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Copyright of Journal of Remote Sensing is the property of Editorial Office of Journal of Remote Sensing & Science Publishing Co. 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 Yellow River is the property of Editorial Board of Yellow River 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.)

[Objective]Water use efficiency (WUE) and the factors affecting its spatiotemporal variation are important in water management at catchment scale. The objective of this paper is to analyze the variations of WUE and its determinants in the source region of Yellow River (SRYR).[Method]The analysis was based on MODIS remote sensing data, from which we estimated the ecosystem WUE from 2000 to 2014 and its spatiotemporal variation, as well as the underlying drivers using trend analysis and correlation analysis.[Result]Spatially, the mean annual WUE increased from the west to the east, with an average of (0.59±0.35) gC/(m² •mm) from 2000 to 2014. Temporally, WUE did not show any decreasing or increasing trend (p>0.05). The areas that have seen a significant increase in WUE account for 30.29% of the studied region, distributing mainly in the west and north of SRYR. Areas with low and medium vegetation coverage are dominated by grassland and farmland. Spatial variation of WUE was mainly affected by hydrothermal factors and leaf area index. [Conclusion]In the context of mediating the detrimental effects of climate warming and flooding, improving vegetation in areas with low and medium vegetation coverage is expected to enhance WUE significantly. [ABSTRACT FROM AUTHOR]

Copyright of China Rural Water & Hydropower is the property of China Rural Water & Hydropower 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 Railway Construction Technology is the property of Railway Construction Technology 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 Food Research & Development is the property of Food Research & Development Editorial Department 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 China Rural Water & Hydropower is the property of China Rural Water & Hydropower 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 Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering 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 Water Conservancy Science & Techonlogy & Economy is the property of Water Conservancy Science & Technology & Economy 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 China Rural Water & Hydropower is the property of China Rural Water & Hydropower 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 Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science 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 China Rural Water & Hydropower is the property of China Rural Water & Hydropower 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 Chinese Journal of Geological Hazard & Control is the property of China Institute of Geological Environmental Monitoring (CIGEM) Editorial Department 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: The spaceborne global navigation satellite system-reflectometry (GNSS-R) technology has been extensively employed in monitoring surface hydrology in recent years. However, research on the key factor of precipitation in the surface hydrological cycle, especially its spatiotemporal relationship with cyclone global navigation satellite system (CYGNSS) signals, remains limited. Therefore, this paper conducts a detailed and comprehensive analysis of the direct relationship between CYGNSS reflectivity and precipitation, taking into account multiple influencing factors and scale effects. Methods: This study utilizes monthly CYGNSS data and precipitation data from 2019 to 2020, taking Guangdong Province, China as the study area. It analyzes the spatiotemporal response relationship between CYGNSS signals and precipitation, while comprehensively considering the influence of different driving factors such as digital elevation model (DEM), slope, land cover type, soil type, and normalized difference vegetation index (NDVI) on the CYGNSS signal-precipitation response. The study also explores scale effects, and uses a factor detector model in the geographical detector to investigate the degree of influence of each driving factor. Results: From 2019 to 2020, the monthly average CYGNSS reflectivity and precipitation show significant seasonal differences and nearly synchronous variations, validating the potential of CYGNSS signals for precipitation monitoring. The positive correlation between CYGNSS signals and precipitation strengthens with increasing spatial scale. For example, at small scale (1 km), the positive correlation between CYGNSS signals and precipitation is 21.00% (significant at the 0.05 level), while at medium scale (3 km) and large scale (9 km), it reaches 26.84% and 40.36% respectively, highlighting the advantage of CYGNSS in monitoring precipitation at larger scales. Additionally, the study found that at different spatial scales, regions with lower DEM and slope (indicating relatively flat terrain), areas with land cover type of cropland, and regions with lower to moderate vegetation coverage exhibited a stronger positive correlation between CYGNSS signals and precipitation. However, the influence of soil type on the relationship between CYGNSS signals and precipitation response varied across different scales. The driving factors 􀆳 influence on the relationship between CYGNSS signals and precipitation is ranked as follows: DEM>NDVI>slope>land cover type>soil type, and their influence becomes stronger with increasing scale. Conclusions: This study elaborates on the response relationship between CYGNSS signals and regional precipitation, providing useful references for further utilizing GNSS-R technology to monitor precipitation and facilitating accurate assessment of surface hydrological changes. The results demonstrate that certain spatiotemporal response relationships exist between CYGNSS signals and precipitation across different scales, and various driving factors have certain influences on their response relationships. [ABSTRACT FROM AUTHOR]

