论文部分内容阅读
洪水脉冲是表征湄公河水文特征,促进湄公河下游包括柬埔寨湿地和越南湄公河三角洲在内的洪泛平原具有高生态生产力的关键因素。就改变的流域水量平衡和海平面上升两个方面,评估了气候变化对湄公河下游洪水脉冲的影响,影响结果由三维水动力学模型模拟生成,模型所使用的边界条件是气候变化影响下设计的海平面变化和湄公河下游主河槽的流量变化。模型模拟结果是预计2010~2049年湄公河下游平均水位和最高水位将提高,以及洪水历时将延长。模拟显示相当一致和变化显著的情况发生在平常水文年和干旱水文年。海平面上升对湄公河三角洲的影响最大,而流域水量平衡的改变对湄公河洪泛平原的上游区影响更加明显一些。预测的影响大多与区域水利基础设施建设造成的结果相对立,因为水位更高,历时更长的洪水会毁坏庄稼、基础设施和行洪区植被,并且会减少肥沃土地的面积。另一方面,洪水还可能会促进生态系统的生产力,增加干旱季节获得水的可能性。
Flood pulses are a key factor in characterizing the Mekong’s hydrological characteristics and promoting high ecological productivity in flood plains, including the Cambodian wetlands and the Mekong Delta in Vietnam, in the lower Mekong. The impacts of climate change on flood pulses in the lower Mekong are assessed in terms of changing water balance and sea level rise in the basin. The impact results are modeled by a three-dimensional hydrodynamic model. The boundary conditions used in the model are those designed under the influence of climate change Sea level changes and changes in the main channel of the lower Mekong. The model simulation results show that the average and maximum water levels in the lower Mekong River from 2010 to 2049 are expected to increase, and flood duration will be extended. The simulations show a fairly consistent and dramatic change in the normal and arid hydrological years. The sea level rise has the greatest impact on the Mekong Delta, while changes in the water balance in the basin have had a more pronounced impact on the upper reaches of the floodplain in the Mekong. The effects of projections are largely opposed to the results of regional water infrastructure construction, as higher water levels and longer-lasting floods can destroy crops, infrastructure and floodplain vegetation and reduce the area of fertile land. On the other hand, floods may also promote ecosystem productivity and increase the likelihood of access to water during the dry season.