The Weihe River-Mihe River Delta in China's Bohai Sea coast is formed by several rivers and has been growing for thousands of years. The delta is made up of clayey silt from all rivers, fine sand from individual river mouths, and bay silt between river mouths. The delta has no distinct abandoned lobe, and the sand and silt layers alternate due to river mouth movement. The coast has extended 20-55 km over the past 7000 years, with a thickness of over 20 meters. The distance between river mouths is around 20 km or less.