| Cite this article: | 化骞寂,冯绍元,葛洲,等.河套灌区典型区周年内耕层土壤盐分时空变异研究[J].灌溉排水学报,0,():-. |
| HUA Qianji,FENG Shaoyuan,GE Zhou,et al.河套灌区典型区周年内耕层土壤盐分时空变异研究[J].灌溉排水学报,0,():-. |
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| Analyzing spatiotemporal characteristics of Plough layer soil salinity in typical area of Hetao Irrigation Distric all year round |
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HUA Qianji, FENG Shaoyuan, GE Zhou, XU Ying
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College of Hydraulic Science and Engineering,Yangzhou University
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| Abstract: |
| 【Background】Soil salinization is the important reason of land degradation and seriously threatens agricultural sustainability. It also makes agro-ecological systerm more vulnerable or worse in arid and semi-arid regions like Hetao irrigation distric in Inner Mongolia. Hetao irrigation distric is a typical irrgted area of soil salinization of north China with shallow groundwater, scarce precipitation and intensive evaporation. It is necessary to understand spatial and temporal distributions of soil salinity for controling soil salinization of the irrigation distric.【Objective】This paper aims to study the spatiotemporal variation law of Plough layer soil salt and analyze its salinization risk in typical area of Hetao Irrigation Distric all year round.【Methods】The spatial variability of the Plough layer soil salt in the study area from the autumn of 2018 to the autumn of 2019 was analyzed by geostatistics and descriptive statistics all year round (from the autumn of 2018 to the autumn of 2019). The probability distribution map of soil salt was obtained by interpolating the observed data using the indicator Kriging method, and the distribution law was analyzed.【Results】①In all periods, the soil salt content was 0~10 cm>10~20 cm>20~40 cm. Salt of soil layers in cultivated land was accumulated gradually during summer irrigation, and soil salt content change of the natural land was very small before the third irrigation, and then salt accumulation speed increased rapidly. From 20~40 cm to 0~10 cm, salt accumulation speed also increased rapidly both in the cultivated land and natural land. And salt accumulation speed of the natural land was greater than of the cultivated land.In all period, the soil salinity variation of 0~10 cm soil layer is almost strong, while that of 10~20 cm and 20~40 cm soil layer is medium, and the coefficient of variation of soil salinity of wasteland is almost greater than that of cultivated land.②The semivariance model of soil salt at the depth of 0~40cm in all periods can be fitted with spherical model, and the range was 1104-1994. Soil salt belonged to moderate spatial autocorrelation, and the spatial structure before the autumn irrigation was slightly stronger than that of other periods.③In the 2019, the area of high-risk section of soil salinization increased gradually (the area of high-risk section with soil salt content greater than 1 g?kg-1 increased from 26% to 90%), and the areas increased faster from the first irrigation to the second irrigation and from the third irrigation to the fifth irrigation.【Conclusion】Soil salinity accumulation in surface layer in all periods was obvious and soil salinity was accumulated gradually during the whole summer irrigation. The effectiveness of dry drainage in soil salinity control was significant. The spatial structure of soil salt in the study area had little change from the first irrigation to the fifth irrigation.The distribution pattern of salinization in different periods of the same year was similar, but the degree of salt accumulation and salinization area increase gradually with time, which showed it is more important to desalinize by irrigating in autumn under the condition of water-saving irrigation. |
| Key words: soil salinity; hetao irrigation distric; analysis of salinization risk; indicator Kriging |
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