Social Vulnerability Assessment by Mapping Population Density and Pressure on Cropland in Shandong Province in China during the 17th–20th Century

Abstract

Cropland area per capita and pressure index on cropland are important parameters for measuring the social vulnerability and sustainability from the perspective of food security in a certain region in China during the historical periods. This study reconstructed the change in spatial distribution of cropland area per labor/household and pressure index on cropland during the 17th-20th century by using historical documents, regression analysis, pressure index model, and GIS (geographic information system). Following this, we analyzed the impacting process of climate change and sustainability of cropland use during the different periods. The conclusions of this study are as follows: (i) there was an obvious spatial difference of labor/household density, as there was higher density in three agricultural areas, which had the same pattern as cropland distribution during the same periods; (ii) Cropland area per capita was relatively higher during the 17th-18th century, which were above 0.4 ha/person in the majority of counties and were distributed homogenously. Until the 19th century and the beginning of 20th century, cropland area per capita in a considerable proportion of regions decreased below 0.2 ha/person, which embodies the increase in social vulnerability and unsustainability at that time; (iii) The pressure index on cropland also showed a spatial pattern similar to cropland area per capita, which presented as having a lower threshold than nowadays. During the 17th-18th century, there was no pressure on cropland. In comparison, in the 19th century and at the beginning of 20th century, two high-value centers of pressure index on cropland appeared in the Middle Shandong and the Jiaodong region. As a result, pressure on cropland use increased and a food crisis was likely to have been created; (iv) A higher extent of sustainable cropland use corresponded to the cold period, while a lower extent of sustainable cropland use corresponded to the warm period in Shandong over the past 300 years. The turning point of the 1680s from dry to wet was not distinctively attributed to the decrease in the extent of sustainable cropland use in Shandong. Since the beginning of the 20th century, the increasing pressure on the sustainability of cropland use finally intensified the social conflict and increased the probability of social revolts.

Has “Grain for Green” threaten food security on the Loess Plateau of China?

“…The cropland pressure index was used to measure the cultivated land shortage and reflects regional food security (Ye et al 2017), which can be expressed with the following equations:…”

Exploring Spatiotemporal Pattern of Grassland Cover in Western China from 1661 to 1996

“…Indeed, at that time, approximately 80% of the Chinese population lived in eastern agricultural areas but as the number of people grew rapidly, limited cropland resources struggled to sustain these levels [44]. Generally, per capita cropland area (PCA) is often used to weigh food security in a country or region [65] and this variable can be calculated by dividing cropland area by human population data. The minimum PCA refers to the area necessary to support a person; previous studies suggest that minimum PCA was 0.27 ha in the north of China under productive conditions, given the technological level at that time [66,67].…”

Reconstruction of cropland spatial patterns of the Manas River Basin of Xinjiang in the late Qing and Republican period

“…)" [3][4][5][6] 、 "全球土地利用数据集(Sustainability and the Global Environment, SAGE)" [7] 、 "全球农牧 空间数据集 (PJ Database) " [8] 以及 "全球土地利用数 据集 (KK10) " [9] 。这些数据集在一定程度上揭示了 全球或区域土地利用与土地覆被变化的趋势。然 而， 全球性数据集在用于区域尺度研究中依然存在 一定的局限性和矛盾性 [4] [10][11][12][13] 。葛全胜 等 [14] 、 何凡能等 [15][16][17] 、 李美娇等 [18,19] 、 杨绪红等 [20] 对宋、 元、 明、 清时期传统农耕区耕地面积和耕地网格化 数据进行了重建； 叶瑜等 [21] 、 李士成等 [22] 对东北地区 的耕地面积和森林网格化数据进行了重建； 金晓斌 团队 [23][24][25] 利用 CA (元胞自动机) 重建了苏皖地区的 耕地网格化数据集； Wei 等 [26] 、 Ye 等 [27] 、 Ye 等 [28] 重建 了华北地区的耕地面积和分布， 建立了区域网格化 数据集。在非传统农耕区， 研究者还关注了青藏高 原地区 [29][30][31][32] 、 黑河流域 [33,34] [35] 。绿洲区土地覆被抗干扰性低， 区域生态脆弱， 受气候波动、 河流变迁、 人为垦殖等的影响明显 [36] ， 也对干旱区生态环境产生了影响。可以说， 绿洲土 地利用与土地覆被变化是绿洲环境变化的核心。 对于新疆绿洲土地利用的研究， 目前主要集中在 1949 年以后， 与历史时期土地利用变化相关的研 究， 现仅有张莉 [37] 重建了清代以来天山北麓县级耕 地面积和垦殖率， 杨越 [38] [37] 的上限。对限制性因子进行标准化处理， 方式 [29][30][31] 进行标准化， 标准化方式 [29][30][31] 如下：…”