Forest ecosystem, as a predominant component of terrestrial ecosystems in view of carbon sinks, has a high potential for carbon sequestration. Accurately estimating the carbon sequestration rate in forest ecosystems at provincial level, is a prerequisite and basis for scientifically formulating the technical approaches of carbon neutrality and the associated regulatory policies in China. However, few researches on future carbon sequestration rates (CSRs) for Chinese forest ecosystems for provincial-level regions (hereafter province) have been reported, especially for forest soils. In this study, we quantitatively assessed the carbon sequestration rates of existing forest ecosystems of all the provinces from 2010 to 2060 using the Forest Carbon Sequestration model (FCS), in combination with large quantities of field-measured data in China under three future climate scenarios (RCP2.6, RCP4.5, and RCP8.5). Results showed that CSRs across provinces varied from 0.01 TgC a^-1 to 36.74 TgC a^-1, with a mean of 10.09 ± 0.43 TgC a^-1. Inter-provincial differences have been observed in forest CSRs. Regarding the spatial variations in CSRs on a unit area basis within provinces, the eastern region provinces have a larger capacity for sequestration than the western region, while the western region has greater CSR per unit GDP and per capita. Moreover, there are significant negative correlations between the CSRs per capita in each province and the corresponding GDP per capita, under the assumption that GDP per capita is constant in the future across provinces. In summary, there is a significant regional imbalance in CSR among provinces. Special technological and policy interventions are required to realize carbon sink potential sustainably. An overlap in China’s poorer areas and areas with stronger carbon sinks has indicated that existing policies to support traditional carbon trading are insufficient. Regulatory measures such as “regional carbon compensation” must be adopted urgently in line with the Chinese characteristics, so that people in western or underdeveloped regions can consciously strengthen forest protection and enhance forest carbon sinks through coordinated regional development while ensuring that China’s forests play a greater role in carbon neutrality strategies.

Cropland displacement, as an important characteristic of cropland change, places more emphasis on changes in spatial location than on quantity. The effects of cropland displacement on global and regional food production are of general concern in the context of urban expansion. Few studies have explored scale-effects, however, where cropland is displaced not only within, but also outside, the administrative boundary of a certain region. This study used a spatially explicit model (LANDSCAPE) to simulate the potential cropland displacement caused by urban land expansion from 2020 to 2040 at four scales of the Chinese administration system (national, provincial, municipal, and county levels). The corresponding changes in potential cereal production were then assessed by combining cereal productivity data. The results show that 4700 km² of cropland will be occupied by urban expansion by 2040, and the same amount of cropland will be supplemented by forest, grassland, wetland, and unused land. The potential loss of cropland will result in the loss of 3.838×10⁶ tons of cereal production, and the additional cropland will bring 3.546×10⁶ tons, 3.831×10⁶ tons, 3.836×10⁶ tons, and 3.528×10⁶ tons of potential cereal production in SN (national scale), SP (provincial scale), SM (municipal scale), and SC (county scale), respectively. Both SN and SC are observed to make a huge difference in cereal productivity between the lost and the supplemented cropland. We suggest that China should focus on the spatial allocation of cropland during large-scale displacement, especially at the national level.

The black soil region of northeast China is a vital food base and is one of the most sensitive regions to climate change in China. However, the characteristics of the crop phenological response and the integrated impact of climate and phenological changes on agricultural productivity in the region under the background of climate change are not clear. The future agricultural risk assessment has been insufficiently quantified and the existing risk level formulation lacks a sound basis. Based on remote sensing products, climate data, and model simulations, this study integrated a logistic function fitting curvature derivation, multiple linear regression, and scenario simulation to investigate crop phenology dynamics and their climate response characteristics in the black soil region. Additionally, the compound effects of climate and phenology changes on agricultural production and possible future risks were identified. The key results were as follows: (1) From 2000 to 2017, 29.76% of the black soil region of northeast China experienced a significant delay in the start of the growing season (SOS) and 16.71% of the total area displayed a trend for the end of the growing season (EOS) to arrive earlier. The time lagged effects of the SOS in terms of the crop response to climatic factors were site and climatic parameter dependent. The influence of temperature was widespread and its effect had a longer lag time in general; (2) Both climatic and phenological changes have had a significant effect on the inter-annual variability of crop production, and the predictive ability of both increased by 70.23%, while the predictive area expanded by 85.04%, as compared to that of climate change in the same period of the growing season; (3) Under the RCP8.5 scenario, there was a risk that the future crop yield would decrease in the north and increase in the south, and the risk area was constantly expanding. With a 2.0℃ rise in global temperature, the crop yield of the southern Songnen black soil sub-region would reduce by almost 10%. This finding will improve our understanding of the mechanisms underlying climate change and vegetation productivity dynamics, and is also helpful in the promotion of the risk management of agrometeorological disasters.

With the continuous enhancement of regional connectivity, the indirect use of land resources through the pathways of trade in goods and services plays an increasingly important role in the overall utilization of land resources. Despite this, relevant research in this field is still in its infancy, and few papers have addressed this issue. This paper uses a multi-regional input-output model to calculate the embodied land in the 30 provinces (autonomous regions and municipalities) and eight regions of China from the perspective of regional trade and further analyzes the spatial pattern of characteristics associated with embodied land flows. The results show that the amount of embodied land occupied by China’s inter-regional trade accounts for 21.39% of the country’s total land, and an average of 38.54% of China’s provincial land demand is met by land exports from other provinces. More than 80% of land consumed by Beijing, Tianjin, and Shanghai is from other provinces. The provinces of Heilongjiang, Inner Mongolia, Xinjiang, and Hebei are the largest net exporters of cultivated land, forest and grazing and aquatic land, fishery land, and built-up land, respectively (the outflows account for 42.26%, 27.53%, 38.66%, and 35.28% of the corresponding land types in the province); and Guangdong, Shandong, and Zhejiang are the main net importers. The flow of agricultural land (cultivated land, forest land, grazing land, and aquatic land) generally shows a shift from west to east and from north to south. The regions in northeast and northwest China have the largest scale of agricultural land outflows, mainly into East and South China. In addition, 8.43% of cultivated land, 7.47% of forest land, 6.41% of grazing land, 6.88% of aquatic land, and 18.35% of built-up land in China are provided for foreign use through international trade. This paper provides feasible ideas and a theoretical basis for solving the contradiction between land use and ecological protection, which could potentially help to achieve sustainable land use in China.

