Search

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Geology & Resources is the property of Geology & Resources Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Geomechanics is the property of Journal of Geomechanics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An increasing and wide attention has been paid to the effect of artificial reservoirs on river geomorphology, water ecological environment system and hydrological characteristics. In this paper, two reservoirs on the Shiguan River, a tributary of the Huaihe River Basin, Meishan Reservoir and Nianyushan Reservoir are used as the study area. Samples are taken from the water body of the reservoirs, the Jiangjiaji section in the downstream of the reservoir, the Wangjiaba and Runheji sections at the upstream and downstream sections of the main stream of the Huaihe River in December 2020 to analyze the spatiotemporal variation characteristics of hydrochemistry ion, electrical conductivity, hydrogen and oxygen isotope content, and discuss the impact of reservoir construction on the water cycle of the basin. The results show that the two isotopic compositions of the water body have the same trend along the river direction, and the overall trend is positive. One is the dam interception and the other is the influence of latitude effect. The temporal change of isotopic concentration of the water bodies in the Meishan Reservoir and Nianyushan Reservoir is relatively stable, the isotopic temporal change of the upstream Wangjiaba Station is relatively stable, and that of the two sections on the tributary and the main stream affected by the reservoir fluctuates greatly. Hydrogen and oxygen isotopic composition of the river and the reservoir deviates from the local atmospheric precipitation line, mainly due to the interception effect of the reservoir, so that the evaporation is stronger than that of the ordinary river. The lower reaches of Jiangjiaji and Runheji Cl- and the electrical conductivity are affected by the water discharge from the reservoir, the value of which decreases. Jiangjiaji is closer to the reservoir and has a greater impact. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Natural Resources / Ziran Ziyuan Xuebao is the property of Journal of Natural Resources and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aiming at the large deviation of radar heavy precipitation estimation, we propose an effective radar heavy precipitation estimation method based on recurrent neural network (RNN). Based on the understanding of precipitation evolution, we redesigned RNN network structure to merge previous rain gauge measurements in order to improve quantitative precipitation estimation. The weather radar combined with previous three-times rain gauge measurements can effectively reduce large deviations in heavy precipitation estimation by ZR relationship. In this paper, the RNN and the ZR relationship method are compared in the 2015 summer precipitation test dataset. The root mean square error (RMSE) of the RNN method is reduced by 24.28%, and the median absolute error (Median AE) is reduced by 32.83% compared to the ZR relationship by real-time calibration method where rainfall intensity is greater than or equal to 30 mm/h. Therefore, estimating precipitation by RNN method has a significant effect on quantitatively estimating heavy precipitation, and has business application value. [ABSTRACT FROM AUTHOR]

