基于数据融合算法的灌区蒸散发空间降尺度研究

发布时间：2018-03-08 17:05

本文选题：遥感　切入点：数据融合　出处：《农业机械学报》2017年04期 　论文类型：期刊论文

【摘要】：采用Landsat和MODIS数据,通过增强自适应融合算法(Enhanced spatial and temporal adaptive reflectance fusion model,ESTARFM)对蒸散发进行空间降尺度,构建田块尺度蒸散发数据集;利用2015年田间水量平衡方法计算的蒸散发数据对融合结果进行评价。在融合蒸散发基础上,结合解放闸灌域2000—2015年间种植结构信息,提取不同作物各自生育期和非生育期内年际蒸散发量,并分析了大型灌区节水改造以来,作物蒸散发占比的年际变化。研究结果表明:融合蒸散发与水量平衡蒸散发变化过程较吻合,小麦耗水峰值出现在6月中下旬—7月初,玉米和向日葵峰值出现在7月份。在相关性分析中,玉米、小麦和向日葵的决定系数R2分别达到了0.85、0.79和0.82;生育期内玉米(5—10月份)、小麦(4—7月份)和向日葵(6—10月份)的均方根误差均不高于0.70 mm/d;平均绝对误差均不高于0.75 mm/d;相对误差均不高于16%。在农田蒸散发总量验证中,融合蒸散发与水量平衡蒸散发相关性较好,两者决定系数达到了0.64。基于ESTARFM融合算法生成的高分辨率蒸散发(ET)结果可靠,具有较好的融合精度。融合结果与Landsat蒸散发的空间分布和差异性一致,7月23日、8月24日和9月1日相关系数分别达到0.85、0.81和0.77;差值均值分别为0.24 mm、0.19 mm和0.22 mm;标准偏差分别为0.81 mm、0.72 mm和0.61 mm。ESTARFM融合算法在农田蒸散发空间降尺度得到较好的应用,可有效区分不同作物蒸散发之间的差异。不同作物在生育期和非生育期内耗水量差别较大;生育期内套种(4—10月份)耗水量最大,达到637 mm,玉米(5—10月份)和向日葵(6—10月份)次之,分别为598 mm和502 mm,小麦(4—7月份)最低为412 mm;非生育期内,小麦(8—10月份)耗水量最大,年均达到214 mm,玉米(4月份)和向日葵(4—5月份)分别为42 mm和128 mm。不同作物多年平均耗水量(4—10月份)差异较小,其年际耗水总量主要随作物种植面积的变化而变化。
[Abstract]:Based on the Landsat and MODIS data, an enhanced spatial and temporal adaptive reflectance fusion model is used to downscale the evapotranspiration and construct a field scale evapotranspiration dataset. The data of evapotranspiration calculated by the field water balance method in 2015 were used to evaluate the fusion results. Based on the fusion evapotranspiration, the information of planting structure in the irrigation area of Jiefang Gate from 2000 to 2015 was combined. The interannual evapotranspiration of different crops during their respective growth period and non-growth period was extracted, and the water saving transformation of large irrigation area was analyzed. The interannual variation of crop evapotranspiration. The results show that the process of evapotranspiration is consistent with that of water balance evapotranspiration, and the peak value of wheat water consumption appears in the middle and late days of June to the beginning of July. The peak value of maize and sunflower appeared in July. In the correlation analysis, corn, The mean square root errors of wheat and sunflower were less than 0.70 mm / d, the mean absolute error was not higher than 0.75 mm / d, and the mean absolute error was not higher than 0.75 mm / d, respectively, and the mean root mean square error (RMS) of wheat and sunflower was 0.85 mm / d and 0.82 mm / d, respectively, and the mean root mean square error (RMS) was not higher than 0.70 mm / d, respectively, and the mean absolute error was not higher than 0.75 mm / d. The error is not higher than 16. In the verification of the total evapotranspiration of farmland, The correlation between fusion evapotranspiration and water balance evapotranspiration is good, the determination coefficient of them is 0.64. The result of high resolution evapotranspiration based on ESTARFM fusion algorithm is reliable. The fusion result is consistent with the spatial distribution and difference of Landsat evapotranspiration. The correlation coefficients of July 23rd, August 24th and September 1st are 0.85mm 0.81 and 0.77mm, respectively. The average value of the difference is 0.24mm / 0.19mm and 0.22mm respectively. The difference between 0.81 mm 0.72 mm and 0.61 mm.ESTARFM fusion algorithm was applied to the spatial downscaling of farmland evapotranspiration. The difference of evapotranspiration between different crops can be effectively distinguished. There are great differences in water consumption between different crops during growth period and non-growth period. The water consumption of interplanting during growth period is the highest, which is 637 mm, followed by May to October of maize and June to October of sunflower. 598 mm and 502 mm, respectively. The lowest in April to July was 412 mm. In the non-growth period, the water consumption of wheat was the highest in August to October. The annual average annual water consumption was 214mm, April) and sunflower (April / April) were 42 mm and 128 mm. respectively. The annual average annual water consumption of different crops varied slightly, and the total annual water consumption mainly varied with the crop planting area.
【作者单位】：中国水利水电科学研究院流域水循环模拟与调控国家重点实验室;国家节水灌溉北京工程技术研究中心;
【基金】：“十二五”国家科技支撑计划项目(2012BAD08B01) 国家自然科学基金项目(51679254) 国家重点研发计划项目(2016YFC0400101)
【分类号】：S161.4

【相似文献】