Tidal flats, a precious resource that provides ecological services and land space for coastal zones, are facing threats from human activities and climate change. In this study, a robust decision tree for tidal flat extraction was developed to analyse spatiotemporal variations in the Bohai Rim region during 1984-2019 based on 9539 Landsat TM/OLI surface reflection images and the Google Earth Engine (GEE) cloud platform. The area of tidal flats significantly fluctuated downwards from 3551.22 to 1712.36 km² in the Bohai Rim region during 1984-2019, and 51.31% of tidal flats were distributed near the Yellow River Delta and Liaohe River Delta during 2017-2019. There occurred a drastic spatial transition of tidal flats with coastline migration towards the ocean. Low-stability tidal flats were mainly distributed in reclamation regions, deltas, and bays near the estuary during 1984-2019. The main factors of tidal flat evolution in the Bohai Rim region included the direct impact of land cover changes in reclamation regions, the continuous impact of a weakening sediment supply, and the potential impact of a deteriorating sediment storage capability. The extraction process and maps herein could provide a reference for the sustainable development and conservation of coastal resources.

Recently, whether drylands of Northwest China (NW) have become wetting has been attracting surging attentions. By comparing the Standard Precipitation Evapotranspiration Indices (SPEI) derived from two different potential evapotranspiration estimates, i.e., the Thornthwaite algorithm (SPEI_th) and the Penman-Monteith equation (SPEI_pm), we try to resolve the controversy. The analysis indicated that air temperature has been warming significantly at a rate of 0.4°C decade^?1 in the last five decades and the more arid areas are more prone to becoming warmer. Annual precipitation of the entire study area increased insignificantly by 3.6 mm decade^?1 from 1970 to 2019 but NW presented significantly increasing trends. Further, the SPEI_th and SPEI_pm demonstrated similar wetting-drying-wetting trends (three phases) in China’s drylands during 1970-2019. The common periodical signals in the middle phase were identified both by SPEI_th and SPEI_pm wavelet analysis. Analysis with different temporal intervals can lead to divergent or even opposite results. The attribution analysis revealed that precipitation is the main climatic factor driving the drought trend transition. This study hints that the wetting trend’s direction and magnitude hinge on the targeted temporal periods and regions.

Monitoring alpine lakes is important for understanding the regional environmental changes caused by global warming. In this study, we provided a detailed analysis of alpine lake changes in the Tianshan Mountains (TS) and discussed their driving forces based on Landsat TM/ETM+/OLI, WorldView-2, Bing, Google Earth, and ASTER imagery, along with climatic data from 1990 to 2015. The results showed that during the study period, the total number and area of alpine lakes in the eastern TS exhibited an increasing trend, by 64.06% and 47.92%, respectively. Furthermore, the continuous expansion of glacial lakes contributed 95.12% and 94.17% to the total increase in the number and area, respectively, of alpine lakes. Non-glacial lakes exhibited only intermittent expansion. Since the 1990s, the new glacial lakes in the eastern TS have been mainly proglacial and extraglacial lakes. Over the past 25 years, eastern TS has experienced a temperature increase rate of 0.47 °C/10a, which is higher than that in other TS regions. The rapidly warming climate and glacier recession are the primary causes of the accelerated expansion of glacial lakes in the eastern TS.

Understanding the radial growth trends of trees and their response to recent warming along elevation gradients is crucial for assessing how forests will be impacted by future climate change. Here, we collected 242 tree-ring cores from five plots across the Qinghai spruce (Picea crassifolia Kom.) forest belt (2600-3350 m a.s.l.) in the central Qilian Mountains, Northwest China, to study trends in the radial growth of trees and their response to climate factors with variable elevation. All the sampled P. crassifolia chronologies showed an increasing trend in the radial growth of trees at higher altitudes (3000-3350 m), whereas the radial growth of trees at lower altitudes (2600-2800 m) has decreased in recent decades. The radial growth of trees was limited by precipitation at lower elevations (L, ML), but mainly by temperature at higher elevation sites (MH, H, TL). Climate warming has caused an unprecedented increase in the radial growth of P. crassifolia at higher elevations. Our results suggest that ongoing climate warming is beneficial to forest ecosystems at high elevations but restricts the growth of forest ecosystems at low elevations.

Water use efficiency (WUE) is an important variable to explore coupled relationships in carbon and water cycles. In this study, we first compared the spatial variations of annual gross primary productivity (GPP) and evapotranspiration (ET) using four GPP and ET products. Second, we selected the products closest to the flux towers data to estimate WUE. Finally, we quantitatively analyzed the impact of climate change and soil water content on WUE. The results showed that: (1) Four GPP and ET products provided good performance, with GOSIF-GPP and FLDAS-ET exhibiting a higher correlation and the smallest errors with the flux tower data. (2) The spatial pattern of WUE is consistent with that of GPP and ET, gradually decreasing from the northeast to the southwest. Higher WUE values appeared in the northeast forest ecosystem, and lower WUE values occurred in the western Gobi Desert, with a value of 0.28 gC m^?2 mm^?1. The GPP and ET products showed an increasing trend, while WUE showed a decreasing trend (55.15%) from 2001 to 2020. (3) The spatial relationship between WUE and driving factors reveal the variations in WUE of Inner Mongolia are mainly affected by soil moisture between 0 and 10 cm (SM0-10cm), vapor pressure deficit (VPD), and precipitation, respectively. (4) In arid regions, VPD and precipitation exhibit a major influence on WUE. An increase in VPD and precipitation has a negative and positive effect on WUE, with threshold values of approximately 0.36 kPa and 426 mm, respectively. (5) In humid regions, SM0-10cm, VPD, SM10-40cm, and SM40-100cm exert a significant impact on WUE, especially SM0-10cm, and weakens with increasing soil depths, these differences may be related to physiological structure and living characteristics of vegetation types in different climate regimes. Our results emphasize the importance of VPD and soil moisture in regional variability in WUE.

