降雨持续时间 meaning in English

duration of fall
duration of rainfall
rainfall duration

Laws about volumetric moisture content changes and wetting deformation in unsaturated zone are analysed according to different rainfall intensities and duration by saturated - unsaturated seepage theory in this text
摘要运用非饱和渗流理论分析了不同降雨强度和降雨持续时间对土坝非饱和区含水率变化规律。
The experiment indicated that the lower rainfall intensity treatment , lasting longer time , caused more losses amounts of runoff nitrogen than that under the high rainfall intensity with same total rainfall amount
试验还表明，在降雨量相同的条件下，降雨持续时间长的小雨引起的农田氮素径流流失量要超过降雨持续时间短的大雨。
The result shows soil masses in surface layer reach saturation more easily under great rainfall intensity and long - lasting rainfall , at the same time , there are big infiltration depth and influence of wetting deformation
结果显示，降雨强度越大、降雨持续时间越长，非饱和区土体含水率变化也大，坝坡表层土体较容易达到饱和，并且降雨影响深度也大，对坝坡表面湿化裂隙的产生及坝坡稳定性影响大。