渠系水利用系数测算方法研究

根据渠道水入渗理论和渠道流量、损失量的试验数据,研究渠道水入渗的过程,分析入渗的影响因素,建立渠道水损失和渠系特征(渠系分布、渠道断面、设计流量)、渠床特征(衬砌类型、土壤质地、地下水埋深等)的关系。对原有输水损失系数经验公式进行改进,得出无论是Kostiakov经验公式计算还是积分改进公式计算,渠道流量与长度均与渠道损失流量成正相关关系。但是随着渠道长度的增加,Kostiakov经验公式体现出了不足,其计算结果与积分改进公式计算结果的相对误差逐渐增大。同时在江西省赣抚平原灌区采用动水测定法引入实测数据对改进的经验公式进行验证,验证结果表明改进经验公式法计算过程中采用某级渠道的灌溉水利用系数作为扩大指标来计算同级其他渠道流量不能真实反映整个渠系情况,较实际情况存在偏差,但改进经验公式求得的结果代表了渠道的现有衬砌状况,更为合理可靠。

Study on Calculation Method of Canal Water Utilization Coefficient

Based on the channel water infiltration theory and the experimental data of channel flow and loss,this paper studies the process of channel water infiltration,analyzes the influencing factors of infiltration,and establishes channel water loss and canal characteristics(canal distribution,channel section,design flow).The relationship between the characteristics of the canal bed(type of lining,soil texture,depth of groundwater,etc.),the empirical formula of the original water loss coefficient is improved,and it is concluded that both the Kostiakov empirical formula calculation and the integral improvement formula calculation,the channel flow rate and the length are It has a positive correlation with the channel loss flow,but with the increase of the channel length,the Kostiakov empirical formula shows a deficiency,and the relative error between the calculation result and the calculation result of the integral improvement formula is gradually increased.At the same time,the improved empirical formula was verified by using the measured data by using the dynamic water measurement method in the irrigation area of the Jiangxio Plain of Jiangxi Province.The verification results show that the irrigation water utilization coefficient of a certain channel is used as an expansion index in the calculation process of the improved empirical formula method.The flow of other channels can not truly reflect the whole channel system,which is different from the actual situation.However,the results obtained by the improved empirical formula represent the existing lining conditions of the channel,which is more reasonable and reliable.