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 China Rural Water & Hydropower is the property of China Rural Water & Hydropower 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 Pearl River is the property of Pearl River 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.)

In order to scientifically predict the future sediment load of the Yellow River, support the Yellow River harnessing and development and major project construction and based on the analysis of the characteristics and causes of the variation of water and sediment in the near future, this paper used the hydrological method and the genetic analysis method to predict the future sediment amount of the Yellow River, at the same time, the large flow duration and the water volume which were beneficial to sediment transport were greatly reduced, the dynamics of flow and sediment transport were greatly weakened, and the relationship between water and sediment was still not coordinated. Without considering the sediment retention of the Xiaolangdi Reservoir, the downstream channel would still be silted up. It is considered that the main influencing factors of the recent sediment reduction are the massive construction of water conservancy and soil and water conservation measures and the reduction of rainfall intensity, which account for 80% and 20% respectively, taking into account the existing research results and the uncertainty of the forecast, it is suggested that the average annual sediment hydraulic engineering of the Yellow River in the future should be about 800 million tons. [ABSTRACT FROM AUTHOR]

Copyright of Journal of the Chinese Society of Rare Earths is the property of Editorial Department of Journal of the Chinese Society of Rare Earths 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.)

To explore the characteristics of the evolution of water resources in the Yellow River Basin, information entropy, CEEMDAN, and Copula theories are used to study the temporal and spatial evolution of precipitation in the Yellow River Basin from 1960 to 2017. It is found that, ① In the past 50 years, the precipitation in the Yellow River Basin as a whole has shown a downward trend, but the precipitation in the source area is increasing slowly; ② After 2002, the Spatiotemporal information entropy of precipitation in the Yellow River Basin declined and complexity decreased. ③ CEEMDAN decomposition results show that the observation and research on precipitation in the Yellow River Basin should be mainly focused on the short cycle of 2~4 years, RES balance reflects the overall decline of precipitation sequence but gradually recovered in recent years; ④ Through the Gumbel-Copula function, it is found that the combined distribution of annual and flood season precipitation in the Yellow River Basin at different stages is mainly abundant and dry, and the probability of synchronization increases after the mutation. This paper studies the spatiotemporal characteristics of precipitation in the Yellow River Basin at different stages, which helps to further understand and grasp the characteristics of the water circulation in the Yellow River Basin, and then provide support for the ecological protection and high-quality development of the Yellow River Basin. [ABSTRACT FROM AUTHOR]

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 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.)

(Background) Precipitation is closely related to human production, life and ecology. The change of precipitation is related to the sustainable utilization of regional water resources, the protection of ecological environment and the development of economy and society, The research on the variation characteristics and evolution trend of precipitation has become a hot topic in the field of climate and water resources. Scholars and researchers has paid much attention on the accurate prediction of precipitation. (Objective) The purpose of this paper is to improve the prediction accuracy of precipitation, and reflect the actual characteristics of precipitation. (Method) Based on the advantages of empirical mode decomposition in the analysis and processing of nonlinear time series and other fields, Empirical Mode Decomposition (EMD) was carried out for the monthly average precipitation data of the Yellow River Delta Meteorological Station from 1954 to 2018, and a series of eigenmode functions were obtained. Hilbert transform was performed on IMF, and on this basis, two multi-scale forecast models of precipitation in the Yellow River Delta were established. (Result) The results showed that there were periods of 9, 13, 23, 76 and 135 months in precipitation in the Yellow River Delta, and 9-month fluctuations were the main ones; The 65-year monthly average precipitation data was predicted. The relative error of the model 1 was between 0.9% and 9.8%, and the relative error of the model 2 was between 1.6% and 11.8%. When modeling, the average prediction error of model 1 without considering the initial phase was 2.70%, and the overall prediction accuracy was better than that of model 2 considering the initial phase. (Conclusion)The fitting accuracy and significance of the two models meet the requirements. [ABSTRACT FROM AUTHOR]

