基于长时间序列遥感数据反演NPP的耕地质量评价

为客观获得省域耕地质量分布状况,减少时间断点引起的评价误差,构建了一种基于长时间序列遥感数据反演NPP的耕地质量评价方法。首先,在耕地图斑约束下,采用时序LSWI和EVI数据识别水稻和玉米;然后,采用2000—2010年MODIS的MOD09A1数据,结合气象站点数据,利用VPM模型分别计算水稻和玉米的净初级生产力(NPP),并得到多年NPP均值,可反映耕地种植作物的常年长势,使用距平分析法消除作物类型差异,得到表征耕地质量的评价结果;最后,以吉林省为研究区,对本文提出的方法进行了实证与分析。实验结果表明,长时间序列NPP耕地质量反演结果与耕地质量利用等别整体空间分布一致。其中,吉林省中部与北部由于耕地集中连片,反演结果准确。南部山区耕地斑块破碎,耕地与林地混合,导致反演结果偏高。本文构建的长时间序列NPP耕地质量评价方法对省域范围、集中连片耕地质量评价具有可行性,可为我国耕地质量评价提供科学依据。

Cultivated Land Quality Evaluation Based on Inversion of NPP Based on Long term Sequence Remote Sensing Data

The evaluation of cultivated land quality can provide support for the management of cultivated land quality. In order to objectively obtain the distribution of cultivated land quality in the province and reduce the evaluation error caused by time breakpoints, an evaluation method of cultivated land quality was constructed based on NPP inversion of long term sequence remote sensing data. Firstly, rice and maize were identified by using time series LSWI and EVI data under the constraints of ploughing maps. Then, the MODIS MOD09A1 data from 2000 to 2010 were used, combined with the meteorological site data, the VPM model was used to calculate the NPP of rice and corn respectively, and the average NPP value was obtained for many years, reflecting the long term growth of cultivated crops. The anomaly analysis method was used to eliminate the differences in crop types, and the evaluation results of the quality of cultivated land were obtained. Finally, with Jilin Province as the research area, the method proposed was empirically analyzed. The experimental results showed that the long term sequence NPP cultivated land quality inversion results were consistent with the overall spatial distribution of cultivated land quality utilization. Among them, the inversion results were accurate in the central and northern parts of Jilin Province due to the concentrated arable land. The plaques in the southern mountainous areas were broken, and the cultivated land was mixed with the forest land, resulting in high inversion results. Therefore, the long term NPP cultivated land quality evaluation method constructed was feasible for the evaluation of provincial and central contiguous arable land quality, and can provide scientific support for the evaluation of cultivated land quality in China.