Sea Level Rise Affecting the Vietnamese Mekong Delta: Water Elevation in the Flood Season and Implications for Rice Production
Sea Level Rise Affecting the Vietnamese Mekong Delta: Water Elevation in the Flood Season and Implications for Rice Production
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DOI：
10.1023/b:clim.0000043144.69736.b7
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发表时间：
2004-07
期刊：
影响因子：
4.8
通讯作者：
R. Wassmann;N. X. Hiền;C. T. Hoanh;T. Tuong
中科院分区：
文献类型：
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作者：
R. Wassmann;N. X. Hiền;C. T. Hoanh;T. Tuong
在这项研究中，我们评估了海平面上升的影响，全球气候变化的最确定的后果之一，越南湄公河三角洲（VMD）的水位。我们使用水力模型计算了8月至11月的水位-洪水目前是关键的-分别在海平面上升20 cm（=Δ 20）和45 cm（=Δ 45）的情况下。结果显示，由于海平面上升，水位等高线将向海方向移动25 km（Δ 20）和50 km（Δ 45）。在汛期（8月）开始时，三角洲水位的平均增量分别为14.1 cm（Δ 20）和32.2 cm（Δ 45）。在汛期高峰期（10月），上游的高流量衰减了水位的增量，但平均水位分别上升11.9 cm（Δ 20）和27.4 cm（Δ 45），仍然意味着VMD的洪水问题严重恶化。利用地理信息系统技术划定了脆弱程度不同的地区，由于海平面上升，脆弱性高（230万公顷= VMD的60%）、中等（60万公顷= 15%）和低（100万公顷=25%）的地区。水稻生产将受到潮汐淹没地区过度洪水和VMD中部洪水期延长的影响。除非采取预防措施，否则这些不利影响可能影响VMD的所有三个种植季节，Mua（主要作物），Dong Xuan（冬-春）和He Thu（夏-秋）。
In this study, we assessed the impact of sea level rise, one of the most ascertained consequences of global climate change, for water levels in the Vietnamese Mekong Delta (VMD). We used a hydraulic model to compute water levels from August to November - when flooding is presently critical- under sea level rise scenarios of 20 cm (=Δ 20) and 45 cm (=Δ 45), respectively. The outputs show that the contour lines of water levels will be shifted up to 25 km (Δ 20) and 50 km (Δ 45) towards the sea due to higher sea levels. At the onset of the flood season (August), the average increment in water levels in the Delta is 14.1 cm (Δ 20) and 32.2 cm (Δ 45), respectively. At the peak of the flood season (October), high discharge from upstream attenuates the increment in water level, but average water level rise of 11.9 cm (Δ 20) and 27.4 cm (Δ 45), respectively, still imply a substantial aggravation of flooding problems in the VMD. GIS techniques were used to delineate areas with different levels of vulnerability, i.e., area with high (2.3 mio ha =60% of the VMD), medium (0.6 mio ha = 15%) and low (1 mio ha =25%) vulnerability due to sea level rise. Rice production will be affected through excessive flooding in the tidally inundated areas and longer flooding periods in the central part of the VMD. These adverse impacts could affect all three cropping seasons, Mua (main rainfed crop), Dong Xuan (Winter-Spring) and He Thu (Summer-Autumn) in the VMD unless preventive measures are taken.