Revealing the drivers and scale effects of water pollutant discharges is an important issue in the study of the environmental consequences during urban agglomeration evolution. It is also a prerequisite for realizing collaborative water pollutant reduction and environmental governance in urban agglomerations. This paper takes 305 counties in the Yangtze River Delta (YRD) as an example and selects chemical oxygen demand (COD) and ammonia nitrogen (NH₃-N) as two distinctive pollutant indicators, using the Spatial Lag Model (SLM) and Spatial Error Model (SEM) to estimate the drivers of water pollutant discharges in 2011 and 2016. Then the Multiscale Geographically Weighted Regression (MGWR) model is constructed to diagnose the scale effect and spatial heterogeneity of the drivers. The findings show that the size of population, the level of urbanization, and the economic development level show global-level increase impacts on water pollutant discharges, while the level of industrialization, social fixed assets investment, foreign direct investment, and local fiscal decentralization are local-level impacts. The spatial heterogeneity of local drivers presents the following characteristics: Social fixed assets investment has a strong promoting effect on both COD and NH₃-N discharges in the Hangzhou-Jiaxing-Huzhou region and the coastal area of the YRD; industrialization has a promoting effect on COD discharges in the Taihu Lake basin and Zhejiang province; foreign direct investment has a local inhibitory effect on NH₃-N discharge, and the pollution halo effect is more prominent in the marginal areas of the YRD such as northern Jiangsu, northern Anhui, and southern Zhejiang; local fiscal decentralization has a noticeable inhibitory effect on COD discharge in the central areas of the YRD, reflecting the positive impacts on improved local environmental awareness and stronger constraints of multilevel environmental regulations in the urban agglomeration. Therefore, it is recommended to guide greener development to reduce the water pollutant discharge; to embed an environmental push-back mechanism in the fields of industrial production, capital investment, and financial income and expenditure; and to establish a high-quality development pattern of urban agglomerations systematically compatible with the carrying capacity of the water environment.

Situated in the hinterland of Eurasia, Central Asia is characterized by an arid climate and sparse rainfall. The uneven spatial distribution of water and land resources across the region has pressured economic and social development. An accurate understanding of Central Asia's water resources carrying capacity (WRCC) is vital for enhancing the sustainability of water resources utilization and guiding regional economic and social activities. This study aims to facilitate the sustainability of water resources utilization by evaluating the region's WRCC from the viewpoints of economic and technological conditions and social welfare. A concise yet effective model with relatively fewer parameters was established by adopting water resources data from the Food and Agriculture Organization (FAO) and socioeconomic data from the World Bank. The results indicated that the WRCC of all five Central Asian countries showed an increasing trend with improved water use efficiency from 1995 to 2020. Kazakhstan's WRCC was significantly higher than the other four countries, reaching 54.03 million people in 2020. The water resources carrying index (WRCI) of the five Central Asian countries varied considerably, with the actual population sizes of Turkmenistan and Uzbekistan highly overloaded. Although there has been a decrease in Central Asian countries’ WRCI between 1995 and 2020, water resources utilization problems in the region remain prominent. Based on the water resources carrying capacity evaluation system, to increase available water resources and improve production water use efficiency are key to address these issues. In light of this, this study offers practical and feasible solutions at the policy level: (1) The implementation of signed multilateral agreements on transboundary water resources allocation must proceed through joint governmental efforts. (2) Investments in advancing science and technology need to be increased to improve water use efficiency in irrigation systems. (3) The output of water-intensive crops should be reduced. (4) The industrial structure could be further optimized so that non-agricultural uses are the primary drivers of gross domestic product (GDP) growth.

Rural decline is a global issue accompanied by the regional imbalanced development and dysfunction in rural areas. Coordinated interaction among production, living, and ecological functions is essential for the sustainability of rural regional systems. Based on the framework of “element-structure-function”, an indicator system was constructed to explore the evolution characteristics and driving factors of rural regional functions in the farming-pastoral ecotone of northern China (FPENC) using the models of entropy-based TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution), revised vertical and horizontal comparison, and GeoDetector. The results indicated a gradual synergy of rural production, living, and ecological functions during the period 2000-2020. Improvements were observed in production and living functions, and higher ecological function was found in Hebei, Inner Mongolia, Liaoning, and Shaanxi. However, conflicts between ecological function and production and living functions were evident in Shanxi, Gansu, and Ningxia. The spatial structure played a dominant role in determining rural production, living, and ecological functions, with ratios of 38%, 56%, and 84%, respectively. Land and industry emerged as the main driving factors influencing the evolution of rural regional functions. Notably, combined interactions of rural permanent population and primary industry output (0.73), grassland area and tertiary industry output (0.58), and forest area and tertiary industry output (0.72) were responsible for the changes observed in rural production, living, and ecological functions, respectively. The findings suggest that achieving coordinated development of rural regional functions can be accomplished by establishing differentiated rural sustainable development strategies that consider the coupling of population, land, and industry in FPENC.

