Temporal and Spatial Changes of Land Use in the Yellow River Basin Based on Geo- Information Tupu method

[Objective] The land use of the Yellow River Basin(YRB) has a significant impact on the ecology and economy of the basin. It is extremely important to study the temporal and spatial change of land use in the YRB for the sustainable development of the basin. [Methods]Taking the YRB as the study area, the land use types in the basin were classified and evaluated based on remote sensing monitoring data of five years of land use. The temporal and spatial characteristics of land use in four time series units from 2000 to 2005, 2005 to 2010, 2010 to 2015, and 2015 to 2020 were analyzed by using geo-information Tupu method, and the internal factors of land use change were analyzed from the perspective of increase and decrease. [Results] The results show that from 2000 to 2020, the land type of the YRB is dominated by grassland, the growth trend of woodland is higher than that of grassland, the growth trend of built-up land is higher than that of water area, and the cultivated land and unused land show a decreasing trend; different time series units show similar land changes, with the strongest in 2000-2005. The Tupu units of "cultivated land →grassland", "grassland→cultivated land", "grassland→ unused land" and "unused land→ grassland" are the main changes in the four time series units ;In the rising trend Tupu, grassland is converted from a large number of cultivated land, and the increase of grassland has a tendency to occupy cultivated land. In the falling trend Tupu, a large number of grassland have been converted into cultivated land, and the increase of cultivated land is inclined to occupy grassland. All of them have the most obvious changes in Gansu, the southern part of Ningxia and the northern part of Shaanxi. From the perspective of spatial location, the two may be transformed into each other, and the distribution is relatively concentrated in the pilot areas of the policy of returning farmland to forests.[Conclusion] The analysis of temporal and spatial changes of land use in the YRB in the past 20 years provides a realistic case for the feedback role of land policy in society and environment, and lays a foundation for the harmonious development of human and ecology.