Changes and new thoughts are vital if the farmland drainage method in the Huabei Plain is to be improved. In this article, drainage flow was chosen as the research object. Based on long-series precipitation data, the spatial distribution of precipitation was analysed. The peak value relation index (m) was either adjusted or unadjusted in contrast calculations with the empirical formula and the average draining formula. The adjustment rationality and adjustment range of m were researched. Results of calculations were analysed and used to improve the applicability of the empirical formula. The spatial distribution of precipitation showed a decreasing trend from south-west to north-east. Before adjustment, the result of the empirical formula was equivalent to the flow of 1 day of draining water. After adjusting m to 0.84–0.87, the result was equivalent to the flow of 1.5 days of draining water. With the decrease of rainfall frequency, the drainage flow of the average draining formula was greater than that of the empirical formula and the ratio was 1.13 times when the runoff depth was 50 mm. m can be selected from 0.84 to 0.87 for calculating drainage flow in the Huabei Plain by using the empirical formula and has a direct ratio with precipitation.

中文翻译：

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环境变化下淮北平原农田排水计算方法改进*

改善华北平原农田排水方式，变革和新思路至关重要。本文选择排水流量作为研究对象。基于长序列降水数据，分析了降水的空间分布。峰值关系指数（m）采用经验公式和平均排水公式进行对比计算，调整或不调整。m的调整合理性和调整范围进行了研究。对计算结果进行分析并用于提高经验公式的适用性。降水空间分布呈由西南向东北递减的趋势。调整前经验公式的结果相当于排水1天的流量。将m调整为0.84~0.87后，相当于排水1.5天的流量。随着降雨频率的降低，平均排水公式的排水流量大于经验公式的排水流量，当径流深度为50 mm时，该比为1.13倍。用经验公式计算华北平原的排水流量， m取0.84～0.87，与降水量成正比。