2000—2015年江汉平原农田生态系统NPP时空变化特征

基于MODIS数据和VPM（Vegetation Photosynthesis Model）模型估算2000—2015年江汉平原农田NPP,利用空间自相关和Sen趋势分析方法,分析16年间江汉平原农田NPP的时空变化特征及其影响因素。结果表明：（1）江汉平原农田年均NPP在2000—2005年呈上升趋势,2005—2009年呈波动性下降趋势,2009—2015年呈上升趋势;农田年NPP总量在2000—2015年整体上趋于平稳。（2）高中低产田面积占比分别为66.03%、27.04%和6.93%。2000—2015年NPP具有很强的空间聚集性且呈逐年增强趋势,并随空间距离增加聚集性减弱;江汉平原NPP主要呈高—高聚集和低—低聚集特征。（3）江汉平原农田NPP显著上升、无显著变化和显著下降区域面积分别占1.30%、69.50%和29.20%。

Research on spatiotemporal characteristics of farmland ecosystem NPP in Jianghan Plain from 2000 to 2015

NPP of cropland was estimated based on MODIS data and VPM model between 2000 and 2015 in the Jianghan Plain. The spatial autocorrelation and Sen trend methods were used to analyze the spatiotemporal variations and influencing factors of cropland NPP in the study area during the 16 years. The results show that: (1) The average annual NPP of cropland in the plain increased from 2000 to 2005, decreased from 2005 to 2009, and increased from 2009 to 2015. The annual total of cropland NPP was stable from 2000 to 2015. (2) The proportions of high, medium and low yield fields were 66.03%, 27.04% and 6.93%, respectively. NPP had a strong spatial aggregation from 2000 to 2015, which showed an increasing trend year by year, and its aggregation decreased with the increase of spatial distance. The NPP is characterized by high-high aggregation and low-low aggregation in the Jianghan Plain. (3) No significant change was found in 69.5% of cropland NPP, with 1.30% of cropland NPP rising significantly and 29.20% of cropland NPP decreasing significantly in the Jianghan Plain.