Global extreme hydrological events pose considerable challenges to the sustainable development of human society and river ecology. Land use/cover change (LUCC) is a visible manifestation of human activity and has caused substantial alterations in extreme hydrological regimes across rivers worldwide. The Jinsha River lies upstream of the Yangtze River and its hydrological variability has had profound socioeconomic and environmental effects. In this study, we developed Hydrological Simulation Program-FORTRAN (HSPF) and land-use simulation models of the entire watershed to simulate the effects of LUCC on hydrological extremes and quantify the inter-relationships among them. The main land-use changes between 1995 and 2015 were those associated with cropland, forest land, and grassland. Between 2015 and 2030, it is estimated that the coverage of forest land, grassland, construction land, and unused land will increase by 0.64%, 0.18%, 69.38%, and 45.08%, respectively, whereas that of cropland, water bodies, and snow- and ice-covered areas will decline by 8.02%, 2.63%, and 0.89%, respectively. LUCC has had irregular effects on different hydrological regimes and has most severely altered stream flows. The responses of hydrological extremes to historical land-use change were characterized by spatial variation. Extreme low flows increased by 0.54%-0.59% whereas extreme high flows increased by 0%-0.08% at the lowest outlet. Responses to future land-use change will be amplified by a 0.72%-0.90% reduction in extreme low flows and a 0.08%-0.12% increase in extreme high flows. The hedging effect caused by irregular changes in tributary stream flow was found to alleviate the observed flow in mainstream rivers caused by land-use change. The extreme hydrological regimes were affected mainly by the net swap area transferred from ice and snow area to forest (NSAIF) and thereafter to cultivated land (NSAIC). Extreme low flows were found to be positively correlated with NSAIF and NSAIC, whereas extreme high flows were positively correlated with NSAIC and negatively correlated with NSAIF.

The mass elevation effect (MEE) is a thermal effect, in which heating produced by long wave radiation on a mountain surface generates atmospheric uplift, which has a profound impact on the hydrothermal conditions and natural geographical processes in mountainous areas. Based on multi-source remote sensing data and field observations, a spatial downscaling inversion of temperature in the Tianshan Mountains in China was conducted, and the MEE was estimated and a spatio-temporal analysis was conducted. The GeoDetector model (GDM) and a geographically weighted regression (GWR) model were applied to explore the spatial and temporal heterogeneity of the study area. Four key results can be obtained. (1) The temperature pattern is complex and diverse, and the overall temperature presented a pattern of high in the south and east, but low in the north and west. There were clear zonal features of temperature that were negatively correlated with altitude, and the temperature difference between the internal and external areas of the mountains. (2) The warming effect of mountains was prominent, and the temperature at the same altitude increased in steps from west to east and north to south. Geomorphological units, such as large valleys and intermontane basins, weakened the latitudinal zonality and altitudinal dependence of temperature at the same altitude, with the warming effect of mountains in the southern Tianshan Mountains. (3) The dominant factors affecting the overall pattern of the MEE were topography and location, among which the difference between the internal and external areas of the mountains, and the absolute elevation played a prominent role. The interaction between factors had a greater influence on the spatial differentiation of mountain effects than single factors, and there was a strong interaction between terrain and climate, precipitation, the normalized difference vegetation index (NDVI), and other factors. (4) There was a spatial heterogeneity in the direction and intensity of the spatial variation of the MEE. Absolute elevation was significantly positively correlated with the change of MEE, while precipitation and the NDVI were dominated by negative feedback. In general, topography had the largest effect on the macroscopic control of MEE, and coupled with precipitation, the underlying surface, and other factors to form a unique mountain circulation system and climate characteristics, which in turn enhanced the spatial and temporal heterogeneity of the MEE. The results of this study will be useful in the further analysis of the causes of MEE and its ecological effects.

Karst depressions are common negative topographic landforms formed by the intense dissolution of soluble rocks and are widely developed in Guizhou province. In this work, an inventory of karst depressions in Guizhou was established, and a total of approximately 256,400 karst depressions were extracted and found to be spatially clustered based on multidistance spatial cluster analysis with Ripley's K function. The kernel density (KD) can transform the position data of the depressions into a smooth trend surface, and five different depression concentration areas were established based on the KD values. The results indicated that the karst depressions are clustered and developed in the south and west of Guizhou, while some areas in the southeast, east and north have poorly developed or no clustering. Additionally, the random forest (RF) model was used to rank the importance of factors affecting the distribution of karst depressions, and the results showed that the influence of lithology on the spatial distribution of karst depressions is absolutely dominant, followed by that of fault tectonics and hydrological conditions. The research results will contribute to the resource investigation of karst depressions and provide theoretical support for resource evaluation and sustainable utilization.

Accurately identifying the dominant factor of karst ecosystem services (ESs) is a prerequisite for the rocky desertification control. However, the explanatory power of environmental factors on the spatial distribution of ESs is affected by scaling, and the quantitative research on the scale effect still needs to be further strengthened. This study used the geographical detector to access the explanatory power of environmental factors on soil erosion and water yield at different spatial resolutions, and then explored its differences in three geomorphological-type areas. Results showed that slope and vegetation coverage were the dominant factors of soil erosion, and the interactive explanatory power between the two factors was stronger. Affected by the universality of topographic relief and landscape fragmentation in the study area, the explanatory power of slope and land use type on soil erosion was optimal at low resolution. Precipitation, elevation, and land use type were the dominant factors for the spatial heterogeneity of water yield, and the interaction between precipitation and land use type explained more than 95% of water yield. The spatial variability of elevation in different geomorphological-type areas affected its optimal explanatory power, specifically, in the terrace and hill-type areas, the spatial variability of elevation was weak, its explanatory power was optimal at high resolution. While in the mountain-type areas, the spatial variability of elevation was strong, and its explanatory power was optimal at low resolution. This study quantitatively identified the optimal explanatory power of ES variables through multi-scale analysis, which aims to provide a way and basis for accurate identification of the dominant factors of karst mountain ESs and zoning optimization.

