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Changes and determining factors of crop evapotranspiration derived from satellite-based dual crop coefficients in North China Plain

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The Crop Journal 2022年第5期10卷 1496-1506页

作者： Qinghua Tan Yujie Liu Tao Pan xianfang song Xiaoyan Li Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China State Key Laboratory of Earth Surface Processes and Resource Ecology Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China

Evaluating actual crop evapotranspiration(ET) variations and their determining factors under changing climates is crucial for agricultural irrigation management and crop productivity improvement in nonhumid regions.This study analyzed the spatiotemporal characteristics and detected the determining factors of ETfor winter wheat and summer maize rotation system from 2000 to 2017 in the North China Plain(NCP),by combining the FAO-56 dual crop coefficient approach with remotely sensed vegetation indices(VIs).The results indicated that daily air temperature increased in varying degrees while wind speed and sunshine hours decreased slightly during the growing season of winter wheat and summer maize over the study period.The trends of relative humidity and effective precipitation varied in crop growing seasons.Based on the validated relationship of dual crop coefficients and VIs,the estimated multi-year average ETof winter wheat(370.29±31.28 mm) was much higher than summer maize(281.85±20.14 mm),and the rotation cycle was 652.43±27.67 mm.Annual ETof winter wheat and the rotation cycle increased by 2.96 mm aand 1,77 mm a,respectively.However,the ETof summer maize decreased with distinct spatial variation.Spatially,winter wheat ETincreased significantly in the northeast NCP,covering the Beijing-Tianiin-Hebei areas.Meanwhile,significant increases in summer maize ETwere detected in the southwest NCP.The sensitivity and contribution analysis showed that ETof winter wheat and summer maize was positively sensitive to temperature,wind speed,and sunshine hours while negatively to relative humidity.Moreover,wind speed and sunshine hours contributed most to changes in ET(around 20%-40%).

关键词： Actual crop evapotranspiration Determining factor North China Plain Rotation system Spatiotemporal variation

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黄河上游近60年水沙变化特征及其影响因素

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湖泊科学 2024年第2期36卷 602-619页

作者：张曦泽杨丽虎宋献方中国科学院地理科学与资源研究所陆地水循环及地表过程重点实验室北京100101 中国科学院大学资源与环境学院北京100049

由于受人类活动及气候变化影响,黄河上游干流水沙特征发生显著变化。为探究黄河上游水沙变化情况,基于黄河上游5个水文站19642019年水沙、遥感影像等数据,利用Mann-Kendall检验法、滑动t检验法、累积距平曲线和双累积曲线等突变检验方... 详细信息

由于受人类活动及气候变化影响,黄河上游干流水沙特征发生显著变化。为探究黄河上游水沙变化情况,基于黄河上游5个水文站19642019年水沙、遥感影像等数据,利用Mann-Kendall检验法、滑动t检验法、累积距平曲线和双累积曲线等突变检验方法和小波分析法,对黄河上游水沙变化特征进行研究。利用水沙关系曲线及线性回归法等方法估算人类活动和气候对水沙变化的贡献率,并着重讨论梯级水库建设及土地利用变化对水沙的影响。结果表明:1)黄河上游玛曲-小川段流域内降雨量和径流量变化幅度不明显,贵德站、循化站、小川站19862019年年均输沙量分别减至19641985年的9.8%、24.6%、38.8%,输沙量大大减少。黄河上游玛曲-小川段径流量突变多在1986年,输沙量突变多在1969、1986、2004年,径流量存在8、16、22 a周期,输沙量存在4~8、18~21、27 a周期。2)1969年后,河流输沙能力增强,水沙关系显著改变。在不同时段内,人类活动对径流量变化在19872019年贡献率为66.3%,对输沙量变化在19701986、19872004、20052019年的贡献率为72.96%、70.73%、69.7%。人类活动对黄河上游干流水沙影响占据主导因素。3)刘家峡水库淤积最为严重,单库运行期水库淤积量为2.39亿t,排沙比变化范围为1.39%~10.7%。梯级水库联调使得径流量在19642004年间减少47.8%,19642019年间梯级水库减沙94.8%,梯级水库对输沙量影响远大于对径流量的影响。4)19802020年间,草地面积增加了1880.03 km 2,增幅3.1%,有利于减少输沙量,草地拦沙效益大于截流效益。

