Climate adaptation through rice northward expansion aggravated groundwater overexploitation in Northeast China
Shefang Liang, Weipo Liu, Miao Lu, Lang Xia, Liangzhi You, Yuan Liu, Zhenhuan Liu, Yan Zha, Huajun Tang, Peng Yang
Abstract
Understanding crop migration to adapt to climate change is important to achieve food security and sustainable agriculture. Previous researches mainly focus on the impacts of climate change on crop yields and migration, but environmental feedback has been overlooked. Here we analyze the rice migration and its impact on water use in Sanjiang Plain, Northeast China—which experienced considerable poleward expansion and climate warming. From 2000 to 2020, rice cultivation expanded northeast by 2.19 million hectares, increasing irrigation demand by 6.36 billion tonnes. Rice expansion contributed 122.18% to the abrupt irrigation increase, while the direct impact of climate change resulted in a −22.18% increase due to decreased evapotranspiration and increased precipitation. Such phenomenal rice expansion is considerably associated with the decline of groundwater levels by an average of 4.79 meters. Our findings highlight the urgent need to make integrated strategies balancing crop migration to climate change and water resource conservation. Rice expansion due to crop migration causes over 122% irrigation increases in Northeast China from 2000 to 2020, while climate change reduces irrigation demands by decreased evapotranspiration and increased precipitation, based on a water requirement model using rice maps and groundwater data.