[Objective] The research aimed to analyze temporal and spatial variation of strong precipitation caused flood and agricultural disaster loss in Huaihe River basin of Anhui Province during Meiyu period of 2007.[Method]...[Objective] The research aimed to analyze temporal and spatial variation of strong precipitation caused flood and agricultural disaster loss in Huaihe River basin of Anhui Province during Meiyu period of 2007.[Method] On the basis of rainfalls of each station in Huaihe River basin of Anhui,rainfall data during Meiyu period of 2007 and flood disaster data in the same period,the temporal and spatial distribution characteristics of strong precipitation caused flood during Meiyu period of 2007 and its harm on agriculture were analyzed.The variation rule,distribution characteristics of strong precipitation during Meiyu period in Huaihe River basin of Anhui and its relationship with agricultural disaster loss were discussed.[Result] During Meiyu period of 2007 in Huaihe River basin of Anhui,the rainstorm was more,and the rainfall was large.The precipitation variation showed 'three-peak' trend.Rainfall in Huaihe River basin during Meiyu period of 2007 was greatly more than that homochronously in Yangtze River basin.The rain area over 400.0 mm during Meiyu period mainly located in Huaihe River basin,and the rain area over 600.0 mm mainly located from area along Huaihe River to central Huaibei.The rainfall during Meiyu period gradually decreased toward south and north by the north bank of Huaihe River as the symmetry axis.The rainfall in area along Huaihe River showed wavy distribution in east-west direction.The flood disaster loss index and disaster area of crops in Huaihe River basin of Anhui both increased as rainfall in Meiyu period.[Conclusion] The research provided theoretical basis for flood prevention,disaster reduction and agricultural flood-avoiding development in Huaihe River basin.展开更多
The Anhui Experiment, a pilot experiment of "Yangtze River Geoscience Project "conducted in October,2015,is a large active-source experiment using airgun sources. It was the first 3-dimensional seismic surve...The Anhui Experiment, a pilot experiment of "Yangtze River Geoscience Project "conducted in October,2015,is a large active-source experiment using airgun sources. It was the first 3-dimensional seismic survey with active sources in the Yangtze River. The sources are airguns in 20 fixed shot points,and the observation system consists mainly of109 permanent stations and 11 wide-angle profiles. Using the data from permanent stations,we investigated the seismic signals generated by airgun sources in the Yangtze River. The results show that the airgun signals are observable in the records from permanent stations to a maximum distance of 300 km. Further analysis on absolute amplitude of airgun signals shows that:( 1) the strength of airgun signals is of the order of10 nm at 50 km away from the source,and then,decreases significantly to less than 1nm at 200 km;( 2) an azimuthal anisotropy is observed in spatial distribution of the strength of airgun signals,which may be related to the geometry of Yangtze River; and( 3) a low ambient noise level is essential for retrieving weak airgun signals from the records,and the high-quality China National Seismic Network and regional networks offer a great opportunity to retrieving airgun signals with amplitude as small as nanometers.展开更多
Soil and water loss is now a major environmental problem in many areas of China, especially in the area of the Dabie Mountain, Anhui Province, which results in environmental degradation and does harm to the people’s ...Soil and water loss is now a major environmental problem in many areas of China, especially in the area of the Dabie Mountain, Anhui Province, which results in environmental degradation and does harm to the people’s life and production there. Based on the observational records from the Dasha River, the authors analyze the character of the variation in flow and sediment in different flood and dry seasons from 1970 to 2000. The result shows that human activities had significantly reduced the sediment discharge and sediment module, and increased the runoff in low-water seasons since the 1980s. The average contribution rate of human activities to decreasing sediment was 65.67%, and at the same period the contribution rate of runoff and rainfall was about 34.33%. Therefore, it is necessary to take the biological and engineering measures to solve the problem of soil and water loss in the Dasha River watershed.展开更多