关键词：黄河上游水沙变化人类活动梯级水库土地利用

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Field scale interaction and nutrient exchange between surface water and shallow groundwater in the Baiyang Lake region,North China Plain

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Journal of Environmental Sciences 2016年第7期28卷 60-75页

作者： Bentje Brauns Poul L.Bjerg xianfang song Rasmus Jakobsen Department of Environmental Engineering Technical University of Denmark State Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences Sino-Danish Center for Education and Research Geological Survey of Denmark and Greenland

Fertilizer input for agricultural food production, as well as the discharge of domestic and industrial water pollutants, increases pressures on locally scarce and vulnerable water resources in the North China Plain. In order to：（a） understand pollutant exchange between surface water and groundwater,（b） quantify nutrient loadings, and（c） identify major nutrient removal pathways by using qualitative and quantitative methods, including the geochemical model PHREEQC） a one-year study at a wheat（Triticum aestivum L.） and maize（Zea mays L.） double cropping system in the Baiyang Lake area in Hebei Province, China, was undertaken. The study showed a high influence of low-quality surface water on the shallow aquifer. Major inflowing pollutants into the aquifer were ammonium and nitrate via inflow from the adjacent Fu River（up to 29.8 mg/L NH4-N and 6.8 mg/L NO3-N）, as well as nitrate via vertical transport from the field surface（up to 134.8 mg/L NO3-N in soil water）. Results from a conceptual model show an excess nitrogen input of about 320 kg/ha/a. Nevertheless,both nitrogen species were only detected at low concentrations in shallow groundwater,averaging at 3.6 mg/L NH4-N and 1.8 mg/L NO3-N. Measurement results supported by PHREEQC-modeling indicated cation exchange, denitrification, and anaerobic ammonium oxidation coupled with partial denitrification as major nitrogen removal pathways. Despite the current removal capacity, the excessive nitrogen fertilization may pose a future threat to groundwater quality. Surface water quality improvements are therefore recommended in conjunction with simultaneous monitoring of nitrate in the aquifer, and reduced agricultural N-inputs should be considered.

关键词： Groundwater pollution North China Plain Surface water–groundwater interaction Wheat–maize double cropping Nitrogen Anammox

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Identification of key factors governing chemistry in groundwater near the water course recharged by reclaimed water at Miyun County, Northern China

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Journal of Environmental Sciences 2013年第9期25卷 1754-1763页

作者： Yilei Yu xianfang song Yinghua Zhang Fandong Zheng Ji Liang Dongmei Han Ying Ma Hongmei Bu Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences University of Chinese Academy of Sciences Institute of Beijing Hydraulic Research

Reclaimed water was successfully used to recover the dry Chaobai River in Northern China, but groundwater may be polluted. To ensure groundwater protection, it is therefore critical to identify the governing factors of groundwater chemistry. Samples of reclaimed water, river and groundwater were collected monthly at Chaobai River from January to September in 2010. Fifteen water parameters were analyzed. Two kinds of reclaimed water were different in type （Na-Ca-Mg-Cl-HCO3 or Na-Ca-Cl-HCO3 ） and concentration of nitrogen. The ionic concentration and type in river were similar to reclaimed water. Some shallow wells near the river bed had the same type （Na-Ca-Mg-Cl-HCO3 ） and high concentration as reclaimed water, but others were consistent with the deep wells （Ca-Mg-HCO3 ）. Using cluster analysis, the 9 months were divided into two periods （dry and wet seasons）, and all samples were grouped into several spatial clusters, indicating different controlling mechanisms. Principal component analysis and conventional ionic plots showed that calcium, magnesium and bicarbonate were controlled by water-rock interaction in all deep and some shallow wells. This included the dissolution of calcite and carbonate weathering. Sodium, potassium, chloride and sulfate in river and some shallow wells recharged by river were governed by evaporation crystallization and mixing of reclaimed water. But groundwater chemistry was not controlled by precipitation. During the infiltration of reclaimed water, cation exchange took place between （sodium, potassium） and （calcium, magnesium）. Nitrification and denitrification both happened in most shallow groundwater, but only denitrification in deep groundwater.

