱预警能力和降低灾害风险具有重要意义。利用1981—2020年国家气象信息中心逐日降水格网数据,结合标准化降水指数(Standardized Precipitation Index,SPI),定量评价欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)的第五代再分析陆地产品(Land component of the Fifth Generation of European Reanalysis,ERA5-Land)降水资料在黄河流域及其子流域干旱监测中的误差特征,探讨ERA5-Land降水产品在不同地区和不同时间尺度下对降水的高(低)估以及对干旱特征的描述能力。结果表明:ERA5-Land降水产品在黄河流域对降水量存在明显高估现象,上游地区降水量高估误差最大,中游次之,而下游相对较低。在不同时间尺度下,ERA5-Land降水产品对干湿状况的反映能力存在明显差异,并随时间尺度的增加,差异也增加。针对黄河流域干旱事件,ERA5-Land降水产品存在明显的干旱频次高估和干旱历时低估。上游地区主要以干旱烈度和严重度高估为主,中下游则存在明显的干旱烈度和严重度低估现象。虽然ERA5-Land降水产品能够有效捕获典型干旱事件的空间分布,但对不同等级干旱面积的描述并不准确。因此,使用ERA5-Land降水产品数据进行干旱监测时,需特别注意其高估或低估现象。展开更多
Sediment yield dynamics on the Edwards Plateau region of Texas was dramatically influenced by a multi-year drought that occurred there during the 1950s. To assess the effect of this drought on sediment yield, we used ...Sediment yield dynamics on the Edwards Plateau region of Texas was dramatically influenced by a multi-year drought that occurred there during the 1950s. To assess the effect of this drought on sediment yield, we used the Soil and Water Assessment Tool (SWAT) to identify the factors that contributed erosion and to propose potential mitigation measures in case of future drought recurrence. The basins of interest to this study were Brady Creek One (BC 1) and Deep Creek Three (DC 3), located in McCulloch County, Texas. Although the streams in these basins are not gauged, the land cover and reservoir sediment budgets have been assessed in a past study. Calibration of SWAT flow simulation was accomplished using parameter transfer from a gauging station located in San Saba River. The results showed that sediment yield from storms above 60 mm was five times more during and immediately after drought period than during continuous wet seasons. Approximately half of the total drought period sediment yield was from five major rainstorms. The multi-year drought coupled with historical high grazing intensity resulted in significant loss of plant cover, which was considered critical in determining erosion and sedimentation rates. To test this hypothesis, the model was run for the periods of high land cover (1990s) using the 1950s multi-year drought data which showed that sediment yield was 24% of that simulated for 1950s land cover. It was concluded that maintenance of surface cover could play a critical role associated with multi-year drought extreme events.展开更多
黄土高原是世界上土壤侵蚀最严重和中国增绿幅度最大的地区,研究该区水分利用效率(WUE)时空演变及其与干旱和地表温度(LST)之间的关系,已成为黄土高原最大植被容纳阈值选择的重要参考。基于Theil-Sen趋势法和一阶差分相对贡献量法分析了...黄土高原是世界上土壤侵蚀最严重和中国增绿幅度最大的地区,研究该区水分利用效率(WUE)时空演变及其与干旱和地表温度(LST)之间的关系,已成为黄土高原最大植被容纳阈值选择的重要参考。基于Theil-Sen趋势法和一阶差分相对贡献量法分析了2001—2021年黄土高原不同季节WUE时空变化规律及干旱和LST对WUE变化的贡献情况。结果表明:(1)2001—2021年黄土高原春、秋季WUE平均值小于2.0 g C·m^(-2)·mm^(-1),夏季WUE平均值大于2.0 g C·m^(-2)·mm^(-1)。春、秋季耕地和林地区域WUE高于草地区域,夏季耕地区域WUE最低,林地区域次之,草地区域最高。(2)春、夏季WUE以稳定不变趋势为主,空间分布上均表现为“中部减少,西部和东部稳定不变”的特征,草地区域WUE下降速率>林地区域>耕地区域;秋季WUE以增加趋势为主,草地区域WUE上升速率>林地区域>耕地区域,空间分布上呈“西北增加,东南减少”的特征。(3)春、夏季LST对WUE变化为正贡献度,草地区域表现最为显著,秋季LST对草地和林地区域WUE为负贡献度,但对耕地区域WUE为正贡献度。春、秋季干旱对WUE变化为正贡献度,夏季为负贡献度。以上结果有助于认识气候变化和生态修复工程实施背景下黄土高原干旱和LST与水资源之间的关系。展开更多
基金supported by the National Key Technologies R&D Program of China[grant number 2022YFC3002803]the National Science Fund for Distinguished Young Scholars[grant number 41925021].
文摘Taking Lanjiabao,Shaanxi as an example,the land renovation methods for areas with severe drought,water loss and soil erosion were discussed from the planning and design of land leveling,irrigation and drainage engineering,field road engineering,soil and water conservation and other aspects to fundamentally improve the production conditions of local agriculture,thereby effectively inhibiting soil erosion,reducing the impact of wind and sand,greatly enhancing the ability to withstand natural disasters,improving the natural productivity of farmland,and enhancing adjustment capacity. The planning and design of this case project can provide reference for land renovation activities in similar areas.
