The Delft3D model was used to simulate the flooding process on floodplains of the Lower Yellow River, and the flood disaster parameters such as flooding range and flooding depth were statistically calculated from the model. The process of giving the flood risk’s spatial distribution of the plains includes dividing the hazard-vulnerability units and calculating the hazard and vulnerability of each unit according to the topography and flood-control measures. The United Nations risk assessment index system is used to give out the spatial distribution of the flood risk for each inundation unit. The results show that the relationship between flood risk and flood scenarios response across the study area can be divided into three categories. About 50% of the plain are under “simultaneous flooding and risks”, which means the flood risk level generally varies with the flood scenario. 39.7% of the plains own the trait of “low flooding frequency leads to giant risks”, and for the unit of this category basically has the extreme risk even for the 10-year frequency floods. 11.67% of the plain are stable at a relatively low risk situation, and the flood risk is not affected by the magnitude of the flood, which is classified as “stable low risks”. In order to prevent the flood risk of the Lower Yellow River, the flooding unit of “low flooding frequency leads to giant risks” mainly distributed in Gaocun to Aishan section should give a priority to take the action, and the flood situation of once every ten years or even once every five years should be taken as the reference basis for building flood prevention measures.

Based on the 15 m×15 m spatial distribution raster data of 11 types of land use in 2015 and the landscape pattern index, the landscape pattern characteristics of land use in the counties, floodplains and flood detention areas along the wide reaches of the Lower Yellow River, and gradient characteristics of the landscape patterns of land use in the 18 2km-buffer zones on both sides, are compared and analyzed. The results show that the dry farmland is the dominant landscape within the counties along the wide reaches, followed by the rural residential land, and they account for more than 80% of the total area of the counties. The paddy fields and the other categories of waters have a certain scale and the scale of the grassland is small. Influenced by factors such as functional orientation and natural conditions, there are obvious spatial differences in land use landscape patterns in the counties, floodplains and flood detention areas along the wide reaches of the Lower Yellow River. There are large-scale and densely-distributed construction land in the extra-floodplains area of the counties, the landscape fragmentation of which is high and the patch shape is complex. The landscape diversity of the Dongping Lake flood detention area is high, showing a complex ecological landscape with waters as the main body, and in the other two flood detention areas, the scale of woodland and grassland is small, the patch density and the landscape heterogeneity is low. The overall landscape fragmentation in the wide reaches’ floodplains is lower than that in the extra-floodplains area, the landscape diversity of the wandering reaches’ floodplains is relatively high, and the construction land is relatively large. Within 6 km of the two sides of the wide reaches, the paddy fields and the other categories of waters are large in scale and densely distributed, the scale of the urban land is small, and the overall landscape diversity in this region is high and relatively fragmented; the transition region is from about 6 km to 18 km; the landscape patterns tends to be stable over 20 km away.

Based on the satellite remote sensing image of the lower Yellow River in 2015–2017, adopting the method of manual interpretation, with ArcGIS, the paper analyzes the present distribution of land use/cover type of the lower Yellow River. Based on social and economic statistics, analyze the factors are analyzed affecting the distribution of land use/cover in the lower Yellow River. The results show that the land use/cover on the lower reaches of the Yellow River is mainly used for development, among which the most priority is the cultivated land without facilities, which is accounting for 77.99%, followed by land for survival, accounting for 6.63%. The width of river, the area of the land, the village and the land for industry of the part from Taohuayu to Gaocun is more than that of other parts. The type of land use/cover of the lower Yellow River is quite simple. The area of the land of the lower Yellow River, the economic situation, the attraction of the city development and the water conservancy facilitie around affects land use/cover. The area of the village, the farm land with facilities and brickyard grows with the area of land. The fish ponds and the land for industry appear mostly in lands with better economic situation. Farm land with facilities and land for industry appear mostly in those lands near downtown.