Sediment particles,as one of the key components of drip irrigation technology,significantly affect the service life of emitters and restrict the popularization of drip irrigation technology.Hence,two types of patch dr...Sediment particles,as one of the key components of drip irrigation technology,significantly affect the service life of emitters and restrict the popularization of drip irrigation technology.Hence,two types of patch drip irrigation emitters,focusing on the anti-clogging performance through the experiment,were investigated.The dynamic variations in the clogging characteristics of emitters,specifically were subjected to statistical analysis.The movement mechanism of emitter clogging and discharging sediment was studied.The effects of emitter structure and position factors on emitter clogging were analyzed.The results show that the pressure-compensated emitter exhibits superior anti-clogging perfor-mance,with a service life that is 227.8%greater than that of the labyrinth channel emitter.A single structural factor cannot completely evaluate the anti-clogging performance of emitters.All factors causing emitter clogging should be considered comprehensively.Emitters contain sensitive sediment prone to clogging,however,significant blockage occurs primarily when the sediment content is elevated.The discharge of sediment,denoted as V90,from the emitter is affected by the accumulative effect of clogged sediment.These results may offer valuable insights for the application and advancement of drip irrigation technology.展开更多
The rapid identification of planting patterns for major crops in a large irrigated district has vital importance for irrigation management,water fee collection,and crop yield estimation.In this study,the OTSU algorith...The rapid identification of planting patterns for major crops in a large irrigated district has vital importance for irrigation management,water fee collection,and crop yield estimation.In this study,the OTSU algorithm and Mean-Shift algorithm were employed to automatically determine threshold values for mapping two main rotated crop patterns at the pixel scale.A time series analysis was conducted to extract the spatial distribution of rice-wheat and wheat-maize rotations in the Chuanhang irrigation district from 2016 to 2020.The results demonstrate that both threshold segmentation algorithms are reliable in extracting the spatial distribution of the crops,with an overall accuracy exceeding 80%.Additionally,both Kappa coefficients surpass 0.7,indicating better performance by OTSU method.Over the period from 2016 to 2020,the area occupied by rice-wheat rotation cropping ranged from 12500 to 14400 hm 2;whereas wheat-maize rotation cropping exhibited smaller and more variable areas ranging from 19730 to 34070 hm 2.These findings highlight how remote sensing-based approaches can provide reliable support for rapidly and accurately identifying the spatial distribution of main crop rotation patterns within a large irrigation district.展开更多
基金National Natural Science Foundation of China(52269011,52469008)。
文摘Sediment particles,as one of the key components of drip irrigation technology,significantly affect the service life of emitters and restrict the popularization of drip irrigation technology.Hence,two types of patch drip irrigation emitters,focusing on the anti-clogging performance through the experiment,were investigated.The dynamic variations in the clogging characteristics of emitters,specifically were subjected to statistical analysis.The movement mechanism of emitter clogging and discharging sediment was studied.The effects of emitter structure and position factors on emitter clogging were analyzed.The results show that the pressure-compensated emitter exhibits superior anti-clogging perfor-mance,with a service life that is 227.8%greater than that of the labyrinth channel emitter.A single structural factor cannot completely evaluate the anti-clogging performance of emitters.All factors causing emitter clogging should be considered comprehensively.Emitters contain sensitive sediment prone to clogging,however,significant blockage occurs primarily when the sediment content is elevated.The discharge of sediment,denoted as V90,from the emitter is affected by the accumulative effect of clogged sediment.These results may offer valuable insights for the application and advancement of drip irrigation technology.
基金Jiangsu Water Science and Technology Project(2021081)。
文摘The rapid identification of planting patterns for major crops in a large irrigated district has vital importance for irrigation management,water fee collection,and crop yield estimation.In this study,the OTSU algorithm and Mean-Shift algorithm were employed to automatically determine threshold values for mapping two main rotated crop patterns at the pixel scale.A time series analysis was conducted to extract the spatial distribution of rice-wheat and wheat-maize rotations in the Chuanhang irrigation district from 2016 to 2020.The results demonstrate that both threshold segmentation algorithms are reliable in extracting the spatial distribution of the crops,with an overall accuracy exceeding 80%.Additionally,both Kappa coefficients surpass 0.7,indicating better performance by OTSU method.Over the period from 2016 to 2020,the area occupied by rice-wheat rotation cropping ranged from 12500 to 14400 hm 2;whereas wheat-maize rotation cropping exhibited smaller and more variable areas ranging from 19730 to 34070 hm 2.These findings highlight how remote sensing-based approaches can provide reliable support for rapidly and accurately identifying the spatial distribution of main crop rotation patterns within a large irrigation district.
