Thermal variations of water in the Nam Song stream/Mekong River: II. Experimental data and theoretical predictions
Thermal variations of water in the Nam Song stream/Mekong River: II. Experimental data and theoretical predictions
复制标题
南松溪/湄公河水的热变化：II。
DOI：
10.1007/s40899-016-0043-x
复制
发表时间：
2016
影响因子：
2.1
通讯作者：
Jiftah Ben-Asher
中科院分区：
文献类型：
--
作者：
Koshi Yoshida;Sho Shiozawa;Jiftah Ben-Asher
本研究的目的是以南松江为例，确定参数，并将测量数据与本研究第一篇论文中建立的数学模型进行比较。运动波动方程[特别是Ben-Asher et al. （Sustain Water resource management, 2016）中的Eq. 16a]。[doi: 10.1007/s40899-016-0044-9]扩展为泰勒级数，用于确定几个系统参数，包括热时间常数，稳态解和每日热循环。该模式测量和计算的水温在夜间最低为23-24°C，中午最高为27-29°C。2004年3月16日至3月25日，我们在南松大坝下游4公里处的一个地点监测了河流和空气温度。从一组日正弦曲线中提取每小时平均水温及其标准差。下游监测数据与理论模型假设的结果相似。考虑了日间放水量对其温度和能量输入变化的影响。分析表明，唯一可控制的系统变量是水流速度(V)。它可以通过控制大坝放水来优化。数学分析还识别和量化了控制水环境的参数。理论和实验数据表明，在所研究的条件下，大坝放水量的增加可以防止下游水温的升高，从而有助于保持河流的渔业和生活水质处于更健康的状态。
The goals of this study were to use the Nam Song River as a case study for parameters determination and a comparison between the measured data and the mathematical model developed in the first paper of this study. The kinematic wave equation [especially Eq. 16a in Ben-Asher et al. (Sustain Water Resour Manag, 2016. doi: 10.1007/s40899-016-0044-9 )] was expanded to a Taylor series that was used to determine several system parameters including the thermal time constant, the steady state solution, and the daily thermal cycle. Water temperature measured and calculated by the model varied from minimum of 23–24 °C at night to maximum of 27–29 °C at midday. From March 16 to March 25 2004, stream and air temperature were monitored at a point located 4 km downstream from the Nam Song Dam. The average hourly water temperature and its standard deviation were extracted from a family of daily sinusoidal curves. Monitoring downstream data were similar to results assumed by the theoretical model. The effect of water discharge rate on its temperature and on the changing energy input during daytime hours was considered. The analysis indicated that the only controllable system variable is the water flow velocity (V). It can be optimized through a controlled release of water from the dam. The mathematical analysis also identified and quantified the parameters which govern the water environment. The theory as well as the experimental data indicated that for the conditions studied, an increase in water discharge at the dam prevents an increase in water temperature downstream and thus helps to keep the fisheries and domestic water quality of the river in a healthier condition.