There is a great uncertainty in generation and formation of non-point source (NPS) pollutants, which leads to difficulties in the investigation of monitoring and control. However, accurate calculation of these pollutant loads is closely correlated to control NPS pollutants in agriculture. In addition, the relationships between pollutant load and human activity and physiographic factor remain elusive. In this study, a modified model with the whole process of agricultural NPS pollutant migration was established by introducing factors including rainfall driving, terrain impact, runoff index, leaching index and landscape intercept index for the load calculation. Partial least squares path modeling was applied to explore the interactions between these factors. The simulation results indicated that the average total nitrogen (TN) load intensity was 0.57 t km^-2 and the average total phosphorus (TP) load intensity was 0.01 t km^-2 in Chengdu Plain. The critical effects identified in this study could provide useful guidance to NPS pollution control. These findings further our understanding of the NPS pollution control in agriculture and the formulation of sustainable preventive measures.

Effective soil particle size composition can more realistically reflect the particle size sorting process of erosion. To reveal the individual contributions of rainfall intensity and slope to splash erosion, and to distinguish the enrichment ratio of each size and the critical size in splash, loessial soil collected on the Loess Plateau in May 2019 was tested under different rainfall intensities (60, 84, 108, 132, 156 mm h^-1) and slopes (0°, 5°, 10°, 15°, 20°). The results demonstrated that 99% of splash mass was concentrated in 0-0.4 m. Rainfall intensity was the major factor for splash according to the raindrop generation mode by rainfall simulator nozzles. The contributions of rainfall intensity to splash erosion were 82.72% and 93.24%, respectively in upslope and downslope direction. The mass percentages of effective clay and effective silt were positively correlated with rainfall intensity, while the mass percentages of effective very fine sand and effective fine sand were negatively correlated with rainfall intensity. Opposite to effective very fine sand, the mass percentages of effective clay significantly decreased with increasing distance. Rainfall intensity had significant effects on enrichment ratios, positively for effective clay and effective silt and negatively for effective very fine sand and effective fine sand. The critical effective particle size in splash for loessial soil was 50 μm.

Land subsidence is a geohazard phenomenon caused by the lowering of land elevation due to the compression of the sinking land soil body, thus creating an excessive constraint on the safe construction and sustainable development of cities. The use of accurate and efficient means for land subsidence prediction is of remarkable importance for preventing land subsidence and ensuring urban safety. Although the current time-series prediction method can accomplish relatively high accuracy, the predicted settlement points are independent of each other, and the existence of spatial dependence in the data itself is lost. In order to unlock this problem, a spatial convolutional long short-term memory neural network (ConvLSTM) based on the spatio-temporal prediction method for land subsidence is constructed. To this end, a cloud platform is employed to obtain a long time series deformation dataset from May 2017 to November 2021 in the understudied area. A convolutional structure to extract spatial features is utilized in the proposed model, and an LSTM structure is linked to the model for time-series prediction to achieve unified modeling of temporal and spatial correlation, thereby rationally predicting the land subsidence progress trend and distribution. The experimental results reveal that the prediction results of the ConvLSTM model are more accurate than those of the LSTM in about 62% of the understudied area, and the overall mean absolute error (MAE) is reduced by about 7%. The achieved results exhibit better prediction in the subsidence center region, and the spatial distribution characteristics of the subsidence data are effectively captured. The present prediction results are more consistent with the distribution of real subsidence and could provide more accurate and reasonable scientific references for subsidence prevention and control in the Beijing-Tianjin-Hebei region.

Transpiration (Tc) is a critical component of the global water cycle. Soil moisture (SM) and vapor pressure deficit (VPD) are key regulators of Tc, and exploring their contributions to changes in Tc can deepen our understanding of the mechanisms of water cycling in terrestrial ecosystems. However, the driving roles of VPD and SM in Tc changes remain debated because of the coupling of SM and VPD through land-atmosphere interactions which restrict the quantification of the independent effects of SM and VPD on Tc. By decoupling the correlations between SM and VPD using a novel binning approach, this study analyzed the dominant drivers of vegetation transpiration in subtropical China from 2003 to 2018 based on multi-source data, including meteorological reanalysis, remotely sensed soil moisture, transpiration, and land cover data. The results show that Tc first increased and then remained stable with an increase in SM across the study area but changed slightly with increasing VPD. Overall, the relative contribution of SM to the change in Tc was approximately five times that of VPD. The sensitivities of Tc to SM and VPD differed among vegetation types. Although the sensitivity of Tc to SM was greater than that of VPD for all four vegetation types, the thresholds of Tc in response to SM were different, with the lowest threshold (approximately 35%) for the other forests and the highest threshold (approximately 55% ) for short wood vegetation. We infer that this is associated with the differences in ecological strategies. To verify the reliability of our conclusions, we used solar- induced chlorophyll fluorescence (SIF) data as a proxy for Tc based on the tight coupling between photosynthesis and transpiration. Consistent results were obtained by repeating the analyses. The results of this study, in which the impacts of SM and VPD on Tc were decoupled, are beneficial for further understanding the critical processes involved in water cycling in terrestrial ecosystems in response to climate change.

