Abstract: Water area and cropland are important resources for food production, the temporal and spatial changes of which maintain the sustainable development of regional agriculture. The three northeastern provinces in China are typical areas where human activities have exerted significant impacts on land cover change. It is of great significance to analyze the changes of water areas and croplands and their driving mechanisms from the perspective of humanenvironment coupling system. Through the land use classification data obtained from remote sensing interpretation in the three provinces in 2000, 2005, 2010, and 2015, the spatial and temporal evolution pattern of water areas and croplands were quantitatively expressed using spatial analysis and visualization methods. The results showed that water areas had changed from “slight reduction slight increase-sharp decrease” during the 15 years, with an average annual reduction of 213.48 km². The main reason was that the beaches, lakes, and other waters were converted into croplands. The water areas in the middle and upper reaches of the Songhua River and the Dongliao River watershed had been significantly reduced. The cropland areas had continued to increase due to deforestation and land reclamation, with a rate of 707.94 km²·a^-1. The area of reduced croplands turned into waters was less than that of water areas transferred to croplands. Our results provide scientific support for formulating agricultural resource management policies and implementing agricultural sustainable development planning programs in the three northeastern provinces of China.

Key words: wheat, copper stress, silicon fertilizer, ultrastructure.