Background Regional agricultural development particularly food and economic crop yield depends on arable land entirely. So the change of arable land area affects the regional socio-economic development. This paper aimed to analyzing of the spatial-temporal change characteristics of arable land in Aksu River Basin for past 19 years.

Methods Based on remote sensing and GIS technology, the spatial-temporal variation trend of arable land area in the study area was analyzed by using the remote sensing data of 2000, 2005, 2010, 2015 and 2018. Transfer matrix was used to analyze the transfer characteristics of arable land and other land use types in each period. Finally, using spatial Gini coefficient method, The degree of arable land fragmentation in Aksu River Basin was discussed.

Results The results show that : 1) The area of arable land in Aksu River Basin increased significantly from 2000 to 2018.Specifically, the arable land area was 5 553.4 km² in 2000, accounting for 8.7% of the total area of the study area, and increased to 8 541.9 km² in 2018, accounting for 13.4%, with an annual change rate of 2.99%.2) The characteristics of arable land transfer in the study area are obvious. The arable land area in Aksu River Basin was mainly transferred, and the transferred area was 4 666.38 km², among which the transferred area and transferred area were 3 827.55 km² and 838.83 km² respectively.Grassland, woodland and unused land were mainly transformed into arable land, while grassland, woodland and construction land were mainly transformed out of arable land.In addition, during the study period, the area of arable land converted to construction land was 271.51 km², and the area of construction land converted to arable land was 140.07 km². 3) The degree of arable land fragmentation in the study area showed a fluctuating trend. From 2000 to 2010, the spatial Gini coefficient of arable land increased, and the degree of aggregation of arable land increased, and the degree of fragmentation intensified in 2015, and then gradually increased. However, in general, the spatial Gini coefficient of arable land in all periods of the study area was less than 0.04, indicating that the degree of fragmentation was high and the degree of aggregation was low.

Conclusions With the increase of arable land area in the study area, Aksu River Basin in grassland, forest land, water area gradually reduce, arable land fragmentation degree is high, cause the land desertification, soil erosion and arable land security problems become more and more outstanding. This research may provide reference for promote the adjustment of industrial structure, effectively improve the ecological environment and agricultural production base.