Copyright of Geomatics & Information Science of Wuhan University is the property of Geomatics & Information Science of Wuhan University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Quantitatively evaluation of satellite precipitation and potential evapotranspiration products with the high resolution, wide coverage and dynamic continuity is an important foundation for drought monitoring over mainland China. This paper examined the accuracy of products and the utility of drought monitoring using the newly released long-term (more than 30 years) satellite precipitation products (climate hazards group infrared precipitation with station, CHIRPS) data version 2.0 and potential evapotranspiration products (global land-surface evaporation: the Amsterdam methodology, GLEAM) dataset. We selected standardized precipitation evapotranspiration index (SPEI) and six statistical and classification measures indexes to evaluate accuracy and the utility of CHIRPS and GLEAM-Ep (potential evapotranspiration derived from GLEAM), with China Gauge-based Precipitation Daily Analysis dataset (CGDPA) and potential evapotranspiration calculated by Penman-Monteith (PM-Ep) as evaluation reference data sets. The results showed that CHIRPS and GLEAM-Ep performed well in eastern and southwest of China. However, their performance in western China was uncertain due to the sparsity of meteorological stations. SPEIs (SPEI value calculated by the CHIRPS and GLEAM-Ep) had a good performance on drought monitoring in eastern and southwestern China. Values of correlation coefficient (CC) between SPEIs and SPEIm (SPEI value calculated by the CGDPA and PM-Ep) were more than 0.6 in southeastern China, southwestern China, the middle and lower reaches of the Yangtze River region and northern China, especially in relatively humid areas, which the correlation coefficient values were more than 0.7 and the root mean-squared error (RMSE) values were less than 0.8. In order to further evaluate the performance of SPEIs in drought monitoring at spatial and temporal scales, the SPEIs3 (SPEIs at three-month scale) and SPEIm3 (SPEIm at three-month scale) in southeastern China, southwestern China, the middle and lower reaches of the Yangtze River region and northern China were compared. SPEIs3 had a better simulation effect on the evolution process of the ratio of drought area in those regions during1981-2016. And the success ratio of simulating drought duration was about 0.93, 0.57, 0.71 and 0.81, respectively. Moreover, SPEIs3 displayed a high accuracy over the four regions in capturing drought, which was the spatial distribution of typical drought events on specific month. In conclusion, SPEI based on long-term CHIRPS and GLEAM-Ep could be applied to monitor and evaluate drought in eastern and southwestern China. This paper can provide reliable reference for monitoring and warning of drought events and water resources management in those regions. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Natural Resources / Ziran Ziyuan Xuebao is the property of Journal of Natural Resources and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Natural Resources / Ziran Ziyuan Xuebao is the property of Journal of Natural Resources and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Plateau Meteorology is the property of Plateau Meteorology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Plateau Meteorology is the property of Plateau Meteorology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Plateau Meteorology is the property of Plateau Meteorology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Natural Resources / Ziran Ziyuan Xuebao is the property of Journal of Natural Resources and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nonferrous Metals (Mining Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Objectives]This paper was aimed to reveal the nitrogen source and transfer law of nitrate in the water under the current water and fertilizer utilization background of typical "four element isomorphism" system in Hani rice terrace. [Methods]The contents of nitrate δ15N and δ18O in different locations of Xiaozhai area in May and October were measured, and the contribution rate of nitrate to nitrogen source was calculated by stable isotope analysis in R(SIAR). [Results]The nitrate δ15N and δ18O in different water bodies and different locations in Hani rice terrace system were significantly different, and the main water body displayed nitrification; in the main terrace area, with the decrease of altitude, the nitrate δ15N in surface water decreased, the soil water increased, and the changes of side channel water and river water were more complex. The nitrate source contribution rates of chemical fertilizer, sanitary sewage+ manure, soil nitrogen and atmospheric precipitation were 7.1%-26.7%,17.7%-29.7%,25.5%-36.7% and 20.1%-37.4% respectively by using SIAR model. The nitrate sources of forest water were mainly atmospheric precipitation and soil nitrogen, the main sources of field water were chemical fertilizer and sanitary sewage + manure in fertilization period, and the main sources of soil nitrogen and atmospheric precipitation in harvest period; the nitrate sources of forest water were mainly atmospheric precipitation and soil nitrogen. The main sources of water in fertilizing and harvesting period were soil nitrogen and sanitary sewage + manure; the downstream river water was mainly soil nitrogen, and chemical fertilizer was also the main source in May. [Conclusions]The application of sewage and manure increased the δ15N of nitrate in Hani rice terrace, and also migrated to the downstream river, but more of it was enriched in the soil; chemical fertilizer was the main nitrate source of Hani rice terrace migrating to the downstream river, and the nitrate transport in October was relatively less than that in May. Hani rice terrace showed the dual characteristics of nitrate source and sink. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Natural Resources / Ziran Ziyuan Xuebao is the property of Journal of Natural Resources and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The northern part of Zhangqiu district in Jinnan City has developed a thick sedimentary formation from the late Paleozoic to the Cenozoic. In this district, relatively well-developed fault structures and magmatic rocks provide good geothermal conditions. Abundant geothermal resources have been discovered in the study area, with three geothermal wells located near the fault zone. Therefore, establishing the genesis model of geothermal resources is significant for their future sustainable development and utilization. Based on hydrochemical and isotopic data of the study area, hydrochemical characteristics, water-rock interaction process, recharge source and formation age of geothermal water have been analyzed in this study. Besides, the elevation of the recharge area, thermal reservoir temperature, and depth of hot water circulation have also been calculated. Research findings show that geothermal water in the study area is composed of Cl·SO4-Na·Ca or SO4·Cl-Ca·Na, whose hydrochemical components mainly come from water-rock dissolution in the similar hydrogeochemical process. The source of water recharge is supplied by atmospheric precipitation, at an elevation from +563 m to +616 m. The 14C apparent age ranges from 5.55 ka to 29.71 ka. The geothermal water is mixed with modern water and ancient water. The chalcedony temperature scale shows that the temperature of geothermal reservoir is at 41.9-52.4 °, with the circulation depth of geothermal water at 622-1,565 m. The study area is a small-opened karst hot reservoir with deep circulation, during which geothermal water is heated up. Formation and enrichment of geothermal water are significantly controlled by fault structures. The geothermal reservoir is of stratified and banded type, belonging to geothermal resources at medium-low temperature. [ABSTRACT FROM AUTHOR]