The increasing frequency of recent droughts has an adverse effect on the ecosystem of the Mongolian Plateau. The growth condition of NPP is considered an indicator of the ecological function. Therefore, identifying the relationship between NPP and drought can assist in the prevention of drought-associated disasters and the conservation of the ecological environment of the Mongolian Plateau. This study used the Carnegie-Ames-Stanford Approach (CASA) model to simulate the NPP capacity of the Mongolian Plateau between 1982 and 2015, as well as drought indicators (drought probability, vulnerability, and risk) to explore the drought risk of NPP. The findings pointed to an overall increase in NPP with regional variances; however, the NPP rate in Inner Mongolia was considerably higher than that in Mongolia. The standardized precipitation evapotranspiration index (SPEI) showed an overall downward trend, with Inner Mongolia experiencing a substantially lower rate of decline than Mongolia. The areas most likely to experience drought were primarily in the center and north while the areas with the highest drought vulnerability were primarily in the northeast, center, and southeast. Mongolia showed a higher probability of drought compared to Inner Mongolia. Drought-prone regions of the Mongolian Plateau increased during the 21st century while drought-vulnerable areas increased and shifted from north to south. Alpine grasslands and coniferous forests were least vulnerable to drought, while other vegetation types experienced temporal variation. In the 21st century, the primary determinants of drought risk shifted from precipitation and the normalized difference vegetation index (NDVI) to temperature and relative humidity.

The Qinghai-Tibet Plateau (QTP), also known as the Third Pole of the Earth, is a vital ecological security barrier for China. It is a tremendously sensitive region affected by the impacts of global climate change. The escalating intensity of climate change has presented profound challenges to its ecosystem functions and stability. This study first analyzes the spatiotemporal variations of the QTP ecosystem patterns and the key functions of the Plateau including water conservation, soil conservation, and windbreak and sand fixation from 2000 to 2020. It clarifies the regional differences in ecosystem functions and their importance, further evaluates the stability of ecosystem functions, and lays a scientific foundation for an ecological civilization on the Plateau by implementing conservation and restoration projects. The main results show that: (1) From 2000 to 2020, the wetland area in the QTP increased, while the grassland area significantly decreased. There were improvements in water conservation and windbreak and sand fixation capacities, with annual rates of change being 3.57 m³·ha^-1·a^-1 and 0.23 t·ha^-1·a^-1, respectively. However, the overall soil conservation trend declined during the same period, with an annual change rate of -0.16 t·ha^-1·a^-1. (2) The core areas of water conservation, soil conservation, and windbreak and sand fixation on the QTP accounted for 12.7%, 13.9%, and 14.2% of the total area, respectively. The core water conservation areas are mainly the southeastern QTP, Sanjiangyuan, and Naqu, while the core windbreak and sand fixation areas were concentrated in the central and western parts of the Plateau. The core soil conservation areas surrounded the entire interior of the Plateau. (3) From 2000 to 2020, the water conservation, soil conservation, and windbreak sand-fixation function on the QTP had higher stability in the southeastern and central parts, while stability was lower in the western region. Considering the stability assessment and ecological protection and restoration practices, the QTP can be divided into three major categories and 16 ecological functional zones. Differentiated ecological protection and restoration efforts can be implemented based on the different core ecosystem functions and zoning.

Global warming is causing melting of glaciers, which is affecting socioeconomic development. It is essential to study the combined influence of changes in structures of glaciers on human well-being and socioeconomic systems. Herein, we considered Qilian Mountains as an example, quantified the regional socioeconomic benefits of glaciers and human well-being, and attempted to draw a correlation between glacier service value and human well-being. The findings of our study reveal that the value of glacier services in Qilian Mountains decreased from 1.84 × 10¹⁰ yuan in 1998 to 1.72 × 10¹⁰ yuan in 2018, with a spatial trend of circling down from the central region to the western and eastern regions. The distribution of human well-being showed an increasing trend, and a phenomenon of “low value central and western clustering, high value eastern sporadic distribution.” There is an increasing degree of coordination between human well-being and glacier services value; the spatial distribution shows a decreasing trend from the west to the east, with differences in the nature of coordinated development in different regions at the same coordination stage being obvious. We analyzed the changes in glacier services value and their relationship with human well-being from both micro and macro perspectives to provide theoretical support for formulating management strategies for glacier resource conservation and improving the interface between glacier service evaluation results and government decision-making.

Quantitative assessments of the impacts of climate change and anthropogenic activities on runoff help us to better understand the mechanisms of hydrological processes. This study analyzed the dynamics of mountainous runoff in the upper reaches of the Shiyang River Basin (USRB) and its sub-catchments, and quantified the impacts of climate change and human activities on runoff using the improved double mass curve (IDMC) method, which comprehensively considers the effects of precipitation and evapotranspiration on runoff, instead of only considering precipitation as before. The results indicated that the annual runoff depth in the USRB showed a slightly increased trend from 1961 to 2018, and sub-catchments were increased in the west and decreased in the east. The seasonal distribution pattern of runoff depth in the USRB and its eight sub-catchments all showed the largest in summer, followed by autumn and spring, and the smallest in winter with an increasing trend. Quantitative assessment results using the IDMC method showed that the runoff change in the USRB is more significantly affected by climate change, however, considerable differences are evident in sub-catchments. This study further developed and improved the method of runoff attribution analysis conducted at watershed scale, and these results will contribute to the ecological protection and sustainable utilization of water resources in the USRB and similar regions.

Exploring the coupling coordinated level of rural population-land-industry (PLI) and its underlying driving mechanism contributes to the scientific decision-making on rural sustainable development. This study assessed the coupling coordinated level of PLI based on an improved evaluation index system and then revealed the regional differentiation and driving mechanism in China’s rural areas in 2020. The results showed that the rural PLI coupling coordinated degree was 0.4694, and thus was in the stage of approximate incoordination. In addition, China’s rural PLI coupling coordinated degree formed a spatially heterogeneous pattern with high levels in the northeast, eastern and central regions, and the intragroup difference contributed more than 80% to the total difference. The rural PLI coupling coordinated level was influenced by the combined effects of rural kernel and peripheral systems, but the rural kernel system mostly determined the differentiation. In the future, rural areas should first exploit population quality improvement projects, land consolidation projects and industrial integration development strategies to promote benign mutual feedback of PLI. Second, driving factors should be comprehensively regulated by implementing a “one village, one product” strategy, breaking the urban-rural dual system, improving agricultural machinery subsidies policy, and promoting urban-rural integrated development.

