hekouquIntroduction：Introduction to the estuary: The estuary area is affiliated to Dongying City, Shandong Province, and is an administrative district. It is located in the northern part of Shandong Province, on the south bank of the Bohai Sea, and on the north side of the Yellow River estuary. It is one of the frontier cities of the Yellow River Delta and one of China's second largest oilfields – Shengli Oilfield. It is the intersection of the Bohai Economic Zone and the Yellow River Economic Belt, and has a significant location advantage. In November 1982, according to the State Council (82) National Letter No. 249, “Reply on the Establishment of Dongying City in Shandong Province”, the Hekou District was established as the jurisdiction of Dongying City. The Yellow River Delta, where the estuary is located, is a typical alluvial plain of the Yellow River. It is the “Golden Triangle” with the most abundant land, oil, natural gas, salt brine, geothermal and shallow sea resources in China's coastal areas. Xianhe Town was rated as a national demonstration residential community, a national demonstration town for small towns, a beautiful township in the country, and won the “Shandong Human Settlements Award”; Gudao Town was listed as the central town of Shandong Province; "Qilu Cup" activities in advanced urban areas.