The coupling and coordination relationship between ecology and the economy in the Yellow River Basin is a hot topic in sustainable development research. Said research has important guiding significance for the ecological security and comprehensive development of the Yellow River Basin. Taking the Yellow River Basin as the object of our study, based on the data of the economy, energy consumption data, ecology data and water resources data, we construct an indicator system of the economic development and ecological status of the Yellow River Basin and use the principal component analysis method to calculate the economic development and ecological status index. Then, we use the evaluation method, the coupling degree model and the coupling coordination degree model to analyze the time and space evolution trends of economic development and ecological state, coupling degree and coupling coordination degree. The results show that: (1) From 2000 to 2018, the economic development index of the Yellow River Basin rose steadily; the ecological status index showed a slow rise and then a downward trend. (2) The degree of coupling between economic development and ecological state has been considered as intensity coupling after 2005. The coupling trend slowly increased and then decreased, indicating that the interaction effect between the economy and ecology was first significantly enhanced and then slowly weakened. (3) The degree of coupling coordination increased from 0.2994 to 0.6266 and then decreased to 0.5917, reflecting the continuous improvement of the relationship between the regional economy and the ecological environment and the trend toward coordination. From 2015 to 2018, due to the gradual increase in the difference between economic development and ecological conditions, the coupling and coordination between the two decreased. Studies have shown that ecological construction and protection should be strengthened to ease the contradiction between the economy and ecology and achieve coordinated development.

The ecological system is the basis of human survival and global environmental protection. In the process of development, countries will pay close attention to the changing state of the ecosystem. Taking the ecosystem pattern as the research object, a three-layer analysis method was proposed. The transfer matrix and landscape index were used as the first layer to analyze the basic changes. Grey correlation, range-coupling coordination and relative priority were used as the second layer to analyze the reasons of the change. The interval-entropy weight, TOPSIS (Technique for Order Preference by Similarity to an Ideal Solution), was used as the third layer to evaluate the quality of the change. The ten counties in the worst-hit areas of the Wenchuan earthquake were analyzed from different angles, with county region, intensity zone and ecosystem as the objects, and the following results were obtained: (1) Taking Mianzhu City as an example, from 2000 to 2010 and 2018, the conversion ratio of forest, grassland and farmland is 54.24, 59.19, 17.21, 20.06, 37.39 and 52.86%, which were distributed in the north, central and southern parts, respectively. (2) Taking the ninth intensity zone as an example, the forest landscape fragmentation increased, disturbance decreased, and species diversity increased. There is a high influence and restriction relationship between ecosystem and landscape pattern in the total landscape area change. Additionally, the relationship between them tends to develop in a benign way. As of 2018, it is in the change state of moderate imbalance-ecosystem lag. (3) Taking the county ecosystem change as an example, urban type is the best in the counties of ecosystem change, of which Shifang is the best and Pingwu is the worst. The results show that this method can effectively compare and analyze the changes in the multi-regional ecosystem pattern, which has the characteristics of universality and can also be applied to the research of ecosystem pattern change in special regions.