The Swarm satellite is equipped with the Global Positioning System (GPS) receiver and ac⁃ celerometer, which can be used to restore Earth’s temporal gravity field model. Firstly, the terrestrial wa⁃ ter storage (TWS) variability and 2015-2016 drought induced TWS deficits in the Amazon basin are esti⁃ mated from the Swarm time ⁃ variable gravity field model between December 2013 and December 2016. Then, the estimated results from Swarm data are compared to the results derived from Gravity Recovery and Climate Experiment (GRACE), three hydrological models （Global Land Data Assimilation System (GLDAS)， Climate Predication Center (CPC)， National Centers for Environmental Prediction (NCEP)) and 4 virtual stations (AMZ_076， AMZ_152， AMZ_ 228 and AMZ_215). Finally, the precipitation and temperature data are employed to study the origination of the drought event in the Amazon basin. The re⁃ sults indicate that the TWS derived from Swarm, GRACE, hydrological models, and virtual stations are in high consistency in the space/time distribution; Swarm provided a new perspective in detecting TWS, which has a potential to substitute GRACE satellite in studying the extremely drought and flood in the Ama⁃ zon basin. The results in this paper may provide a reference in understanding Earth’s mass transformation by Swarm. [ABSTRACT FROM AUTHOR]

Typhoon precipitation is conspicuous in southeastern China, but little is known about the characteristics of the stable isotopes in these heavy rainfall events. It is thus highly needed to study the variation and controlling factors of the stable isotopes in extreme precipitation events. According to the meteorological data and stable isotope compositions of precipitation in Taipei and Fuzhou, the No. 21 Typhoon “Dujuan”led to landfall twice in Yilan County, Taiwan Province and Putian City, Fujian Province respectively, from September 28th to 29th, 2015. This paper analyzed the characteristic of stable isotopes in the precipitation of Typhoon “Dujuan”and the influence factors. During the period of Typhoon“Dujuan”, the δ18O varied from -3.4‰ to -15.0‰ with a fluctuation range of 11.6‰. The stable isotope compositions in the precipitation at the front and back in these two places are relative positive, and the average values vary from -4‰ to -6‰. The stable isotope composition of precipitation in the central area of these two places are most negative, and the average values are - 12.4‰ and -13.2‰, respectively. The stable isotope compositions of front-end and back-end precipitation in two places are relative positive and the water vapor is obviously affected by “evaporation effect”. The stable isotope composition of middle- end precipitation is mainly influenced by “cloudy and rainy area effect”, which has the most negative values. In the sharp rise process of the airflow in cloudy and rainy area of Typhoon, water vapor rapidly condensed and fell in supersaturated environment, and the effect of kinetic fractionation is small, so the δ18O is most negative. Characteristics of δ18O, deuterium excess and simulated vapor transport trajectories suggest that the water vapor source of precipitation with Typhoon “Dujuan”is the western Pacific Ocean. [ABSTRACT FROM AUTHOR]

In this paper, based on the climatic data of past years, the amino acid contents of 0. sinensis, polypide and stroma were measured with amino acid analyzer, and the amino acid contents of different parts of O. sinensis were comparatively studied. The result showed that the amino acid contents among O. sinensis, polypide and stroma had significant differences, meanwhile the ecological factor had a significant effect on O. sinensis. This research would provide a reference for the amino acid contents of O. sinensis by using the ecological factors. [ABSTRACT FROM AUTHOR]

Copyright of China Sciencepaper is the property of China Sciencepaper and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Taking the descriptive statistics, simple correlation and canonical correlation analysis as methods, this paper studied the relationship between major climatic factors and chemical compositions of flue-cured tobacco in Baoshan. The result indicated that CD climate in Baoshan was suitable for planting high-quality flue-cured tobacco. (2) the influences of climatic factors on tobacco leaf chemical composition were in the following order: temperature> precipitation>sunshine; protein contents, ratio of potassium to chlorine, reducing sugar and total N were obviously affected by meteorological parameter, and the weather in July had the greatest impact on chemical compositions. (3) tobacco leaf protein contents showed a significant negative correlation with sunshine hours in September, mean precipitation in July and August, and mean temperature in May, June and July; Reducing sugar was significantly negative correlated with mean precipitation in May, mean monthly temperature, while significant positive correlation with mean precipitation in July. The total N showed a significant negative relationship with mean temperature in May, sunshine hours in September and mean precipitation in July and August. The correlation of potassium ratio to chlorine was significantly positive with mean temperature in August and September, and significantly negative with sunshine hours in July. The influences of temperature and precipitation on tobacco leaf chemical compositions were: reducing sugar > total N > protein, and total N >reducing sugar >protein, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Natural Resources / Ziran Ziyuan Xuebao is the property of Journal of Natural Resources and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)