| Popis: |
The Landsat TM/ETM+/OLI remote sensing images as of 1991, 1995, 1999, 2004, 2009, and 2013 were selected as data sources to analyze large scale range coastal wetland degradation in the Yellow River Delta in the view of landscape and land use. The Markov process model was applied to simulate and predict the evolution trends of coastal wetlands of 2021 in the region. Results showed that the most serious wetland degradation in the Yellow River Delta appeared in the two periods of 1999-2004 and 2004-2009. The area proportion of degraded wetlands to the total natural wetlands was nearly 40%. The wetland degradation in the study area had been alleviated to a certain degree since 2009. Up to 2021, the proportion of wetlands to land area would fall to 60%. Compared with 2013, the proportion of natural wetland and constructed wetland would decrease by 4.52 percent point and 3.08 percent point, respectively. The area of marshes, shrub wetlands, forest wetlands, and salt marshes would decline by 32.21, 15.76, 19.33 km2 and 74.86 km2, respectively. Therefore, the ecological protection and restoration work of coastal wetlands in the Yellow River Delta will be still arduous in the future. |
