Dynamic Characteristics of the Water Conservation Functions of Ecosystems in the Yi–Luo River Basin

Water conservation is among the most important ecosystem service functions, and its dynamic changes can reflect the health of regional ecosystems. As one of the ten major tributaries of the Yellow River, the Yi–Luo River in Henan Province plays a significant role in maintaining regional ecological health through the ecosystem water conservation functions of its basin. To explore the characteristics of these functions, this study employed ecosystem transfer matrix and water balance methods to analyze the changes in ecosystem types in the basin and the dynamic changes in the corresponding water conservation functions from 2010 to 2020. The results showed that from 2010 to 2020, the dominant ecosystem types were farmland, forestland, and shrubland, and the main transformations between different ecosystem types were from farmland to urban areas and wetland, from grassland to shrubland, and from shrubland to forestland. The water conservation functions of the different ecosystem types varied significantly, with the average water conservation capacities ranked as follows: forestland > wetland > shrubland > grassland > farmland > others > urban areas. Due to the decreased water conservation depths in the forestland and shrubland ecosystems, the overall water conservation depth decreased over the study period. In addition, the water conservation capacities of the farmland, forestland, and shrubland ecosystems were the highest, reaching 12.94 × 108, 12.15 × 108 and 9.73 × 108 tons, respectively, accounting for 34.47%, 32.35%, and 25.91% of the total water conservation capacity, respectively. Overall, water conservation in the study area was high in the south and low in the north, and there was an overall decreasing trend over time. Moreover, the regions with critical and important water conservation functions accounted for the largest proportion (47.2%). The critical and important regions were mainly located in the higher altitudes of Luanchuan County and Lushi county, while the moderate and average regions were primarily located in the plains, and weak regions were distributed mainly in the urban area of Luoyang city. Through analysis of the spatiotemporal changes and degree of importance of water conservation functions in the Yi–Luo River Basin, the key regions for ecological protection and construction were identified. The study results can be used to help enhance ecological security in the Yellow River Basin of Henan Province and play a significant role in promoting the regional economy as well as the health and sustainable development of the ecological environment.