在此基础上叙述本文的城市洪水模型的改进过程：扩散系数用地面高程函数代替，综合降雨函数、渗透函数和排水函数形成函数项。

And it clarify the process of rectified model: replace terrain function to diffusion parameter, integrate rainfall function, drain function and seepage function to function item.

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这些全都是沿海城市，因此会由于海拔的稍稍变化而遭受到来自于海洋的洪水和河流排水缓慢，这都是下沉的迹象。

These are coastal cities, all, thus subject to inundation from the sea or slow draining rivers due to scarce difference in sea level elevation, all signs of sinking.

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