江苏里下河平原农田涝灾的情景模拟分析——以高邮灌区典型圩垸为例

为了分析环境改变后江苏里下河平原农田涝灾的变化特点,以高邮灌区某典型圩垸为例,利用构建的农田涝灾分布式模型模拟了不同暴雨强度、斗沟规模、外排条件、抽排能力和泵站调度规则等环境因子改变条件下的涝灾减产分布.结果表明:现状条件下,在遭遇5%暴雨时受涝面积比为10.47%,最大减产率为4.07%;遭遇2%和1%暴雨时,受涝面积比增至56.54%和86.87%,最大减产率增至10.32%和13.37%.若将斗沟深度由现状的1.3 m挖深至2.0 m,则可以使5%, 2%和1%暴雨条件的受灾面积分别减少14.73%,16.11%和3.91%,最大减产率分别降低5.16%,4.75%和3.81%.若将外河水位预降0.5 m,则可以使5%,2%和1%暴雨条件的受灾面积分别减少86.87%,13.62%和8.52%,最大减产率分别降低66.59%,40.60%和28.12%.若将泵站外排能力由现状的9 m³/s提高到14 m³/s,在遭遇5%暴雨时,受灾情况无变化;2%和1%暴雨条件下的受灾面积分别减少31.68%和11.52%,最大减产率分别降低31.10%和11.44%.单纯降低泵站启排水位而不同时降低外河闸的关闸警戒水位,对涝灾减轻效果几乎没有影响.

Scenarios analysis of field waterlogging in Lixiahe Plain,Jiangsu Province -case study of a typical polder in Gaoyou Irrigation District

In order to analyze the changing characteristics offield waterlogging in the Lixiahe Plain in Jiangsu Province after environmental changes, taking a typical polder in Gaoyou Irrigation District as an example, the waterlogging distribution and production reduction were simulated with a distributed model of field waterlogging under varying conditions of environmental factors such as rainstorm intensity, bucket scale, efflux conditions, pumping capacity, and pumping station scheduling rules, etc. The results show that under current conditions, the area affected by waterlogging in the study area will be 10.47% when 5% rainstorm is encountered, with 4.07% maximum yield reduction rate. However, when 2% and 1% rainstorms are encountered, the ratio of waterlogged area increases to 56.54% and 86.87%, and the maximum yield reduction rate increases to 10.32% and 13.37%. If the depth of the bucket ditch is dug from the current 1.3 m to 2.0 m, the area affected by 5%, 2%, and 1% rainstorm conditions can be reduced by 14.73%, 16.11%, and 3.91%, and the maximum yield reduction rate can be reduced by 5.16%, 4.75%, and 3.81%. If the water level of the outer river is pre-dropped by 0.5 m, the area affected by 5%, 2%, and 1% rainstorm conditions can be reduced by 86.87%, 13.62%, and 8.52%, and the maximum yield reduction rate can be reduced by 66.59%, 40.60%, and 28.12%. If the efflux capacity of the pumping station in the study area is increased from the current 9 m³/s to 14 m³/s, the situation remains unchanged when 5% rainstorm is encountered, while under 2% and 1% rainstorm conditions, the affected area can be reduced by 31.68% and 11.52%, and the maximum yield reduction rate can be reduced by 31.10% and 11.44%. Decreasing the drainage level valve of the pumping station without lowering the warning water level of the outer river has almost no impact on the flood mitigation effect.