Flow in upland field drains for groundwater level control is considered as unsteady flow.
旱田田间排水沟的排水水流一般为非恒定流 ,一般采用复杂的迭代法计算这类排水沟的间距。
Aiming at inefficient of the traditional method of trial experience,this paper solved the non-linear optimization problem of field drainage engineering by using genetic algorithm(GA).
从田间排水系统的任务出发,分别介绍了田间排水沟的断面优化设计和间距优化设计方法,并运用遗传算法进行模型求解。
The formula is applied to calculate the optimized spacing of drainage ditches in field for two kinds of soil.
76m,潜水蒸发对排水沟间距有较大的影响。
Effect of Rainfall Runoff on Nitrogen and Phosphorus Loss in Farming Drainage Ditch
降水对农田排水沟渠中氮磷流失的影响
Interception and Removal Effection of Agriculture Drainage Ditch on Nitrogen and Phosphorus;
农田排水沟渠对流失氮、磷的截留和去除效应
Comparison on Removal of Nitrogen and Phosphorus form Hibernal Farmland Drainage by Three Kinds of Ditches
三种类型农田排水沟渠氮磷拦截效果比较
Further discussion on the calculation method of field drain spacing
对蒸发影响下农田排水沟（管）间距计算方法的探讨
Research on the Filtration System of Farmland Drainage Ditch Construction and the Embankment Material
农田排水沟道渗滤系统构建及护砌材料试验研究
The farmers dug ditches in the rain to lead away the flow.
农民们冒雨开沟排水。
In drainage of agricultural lands, a filter or gravel envelope is used to prevent the entrance of fine sand and silt into the drains.
在农田排水中常常采用砾石或过滤层来防止粉细砂和泥沙进入排水沟。
He made ditches in the fields to draw off the water.
他在田里挖了沟以便排水。
They were busy trenching the fields for draining.
他们忙着在田里开沟排水。
A drainage passage, as to a culvert.
排水沟排水通道，如阴沟
Study on Farmland Drainage Indices and Drainage Control Based upon Crop;
基于作物的农田排水指标及排水调控研究
Study on Farmland Drainage Index and Optimal Planning of Drainage Project;
农田排水指标与排水工程最优规模的研究
A gutter or groove in a roof.
排水天沟屋顶的槽或沟
Purification Efficiency of Agriculture Wastewater in Constructed Wetland;
人工湿地对农田排水净化效果的研究
Study of laws of nitrogen losses from farmland drainage in Zhanghe Irrigation District
漳河灌区农田排水氮素流失规律研究
Spatial Variability of Field Ditches Water Quality in the Mixed Area of Suburban Residents and Farmland
城郊居民农田混合区田间沟渠水质空间变异特征研究
A channel at the edge of a ship's deck to drain away water.
舷侧排水沟轮船甲板边上排水的沟
Investigation of Irrigated Water Qualities in Xinjiang Farmland and Discussion of Treatment Methods with It;
新疆农田灌溉排水水质调查和其处理方法探讨