为了明晰人类活动对冶木河流域水文情势的影响效果,基于冶力关水文站1981—2020年的年径流量和日均流量数据,采用曼宁肯德尔-彭曼(Mann-Kendall-Pettitt,MK-P)突变点检测、水文指标(Indicators of Hydrologic Alteration,IHA)和动态时...为了明晰人类活动对冶木河流域水文情势的影响效果,基于冶力关水文站1981—2020年的年径流量和日均流量数据,采用曼宁肯德尔-彭曼(Mann-Kendall-Pettitt,MK-P)突变点检测、水文指标(Indicators of Hydrologic Alteration,IHA)和动态时间弯曲(Dynamic Time Warping,DTW)算法计算了基准期和黄河流域生态保护和高质量发展重大国家战略实施影响期的水文指标变化情况及两个时期的水文情势相似度。基于全球陆面数据同化系统(Global Land Data Assimilation System,GLDAS)提取冶木河陆地水储量,分析其与径流量的相关关系及变化时间点。研究结果表明:1)冶木河径流量平稳变化点和陆地水储量变化点均为2018年。2)战略实施影响期的径流量大于基准期,径流量平均增大29.79%。3)基准期和战略实施影响期5组水文情势指标的相似度分别为0.025、0.025、0.25、0.1、0,说明冶木河流量极值出现的次数增加,小流量持续情况有所好转。4)战略实施影响期实施的水源涵养措施袭夺了河川基流,减水效果较明显。5)陆地水储量与径流量相关关系较弱。展开更多
Vegetation is the main component of the terrestrial ecosystem and plays a key role in global climate change. Remotely sensed vegetation indices are widely used to detect vegetation trends at large scales. To understan...Vegetation is the main component of the terrestrial ecosystem and plays a key role in global climate change. Remotely sensed vegetation indices are widely used to detect vegetation trends at large scales. To understand the trends of vegetation cover, this research examined the spatial-temporal trends of global vegetation by employing the normalized difference vegetation index(NDVI) from the Advanced Very High Resolution Radiometer(AVHRR) Global Inventory Modeling and Mapping Studies(GIMMS) time series(1982–2015). Ten samples were selected to test the temporal trend of NDVI, and the results show that in arid and semi-arid regions, NDVI showed a deceasing trend, while it showed a growing trend in other regions. Mann-Kendal(MK) trend test results indicate that 83.37% of NDVI pixels exhibited positive trends and that only 16.63% showed negative trends(P < 0.05) during the period from 1982 to 2015. The increasing NDVI trends primarily occurred in tree-covered regions because of forest growth and re-growth and also because of vegetation succession after a forest disturbance. The increasing trend of the NDVI in cropland regions was primarily because of the increasing cropland area and the improvement in planting techniques. This research describes the spatial vegetation trends at a global scale over the past 30+ years, especially for different land cover types.展开更多
文摘为了明晰人类活动对冶木河流域水文情势的影响效果,基于冶力关水文站1981—2020年的年径流量和日均流量数据,采用曼宁肯德尔-彭曼(Mann-Kendall-Pettitt,MK-P)突变点检测、水文指标(Indicators of Hydrologic Alteration,IHA)和动态时间弯曲(Dynamic Time Warping,DTW)算法计算了基准期和黄河流域生态保护和高质量发展重大国家战略实施影响期的水文指标变化情况及两个时期的水文情势相似度。基于全球陆面数据同化系统(Global Land Data Assimilation System,GLDAS)提取冶木河陆地水储量,分析其与径流量的相关关系及变化时间点。研究结果表明:1)冶木河径流量平稳变化点和陆地水储量变化点均为2018年。2)战略实施影响期的径流量大于基准期,径流量平均增大29.79%。3)基准期和战略实施影响期5组水文情势指标的相似度分别为0.025、0.025、0.25、0.1、0,说明冶木河流量极值出现的次数增加,小流量持续情况有所好转。4)战略实施影响期实施的水源涵养措施袭夺了河川基流,减水效果较明显。5)陆地水储量与径流量相关关系较弱。
基金supported by the National Natural Science Foundation of China (30700260)National Key Technolo-gies R&D Program in the 10th 5-year-plan of China (2004BA720A22)
基金Under the auspices of National Natural Science Foundation of China(No.41771179,41871103,41771138)the National Key Research and Development Project(No.2016YFA0602301)
文摘Vegetation is the main component of the terrestrial ecosystem and plays a key role in global climate change. Remotely sensed vegetation indices are widely used to detect vegetation trends at large scales. To understand the trends of vegetation cover, this research examined the spatial-temporal trends of global vegetation by employing the normalized difference vegetation index(NDVI) from the Advanced Very High Resolution Radiometer(AVHRR) Global Inventory Modeling and Mapping Studies(GIMMS) time series(1982–2015). Ten samples were selected to test the temporal trend of NDVI, and the results show that in arid and semi-arid regions, NDVI showed a deceasing trend, while it showed a growing trend in other regions. Mann-Kendal(MK) trend test results indicate that 83.37% of NDVI pixels exhibited positive trends and that only 16.63% showed negative trends(P < 0.05) during the period from 1982 to 2015. The increasing NDVI trends primarily occurred in tree-covered regions because of forest growth and re-growth and also because of vegetation succession after a forest disturbance. The increasing trend of the NDVI in cropland regions was primarily because of the increasing cropland area and the improvement in planting techniques. This research describes the spatial vegetation trends at a global scale over the past 30+ years, especially for different land cover types.
