College;
of;
Resources;
Science;
and;
Technology,;
Beijing;
Normal;
University,;
Beijing;
100875,China;
National;
Remote;
Sensing;
Center;
of;
China,;
Chinese;
Ministry;
of;
Science;
andTechnology,;
Beijing;
100862,;
China;
中国; 北方地区; 农牧交错带; 生态环境; 空间格局; 农业生态;