Colloform pyrite(CPy)is widely distributed in the Tongling mineralization cluster of the Middle-Lower Yangtze River Mineralization Belt(MLYRMB),China.There have many debates as to whether such CPy is associated with L...Colloform pyrite(CPy)is widely distributed in the Tongling mineralization cluster of the Middle-Lower Yangtze River Mineralization Belt(MLYRMB),China.There have many debates as to whether such CPy is associated with Late Mesozoic igneous or Carboniferous sedimentation.CPy from the Xinqiao deposit,a representative of the stratabound sulfide deposits in the MLYRMB,was studied by powder X-ray diffraction(XRD),field-emission scanning electron microscopy(SEM),and high-resolution transmission electron microscopy(TEM).The results show that CPy mainly comprises pyrite,pyrrhotite,quartz,and illite.Pyrite in CPy shows cubic,globule,and xenomorphic morphologies.No octahedral or pyritohedron was observed.Most of the quartz crystals display xenomorphic morphology,where pyrite mold are popular on the surface.Organic matter(OM),which is usually bound to illite,is an important component in CPy.Morphological investigations which exhibit detrital features of quartz and clay minerals indicate that they were derived from continental weathering.Specially,some hexagonal pyrrhotite nanoparticles which show mackinawite morphology are coexisted with OM.The results indicate that the transformation process of sulfides possibly is mackinawite(the precursor)—hexagonal pyrrhotite-pyrite.Thus,compositional and micro-textural characteristics of CPy in Xinqiao deposit suggest it to be a sedimentary origin rather than a hydrothermal origin which is associated with Yanshanian magmatism.Moreover,the coexistence of CPy and stratabound sulfide orebodies in the MLYRMB suggests a causal link between the two.It is considered that CPy might have served as a Cu mineralization geochemical barrier for the Cu-bearing ore-forming fluids,which originated from the Mesozoic magma in the MLYRMB.展开更多
为快速、客观、定量地评价长江岸线湖南段生态环境质量变化,以1990、2000、2010、2020年的Landsat遥感影像为数据源,采用遥感生态指数(RSEI)模型对该区的生态环境质量进行监测与评价。结果表明:1990、2000、2010、2020年的遥感生态指数...为快速、客观、定量地评价长江岸线湖南段生态环境质量变化,以1990、2000、2010、2020年的Landsat遥感影像为数据源,采用遥感生态指数(RSEI)模型对该区的生态环境质量进行监测与评价。结果表明:1990、2000、2010、2020年的遥感生态指数均值分别为0.6848、0.6729、0.5912、0.7786,呈现先降后升的变化趋势,但1990—2010年RSEI值的降低幅度小于2010—2020年RSEI值的增加幅度。1990—2020年长江岸线湖南段生态环境质量变好的区域面积最大,不变的区域面积次之,变差的区域面积最小,其面积占比分别为46.27%、27.04%和26.69%;生态环境质量等级变化以上升1、2个等级和下降1个等级的为主,且上升1、2个等级的区域面积之和比下降1个等级的区域面积增加了31.4055 km 2,区域面积占比增加了20.28%。从整体上看,1990—2020年长江岸线湖南段生态环境质量变化是一个渐变的过程,虽然在1990—2010年出现了生态退化现象,但2016年后随着生态保护政策的实施,生态环境质量得到了显著改善。展开更多
基金Supported by Meteorological Open Research Fund of Huaihe River basin,China(HRM200805)Soft Science Research Plan of Ministry of Science and Technology,China(2007GXS3D087)
文摘[Objective] The research aimed to analyze temporal and spatial variation of strong precipitation caused flood and agricultural disaster loss in Huaihe River basin of Anhui Province during Meiyu period of 2007.[Method] On the basis of rainfalls of each station in Huaihe River basin of Anhui,rainfall data during Meiyu period of 2007 and flood disaster data in the same period,the temporal and spatial distribution characteristics of strong precipitation caused flood during Meiyu period of 2007 and its harm on agriculture were analyzed.The variation rule,distribution characteristics of strong precipitation during Meiyu period in Huaihe River basin of Anhui and its relationship with agricultural disaster loss were discussed.[Result] During Meiyu period of 2007 in Huaihe River basin of Anhui,the rainstorm was more,and the rainfall was large.The precipitation variation showed 'three-peak' trend.Rainfall in Huaihe River basin during Meiyu period of 2007 was greatly more than that homochronously in Yangtze River basin.The rain area over 400.0 mm during Meiyu period mainly located in Huaihe River basin,and the rain area over 600.0 mm mainly located from area along Huaihe River to central Huaibei.The rainfall during Meiyu period gradually decreased toward south and north by the north bank of Huaihe River as the symmetry axis.The rainfall in area along Huaihe River showed wavy distribution in east-west direction.The flood disaster loss index and disaster area of crops in Huaihe River basin of Anhui both increased as rainfall in Meiyu period.[Conclusion] The research provided theoretical basis for flood prevention,disaster reduction and agricultural flood-avoiding development in Huaihe River basin.