Copyright of Journal of the Chinese Society of Rare Earths is the property of Editorial Department of Journal of the Chinese Society of Rare Earths 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 Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica 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 Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research 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 Yellow River is the property of Editorial Board of Yellow River 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 Guangxi Normal University - Natural Science Edition is the property of Gai Kan Bian Wei Hui 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 Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering 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 present paper aimed to study the effect of meteorological characteristics on the safety of power grid in plateau area. 【Method】In this paper, the reanalysis data(0.125°×0.125°) provided by ECMWF were analyzed in the plateau area, including precipitation, temperature and snow depth. 【Result】The precipitation in summer was obviously higher than the other seasons. There were more precipitation in Shannan area, with an average annual occurrence of 14 extreme precipitation.The temperature of Qinghai-Tibet plateau dropped sharply in winter. The lowest temperature in Lhasa was-14 °C, and the temperature in Changdu was below-6 °C, such cold weather might cause freezing disasters, and there might be ice cover accidents on transmission lines. The variation trend of snow depth on the Tibetan plateau was single peak and it was obviously higher than other seasons in spring and winter. Shannan was a large snowfall area in spring, and its snow depth decreased obviously in summer and autumn. The snowy area in winter enlarged, both Shannan and Linzhi were in the high snowfall area, and the frequency of extreme snowfall events was high. 【Conclusion】We should focus on the characteristics of snow depth in spring and winter in central and Eastern Tibet to prevent the threat to the power grid caused by snow. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering 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 Pearl River is the property of Pearl River 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 Acta Geoscientica Sinica is the property of Acta Geoscientica Sinica 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 Engineering Geology / Gongcheng Dizhi Xuebao is the property of Journal of Engineering Geology 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 Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering 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 Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research 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.)

[Objective] The present paper aimed to provide a scientific reference for drought prevention and disaster avoidance of sugarcane production, the temporal and spatial characteristics of sugarcane drought in different growth period in Guangxi were analyzed in recent 60 years. [Method] Firstly the development period of sugarcane, soil data and meteorological data from 1961 to 2020 in Guangxi were collected for the study. Under major concentration for effectiveness of precipitation and dynamic change characteristics of crop coeffi cient, the temporal and spatial variation characteristics of sugarcane drought in growth period were analyzed by linear and periodic analysis method and spatial station technology basing on crop water deficit index. [Result] The interannual drought incidence was the highest in maturity stage, followed by stem elongation stage, and the least in seedling stage and in tillering stage. Light and medium drought are mainly in seedling stage, tillering stage and stem elongation stage. Heavy and extreme drought are mainly in maturity stage. During the study period, there was no obvious linear change trend in the interannual drought incidence at all levels and with a periodic change on the scale of 2 - 5 years. The years of occurrence were mainly in 1970s and 1980s. In terms of spatial distribution, in the seedling stage light drought and medium drought were mainly distributed in the west and south of Guangxi. The occurrence frequency of light drought was less than 40%. The occurrence frequency of medium drought was less than 30 % . The occurrence frequency of heavy drought was less than 10 % and its distribution range was small. In the tillering stage, light drought occurred in all over the region. The occurrence frequency in the southwest of Guangxi was the highest, generally between 21 % and 40%. Medium drought was mainly distributed in the southwest of Guangxi and the occurrence frequency was less than 10% . The occurrence frequency of severe drought was less than 10 % and its distribution range was small. In the stem elongation stage, mild drought was distributed in the whole region with the occurrence frequency between 11 % and 70%. Medium drought was mainly distributed in the northeast of Guangxi with the occurrence frequency between 21 % and 60%. Heavy drought was mainly distributed in the northeast of Guangxi with the occurrence frequency less than 20%. There was no extreme drought in the seedling stage, tillering stage and stem elongation stage during the study period. In the maturity stage, light drought, medium drought, heavy drought and extreme drought were distributed in whole study region. The occurrence frequency of light drought was less than 30%. The occurrence frequency of medium drought and severe drought were less than 40%. The occurrence frequency of extreme drought was the most and its distribution was wide. The regions with high extreme drought occurrence frequency were mainly distributed in the center, south and east of Guangxi with the occurrence frequency between 31 % and 50%. [Conclusion] The light and medium drought are the main drought in the seedling stage, tillering stage and stem elongation stage of sugarcane in Guangxi during the sugarcane development. The heavy and extreme drought is the main drought in the maturity stage. In the maturity stage of sugarcane, the heavy and extreme drought occur once every 2 - 3 years in the center, south and east of Guangxi. The regions above should be get more attention for drought prevention and disaster avoidance. [ABSTRACT FROM AUTHOR]

