黑龙江国土资源

三江平原作为国家粮食安全核心区，其植被覆盖度(fractional vegetation coverage, FVC)动态变化对黑土保护与农业可持续发展至关重要。本文整合2000-2020年MODIS遥感影像、气象、社会经济与土地利用数据，基于Google Earth Engine(GEE)平台构建长时间序列FVC数据集，结合Theil-Sen趋势分析、土地转移矩阵及XGBoost模型，揭示三江平原FVC时空演变规律及其驱动机制。结果表明：(1)2000-2020年间，三江平原FVC整体呈微弱上升趋势，速率为0.0025/yr,生长季平均FVC最大值为0.79;(2)驱动因子中降水量(8.8393mm/yr)和平均地表气温(0.0441℃/yr)随着时间的推移也呈微弱上升趋势，土地利用类型中耕地面积增加，由林、草、水域等转化而成。(3)驱动因素分析表明，土地利用类型是影响FVC变化的主要因素(贡献率约52%),其后依次为降水量(22%)、气温(12%),而地区GDP(约9%)和人口密度(约5%)等社会经济因素的作用相对较弱。本文为协调三江平原粮食生产与生态保护提供数据支撑，建议优先管控耕地，加强林草恢复与水域保护。

As the core area of national food security, the dynamic changes in Fractional Vegetation Coverage(FVC) in the Sanjiang Plain are crucial for the protection of black soil and sustainable agricultural development.This article integrates MODIS remote sensing images, meteorological, socioeconomic, and land use data from 2000 to 2020.Based on Google Earth Engine(GEE) platform, FVC data set with long series is constructed.Combining Theil—Sen trend analysis, land transfer matrix, and XGBoost model, the spatiotemporal evolution law and driving mechanism of FVC in the Sanjiang Plain are revealed.The results showed that:(1)From 2000 to 2020,the FVC in the Sanjiang Plain showed a slight upward trend;(2)The driving factors of rainfall(8.8393mm/yr) and surface temperature(0.0441℃/yr) also showed a slight upward trend.The increase in arable land area in land use types was transformed from forests, grasslands, water bodies, etc.(3)The analysis of driving factors shows that land use type is the primary factor affecting FVC changes(52%),followed by precipitation(22%) and temperature(12%),while the role of socio-economic factors, such as regional GDP(9%) and population density(5%),is relatively weak.This article provides data support for coordinating grain production and ecological protection in the Sanjiang Plain, and suggests prioritizing the control of arable land, strengthening forest and grass restoration, and water conservation.