文摘A number of very serious drough disasters occurred in many regions of Aftica during past 30 years. It is commonly considered that they are among the most serious disasters after the World War II. The basic situation of the droughs and drough disasters are introduced briefly, and the main causes resulting 1i drought disasters are analysed in the paper. The lack of rainfall is one of the factors producing the drough disasters in Africa, but it is not the real one. From environmental viewpoints, the drough disasters in Africa resulted from unsuitable land use and management by man, and in essence they are the results of man-made environmental disturbance. Finally, the strategy for preventing drought disasters in Africa is suggested.
文摘The article discusses the effective use of degraded foothill lands of the Kamashy district of the Kashkadarya region of Uzbekistan. Sustainable land use in the arid lands of the foothill zone, due to water conservation, growing seedlings of nut and fruit trees, growing fodder crops in row spacing, allows local livestock breeders to create a rational model of agroforestry system of land use. The organization and development of agroforestry will ensure sustainable land use, create additional jobs, increase household incomes and improve the standard of living of the population.
文摘ERA5-Land再分析产品作为全球重要的地表要素数据,其在干旱监测中的误差评估对进一步提升干旱预警能力和降低灾害风险具有重要意义。利用1981—2020年国家气象信息中心逐日降水格网数据,结合标准化降水指数(Standardized Precipitation Index,SPI),定量评价欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)的第五代再分析陆地产品(Land component of the Fifth Generation of European Reanalysis,ERA5-Land)降水资料在黄河流域及其子流域干旱监测中的误差特征,探讨ERA5-Land降水产品在不同地区和不同时间尺度下对降水的高(低)估以及对干旱特征的描述能力。结果表明:ERA5-Land降水产品在黄河流域对降水量存在明显高估现象,上游地区降水量高估误差最大,中游次之,而下游相对较低。在不同时间尺度下,ERA5-Land降水产品对干湿状况的反映能力存在明显差异,并随时间尺度的增加,差异也增加。针对黄河流域干旱事件,ERA5-Land降水产品存在明显的干旱频次高估和干旱历时低估。上游地区主要以干旱烈度和严重度高估为主,中下游则存在明显的干旱烈度和严重度低估现象。虽然ERA5-Land降水产品能够有效捕获典型干旱事件的空间分布,但对不同等级干旱面积的描述并不准确。因此,使用ERA5-Land降水产品数据进行干旱监测时,需特别注意其高估或低估现象。
文摘Sediment yield dynamics on the Edwards Plateau region of Texas was dramatically influenced by a multi-year drought that occurred there during the 1950s. To assess the effect of this drought on sediment yield, we used the Soil and Water Assessment Tool (SWAT) to identify the factors that contributed erosion and to propose potential mitigation measures in case of future drought recurrence. The basins of interest to this study were Brady Creek One (BC 1) and Deep Creek Three (DC 3), located in McCulloch County, Texas. Although the streams in these basins are not gauged, the land cover and reservoir sediment budgets have been assessed in a past study. Calibration of SWAT flow simulation was accomplished using parameter transfer from a gauging station located in San Saba River. The results showed that sediment yield from storms above 60 mm was five times more during and immediately after drought period than during continuous wet seasons. Approximately half of the total drought period sediment yield was from five major rainstorms. The multi-year drought coupled with historical high grazing intensity resulted in significant loss of plant cover, which was considered critical in determining erosion and sedimentation rates. To test this hypothesis, the model was run for the periods of high land cover (1990s) using the 1950s multi-year drought data which showed that sediment yield was 24% of that simulated for 1950s land cover. It was concluded that maintenance of surface cover could play a critical role associated with multi-year drought extreme events.
文摘黄土高原是世界上土壤侵蚀最严重和中国增绿幅度最大的地区,研究该区水分利用效率(WUE)时空演变及其与干旱和地表温度(LST)之间的关系,已成为黄土高原最大植被容纳阈值选择的重要参考。基于Theil-Sen趋势法和一阶差分相对贡献量法分析了2001—2021年黄土高原不同季节WUE时空变化规律及干旱和LST对WUE变化的贡献情况。结果表明:(1)2001—2021年黄土高原春、秋季WUE平均值小于2.0 g C·m^(-2)·mm^(-1),夏季WUE平均值大于2.0 g C·m^(-2)·mm^(-1)。春、秋季耕地和林地区域WUE高于草地区域,夏季耕地区域WUE最低,林地区域次之,草地区域最高。(2)春、夏季WUE以稳定不变趋势为主,空间分布上均表现为“中部减少,西部和东部稳定不变”的特征,草地区域WUE下降速率>林地区域>耕地区域;秋季WUE以增加趋势为主,草地区域WUE上升速率>林地区域>耕地区域,空间分布上呈“西北增加,东南减少”的特征。(3)春、夏季LST对WUE变化为正贡献度,草地区域表现最为显著,秋季LST对草地和林地区域WUE为负贡献度,但对耕地区域WUE为正贡献度。春、秋季干旱对WUE变化为正贡献度,夏季为负贡献度。以上结果有助于认识气候变化和生态修复工程实施背景下黄土高原干旱和LST与水资源之间的关系。
