Water temperatures and heat budgets in Dorset chalk water courses
Water temperatures and heat budgets in Dorset chalk water courses
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多塞特郡 白垩水道的水温和热量预算
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
Yuqing Zhang
中科院分区：
文献类型：
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作者：
B. Webb;Yuqing Zhang
在英国多塞特，实地测量已经建立了两条水道上的站点的热量预算，这些水道以上部白垩为主。1994年冬季和夏季期间，在Piddle河一条支流的一个泉源附近的一个站点和位于here河下游的一个站点收集了关于主要平流和非平流热通量的资料。热能输入以辐射通量为主，夏季和冬季的净辐射接收平均占非平流总量的90%左右。来自大气的感热（对流/传导）传输在夏季因泉水流水温较低而增强，而冬季相对温暖的水温则增加了蒸发热损失，这是该季节主要的非平流热损失成分。显热传递和背辐射也造成了显著的热损失。夏季测量结果显示，皮德尔河支流的无植被砾石床的热量传导是主要的损失形式，但夏季河床上的杂草覆盖大大减少了这种输出。在非平流热通量分量中明显存在相当大的日变异性。通过降水平流到研究流域的热量可以忽略不计，但地下水流入在冬季和夏季都增加了河道的热量储存。这种影响在源头和夏季最明显，因为夏季流量较低。版权所有©1999 John Wiley & Sons， Ltd
Field measurements have established the heat budgets for stations on two water courses which drain catchment areas dominated by the upper chalk in Dorset, UK. Information on the main advective and non-advective heat fluxes were collected during winter and summer periods in 1994 at a site near to a spring source on a tributary of the River Piddle, and at a station situated downstream on the River Bere. Inputs of heat energy were dominated by radiative fluxes, with net radiation receipt accounting on average for around 90% of the non-advective total in both summer and winter. Sensible heat (convective/conductive) transfer from the atmosphere was enhanced in the summer by the lower water temperature of these spring-fed streams, while relatively warm water temperatures during winter enhanced heat losses by evaporation, which was the dominant non-advective heat loss component in this season. Significant heat losses also occurred by sensible transfer and by back radiation. Summer measurements revealed that conduction of heat into the non-vegetated gravel bed of the River Piddle tributary was the dominant form of loss, but this output was strongly reduced in summer by weed cover on the bed of the River Bere. Considerable daily and diel variability was evident in non-advective heat flux components. Heat advected into the study reaches via precipitation was negligible, but groundwater inflows added to the heat storage of the water courses in both winter and summer. This effect was most marked at the headwater site and in the summer season because of lower streamflow discharge. Copyright © 1999 John Wiley & Sons, Ltd.