1700—1978年云南山地掌鸠河流域耕地时空演变的网格化重建

基于多源数据资料重建小尺度区域历史时期土地利用/覆盖变化,对深入理解土地利用变化的驱动力机制及其环境和气候效应具有重要意义。本文利用从流域尺度聚落格局演变重建到聚落尺度耕地数量和空间分布重建,再到流域尺度耕地格局重建的思路,以云南山地典型的中小流域为研究区,以历史文献资料、田野考察资料、历史地理学研究成果、档案资料、现代统计资料、地理基础数据为支撑,综合考虑区域自然因素（坡度、海拔高度）、人文因素（人口、政策、农业技术、耕地与居民点距离）,设计了历史时期山地小尺度区域耕地网格化重建模型,重建了1700—1978年具有明确时间和空间属性的网格化耕地格局。结果表明：① 掌鸠河流域的耕地面积近300 a增长6.3倍,垦殖率从1700年的2.1%上升到1978年的15.6%。② 不同地形区的耕地面积差异较为显著,其中山区和半山区的耕地面积最大,且增长速度最快;平坝区和中下游河谷区的耕地面积增长相对平缓,是自然环境、人口、政策和农业技术等因素综合作用的结果。③ 通过总耕地面积和人均耕地面积等对结果进行验证,证明了重建结果的合理性。本文设计的网格化重建模型可以为模拟具有明确时间和空间属性的小尺度区域历史耕地网格化数据集提供参考。

Gridded reconstruction of spatiotemporal evolution of cropland in the Zhangjiu River Basin in Yunnan Province from 1700 to 1978

The reconstruction of land use/land cover change within small-scale areas during historical periods based on multi-source data is of great significance for obtaining an in-depth understanding of the mechanisms driving land use change and their effects on the environment and climate. Herein, we reconstructed the evolution of settlement patterns at the basin scale, the amount and spatial distribution of cropland at the settlement scale, as well as the cropland pattern at the basin scale. Typical small and medium-scale watersheds in the mountainous areas of Yunnan Province were used as the study area. Abided by historical documents, field investigation data, historical geographical research results, archival data, modern statistical data, and basic geographical data, we considered regional natural factors (slope and altitude) and anthropogenic factors (population, policies, agricultural technology, and distance between croplands and settlements) and built a gridded model for cropland reconstruction in historical periods in the small-scale mountainous areas. We then reconstructed gridded cropland patterns with clear temporal and spatial attributes for the past 300 years. The results showed that: (1) over the past 300 years, the area of cropland in the Zhangjiu River Basin has increased 6.3 times, and the reclamation rate increased from 2.1% in 1700 to 15.6% in 1978. (2) The cropland area differed considerably in various terrains. The cropland area in mountainous and semi-mountainous areas was the largest and increased rapidly, whereas the cropland area in the flatlands and the middle and lower reaches of the valley area increased slowly, which was caused by a combination of factors, such as the natural environment, population, policies, and agricultural technology. (3) The results were verified using the total cropland area and per capita cropland area. The gridded reconstruction model devised in this study can be used as a reference for simulating historical cropland in small-scale areas with distinct spatial and temporal attributes using gridded datasets.