The Yellow River Delta has a lot of land that could be used for development, but a lot of the soil is too salty for farming. By studying samples from different areas, researchers found that soil salt levels vary at different depths and scales. They discovered that areas like former swamps and tidal flats have more salt than flood plains. The saltiness of the soil changes depending on the location and size of the area being studied. The researchers also found that certain factors, like the shape of the land, can affect how salty the soil is. This information can help plan better ways to study and use the salty soil in the future.