Under the background of changing global environment and frequent anthropogenic activities, rainfall-runoff relationship has suffered tremendous change in many regions of China, particularly in arid and semi-arid regions. The Jinghe River basin (JRB) in the middle of the Loess Plateau, which is the major base of grain production in Shannxi Province, has experienced significant changes in hydro-climatic variables and the relationship between them during the past decades, causing many water resources problems. In this paper, we focused on analyzing the variation characteristics of rainfall-runoff relationship in JRB, and quantitatively assessing the effects of climate changes and human activities on the runoff reduction. It was of great importance for mastering the evolution of hydrological cycle, water resources planning and management, and water and soil conservation in JRB. The monthly rainfall and runoff data were used in the study and summed annually to investigate the variation characteristics in 1960-2010. To detect the change points of rainfall-runoff relationship, the sliding partial correlation coefficients method was proposed and the change points were further confirmed by the double mass curve method. On the basis of the studies, the relative changes of rainfall, runoff, and rainfall-runoff relationship were analyzed around the change points. Moreover, we also introduced the Archimedean Copula function, from the perspective of probability, to analyze the probability of synchronous-asynchronous encounter of rainfall and runoff in JRB. What caused the variation of rainfall-runoff relationship? Climate change or human activities? To figure out this, the method of slope change ratio of cumulative quantity (SCRCQ) was adopted in this paper. According to these results, we obtained the following conclusions: (i) Annual runoff and rainfall presented wavelike decrease change. Nevertheless, annual runoff declined more greatly than rainfall; especially, in some periods annual rainfall increased, however, runoff decreased. This illustrated that some non-rainfall factors caused the occurrence of phenomenon in JRB; (ii) Change points of rainfall-runoff relationship occurred in 1996 validated by the sliding partial correlation coefficients method and double mass curve method. Meanwhile, we could ascertain the conclusion by the evidence of the process of human activities in JRB, which presented the increasing industrial, agricultural and domestic water consumption and large-scale water conservancy and soil conservation projects since 1990s; (iii) To compare the magnitude of the changes of rainfall, runoff and rainfall-runoff relationship, the hydrological variables series were divided into the periods of 1960-1996 and 1997-2010. Compared to runoff and rainfall in 1960-1996, the annual mean runoff and rainfall in 1997-2010 dropped 43.47% and 6.64%, respectively. The change of monthly rainfall had no significance in different periods. On the contrary, monthly runoff decreased more greatly and the difference was smaller in each month i.e. the runoff distribution for each month was more uniform. The correlation between rainfall and runoff diminished and runoff yield decreased under the same rainfall. When precipitation was above 400 mm, the relative change rate of runoff was above 40% in 1997-2010 compared to that in 1960-1996; (iv) The joint distributions of rainfall and runoff constructed by the Archimedean Copula function were different in 1960-1996 and 1997-2010, and the distributions in the 2 periods were fitting Clayton and Gumbel-Hougaard Copula better, respectively. The probabilities of synchronous-asynchronous encounter of the same rainfall and runoff changed strikingly in different periods. For instance, when rainfall was less than 550 mm and runoff was less than 40 mm, the probability of synchronous-asynchronous encounter was 44% in 1960-1996 and 73% in 1997-2010; (v) In JRB, human activities, i.e. non-rainfall factors, have played a fundamental role in rainfall-runoff relationship change. Further compared with some research results, the irrigation, the construction of reservoirs and the water-and-soil conservation measures in the region should be responsible for the change to a large extent. Compared to the period of 1960-1996, the contribution from human activities in the period of 1997-2010 reached about 81% and climate change was merely around 19% obtained by the method of SCRCQ. The research results can provide theoretical basis for water resource management and water and soil conservation for the administrators. [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 Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering 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.)

