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Highlights • Our RS-based method integrates 11 dimensional features to map urban land use. • We develop multi-dimensional DPSIR-based indicators to analyze urban land expansion. • Increasing sprawl while decreasing density reduces economic-socio-ecological benefits. • Quantifying the interactions between multiple indicators can aid urban planning. • Optimizing multi-dimensional trade-offs and synergies is the key to sustainability. Abstract Rapid urban land expansion not only stimulates socioeconomic development, but can lead to negative impacts that threaten regional food security, ecological construction, and sustainable urban development, including losses of cropland and habitats, the creation of housing bubbles, and reductions in biodiversity. Because these economic-socio-ecological problems are generally more serious in ecologically fragile areas, this study focuses on trends seen in Ganzhou District, a typical oasis city within the Heihe River Basin (HRB) in an arid-to-semi-arid area of China. We apply a remote-sensing (RS)-based method that incorporates 11 dimensional features of Thematic Mapper and Enhanced Thematic Mapper Plus (TM/ETM+) images to map changes in urban land, and also develop a series of multi-dimensional indicators within a drivers, pressures, states, impacts, and responses (DPSIR) framework to quantify urban land expansion. The results of this study show that the urban land area of Ganzhou District in 2016 had expanded by 394.43% from 1987 levels, from 1979.64 ha to 9787.86 ha. These increasing pressures, jointly driven by gross domestic product (GDP), urban population, cropland area, and the industrial structure indicator (ISI), have led to the worsening economic-socio-ecological states and impacts of urban land expansion. Specifically, between 1987 and 2016, expansion intensity (EIPI) and expansion rate pressure indicators (ERPI) increased from 60.27 ha/a to 520.88 ha/a, and from 3.04%/a to 10.21%/a, respectively. Thus, the state indicators of economic development (EDSI), population carrying capacity (FDSI), food security (FSSI), and ecological construction (ECSI) decreased by 2.21 × 103 USD/ha, 17.62 population/ha, 34.20, and 10.80, respectively. Moreover, the impact indicators of economic development (EDII), population carrying capacity (FDII), and food security (FSII) decreased by 150.68 × 103 USD/ha, 62.12 population/ha, and 27.31, respectively, while the ecological construction impact indicator (ECII) increased by 29.39 between 1997 and 2007 and decreased by 13.31 between 2007 and 2016. Data also show that the area and proportion of cropland and ecological land occupied by urban land expansion increased over time. We therefore propose a series of economic-socio-ecological responses to help limit urban sprawl and foster compact green cities. Measures include planning urban growth boundaries, revitalizing urban centers and brownfields, using and re-using urban land more efficiently, strengthening land regulations, curbing excessive cropland expansion, cultivating more urban green spaces, and optimizing the trade-offs and synergies between multiple conflicting dimensions. [ABSTRACT FROM AUTHOR]

Net Primary Productivity (NPP) is one of the significant indicators to measure environmental changes; thus, the relevant study of NPP in Northeast China, Asia, is essential to climate changes and ecological sustainable development. Based on the Global Production Efficiency (GLO-PEM) model, this study firstly estimated the NPP in Northeast China, from 2001 to 2019, and then analyzed its spatio-temporal evolution, future changing trend and phenology regularity. Over the years, the NPP of different forests type in Northeast China showed a gradual increasing trend. Compared with other different time stages, the high-value NPP (700–1300 gC·m−2·a−1) in Changbai Mountain, from 2017 to 2019, is more widely distributed. For instance, the NPP has an increasing rate of 6.92% compared to the stage of 2011–2015. Additionally, there was a significant advance at the start of the vegetation growth season (SOS), and a lag at the end of the vegetation growth season (EOS), from 2001 to 2019. Thus, the whole growth period of forests in Northeast China became prolonged with the change of phenology. Moreover, analysis on the sustainability of NPP in the future indicates that the reverse direction feature of NPP change will be slightly stronger than the co-directional feature, meaning that about 30.68% of the study area will switch from improvement to degradation. To conclude, these above studies could provide an important reference for the sustainable development of forests in Northeast China. [ABSTRACT FROM AUTHOR]