## 4 Discussion  
In the period of 2000-2010, the influence of the four driver groups on GCO is ranked as follows: urbanization > weather variables > economic factors > human activities. Urbanization was the dominant driver group in 11 counties (HH, WC, TKT, QSH, HL, BT, TMY, GY, DS, ZGE, and YJHL; see Figure 7). Urbanization is the unique driver group in five counties (WC, QSH, HL, GY, and DS; see Figure 7). Weather variables also had a stronger effect in eight counties (DMJ, HJ, DLT, ZGE, YGHL, WS, ETKQ, and EKT), seven of them being part of Ordos. Among these eight counties, weather variables were the unique drivers in six: DMJ, HJ, DLT, WS, ETKQ, and ETK. Economic factors constituted the dominant driver group in seven counties: HH, TKT, TMZ, BT, TMY, ZGE, and YJHL. Human activities constituted the major driver group in four counties: HH, TKT, TMZ, and TMY. Ultimately, the combination of human activity, economic factors, and urbanization represented the dominant driver groups in HH, TKT, and TMY. Both human activities and economic factors were the major driver groups in TMZ. The dominant driver group in BT is made up of economic factors and urbanization. Weather variables, economic factors, and urbanization were the major driver groups in ZGE and YJHL. After 2010, the overall ranking of the impact of each driver group on grassland conversion remained unchanged compared with the period from 2000 to 2010: urbanization > weather variables > economic > human activities. Compared with the previous period, the effect of urbanization was decreased; it was the dominant effect in ten counties (HH, WC, TKT, TMZ, QSH, HL, BT, TMY, DS, and DLT; see Figure 8). The urbanization effect increased in Hohhot and decreased in both Baotou and Ordos. The effect of weather variables was still the dominant driver group in seven counties, and it had the largest effect in Ordos. The economic effect was still the major driver group in seven counties, and the economic effect decreased in Hohhot and increased in Ordos (see Figure 8). The effect of human activities increased during this period, especially in BT and DS. Overall, the partial order ranking for all drivers seems unchanged compared with the previous period. However, for the urbanization-related drivers, the effect decreased, and the effect of human activities increased. Figure 8: Primary drivers and their rankings for GCO (2010 to 2020). The Intensity of Land-Use and Land-Cover Change and Grassland Conversion in Hohhot-Baotou-Ordos Has Increased Since 2000  
The research results indicate that during both study periods, the intensity of land-use change and the proportion of GCO and GCI gradually increased, showing significant spatial characteristics. During the period from 2000 to 2010, 6.9% of the study area experienced changes; these changes were mainly concentrated in the three major cities in the western part of the study area and their surrounding areas. This value increased to 11% in the 2010-2020 period, with significant LUCC changes occurring across the entire study area but still primarily around the three major cities and their surroundings. GCO accounted for 2.1% and 4.8%, while GCI accounted for 3.5% and 4.7% during the two study periods (Figures 4 and S4). The increase in the intensity of land-use change suggests more frequent and drastic transformations in land-use patterns within the region. Previous studies have shown that human activities such as urban expansion, industrial development, and resource exploitation are key drivers of increased intensity in land-use change in this region [51; 52], as is consistent with the findings of this study. This change has exacerbated the occupation and disturbance of grassland resources, putting greater pressure on the protection of grassland ecosystems [53; 54].