基金jointly supported by the Fundamental Research Funds for Central Public Welfare Research Institutes(DQJB15B09)National Natural Science Foundation of China(41574052,41374070)Academician of Chen Yong Workstation Project of Yunnan Province(2014IC007)
文摘The Anhui Experiment, a pilot experiment of "Yangtze River Geoscience Project "conducted in October,2015,is a large active-source experiment using airgun sources. It was the first 3-dimensional seismic survey with active sources in the Yangtze River. The sources are airguns in 20 fixed shot points,and the observation system consists mainly of109 permanent stations and 11 wide-angle profiles. Using the data from permanent stations,we investigated the seismic signals generated by airgun sources in the Yangtze River. The results show that the airgun signals are observable in the records from permanent stations to a maximum distance of 300 km. Further analysis on absolute amplitude of airgun signals shows that:( 1) the strength of airgun signals is of the order of10 nm at 50 km away from the source,and then,decreases significantly to less than 1nm at 200 km;( 2) an azimuthal anisotropy is observed in spatial distribution of the strength of airgun signals,which may be related to the geometry of Yangtze River; and( 3) a low ambient noise level is essential for retrieving weak airgun signals from the records,and the high-quality China National Seismic Network and regional networks offer a great opportunity to retrieving airgun signals with amplitude as small as nanometers.
基金Under the auspices of the Natural Science Foundation of Anhui Education Office (No. 2006KJ161C), Special FundProject of Anhui Provincial Irrigation Office (No. 2001-11)
文摘Soil and water loss is now a major environmental problem in many areas of China, especially in the area of the Dabie Mountain, Anhui Province, which results in environmental degradation and does harm to the people’s life and production there. Based on the observational records from the Dasha River, the authors analyze the character of the variation in flow and sediment in different flood and dry seasons from 1970 to 2000. The result shows that human activities had significantly reduced the sediment discharge and sediment module, and increased the runoff in low-water seasons since the 1980s. The average contribution rate of human activities to decreasing sediment was 65.67%, and at the same period the contribution rate of runoff and rainfall was about 34.33%. Therefore, it is necessary to take the biological and engineering measures to solve the problem of soil and water loss in the Dasha River watershed.
