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Copyright of Research of Soil & Water Conservation is the property of Institute of Soil & Water Conservation, Chinese Academy of Sciences & Ministry of Water 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 Research of Soil & Water Conservation is the property of Institute of Soil & Water Conservation, Chinese Academy of Sciences & Ministry of Water 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 Research of Soil & Water Conservation is the property of Institute of Soil & Water Conservation, Chinese Academy of Sciences & Ministry of Water 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 Research of Soil & Water Conservation is the property of Institute of Soil & Water Conservation, Chinese Academy of Sciences & Ministry of Water 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.)

[Objective] The aims of this study are to investigate the spatial and temporal changes of runoff and sediment load in the Kuye River Basin, to quantify the contribution of climate change and human activities to variation of runoff and sediment load, and to provide scientific basis for the rational use of water resources and the optimal allocation of soil and water conservation measures in the Kuye River Basin. [Methods] Based on the runoff, sediment load and rainfall data of Xinmiao, Wangdaohengta, Shenmu and Wenjiachuan hydrological stations in Kuye River Basin from 1960 to 2020, the spatial and temporal variation characteristics of runoff and sediment load were analyzed by the linear trend method, Mann-Kendall trend test and Pettitt mutation test, and the double mass curve was used to quantitatively analyze the contribution rate of climate change and human activities to runoff and sediment load variation in different periods. [Results] Annual runoff and sediment load in the Kuye River Basin showed a significant decreasing trend from 1960 to 2020 (p<0.01). The runoff reduction rates of Xinmiao, Wangdaohengta, Shenmu and Wenjiachuan hydrological stations were 2.4 million m³/a, 3.4 million m³/a, 8.1 million m³/a, 10.6 million m³/a, the reduction rates of sediment load were 0.438 million t/a, 0.693 million t/a, 1.603 million t/a and 2.721 million t/a, respectively. The annual runoff and sediment load of each hydrological station changed abruptly both in 1979 and 1996, so the runoff and sediment load sequences could be divided into the reference period (1960-1979, P1) and the change period (1980-1996, P2;1997-2020, P3). During the study period, the average annual runoff depth and sediment load modulus of different sub-basins showed a decreasing trend, but there were differences in space. [Conclusion] The increasing human activities (water conservancy and soil conservation measures, coal mining, etc.) are the dominant factors on variation of runoff and sediment load in the Kuye River Basin. Compared with the base period, the runoff and sediment load of each hydrological station decreased in both P2 and P3 periods, and reduction was more intense in P3 period. In the P2 and P3 periods, the contribution of human activities to the reduction of runoff sediment transport was higher than that of rainfall changes. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality 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.)

Aggregate stability (MWD) is an important indicator of soil structure stability, and closely correlated to the processes of slope hydrology and soil erosion. Up to date, few studies are conducted to investigate the variation of MWD and influencing factors on the regional scale. In order to study the variation characteristics of MWD and influencing factors in the Loess Plateau, a 508 km long transect including seven sampling sites along the precipitation gradient was laid out in this study. The MWD of cropland, grassland and woodland on each sampling site were measured, in the meantime soil mechanical composition, bulk density, soil organic matter, root mass density and vegetation coverage of each sampling site were also measured. The results indicated that there existed significant (P<0.05) difference between the MWD of cropland and the MWD of grassland and woodland. Cropland had the largest mean MWD, followed by woodland; the cropland had the lowest mean MWD. The ratios of the mean MWD of grassland and woodland to the mean MWD of cropland were 2.94 and 2.39, respectively. The reason why the mean MWD of cropland was lowest could be explained by the fact that the lower soil organic matter and root mass density of cropland, and the disturbance of MWD induced by the frequent tillage operations. The MWD of cropland showed a decreasing trend from south to north along the precipitation gradient. The changing trends of the MWD of grassland and woodland were similar, which could be attributed to the similarity of the near surface characteristics (such as non-disturbance, high plant residue return) of grassland and woodland. The MWD of the Yijun was slightly lower than the MWD of Fuxian, and then the MWD of sampling sites showed a generally decreasing trend from Fuxian to Erdos. The MWD of cropland, and grassland and woodland were all influenced by soil organic matter, annual average precipitation and annual average temperature. In addition, there existed a significant (P<0.05) relationship between the MWD of cropland and soil mechanical composition, however the MWD of grassland and woodland were closely related to root mass density. The poor relationship between the MWD of cropland and root mass density were attributed to its low root mass density and frequent tillage operation. The fact that grassland and woodland had high soil organic matter and root mass density which masked the influence of soil mechanical composition well explained that no significant (P>0.05) relationship was found between the MWD of grassland and woodland and soil mechanical composition. The annual average precipitation and annual average temperature influenced the MWD of cropland, grassland and woodland by affecting root mass density and soil organic matter. No-linear regression demonstrated the MWD of cropland could be satisfactorily simulated by median soil grain size and annual average precipitation with the coefficients of determination (R2) of 0.95 and the Nash-Sutcliffe efficiency (NSE) of 0.99. The MWD of grassland and woodland could be simulated by soil organic matter, root mass density and annual average temperature. The simulated result of grassland and woodland was not as good as that of the cropland with the coefficients of determination (R2) of 0.64 and the Nash-Sutcliffe efficiency (NSE) of 0.64, which under-predicted low measured MWD and over-predicted high measured MWD. The results of this study will be of great significance in understanding the spatial variation of aggregate stability (MWD) along the precipitation gradient and its influencing factors, and analyzing the regional change law of hydrological and erosional processes. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology 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.)