Exploring the spatial zoning of urban territories and their ecological effects under different decision preferences is an important approach to promote the sustainable utilization of regional resources. This paper constructs an index system for evaluating the suitability of territorial space development from the perspectives of urban development, agricultural production, and ecological conservation. It predicts and simulates the trade-offs between territorial space development and protection in Ezhou under different decision preferences using the Analytic Hierarchy Process (AHP) and Ordered Weighted Averaging (OWA) method. The modified equivalent factor method is used to analyze the ecosystem service values of different functional areas. The results indicate the following: (1) the preferences of decision-makers considerably influence the level of territorial space suitability. Higher (lower) levels of concern for risk result in more optimistic (pessimistic) evaluators, and this affects the priority given to ecological protection (development and utilization). (2) Under the ecological priority scenario, the status quo scenario and development priority scenario, there are significant differences in regional suitability levels. The ecological priority scenario gives high importance to ecological protection, resulting in the absolute protection of the Liangzi lake area, with 42.59% of Liangzihu district considered unsuitable for development. In contrast, the development orientation scenario designates Echeng district, an economic and political center, as highly suitable for development, with over 60% of the area available for development. (3) The total value of ecosystem services in Ezhou city was 213.355 billion yuan in 2018. Ecosystem service values were mainly provided by the water area in the permanently unsuitable development zone, leading to a mismatch between the supply and demand of ecosystem services under different scenarios.

Regional and persistent PM_2.5 pollution seriously undermines the development of urban ecological civilizations and the advancement of high-quality economies. The producer service sector, an example of a typical knowledge-intensive service industry, plays an important role in advancing the manufacturing industry and fostering economic growth while concurrently improving urban environmental conditions. Based on panel data of prefecture-level cities in the Yellow River Basin from 2006 to 2019, this study constructed a Spatial Durbin Model and a mediation effect model to comprehensively explore the impact of producer services agglomeration on PM_2.5 pollution. The main conclusions are as follows: (1) From 2006 to 2019, PM_2.5 pollution in the study area exhibited an initial rise followed by a subsequent decline, with notable spatial heterogeneity. PM_2.5 pollution in the lower reaches of the Yellow River was significantly higher than in the middle and upper reaches. In addition, the spatial pattern of producer services agglomeration showed distinct “core-edge” characteristics. (2) The agglomeration of producer services had a significant negative impact on local and adjacent PM_2.5 pollution, and there was a more pronounced haze reduction effect in the case of specialized agglomerations of producer services and low-end producer services. (3) The agglomeration of producer services indirectly improved PM_2.5 pollution by promoting technological innovation and optimizing industrial structure, with the latter playing a greater mediating effect. This study not only helps expand the theoretical and empirical research on producer services agglomeration but also offers valuable insights for pursuing a green transformation of the Yellow River Basin by optimizing industrial patterns through the producer services sector. This approach represents a reference for curbing PM_2.5 pollution and guiding the region toward a greener future.

Resource-based cities are important bases for resources and energy in China. However, the world and the country’s sustainable development goals require them to undergo transformation. The complexity of this transformation poses challenges for these cities. This study aims to evaluate the transformation performance of resource-based cities in Shaanxi, Gansu, and Ningxia. The findings will help understand their capabilities and achievements in transformation and provide guidance for future transformation planning. To evaluate the transformation performance, this study employs the entropy weight Technique for Order of Preference by Similarity to Ideal Solution method. An index system is constructed, including the industrial diversification and specialization indices. These indices serve as benchmarks for assessing the transformation performance. The period 2010-2019 is considered, and the transformation performance of resource-based cities is evaluated based on different development stages and regions. The results reveal the following insights: (1) Most resource-based cities demonstrate favorable transformation performance. Although variations exist between cities, the gaps are gradually narrowing. (2) Over an extended period, the transformation performance of each city undergoes continuous changes, with high-performing areas shifting. (3) The transformation performance of resource-based cities varies significantly across different development stages. (4) An imbalance exists among the regions where resource-based cities are located, and a diffusion effect can be observed. Accordingly, the following enlightenment and policy suggestions are obtained: (1) exploring targeted management policies for resource-based cities; (2) fostering a dynamic and open transformation environment; (3) promoting the concept of regional cooperation in transformation; (4) improving the business environment; (5) promoting enterprise innovation; (6) establishing and improving a long-term mechanism for sustainable development and a compensation mechanism for resource development; and (7) optimizing the talent training system.

Settlements are excellent spatiotemporal indicators for studying historical human activities and environmental change. This paper discusses the spatial and temporal changes of sites on the Ordos Plateau in China since the Neolithic Age, based on an analysis of spatiotemporal distribution characteristics of the human settlements. The frequency of human settlements on the Ordos Plateau presented a phased fluctuation process, and the sizes were mainly small and medium. The spatial distribution of human settlements was fractal, and the D value of the aggregation dimension was generally small, indicating that the spatial distribution of the sites was agglomerated. Affected by the desert, the sites were mainly distributed in the south and east of the Ordos Plateau. The spatiotemporal distribution pattern of human settlements in the Ordos Plateau resulted from the combined action of natural and human factors, especially climate change. Moreover, local livelihood patterns significantly affected the frequency of human settlements. The number of human settlements in the farming period was large, and the distribution was concentrated. In contrast, the number of sites in the nomadic period was small and scattered. The central government’s policies and the conflicts between farming and nomadic groups further affected the spatiotemporal distribution of human settlements. This study may contribute to a better understanding of historical environmental change and human-land relationships in the Ordos Plateau.

