Anh (2021) asserts that the sediment budget model by Ve et al. (2021) of the subaqueous Red River Delta (RRD) is inaccurate because of some fundamental flaws in the DEM analysis and budget estimation. In fact, bathymetric data from the two earliest charts have been validated with data from a survey carried out over a short time span (1927–1930) and a linear semi-variogram model used to do the kriging interpolation. Different grid cell sizes have a negligible effect on the DEM analysis, and the effect of relative sea-level rise has been ruled out by normalization of bathymetrical data from sequential charts to a common tidal datum. Furthermore, the estimation of the amount of deposited sediment on tidal flats is correct, although a typo of sediment volume unfortunately yielded a wrong value. We can thus confirm that the data in the sediment budget model of Ve et al. (2021) are reliable.

The sediment budget model can be improved by full consideration of sediment from source to sink processes as suggested by Anh (2021). We therefore refine the model by considering river bedload and sand mining in the RRD in the sediment input item, and separate the subtidal RRD into three subzones to calculate their average depositional/erosional sediment volume and mass. In the revisited model, a total of 54.7 Mt./yr is inferred to be deposited in the subaqueous RRD from the intertidal flats to the delta-front slope, of which 75.3% and 24.7% are conceivably sourced by the Red River and eroded from the prodelta and offshore shelf, respectively. However, the controlling mechanism of secular erosion at the prodelta and offshore shelf is so far not well known, and this will need to be investigated in the future.

Anh (2021) 断言 Ve 等人的沉积物收支模型。(2021) 水下红河三角洲 (RRD) 是不准确的，因为 DEM 分析和预算估计中存在一些基本缺陷。事实上，来自两个最早海图的测深数据已通过短时间跨度（1927-1930）的调查数据和用于进行克里金插值的线性半变异函数模型得到验证。不同的网格单元大小对 DEM 分析的影响可以忽略不计，相对海平面上升的影响已被从顺序图表到共同潮汐数据的测深数据归一化排除。此外，对潮滩沉积沉积物量的估计是正确的，但不幸的是，沉积物体积的错误会产生错误的值。因此，我们可以确认 Ve 等人的沉积物预算模型中的数据。(2021) 是可靠的。

如 Anh (2021) 所建议的，通过充分考虑沉积物从源到汇的过程，可以改进沉积物收支模型。因此，我们通过在沉积物输入项中考虑 RRD 中的河床负荷和采砂来改进模型，并将潮下 RRD 分为三个子带，以计算它们的平均沉积/侵蚀沉积物体积和质量。在重新审视的模型中，推断总共有 54.7 Mt./yr 沉积在从潮间带到三角洲前缘斜坡的水下 RRD 中，其中 75.3% 和 24.7% 可能来自红河并被侵蚀分别为前三角洲和近海陆架。然而，目前对前三角洲和近海陆架长期侵蚀的控制机制尚不清楚，这需要在未来进行研究。