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| DOI：10.13522/j.cnki.ggps.2017.0541 |
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| Methods to Optimize Irrigation Furrows at District Scale: Taking Jinghui Irrigation District as an Example |
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NIE Weibo, DONG Shuxin, MA Xiaoyi
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Institute of Water Resources, Xi’an University of Technology, Xi’an 710048, China; College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling 712100, China
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| Abstract: |
| 【Objective】 We propose an optimization method to improve the design of irrigation furrows at district scale by taking Jinghui Irrigation District in Shaanxi province as a demonstrative example. 【Method】 The method was based on the remote-sensing digital images and numerical simulation to obtain the soil infiltration parameters under different soil textures and surface slopes first. We then used these data and the WinSRFR software to sketch the furrows at the irrigation district. 【Result】 ①The surface slope calculated by the proposed method agreed well with the measurements with a mean absolute relative error of 16.8%. The surface slope in the irrigation district was in the range of 2‰~4‰, consistent with the slope of the entire district and thereby proving the reliability of the proposed method. ②The infiltration parameters in the Kostiakov function calculated from the proposed method for soils with different textures changed from 0.916 to 1.675 cm/minα, and the infiltration index varied from 0.490 to 0.553, agreeing well with the values found in the literatures. ③Taking the irrigation performance index more than 80% as the limitation in optimizing the furrows in the district, we obtained rational furrow sizes and layout for different surface slopes and soil types under different irrigation techniques. Under different surface slopes for Lou soil, Loessal soil and Alluvial soils, the optimized furrow lengths were 50~130 m, 50~80 m and 40~80 m, and the widths were 4~8 m, 5~10 m and 6~10 m, respectively. In areas with small surface slope, furrows with short length and long width are preferred, while in areas with steep slope, furrows with long length and short width work better. 【Conclusion】 Comparing with available data in the literature proved that the proposed model is reliable and robust for helping design furrows in irrigation districts. |
| Key words: irrigation district scale; numerical simulation; soil texture; field slope; border patch size |
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