Abstract:
Agricultural drought is the main natural factor restricting agricultural production.Studying its influence mechanism is the premise of scientific response to agricultural drought.Taking the Fuhe River Basin, a tributary of Changjiang River, as the research object, we evaluated the evolution law of agricultural drought based on a dualistic water-cycle model, and analyzed the contribution of climate change and human activities to the evolution of agricultural drought by a multi-factor attribution method.The results showed that the agricultural drought in Fuhe River basin showed a decreasing trend and a sudden change in 1980.Compared with 1956 to 1980,the average monthly drought duration and intensity of agricultural drought in the Fuhe River Basin decreased during 1981 to 2019,the climate change and human activities both played a role in slowing down the drought.Specifically, for irrigate area the contribution rates of climate change and human activities to drought duration were-31.0% and-69.0% respectively, and the contribution rates to drought intensity were-33.5% and-66.5% respectively.For other area, the contribution rates of drought duration change were-74.3% and-25.7%,respectively, and the contribution rates of drought intensity change were-60.1% and-39.9%,respectively.Precipitation, as the key factor leading to the occurrence of drought, had a higher annual mean in variation period than that in the base period, so climate change played a role in slowing down the evolution of agricultural drought.Accordingly, among the indicators of human activities, the increase of reservoir capacity can guarantee the water consumption in the drought period to a certain extent, while the increase of social and economic water intake and irrigated area can make up for the shortage of soil water in the key growth period of crops and ensure the normal development of crops, which can alleviate agricultural drought to a certain extent.