CONCLUSION
Rainwater harvesting was proved to be very helpful
for water and energy conservation by assessing the
water use efficiency (WUE) and energy consumption
for agricultural production in the Loess Plateau.
Supplemental irrigation of rainwater for agricultural
use will significantly improve the crop yield and increase
farmers’ incomes. Furthermore, energy conservation
has been also confirmed by making the comparison
of energy consumption per unit water for domestic
use between the rainwater harvesting system
and main water supply of the city. The results implied
that catchment consumed more energy than the
tank in the rainwater harvesting system.
Consequently, further studies about energy conservation
of rainwater harvesting systems should combine
with more systems such as supplemental irrigation
system and industrialized agriculture system.