Distinguish between the taste of Zibo and the turbidity of Beijing. How to explain it? Thank you for your answers!

Zi, today's Shandong Zi River. Originated in the northeast of Laiwu County, it flows through the east of Linzi City, crosses Guangrao County and flows into Xiaoqing River. Lu is the name of ancient water. Originating in the northeast of Zibo, Shandong Province, it flows from northwest to southeast of Boxing. Downstream of the water. Also known as "land water". According to legend, the two kinds of water have different tastes, so it is difficult to tell them apart when mixed together. "The Warring States Policy Qice VI": "Gold runs across the country, enjoying life and not dying, so it cannot be won." Lu Chunqiu Jing Yu: "Confucius said:' It is also elegant to know the combination of the son and the uncle. During the Spring and Autumn Period, there was a famous chef named Yi Ya. He is Qi Huangong's favorite minister and specializes in cooking Qi Huangong's food. He is good at seasoning and catering, so he is very popular in Qi Huangong. Yiya was the first chef to cook with harmony. He is good at seasoning and cooking. Because he is a chef, a good cook and the first person to open a private restaurant, he is called the founder by the chefs. As a chef, Yiya has amazing taste. Legend has it that a public servant asked Confucius at that time: What is the taste of different waters together? Confucius said: Even if Zishui is mixed with land water, Yi Ya can tell the difference. It can be seen that Yiya at that time had a particularly sensitive taste and superb cooking skills, and even Confucius was admired. "Linzi County Records" also records: "Yi Ya is good at tuning five flavors, and you can know it by tasting water." Mencius said, "There are people who are addicted to the taste of their mouths. Yi Ya got my mouth first, and I am an addict ... As for ignorance, the world is elegant, similar to the mouth of the world. " Mencius also spoke highly of the ability of elegance to reconcile tastes. Therefore, Yi Ya is indeed the most famous chef who is good at blending tastes. Jinghe River, a tributary of Weihe River. There are two sources: South and North. Beiyuan comes from Guyuan County at the eastern foot of Liupanshan Mountain in Ningxia. The south flows out of Huating County, Gansu Province, into Pingliang County, into Shaanxi Province in the southeast, and into Weihe River in Gaoling County. Weifang originated from Bird and Rat Mountain in Weiyuan County, Gansu Province, flows through Shaanxi Province and flows into Jinghe River and Beiluo River, and flows into the Yellow River in Tongguan County. Legend has it that in ancient times, the Jinghe River was clear and the Weihe River was turbid, and there was a clear dividing line at the intersection of the two rivers. "The Book of Songs Gu Feng": "Jing Hunhun, its muddy also." "Characteristic" means that the Jinghe River is clear and the Weihe River is turbid. When Jinghe River flows into Weihe River, the boundary between clarity and turbidity is very clear. The metaphor is very clear, such as advantages and disadvantages, right and wrong.