Analyzing The Rebound Effect Of Agricultural Water Resources

Due to the shortage as well as the waste of agricultural water resources in China and the phenomenon that domestic water resources have been squeezed by industrial and drinking water resources, water conservation has become the fundamental measure to ensure food security. However, one of the main current water-saving measures- improving water-use efficiency-have not achieved the expected water savings and the agricultural water consumption in some areas even increased. This situation implies that the so-called rebound may occur. This study first defines the rebound effect of agricultural water resources on the basis of the energy rebound effect, namely that the expected water savings brought about by agricultural technology advancements and water-use efficiency improvements are partly or even fully offset by the additional water consumption induced by agricultural growth. Then, we expound the mechanism of rebound effect of agricultural water resources and compare the rebound effect of agricultural water resources with the energy rebound effect from the point of the particularity of agricultural water resources. Because of the irreplaceability of agricultural water resources, the rebound effect of agricultural water resources is different in many aspects such as type and mechanism compared with energy rebound effect. On basis of the definition, we point out and compare two calculating models to estimate the rebound effect of agricultural water resources. They are calculating model using price elasticity and calculating model using the contribution rate of technological advances. According to the situation of Chinese agricultural, this paper choice the later one. And the panel data on 31 provinces and municipalities in china during 1998-2012 are adopted to calculate the rebound effect of 31 provinces and municipalities in each year.The results show that the average value of rebound effect of agricultural water resources is 9% and that the characteristics vary by region and period. In terms of region, different areas have different rebound effects and the “backfire effects” even occur in some areas, including Shanxi province, Liaoning province and The Xinjiang Uygur Autonomous Region. In terms of time, though the rebound effects of all areas show downward trends in 1998-2012, some areas fluctuated seriously and the average magnitude of the rebound effects of 31 provinces and municipalities are 35% in 2012. After weighted average with total value agricultural output, we find that middle part of china has the lowest rebound effect of agricultural water resources, followed by western and eastern part. The results show a down trend but eastern and western part experience small rise in recent years.These results suggest current technological advances even bring about more water consumption instead of saving water so that rebound effect of agricultural water resources cannot be denied in agricultural production. Without total agricultural water quota, technological advances may lead to the rebound effect of agricultural water resources. On one hand, Joint effects should be made and the government, producers and consumers should all participant in to save agricultural water effectively. On the other hand, allocating agricultural water quota, reforming agricultural water police and price and strengthening the awareness of saving-water can help to break the bottlenecks of agricultural growth and ensure the food security.