The effect of Ganges river basin irrigation on pre-monsoon rainfall
The effect of Ganges river basin irrigation on pre-monsoon rainfall
复制标题
恒河流域灌溉对季风前降水的影响
DOI：
10.1002/qj.4218
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发表时间：
2021
影响因子：
8.9
通讯作者：
Fletcher J
中科院分区：
文献类型：
--
作者：
Fletcher J
第一个实验研究灌溉对印度季风前降雨的影响，使用高分辨率对流允许模型已经进行。这项研究包括短期（3天）实验和长达一个月的自由运行模拟，可以调查灌溉对中尺度环流和相关降雨的影响。在季风前，我们发现灌溉增加了我们模拟的降雨。有趣的是，在高分辨率模型中发现的降雨量增加主要发生在灌溉附近的山上，而不是灌溉区域本身。这是因为我们应用的灌溉是在低洼地区，因此它增强了山谷流动，从而增强了日驱动的地形降雨。由于恒河流域灌溉发生在世界上降雨率最高的山脉附近，并且容易发生山洪和山体滑坡，这对季风前和季风早期山区的灾害具有重大影响。
The first experiment studying the effect of irrigation on pre‐monsoon rainfall in India using a high‐resolution convection‐permitting model has been carried out. This study includes both short (3‐day) experiments and month‐long free‐running simulations, enabling investigation of the effect of irrigation on mesoscale circulations and associated rainfall.In the pre‐monsoon, it is found that irrigation increases rainfall in our simulations. Intriguingly, the rainfall increase found in the high‐resolution model mostly occurs on the mountains near the irrigation rather than over the irrigated region itself. This is because our applied irrigation is in low‐lying regions, and so it enhances the mountain‐valley flows leading to enhancement of diurnally driven orographic rainfall. Because Ganges basin irrigation occurs near mountains which already have some of the highest rainfall rates in the world, and which are subject to flash flooding and landslides, this has significant implications for hazards in mountainous regions during the pre‐monsoon and early monsoon period.