Analysis on spatial and temporal changes and driving forces of grassland area in Urumqi City

Urumqi City is the capital of Xinjiang, with abundant grassland resources. Exploring the pattern and characteristics of grassland area increase and decrease, identifying the driving factors that affect its changes, and mastering the dynamic changes of different grassland types are of great significance for the rational development, utilization, and protection of grasslands in the region.This study investigates the spatiotemporal changes in grassland area in Urumqi from 1990 to 2020 using a single land use dynamic degree and transfer matrix, and uses correlation analysis to explore the driving factors of grassland area change. The results indicate that over the past 30 years, Urumqi City: 1) The overall grassland area shows a decreasing trend, with a dynamic degree of −0.31%. The net decrease in grassland is 595.47 km², mainly transferred out as unused land. 2) The area of different types of grasslands has changed, with the exception of temperate grassland desertification, temperate desert grassland, and temperate desert grassland showing a decreasing trend. All other types have shown an increasing trend. The largest change in area is the temperate desert grassland, with a net decrease of 787.07 km², mainly occurring in the central and northern regions. The smallest change is the alpine grassland, with a net increase of 0.36 km², mainly occurring in the southern region. 3) The correlation between the total sown area and most grassland types is the highest, with a correlation coefficient between 0.995 and 0.998. It can be seen that human factors were the main reason for the decrease in grassland area in Urumqi from 1990 to 2020.