Abstract:

Based on the monitoring data of national geoinformation, this study analyzes the distribution pattern and change characteristics of natural ecosystems, including forest land, grassland, wetland, and bare land, from 2015 to 2019 in eight cities and one county along the Yellow River in Henan Province, China. Results show that the coverage rates of forest land, grassland, wetland, and bare land along the Yellow River are 36.12%, 2.61%, 2.01%, and 0.56%, respectively. Forest land was dominated by broad-leaved forests and broad-leaved shrub forests. The land coverage of coniferous forests, arbor-shrub-mixed forests, afforested land, and artificial young forests increased, and the land coverage of broad-leaved, coniferous, and broad-leaved shrub-mixed forests decreased during the study period. Grassland was dominated by high-coverage grassland, accounting for 81.47% of the grassland area. During the study period, the area of high-coverage grassland, artificial green grassland, and slope-protected shrub grassland increased and the area of medium-coverage grassland and herbage grassland decreased. The wetland was dominated by rivers, occupying 97.63% of the total wetland area. During the study period, the area of rivers and canals increased. The gravel surface was dominant, accounting for >60% of the total bare land. During the study period, the coverage area of all types of bare land showed a downtrend. Overall, in the Yellow River region of Henan Province, the distribution characteristics of different natural ecosystems differed; forest land was mainly distributed in the middle reaches, while the grassland was mainly distributed in the low reaches; the spatial distribution of the wetland area in the low reaches was higher than that in the middle reaches,while the area of bare land in the middle reaches was higher than that in the low reaches. During the study period, the coverage of forest land and bare land decreased, while that of grassland and wetland increased.

Key words: national geoinformation, ecological system, distribution pattern, Yellow River region, land cover, ecological status