## 4 Discussion and Conclusions
### Conclusions  
Based on the research by [PERSON] et al. [6], the changes in land use in areas along the Grand Canal from 1991 to 2021 and their impact on EVs were analyzed using land use data for three periods (1991, 2006, and 2021) in combination with the ecosystem service coefficients per unit area modified by equivalent factors. The main conclusions are as follows:  
1. The ESV along the Grand Canal generally showed a trend of first increasing and then decreasing, with an overall decrease of CNY 16.684 billion, which can primarily be attributed to the acceleration of the urbanization process. The temporal change in the total ESV along the Grand Canal was mainly related to the transfer between the areas of different land use types during the study period. The above trend led to a reduction in the areas of cultivated land, woodland, and grassland, while the substantial expansion of construction land decreased positive contributions and increased negative contributions to the ESV. 2. The temporal changes in the individual EVs along the Grand Canal varied greatly from 1991 to 2021, with hydrological regulation and nutrient cycling maintenance providing the highest and lowest ESVs, respectively. The EVs of hydrological regulation, water resource supply, environmental purification, biodiversity maintenance, and aesthetic landscape provision showed a trend of first increasing and then decreasing, while the EVs of food production, raw material production, gas regulation, climate regulation, soil conservation, and nutrient cycling maintenance decreased continuously. 3. The spatial pattern of ESV along the Beijing-Hangzhou Grand Canal exhibited distinct regional characteristics. High-value areas are often found scattered amidst what can be described as 'tiger-striped water', a metaphorical representation of the patchy and irregular distribution of water bodies in the upstream, midstream, and downstream regions. These areas are typically rich in natural resources and support a favorable ecological environment, contributing to their high ecosystem service values. In contrast, mid-value areas were contiguously distributed across cultivated land, forests, and grasslands in the middle section of the Grand Canal, where ESVs were relatively moderate and widely distributed. Low-value areas are primarily concentrated in urban clusters in the Beijing-Tianjin region, which may be related to the urbanization process and human activities that disturb the ecosystem. The ESV along the Beijing-Hangzhou Grand Canal has undergone a trend of \"first decreasing and then increasing\". The low-value areas centered in Beijing and Tianjin have gradually expanded, which may be linked to the acceleration of urbanization and increased ecological and environmental pressures in these regions. As the most widely distributed area, the mid-value region exhibited relatively stable ESVs, indicating a certain degree of resilience in maintaining ecosystem services in these regions. Furthermore, ESVs have increased in the northern and southern sections of the Grand Canal, as well as in water bodies such as Hongze Lake, Gaoyou Lake, and Taihu Lake. However, most areas exhibited a decrease in ESVs. The conclusions we described are instrumental for formulating more scientifically sound ecological protection and land use planning to ensure the sustainability of ecosystems. The study discovered that the ESV in moderate-value areas is relatively stable, indicating that these regions possess a certain resilience in maintaining ecosystem services, providing insights into the adaptability and recovery strategies for ecosystems along the Grand Canal. The land use forms on both sides of the canal should be enhanced, considering the current ecological service supply situation, and there should be a strong emphasis on developing high-quality farmland to meet higher standards.