Rui Yan

The coordinated development of ecological protection and socioeconomics in the Tibetan Plateau is of great significance. This study examines the coupling coordination of urban ecosystems and economic development across 15 municipal administrative units in Qinghai Province and the Tibet Autonomous Region, the core areas of the Tibetan Plateau. The findings reveal that a larger proportion of the Qinghai and Tibet ecosystems are classified above the medium vulnerability level, primarily due to inherent natural geographic conditions. Additionally, the area of the two provinces and regions below the medium development level is larger, which is mainly influenced by indicators of economic strength and industrial structure. The degree of coupling coordination between the ecosystem and economic system in Qinghai and Tibet is predominantly driven by economic factors. Given the existing natural environmental conditions, the eastern regions of Qinghai and Tibet still possess certain development potential, while the economic development in the western areas is somewhat constrained by the natural environment. Based on this, further policy recommendations have been proposed to adjust and upgrade the industrial structure, aligning ecological protection with economic development in the Qinghai–Tibet Plateau. These recommendations aim to facilitate the formulation of strategies and policies for sustainable urban construction and social development in such high-ecological-value regions as the Tibetan Plateau.

Floods are among the most common natural disasters worldwide and cause significant losses under climate change. Advanced flood loss assessment helps to improve flood prevention and relief systems. The vulnerability curve is one of the main methods for flood loss risk assessment. However, existing vulnerability curves are mostly established on a large spatial scale, ignoring the intraregional difference in vulnerability. This study aims to quantify the spatial heterogeneity of vulnerability within the region and to clarify the impact and changes of vulnerability on flood loss. Choosing Hubei and Hunan Provinces in China as study areas, this study built vulnerability curves using the mixed-effects model. Then, vulnerability curves and flood intensities under different return periods were combined to assess flood losses. The impacts of vulnerability and flood intensity on flood losses were also analyzed. The results show that 1) the mixed-effects model can be employed to construct separate vulnerability curves for smaller-scale administrative units (cities) while assessing the overall vulnerability of the study area, and the results are more accurate, with R2 values above 0.75, 2) With the increasing return period, the differences in loss rates between cities increase, and 3) Vulnerability difference between cities is the dominant factor influencing flood losses of cities with low return periods. However, with the increasing return period, the difference in hazard intensity between cities exerts a greater impact on city flood losses. This study provides methods and suggestions for systematic flood risk reduction and climate resilience construction path proposal.

Global warming and its associated changes in temperature and precipitation have significantly affected the ecosystem in Southwest China, yet studies that integrate temperature and precipitation changes are inadequate for quantitatively assessing the impacts of extreme events on ecosystems. In this study, the return period of concurrent climate extremes characterized by precipitation deficit and extreme temperature and the spatial and temporal dynamic patterns of their impacts on ecosystems were assessed by using high-precision temperature and precipitation data, as well as NDVI and NPP data collected for the 1985–2015 period. The results show that the 2009 concurrent event had a return period of about 200 years. The return periods of individual climate factors are significantly overestimated or underestimated. Concurrent events significantly reduced the spring and annual Normalized Difference Vegetation Index (NDVI) and net primary productivity (NPP) in Southwest China. The magnitude of the reduction in vegetation greenness and productivity increased with the intensity of concurrent events. Concurrent events beginning in autumn 2009 reduced spring NDVI and NPP by 8.8% and 23%, and annual NDVI and NPP by 2.23% and 7.22%, respectively. Under future climate scenarios, the return period of concurrent events could be significantly shortened, which would have a more severe impact on regional ecosystems.