Sensitivity of Salinity Intrusion to Sea Level Rise and River Flow Change in Vietnamese Mekong Delta-Impacts on Availability of Irrigation Water for Rice Cropping
Sensitivity of Salinity Intrusion to Sea Level Rise and River Flow Change in Vietnamese Mekong Delta-Impacts on Availability of Irrigation Water for Rice Cropping
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DOI：
10.2480/agrmet.64.3.4
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发表时间：
2008-09-01
影响因子：
1.3
通讯作者：
Yokozawa, Masayuki
中科院分区：
文献类型：
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作者：
Khang, Nguyen Duy;Kotera, Akihiko;Yokozawa, Masayuki
在这项研究中，海平面上升和减少的麦公河流量在旱季的盐度入侵和水稻种植在越南湄公河三角洲的综合影响进行了评估。MIKEII模型使用SRES B2气候变化预测的数据，模拟了12月至6月的中期（2030年代中期）和长期（2090年代中期）情景的流量和盐度入侵。两种情景下的海平面上升值分别为+20 cm和+45 cm，而湄公河流量的变化率分别为-15%和-29%。2030年代中期和2090年代中期情景的结果表明，2.5克/升的盐锋可能在主要河道中向上游移动10公里和20公里，在稻田中分别移动20公里和35公里。利用模拟结果计算了灌溉水稻的有效水持续时间。结果表明，在21世纪30年代中期和21世纪90年代中期的情景中，可能种植三季稻的面积将减少约71，000和72，000公顷，而单一作物面积将增加约38，000和179，000公顷。分别利用地理信息系统技术，三角洲被分为三个区域，反映了不同的水稻作物脆弱性水平;高脆弱性区域和中等脆弱性区域的面积分别约为200 000公顷和400 000公顷。分别
The combined impact of sea level rise and reduction of the Mckong River flow in the dry season on salinity intrusion and rice cropping in the Vietnamese Mekong Delta was assessed in this study. The MIKEII Model was used to simulate flow and salinity intrusion from December to June for the medium-term (mid-2030s) and long-term (mid-2090s) scenarios using data derived from the SRES B2 climate change projection. The sea level rise values for two scenarios were +20 cm and +45 cm, while the rates of change for the Mekong River flow were -15% and -29%, respectively. The results obtained for the mid-2030s and mid-2090s scenarios show that the 2.5 g/L saline front is likely to shift upstream by 10 km and 20 km in the main river channels, and up to 20 km and 35 km in the paddy field, respectively. The simulated salinity intrusion results were then used to compute durations of available water for irrigation rice cropping. The results indicate that area where triple rice crops are possible, will be reduced by approximatly 71,000 and 72,000 ha, while single crop areas will be increased by approximately 38,000 and 179,000 ha for the mid-2030s and mid-2090s scenarios. respectively. Using GIS techniques the delta was divided into three areas reflecting different rice crop vulnerability levelslp; areas of high and medium vulnerabiliy measured approximately 200,000 ha and 400,000 ha. respectively.