关键词： reclaimed water groundwater chemistry multivariate analysis Chaobai River water-rock interaction evaporation crystallization cation exchange denitrification

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基于高密度电测法的西沙东岛地下淡水透镜体识别

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资源科学 2024年第3期46卷 635-646页

作者：韩冬梅曹国亮蔡砥柱宋献方邢子浩孟庆杰中国地质调查局海口海洋地质调查中心海口571127 中国科学院地理科学与资源研究所陆地水循环及地表过程重点实验室北京100101 中国科学院大学资源与环境学院北京100049 中国地质大学(北京)水利部地下水保护重点实验室(筹) 北京100083 中国地质大学(北京)水资源与环境学院北京100083

[目的]珊瑚岛地下淡水透镜体是维持岛上居民生产生活、生态涵养所必需的重要资源。准确识别珊瑚岛地下淡水透镜体的形态,揭示地下淡水补给机制,是珊瑚岛地下水资源评价的重要基础,对实现科学管理海岛地下水资源至关重要。[方法]本文以... 详细信息

[目的]珊瑚岛地下淡水透镜体是维持岛上居民生产生活、生态涵养所必需的重要资源。准确识别珊瑚岛地下淡水透镜体的形态,揭示地下淡水补给机制,是珊瑚岛地下水资源评价的重要基础,对实现科学管理海岛地下水资源至关重要。[方法]本文以西沙群岛的东岛为研究对象,结合水文地质调查,对高密度电阻率法实测剖面数据进行反演解译,基于电阻率和地下水总溶解固体浓度关系识别了咸淡水界面。[结果]①根据高密度电阻率法反演电阻率首次识别了西沙东岛地下淡水透镜体发育特征,该方法在西沙珊瑚岛具有较好的适用性;②东岛淡水透镜体主要发育于岛屿西北和南侧沙堤,厚度较薄,仅3~7m,局部地区甚至无地下淡水;③东岛地下咸淡水界面形态说明沙堤以内植被根系吸水是造成淡水透镜体较薄的主要原因,植被分布对东岛地下淡水资源具有重要影响。[结论]在保护西沙珊瑚岛生态系统的前提下,适当减少人工椰树林种植面积,可有效增加岛屿降雨形成的地下淡水资源,有利于发挥珊瑚岛地下淡水透镜体对岛屿水安全的保障作用。

关键词：珊瑚岛淡水透镜体高密度电法咸淡水界面西沙东岛

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Impact of reclaimed water in the watercourse of Huai River on groundwater from Chaobai River basin, Northern China

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Frontiers of Structural and Civil Engineering 2017年第4期11卷 643-659页

作者： Yilei YU xianfang song Yinghua ZHANG Fandong ZHENG Licai LIU Beijing Key Laboratory of Wetland Services and Restoration Institute of Wetland Research Chinese Academy of Forestry B eijing 100091 China Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Beijing Water Science and Technology Institute Beijing 100048 China

