沟灌土壤入渗参数和糙率估算及灌水技术要素组合研究

Estimation of infiltration parameters and manning roughness and research of optimized combination of technical elements for furrow irrigation

以SIPAR_ID模型为基础,利用水流推进资料估算了大田沟灌土壤入渗参数和糙率值,克服了以往采用水量平衡模型估算土壤入渗参数和糙率值时一些不合理的假设条件,且工作量大的缺点。用估算结果模拟了沟灌水流推进过程以及沟首水深数据,结果表明各试验点水流推进过程误差绝对值的均值分别为4.06%、4.57%和4.47%,沟首水深误差绝对值的均值分别为8.07%、10.26%和8.49%,说明采用SIPAR ID模型估算土壤入渗参数和糙率值是可行的,具有高的估算精度。根据估算的土壤入渗参数和糙率值,采用WinSRFR模型模拟了研究区域各试验点的沟灌灌水质量,提出了各试验点理论需水量分别为60 mm、80 mm和100 mm条件下合理的沟灌灌水技术要素组合,其灌水效率和灌水均匀度均在85%以上,表明可获得高的灌水质量,达到常规沟灌节水的目的。

Surface irrigation parameters identification parameters and Manning roughness according to the water were used to simulated water advance trajectory and water （SIPAR_ ID） model was employed to estimate the infiltration advance trajectory of furrow irrigation, and these parameters depth at the upstream end of furrow irrigation. The results showed that the mean error absolute values between simulated value and measured value of water advance trajectory were 4.06 %, 4.57 % and 4.47, and the mean error absolute values of water depth were 8.07 %, 10.26 % and 8.49 %, respectively. These indicated that it is reliable to use SIPAR_ ID model to estimate the infiltration parameters and Manning roughness, and it has a high accuracy. WinSRFR model was also employed to simulate furrow irrigation performance in every test site, and the result discovered that the theoretical irrigation reqirement of each test site was determined by the combination of reasonable irrigation technical elements under 60 mm, 80 mm and 100 mm depth, respectively. In this way both the irrigation efficiency and the distribution uniformity were over 85 %, which can be used to enhance the irriga- tion performance and attain the aim of saving water of furrow irrigation.