Application of remote sensing for estimating crop water requirements, yield and water productivity of wheat in the Gezira Scheme
Application of remote sensing for estimating crop water requirements, yield and water productivity of wheat in the Gezira Scheme
复制标题
DOI：
10.1080/01431160903246733
复制
发表时间：
2010-05
影响因子：
3.4
通讯作者：
B. Ahmed;H. Tanakamaru;A. Tada
中科院分区：
文献类型：
--
作者：
B. Ahmed;H. Tanakamaru;A. Tada
准确估算区域尺度的蒸散量（ET）和作物水分生产率（WP）对于干旱地区的节水灌溉管理具有重要作用。杰济拉计划中的三个站点分别代表研究领域（杰济拉研究站，GRS）、采用参与式水管理方法的农民田地（Abdelhakam 区块）和普通农民田地（Madina 区块），利用遥感数据结合地面观测来估算小麦的空间蒸散发、作物产量和湿气。该方法基于地表能量平衡，通过将 Landsat 7 ETM+ 和中分辨率成像光谱辐射计 (MODIS) 的遥感数据与常见气象数据相结合来估计感热和潜热通量。土地表面能量平衡算法（SEBAL）估计的蒸散量与基于参考蒸散量（ETo）-作物系数（k c）方法计算的生长季蒸散量之间的比较显示出良好的一致性。 GRS 整个季节小麦基于 SEBAL 的平均蒸散量为 396 毫米。 SEBAL 估计的 k c 在初期、中期和后期阶段分别为 0.46、1.07 和 0.3，而根据水耗竭测量确定的 k c 值分别为 0.5、1.15 和 0.5。 GRS、Abdelhakam 区块和 Madina 区块的平均作物产量分别为 2.4、1.9 和 1.4 t ha−1。三个位置的 WP 平均值分别为 0.52（变异系数，CV = 0.31）、0.50（CV = 0.33）和 0.43（CV = 0.45）kg m−3。如果达到变异系数（CV = 0.15），三个地点的节水率可分别达到 21%、42% 和 53%。
An accurate estimate of the evapotranspiration (ET) and crop water productivity (WP) at the regional scale plays a significant role in managing water-saving irrigation in the dry region. Three sites in the Gezira scheme representing research field (Gezira Research Station, GRS), farmers' fields with participatory water management approach (Abdelhakam block) and ordinary farmers' fields (Madina block) were selected to estimate spatial ET, crop yield and WP of wheat using remote sensing data coupled with ground observations. The methodology is based on surface energy balance to estimate sensible and latent heat fluxes by combining remotely sensed data from Landsat 7 ETM+ and Moderate Resolution Imaging Spectroradiometer (MODIS) with common meteorological data. A comparison between Surface Energy Balance Algorithm for Land (SEBAL) estimated ET and ET calculated based on reference evapotranspiration (ETo)-crop coefficient (k c) approach over the growing season exhibited a good agreement. The average SEBAL-based ET of wheat for the entire season at GRS was 396 mm. SEBAL estimated k c were 0.46, 1.07 and 0.3 at the initial, mid season and late season stages, respectively, whereas the k c values determined from water depletion measurements were 0.5, 1.15 and 0.5, respectively. The average crop yield at GRS, Abdelhakam block and Madina block were 2.4, 1.9 and 1.4 t ha−1, respectively. The mean values of WP for the three locations were 0.52 (coefficient of variation, CV = 0.31), 0.50 (CV = 0.33) and 0.43 (CV = 0.45) kg m−3, respectively. Achieving a coefficient of variation (CV = 0.15), water savings at the three locations could reach 21%, 42% and 53%, respectively.