Reclaimed water is efficient for replenishing the dry rivers in northern China, but regional groundwater may be at risk from pollution. Therefore, samples of reclaimed water, river water, and groundwater were collected at the Huai River in the Chaobai River basin in 2010. The water chemistry and isotopic compositions of the samples were analyzed in the laboratory. The reclaimed water had stable compositions of water chemistry and isotopes, and the Na. Ca-HCO3. C1 water type. The water chemistry of the river water was consistent with that of the reclaimed water. A June peak of total nitrogen was the prominent characteristic in the shallow groundwater, which also had the Na. Ca-HCO3. C1 water type. However, the water chemistry and isotopes in most of the deep groundwater remained stable, and the water type was Ca-Mg-HCO3. The amount of reclaimed water recharging the groundwater was about 2.5 - 107 m^3/yr. All of the shallow groundwater was impacted by the reclaimed water, with the mixing proportion of reclaimed water ranging from 42% to 80 % in the dry season and from 20% to 86% in the wet season. Only one deep well, with proportions of 67% （dry season） and 28% （wet season）, was impacted. TDS, EC, and major ions （Na, K, C1, NHn-N, NO2-N, and NO3-N） were increased in the impacted wells.

关键词： groundwater hydrochemistry Huai River reclaimed water stable isotopes

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黄南州“4·23”暴雪天气过程数值预报产品检验

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河南科技 2024年第1期51卷 104-108页

作者：彭英超宋仙芳郭安欣黄南藏族自治州气象局青海同仁811399

【目的】对2022年4月23日出现的暴雪天气进行数值模式检验分析,检验各种数值预报产品对强降雪的预报能力,从而提高本地暴雪预报准确率。【方法】选取此次暴雪天气过程(四个国家站及区域自动站24 h累计降雪量≥10 mm),采用天气学分析、... 详细信息

【目的】对2022年4月23日出现的暴雪天气进行数值模式检验分析,检验各种数值预报产品对强降雪的预报能力,从而提高本地暴雪预报准确率。【方法】选取此次暴雪天气过程(四个国家站及区域自动站24 h累计降雪量≥10 mm),采用天气学分析、对比分析法,利用EC-thin,CMA-3KM和CMA-GFS三种模式与暴雪个例实况进行检验对比评估。【结果】(1)环流形势场对比CMA-GFS模式对于高原槽预报较EC稳定且准确,基本与实况吻合,而EC越靠近临近时次预报更为准确;从槽线移速来看,两家模式均预报槽线移速比实况快。(2)24小时降水预报检验,EC模式对落区、强度的把握明显优于CMA-GFS模式,且临近时次预报效果最佳。(3)一般性降水准确率预报CMA-3KM参考性最好,且最稳定,准确均在70%以上;三种模式的暴雪的准确率并不稳定,夜间出现的暴雪预报效果08时次优于20时次。【结论】CMA-3KM预报降水效果较好,但稳定性不高,EC模式对降水的落区、强度的把握优于CMA_GFS模式,且临近时次预报效果最佳。

关键词：暴雪天气检验 CMA-3KM ECMWF模式 CMA-GFS模式

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Water quality of reclaimed water from treated urban wastewater in Chaobai River Basin,North China

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Chinese Journal of Population,Resources and Environment 2014年第2期12卷 103-109页

作者： Yilei Yu xianfang song Yinghua Zhang Fandong Zheng Licai Liu Institute of Wetland Research Chinese Academy of Forestry Key Laboratory of Water Cycle and Relate Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences Beijing Water Science & Technology Institute

The utilization of reclaimed water could be an efficient tool to alleviate water scarcity,especially for dry river augmentation.However,it is crucial to monitor water quality to ensure safety to human health and to avoid negative effects on the environment.Reclaimed water samples were collected bimonthly from May to November in 2010 in Chaobai River,and the physiochemical parameters were determined.The main results are as follows:The parameters exceeding the threshold value of the water guidelines are mainly nutrition related to nitrogen and phosphorus,which are known to increase the risk of eutrophication in surface waters.Additionally,nitrite and nitrate can be detrimental to human health.The majority of the parameters have a peaking concentration in May,whereas others either show significant temporal variation over the entire period or remain relatively constant in all four months.Correlation analysis shows that some parameters(pH,T and B) have no significant correlation with others,whereas significant positive correlation was found for Sr with EC and TDS,for CI with TDS,for Si02 with TP and for NO3-N with TN and a significant negative correlation between SO4 and Ba.According to principal component analysis,60.108%of the total data is represented by dominant solutes,and the second principal component with a percentage of 31.876 comprises parameters related to nitrogen.Subsequent cluster analysis of parameters identified four groups,which represent different compositions,and samples in May differ from others.

