Evolvement rules of basin flood risk under low-carbon mode. Part II: risk assessment of flood disaster under different land use patterns in the Haihe basin.

Land use pattern contains a large amount of information about the flood hazard-formative environments, which is the most sensitive factor in hazard-formative environments. In this paper, based on the land use pattern in 2008 (the base year) and in 2020 (the planning year), the comparative analysis of flood disaster risk changes in Haihe basin were studied by the spatial analysis function of ARCGIS and the analytic hierarchy process (AHP). The results showed the flood disaster risk in Haihe basin had an obvious zonality in the space, among which low risk was located in the northwest regions, and high risk was located in the southeast regions. Flood disaster risk in planning year was lower than in the base year. The risk value of 2020 in the mountain decreases from 0.445 to 0.430, while the risk value of the plain increases from 0.562 to 0.564. For the plain, high-risk area in 2020 is increased by 13.2%, which is the biggest change in risk grades. For the mountain, low-risk area and low risk area in 2020 are increased, and the low-risk area is the biggest increase, up to 37.7%. Meanwhile, high-risk area, high risk area, and medium risk area all tend to decrease, and the high-risk area is the biggest decrease, up to 32.6%. Overall, land use planning pattern under low-carbon mode is conducive to the Haihe basin flood control. The research can provide scientific foundations for basin land use planning and flood disaster risk management.