Quantification of the spatial pattern of urban heat island intensities across the transnational urban agglomeration of the Tumen River is important for the promotion of sustainable regional development. This study employed Landsat images and MODIS LST data obtained in 2016 to determine the intensity of urban heat islands in this region, enabling direct comparison of data from the sub-regions of China, Democratic People’s Republic of Korea (DPRK), and Russia. The average urban heat island intensity for the region was found to be 1.0 °C, with the highest intensity of 3.0 °C occurring during the summer time. The intensity of urban heat islands on the Chinese side was higher than on the other two sides, with city size, socio-economic development levels and vegetation coverage significantly affect their intensity. Urban heat island effects in Chinese cities in the region contribute increases in maximum summer temperatures and the number of high-temperature days that pose a threat to the health of their residents. The factors that influence urban heat island intensities in these cities and the impacts of urban heat island effects on the quality of life and health of residents are discussed. Therefore, it is desirable to reduce the impact of urban heat island effects on cities in the region by increasing the area of green spaces they contain, as well as controlling their size and population.

Ecological sensitivity is one of the important indicators of regional ecological fragility, which can represent the sensitivity of ecosystems to natural environmental conditions and human activity disturbances in the region. In this study, the ecological sensitivity of land resources in the Tumen River Basin of China was quantitatively evaluated by taking 3 ecologically sensitive impact types, including the natural environment, human disturbance, and soil erosion, as evaluation criteria, and 11 ecologically sensitive factors were selected to build an evaluation system using the analytic hierarchy process (AHP) method, to determine the weights of the evaluation factors, combined with geographic information system (GIS) technology. The results show that: (1) Among the three types of ecological sensitivity factors, the influence of human disturbance is the most obvious, and the two factors of land use type and distance from construction land have the highest weights in the comprehensive ecological sensitivity evaluation. (2) There are no extremely sensitive areas or insensitive areas in the Tumen River Basin in China. Highly sensitive areas account for only 0.59% of the total area and are mainly concentrated in the lakes, rivers, and reservoirs in the study area. Moderately sensitive areas account for 54.12%, which are concentrated in the central part of the Tumen River Basin Slightly sensitive areas are mainly located in the mountainous areas in the north and south of the study area. (3) Among the various land resource types, the proportion of slightly sensitive areas and moderately sensitive areas of woodland is close (about 50%), while cultivated land, grassland, construction land, and bare land are mainly moderately sensitive areas (73.95%, 82.07%, 96.59%, and 78.78%), and water bodies are mostly distributed within highly sensitive areas (60.97%), and all wetlands with the smallest area are moderately sensitive. The results of the study can provide data support and a scientific basis for regional ecological protection and development planning.

The transnational area of Changbai Mountain (TACM) is crucial to sustainable development in Northeast Asia owing to its abundant forest, which helps in maintaining biodiversity and multiple ecosystem services. However, the spatiotemporal patterns of forest in the TACM have been poorly understood across the whole region. The objectives of this study were to quantify the spatiotemporal patterns of forest in the TACM from 1977 to 2015, investigate the causes of forest dynamics, and assess the impacts of forest dynamics on habitat quality. To do this, we first extracted the forest in the TACM from Landsat images acquired in 1977, 1988, 1999, 2007, and 2015 using visual interpretation. Then, we analyzed the spatiotemporal patterns of forest in the TACM from 1977 to 2015 using landscape metrics and compared the dynamics of forest between the area in China and the area in the Democratic People’s Republic of Korea (DPRK). After that, we investigated the driving forces of forest dynamics and the impacts of forest dynamics on habitat quality. We found that the TACM experienced a noticeable forest decrease—from 1.57 million ha in 1977 to 1.48 million ha in 2015, a decline of 5.78%—and underwent a forest fragmentation process. In particular, the sub-region in the DPRK had a much larger decrease (17.75%) than the sub-region in China (2.86%). We found that timber harvesting, urban expansion, agricultural reclamation, and typhoon disasters were the main driving forces behind forest decreases in the TACM. Specifically, agricultural reclamation was the most important factor in the DPRK sub-region, while urban expansion was the dominant factor in the Chinese sub-region. Furthermore, such forest loss and fragmentation has resulted in declines in habitat quality across both sides of the TACM. Thus, we suggest that more effective forest management with cooperation between China and DPRK is needed to maintain and improve forest coverage in the TACM.

Nam Shin Kim, Chi Hong Lim, Jin Yeol Cha, Yong Chan Cho, Song Hie Jung, Shi Zhu Jin and Ying Nan. J Ecol Environ 2022;46:. https://doi.org/10.5141/jee.22.054

Ecosystem service flows are critical linkages between ecological supply and human demand. As a vital component of ecosystem services, water yield service is essential for human survival and development. Therefore, it is of great significance to explore the supply–demand relationship of water yield service and its spatial flow process. This study investigates the supply–demand dynamics and spatial flow of water yield service in the transnational area of Tumen River (2000–2020), utilizing the InVEST model and the miniature delivery-path-mechanism model. The results show the following: (1) From 2000 to 2020, the supply of water yield service in the Tumen River Basin exhibited a spatial distribution pattern of “low center, high surrounding”, with significant spatial heterogeneity in the distribution of supply and demand. (2) Despite the substantial surplus of water yield service in the study area, the ecosystem service supply–demand ratio (ESDR) shows an overall declining trend. The dominant spatial mismatch type is high-supply–low-demand (HL type) zones, primarily located in mountainous and hilly areas, accounting for over 40% of the total identified pixel types. (3) Driven by economic and social development, the spatial scope of water yield service flow has gradually expanded. Supply-side flows initially increased before declining, while demand-side flows followed the opposite trend. By mapping ecosystem service flows, this study provides a reference and basis for establishing the regional ecological compensation mechanism and promoting integrated water resource management, both of which are crucial for the long-term sustainable development of the basin.