关键词： water quality treated urban wastewater water guide

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重点环节护理模式在慢性根尖周炎患者根管治疗中的临床效果

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临床医学工程 2024年第6期31卷 731-732页

作者：覃沅华宋朝晖曲晓东邹鲜芳周燕平柳州市人民医院口腔科广西柳州545006 柳州市人民医院供应室广西柳州545006

目的探讨重点环节护理模式应用于慢性根尖周炎患者根管治疗中的临床效果。方法94例慢性根尖周炎行根管治疗的患者随机分为两组,对照组予以常规护理,观察组予以重点环节护理模式,比较两组的焦虑症状、疼痛程度以及并发症。结果干预后,观... 详细信息

目的探讨重点环节护理模式应用于慢性根尖周炎患者根管治疗中的临床效果。方法94例慢性根尖周炎行根管治疗的患者随机分为两组,对照组予以常规护理,观察组予以重点环节护理模式,比较两组的焦虑症状、疼痛程度以及并发症。结果干预后,观察组的SAS评分、NRS评分均低于对照组(P<0.05)。观察组的并发症发生率为6.38%,低于对照组的21.28%(P<0.05)。结论重点环节护理模式有利于减轻慢性根尖周炎根管治疗患者的焦虑症状及疼痛程度,降低并发症发生风险。

关键词：慢性根尖周炎根管治疗重点环节护理焦虑症状疼痛并发症

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Characteristics of δ^(18)O in precipitation over Eastern Monsoon China and the water vapor sources

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Chinese Science Bulletin 2010年第2期55卷 200-211页

作者： LIU JianRong song xianfang YUAN GuoFu SUN XiaoMin LIU Xin Key Laboratory of Water Cycle & Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research ChineseAcademy of Sciences Beijing 100101 China Graduate University of Chinese Academy of Sciences Beijing 100049 China CERN Sub-center of Water Beifing 100101 China

Monsoon circulation is an important carrier of water vapor transport, and it impacts the precipitation of the monsoonal regions through the constraints and controls of large-scale water vapor transport and distributions as well as the water vapor balance. An overall research on stable Hydrogen and Oxygen isotopes in precipitation over Eastern Monsoon China could benefit a comprehensive understanding of the monsoonal precipitation mechanism. Seventeen field stations of the Chinese Network of Isotopes in Precipitation (CHNIP) have been selected to collect monthly composite precipitation samples during the years 2005―2006. Components of δ D and δ 18O have been analyzed to achieve the spatiotemporal distributions. The established Local Meteoric Water Line δ D=7.46δ 18O+0.90 based on the 274 obtained monthly samples could be treated as isotope input functions across the region, due to basically reflecting the specific regional meteorological conditions over Eastern Monsoon China. The δ-value depleted from coastal to inner area. In Southern China and Northeastern China there were typical periodic patterns of δ18O. Different dominant affecting metrological factors have been raised with different regions. From south to north, the temperature effect of δ18O enhanced, while the amount effect changed from existing at an all-year-scale in Southern China to being only remarkable during the main rainy seasons in North China and Northeastern China. Main geographical controls varied from altitude in Southern China and North China to latitude in Northeastern China. Furthermore, δ18O had an implication of advance and retreat of the monsoon as well as rainfall belt transfer. δ 18O was also a tracer for the movement path of typhoon and tropical storms.

关键词：中国东部季风环流降水机制水汽来源特征氧同位素水汽输送平衡控制

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