High uncertainties detected in the wetlands distribution of the Qinghai–Tibet Plateau based on multisource data

Abstract

Twenty wetland-related data products (including remote sensing datasets, compilation datasets and model simulation datasets) were collected to evaluate the characteristics (area and distribution) of the wetlands in the Qinghai–Tibet Plateau (QTP) during four stages (1980s, 1990s, 2000s, and 2010s). We conducted a statistical analysis of the wetland areas from different datasets and compared the pixel consistency regarding wetland spatial distribution. The results showed that high uncertainty exists in the wetland area and low consistency exists in the distribution among the different datasets. The wetland area in the QTP ranged from 1.5 × 104 to 121.16 × 104 km2. In the remote sensing datasets, the wetland area in the QTP ranged from 3.25 × 104 to 11.28 × 104 km2, the calculated area was between 1.50 × 104 and 72.21 × 104 km2 in the compilation datasets, and the area simulated from model datasets was between 3.81 × 104 and 121.16 × 104 km2. For the total wetland area in the QTP, the uncertainty in the measured datasets was lower than that in the model simulation datasets. However, for the distribution of wetlands, the measured datasets were more inconsistent than the model datasets. In the measured datasets, as the pixel consistency increased, the corresponding probability throughout the area decreased. The probability of achieving 75% consistency was less than 2%, and was 0.61%, 0.35%, 1%, and 1.43% in the four stages, respectively. In the model products, the probability of achieving 75% consistency was 40.39%. Our study will enrich the global wetland database and contribute to the establishment of a plateau wetland information system, which will be significant for the protection and management of wetlands.