水循环过程中，除了自然力驱动的水的自然水循环，还包括社会力所驱动的社会水循环。在社会水循环过程中，内在驱动力是水的经济社会效益，而外在的物化表现则是“电力”驱动的“水泵”。   

    Vast amounts of energy are needed for the transportation, distribution and treatment of water. Pumping it over mountain ranges or from deep underground aquifers also requires a significant amount of energy. But the largest share of energy use comes from individual customers who heat water to bathe, cook and run businesses.

    研究结果正如上面所说， 能源消耗最大的位于用水终端的个体水消费者。

    Results：

    （1）In the sector of water extraction and delivery, only 23% of electricity requirements are used for water pumping out, purification, and distribution. Energy costs vary depending on the pumping distance, water quality, water pipelines, and water source. Groundwater pumping can increase energy use 30% over surface water sources.

(2) End use: In this sector, up to 73% electricity requirements are needed in water cycle by homes, farms, and businesses. It is reported that household appliance such as washing machine, dishwasher, water heaters, and dryers use the largest amount of electricity in water cycle, 28%.

(3) Waste water management just costs only 4% energy, which not only reveals waste treatment currently need less energy but shows there is lot of potentiality we can clean much more discharged water again. So far, only 4% electricity was used for water cleaning before it is discharged to water source. However, with the population growth and increasingly stringent treatment standards, more and more energy is needed, which could soon lead to increased wastewater management costs.

Discussion

Based on the results above, I suggest we should shift our eyes from water to energy and water together. How to do some comprehensive research on water cycle driven by energy requirements should be the focus of water cycle research in the future.

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