ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

Due to the unbalanced distribution of cultivated land resources in the Beijing-Tianjin-Hebei region, the regional differences of social and economic development are prominent. It is of great significance to clarify the spatial and temporal heterogeneity of cultivated land for the coordinated and sustainable development of the region. Based on the Beijing-Tianjin-Hebei region, the evolution of cultivated land spatial distribution and its influencing mechanism during the period of 1990—2020 were studied by using the dynamic change model of cultivated land and geo-detector methods. The results showed that Beijing took the lead in the construction of industrialized cities, followed by Tianjin, and Hebei lagged behind. The relatively high dynamic value of cultivated land change also appeared one after another. The distribution of cultivated land had a significant agglomeration characteristic, showing a kernel density pattern of “dense in southeast and sparse in northwest”. The characteristics of land use structure change were obvious. Construction land, woodland and water area were the main areas of net increase, while cultivated land, grassland and unused land were the main areas of net decrease. The loss of cultivated land mainly showed the aggregation characteristics around Beijing and Bohai Sea, and the heat of loss in the east was higher than that in the west, and that in the south was higher than that in the north. The influence of socio-economic and policy factors on cultivated land use showed an upward trend, while the influence of natural factors showed a downward trend. The results can provide a scientific basis for farmland protection and regional coordinated development in Beijing-Tianjin-Hebei region.