基于遥感的植被吸收光合有效辐射估算

Assessment of vegetation absorbed photosynthetic active radiation based on remote sensing

植被吸收光合有效辐射(APAR)是指植物实际所吸收的光合有效辐射,是评价植被光合潜力和潜在产量等研究的重要参考指标。基于CASA模型,利用土地利用图和MODIS NDVI数据,以及改进的日照百分比经验统计公式,研究2010年河南省APAR状况,进一步分析河南省APAR的时空分布特征,研究结果较好的反映了河南省APAR分布。2010年河南省APAR总量为8.70×1012MJ。从空间分布上来看,整体上南部和西部比东部和北部高,最大值出现在西部伏牛山地区,与植被的生长周期密切相关,同时受地理纬度影响较大。年内差异较大,5月至8月是植被光合作用效率最高的时间,占全年总量49.58%。

Absorbed photosynthetic active radiation （APAR） is the photosynthetically active radiation absorbed by the plant actually, and is an important reference for evaluation of vegetation photosynthetic potential and the potential yield. In this paper, the APAR is evaluated based on the CASA model, using the land use maps and MODIS NDVI data, referencing to the improved statistical formulas of sunshine percentage, and its temporal and spatial distributions are analyzed in Henan Province. The results reflect better the situation of APAR in Henan Province, indicating that the selected method is suitable for this study area. The total APAR was 8.70× 10^12 MJ in 2010 For its spatial distribution, the south and west one is higher than the east and north one, and the maximum occurs in the western Funiu Mountain region, which is closely related to the vegetation growth cycle, and influenced by the geographic latitude. The difference is great during the year, and the highest one occurs during May and August, accounting for 49.58% of the total.