但上述这些方法通常并非很可靠其不确定性主要来自流量测量设备不稳定、关于参考流量的假设耗水量并非严格与污水流量相匹配或依据干旱天气做出的假设无法验证的无地表水流入不严谨翻译

However, these methods are often not very reliable, and their uncertainty mainly comes from unstable flow measurement equipment, assumptions about reference flow (water consumption does not strictly match sewage flow), or assumptions made based on drought weather (unverified absence of surface water inflow) that are not rigorous.