Recently water resources reanalysis (WRR) global streamflow products are emerging from high- resolution global models as a means to provide long and consistent global streamflow products for assessment of global challenge such as climate change. Like any other products, the newly developed global streamflow products have limitations accurately represent the dynamics of local streamflow hydrographs. There is a need to locally evaluate and apply correction factors for better representation and make use of the data. This research focuses on the evaluation and correction of the bias embedded in the global streamflow product (WRR, 0.25°) developed by WaterGAP3 hydrological model in the upper Blue Nile basin part of Ethiopia. Three spatiotemporal dynamical bias correction schemes (temporal-spatial variable, temporal-spatial constant and spatial variable) tested in twelve watersheds of the basin. The temporal-spatial variable dynamical bias correction scheme significantly improves the streamflow estimation. The Nash-Sutcliffe coefficient (NSCE) improves by 30% and bias decreases by 19% for the twelve streamflow gauging stations applying leave one out cross-validation approach in turn. Therefore, the temporal-spatial variable scheme is applicable and can use as one method for the bias correction to use the global data for local applications in the upper Blue Nile basin.

中文翻译：

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动态偏差校正程序，可改善蓝尼罗河上游流域局部应用的全球网格化日流量数据

最近，水资源再分析（WRR）全球流量产品正在从高分辨率的全球模型中兴起，以此为评估气候变化等全球挑战提供长期而一致的全球流量产品。像任何其他产品一样，新开发的全球水流产品也有局限性，无法准确代表当地水流水位图的动态。需要在本地评估和应用校正因子，以更好地表示和利用数据。这项研究的重点是评估和纠正由WaterGAP3水文模型开发的埃塞俄比亚青尼罗河盆地部分地区全球径流产品（WRR，0.25°）中所含的偏差。三种时空动态偏差校正方案（时空变量，时空常数和空间变量）在流域的十二个流域中进行了测试。时空变量动态偏差校正方案显着改善了流量估计。纳什-舒特克利夫系数（NSCE）改进了30％，偏差降低了19％，这是依次采用留出交叉验证方法的十二个流量测量站的结果。因此，时空变量方案是适用的，并且可以用作偏差校正的一种方法，以将全局数据用于上部Blue Nile盆地的局部应用。纳什-舒特克利夫系数（NSCE）改进了30％，偏差降低了19％，这是依次采用留出交叉验证方法的十二个流量测量站的结果。因此，时空变量方案是适用的，并且可以用作偏差校正的一种方法，以将全局数据用于上部Blue Nile盆地的局部应用。纳什-舒特克利夫系数（NSCE）改进了30％，偏差降低了19％，这是依次采用留出交叉验证方法的十二个流量测量站的结果。因此，时空变量方案是适用的，并且可以用作偏差校正的一种方法，以将全局数据用于上部Blue Nile盆地的局部应用。