基金supported by the National Natural Science Foundation of China(Grant nos 41672038,41572029,41872043)the National Key Research and Development Program of China(Grant no.2016YFC0600209)。
文摘Colloform pyrite(CPy)is widely distributed in the Tongling mineralization cluster of the Middle-Lower Yangtze River Mineralization Belt(MLYRMB),China.There have many debates as to whether such CPy is associated with Late Mesozoic igneous or Carboniferous sedimentation.CPy from the Xinqiao deposit,a representative of the stratabound sulfide deposits in the MLYRMB,was studied by powder X-ray diffraction(XRD),field-emission scanning electron microscopy(SEM),and high-resolution transmission electron microscopy(TEM).The results show that CPy mainly comprises pyrite,pyrrhotite,quartz,and illite.Pyrite in CPy shows cubic,globule,and xenomorphic morphologies.No octahedral or pyritohedron was observed.Most of the quartz crystals display xenomorphic morphology,where pyrite mold are popular on the surface.Organic matter(OM),which is usually bound to illite,is an important component in CPy.Morphological investigations which exhibit detrital features of quartz and clay minerals indicate that they were derived from continental weathering.Specially,some hexagonal pyrrhotite nanoparticles which show mackinawite morphology are coexisted with OM.The results indicate that the transformation process of sulfides possibly is mackinawite(the precursor)—hexagonal pyrrhotite-pyrite.Thus,compositional and micro-textural characteristics of CPy in Xinqiao deposit suggest it to be a sedimentary origin rather than a hydrothermal origin which is associated with Yanshanian magmatism.Moreover,the coexistence of CPy and stratabound sulfide orebodies in the MLYRMB suggests a causal link between the two.It is considered that CPy might have served as a Cu mineralization geochemical barrier for the Cu-bearing ore-forming fluids,which originated from the Mesozoic magma in the MLYRMB.
基金This work was supported by the projects of National Science Foundation of China （41706099, 51779228, 51379190, 41676085）, and the Science and Technology Plans of Zhejiang province （2015F50011, 2016F50017）. The authors acknowledged the anonymous reviewers＇ comments to improve this paper.
文摘一张稠密的人口和很快发展中的经济描绘的长江三角洲对海平面的上升高度脆弱。从中国海洋的信息网络和浙江的数据省的水文学局被用来分析海平面的上升。在三角洲的海平面的上升的率是 2.4 ? 公里每在 1981-2015 的年。年度在在三角洲的南方翅膀的 Daishan， Dinghai，和 Dongtou 车站海平面是 4.3， 3.1，和 5 ? 公里每年分别地在一样的时期上。在每个车站的 10 年的平均结果也显示海平面的上升的一个可察觉的趋势。海平面的上升被贡献加强的侵蚀的一个更大的比例，在三角洲从 3% ～ 14%。同时，潮汐的水平的 100 年的回来时期在 Dongtou 和 Dinghai 车站减少了到 50 年的等级。而且，在 Yanguan 的潮汐的讨厌的人的到达时间是 4 ? 在 0.145 的海平面的上升中更早的 min ? m 比 0 的 ? m。在表面和底部层的潮汐的讨厌的人和速度的高度在海平面的上升中有增加。高、低的潮层次的最大的增加是 0.122 ? m 并且 0.016 ? m 当最大值在表面和底部速度增加时，层是 0.07 ? m ? s <sup>1</sup> 并且 0.05 ? m ? s <sup>1</sup>, 分别地。海平面的上升将引起防波堤的损坏，因此，构造防波堤的设计标准应该采用高水平在长江三角洲和它的南方翅膀最小化联系风险。
文摘为快速、客观、定量地评价长江岸线湖南段生态环境质量变化,以1990、2000、2010、2020年的Landsat遥感影像为数据源,采用遥感生态指数(RSEI)模型对该区的生态环境质量进行监测与评价。结果表明:1990、2000、2010、2020年的遥感生态指数均值分别为0.6848、0.6729、0.5912、0.7786,呈现先降后升的变化趋势,但1990—2010年RSEI值的降低幅度小于2010—2020年RSEI值的增加幅度。1990—2020年长江岸线湖南段生态环境质量变好的区域面积最大,不变的区域面积次之,变差的区域面积最小,其面积占比分别为46.27%、27.04%和26.69%;生态环境质量等级变化以上升1、2个等级和下降1个等级的为主,且上升1、2个等级的区域面积之和比下降1个等级的区域面积增加了31.4055 km 2,区域面积占比增加了20.28%。从整体上看,1990—2020年长江岸线湖南段生态环境质量变化是一个渐变的过程,虽然在1990—2010年出现了生态退化现象,但2016年后随着生态保护政策的实施,生态环境质量得到了显著改善。
