Rainfall pattern impact on runoff and sediment of the sloping cropland in Northeast China

Rainfall isamajor contributor towater erosion ofsloping cropland inNortheast China. Identifying how rainfall and slope gradient (<i>S</i>) influence runoff depth (<i>RD</i>) and sediment yield (<i>SY</i>) iscrucial for preventing water erosion. Field measurements from runoff plots were collected from 2023 to2024, and <i>K</i>-means clustering was applied toclarify the rainfall patterns. Response of<i>RD</i> and <i>SY</i> tothe rainfall pattern and <i>S</i> were analysed. Key factors impacting <i>RD</i> and <i>SY</i> were explored. The results showed that three rainfall patterns were identified for 34 erosive rainfall events: A(41.2%, medium duration, medium rainfall intensity, and medium rainfall amount (<i>RA</i>)). B (50.0%, short duration, high rainfall intensity, and low <i>RA</i>) and C (5.4%, long duration, low rainfall intensity, high <i>RA</i>). Furthermore, the cumulative <i>RD</i> and <i>SY</i> increased with <i>S</i> for the same rainfall pattern. The cumulative <i>RD</i> and <i>SY</i> responded similarly torainfall patterns for the same <i>S</i>. The contribution ofthe rainfall pattern tothe cumulative <i>RD</i> and <i>SY</i> decreased inthe order ofC, A, and B. Inaddition, rainfall duration (<i>D</i>) and maximum 30-minute rainfall intensity were the key factors affecting <i>RD</i> and <i>SY</i> for rainfall pattern A, respectively. Rainfall erosivity (<i>R</i>) was the key factor affecting <i>RD</i> and <i>SY</i> for rainfall pattern B andC. <i>R</i>and <i>RD</i> were the dominant factors influencing the <i>RD</i> and <i>SY</i> for all rainfall events, respectively.