With the continuous warming of the global climate, the ecological environment and water resources in the Yangtze River Basin are apt to be affected. The analysis and study of the future precipitation change trend in the region will help to provide a theoretical basis for water resources management and ecological protection in the Yangtze River Basin. Based on the observed precipitation data and precipitation data output from 13 global climate models of the Sixth International Coupled Model Comparison Program (CMIP6) with bias correction, this paper evaluates the precipitation simulation ability of climate models in the Yangtze River Basin from 1995 to 2014. The temporal and spatial variation trends of precipitation in 2021-2040 (near term), 2041-2070 (middle term), and 2071-2100 (long term) are analyzed under four SSP scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5). The results show that: ① The model data with bias correction can simulate the characteristics of precipitation well in the Yangtze River Basin on the spatial and temporal scale, which is close to the observed values. ② The annual precipitation in the Yangtze River Basin will increase significantly with the increase in the radiation forcing level. Compared with the historical period (1995-2014), the annual precipitation growth in each scenario is relatively flat in the near term, and the precipitation growth is the largest in the long term. In general, seasonal precipitation shows the largest increase in winter, and the increase in spring and summer precipitation is relatively gentle. In autumn, except for the negative value of the precipitation change rate in the near term under the scenario SSP3-7.0, the other scenarios and periods are slowly increasing with lower change rates. ③ Spatially, the regions with larger annual precipitation increase are concentrated on the source region of the Yangtze River and the middle and upper reaches of the Yangtze River with relatively less precipitation. The high value center of spring precipitation increase is in the source area and the north of the middle and upper reaches, while the precipitation change rate is low in the south of the basin. The precipitation increment in summer and autumn is relatively low, and the near term and middle-term precipitation in the northern part of the middle and upper reaches is lower than that in the historical period. In winter, the precipitation in the whole basin has increased, which shows that the precipitation change rate in the north of the Yangtze River Basin is the largest, and it is smaller in the south. [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 Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering 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.)

Urbanization is an extensive and complicated human activity all over the world. Presently, it is a consensus that urbanization could exert certain impact on local precipitation. However, owning to the complexity of precipitation formation and distribution in different regions, as well as the limitation of metrological observation and numerical simulation models, there are different views on the physical mechanisms and driving factors about urbanization influencing rainfall. In addition, disputes continue on the phenomenon and traits of urban influencing rainfall. Hence, this paper reviews the main mechanisms of urban effects on rainfall. Then, observation analysis and numerical simulation of urbanization impact on precipitation are retrospected. For the former, main results are summarized and compared for studies both based on surface gauge observations and remote sensing data. For the latter, urbanization influence on precipitation are summarized both for single factor and compound factors. Finally, main problems requiring deep exploration in future are recommended from five aspects, i. e. the integrated observation of urban meteorology, the comprehensive detection of urbanization precipitation effects, the refined simulation of urbanization impact on precipitation and the adaptation and regulation measures. This paper is conducive to deepening the understanding of urbanization effect on precipitation. Additionally, it provides valuable references for the adaption and regulation of the negative change of precipitation caused by urbanization. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering 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 Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering 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.)