Megacities serve as global centers for economic, cultural, and high-tech industries. The structural features and population agglomerations are typical traits of urbanization, yet little is known about the morphological features and expansion patterns of megacities worldwide. Here we examined the spatiotemporal variations of urban land in megalopolises from 2000 to 2020 using the Urban Expansion Intensity Differentiation Index. The fractal features and expansion patterns of megacities were analyzed using the Area-Radius Multidimensional Scaling Model. Urban land use efficiency was then evaluated based on the linear relationship between urban land area and population. We found that Southeast Asia and China were the hotspots of urban expansion in megacities from 2000 to 2020, with urban land areas expanding by 3148.32 km² and 5996.26 km², respectively. The morphological features and expansion patterns of megacities exhibited a growing trend towards intensification and compactness, with the average radial dimension increasing from 1.54 to 1.56. The annual decrease in fractal dimensions indicated the integration of inner urban areas. North America and Europe megacities showed a low urban land use efficiency, with a ratio of urban land area to population ranging from 0.89 to 4.11 in 2020. Conversely, South Asia and Africa megacities exhibited a high urban land use efficiency, with the ratios between 0.23 and 0.87. Our results provide information for promoting efficient urban land utilization and sustainable cities. It is proposed to control the scale of urban expansion and to promote balanced development between inner and outer urban areas for achieving resilient and sustainable urban development.

China's mariculture provides more than 60% of the world’s mariculture products and plays an important role in the world’s aquaculture and food supply. Research on changes in the spatial distribution pattern of China’s mariculture, however, remains lacking. To accurately reflect the changes in the spatial pattern of mariculture in China, in this study, we used multitemporal optical and synthetic aperture radar remote sensing images to enhance the characteristics of mariculture and extracted the spatial distribution data for mariculture in China in 2000, 2010, and 2020. Accordingly, we explored the distribution pattern and changes in mariculture in China. We found that, in 2020, China’s mariculture exhibited a distribution pattern of more in the north and less in the south. With the Yangtze River estuary as the boundary, the proportion of mariculture in northern China was 70.9%, and that in southern China was only 29.1%. This difference did not exist in 2000, but it emerged because of the rapid development of mariculture in northern China from 2010 to 2020. In addition, by superimposing the mariculture data with shoreline and water depth data, we found that more than 90% of China’s mariculture area was located in the sea area within 20 km of the shoreline and that more than 80% of the mariculture area was located in the sea area with water depths of less than 20 m. In addition, the spatial distribution of mariculture in China developed from near the shore and moved outward from shallow to deep water areas. We examined the driving factors that influence changes in the spatial distribution of mariculture in China. We argue that technological advancements in mariculture, as well as the intensive concentration of mariculture near the shore, policy constraints and incentives, and economic development, collaborate to shape the current pattern of mariculture development in China.

Polycentric urban development has profound impacts on urban development worldwide. Most studies have identified its complex drivers of social economy and natural condition while ignoring the state-led policy factors. In recent years, China has undergone dramatic administrative division adjustment (ADA) during the process of unique state-led urbanization. However, as a crucial government strategy, the impacts of ADA on urban polycentricity remain unclear. This research investigates the relationship between ADA and urban polycentricity through spatial difference-in-differences models. The results reveal that ADA has contributed to the polycentric urban development in China. Specifically, boundary restructuring has more substantial impacts than hierarchy reorganization. In addition, ADA has significantly promoted urban polycentricity in local cities in central China and neighbouring cities in eastern China, while it has no significant effects in western China. Furthermore, ADA reshapes urban polycentricity mainly by the influencing mechanism of construction land and industrial structure. Policymakers should consider the various ADA’s impacts on urban polycentricity with socio-economic conditions. This research provides a deeper insight into urban spatial transformation with state-led drivers.

Accurately diagnosing and assessing complicated spatial linkages at various scales has become a crucial strategy for enhancing the efficacy of urban government policies and initiatives in the modern era. There is still room for improvement in identifying spatial scale disparities and coupling linkages in cities, although the standard research paradigm on urban sustainability has produced numerous positive outcomes. To advance urban sustainability research from the perspective of spatial coupling, this study used cluster and cross-tabulation analyses for considering urban sustainable development patterns from the requirements of both development scale and spatial accuracy. Subsequently, the spatial unit coupling relationship between district and street scales was explored. Our findings indicated significant scale dependence in the spatial divergence between the built environment sustainability levels of streets and the economic, social, and environmental sustainability levels of districts. The implication is that significant differences exist in the built environment levels of various sustainable development type districts. The scale effect of the spatial coupling relationship influences urban planning and the transition of sustainable development. Maintaining reasonable population density and maximizing the structure and quality of social public resources supply are priorities for streets with the highest habitat sustainability that are located in low-growth type districts. Priority should be given to population deconcentration for high habitat sustainable streets located in synergistic development type districts to increase the level of public service protection. Supporting facilities should be added to medium sustainable streets in low-growth areas to increase the mix of land use, which should encourage additional production activity concentration, thereby fostering overall economic strength. Further, increasing the accessibility of local public service facilities for low and medium sustainable streets located in ecologically biased areas should be prioritized, but a green and low-carbon orientation should be maintained during building.

The construction of rural life circle has an essential impact on the change of rural social space. Analyzing the adaptation relationship between the two can be a new content in the study of “physical-social” space. Using social behavior as a link, we construct a logical relationship framework between rural life circle and social space. Based on the survey data of Baijia village in the loess hilly region, this paper analyzes the characteristics and adaptability of the two and discusses preliminary ideas of life circle reorganization and social space reconstruction. The study results are as follows: (1) Based on the location of four types of service facilities and the travel mode of villagers, two life circles of 15 min and 25 min have been formed in Baijia village. The rural social spaces such as communicative behavior space, health seeking behavior space, leisure behavior space, and consumption behavior space show a specific concentric circle structure and unique hierarchical structure. (2) The analysis of the adaptation between them shows that the 15 min life circle in Baijia village has a high level of adaptation to communicative and leisure behavior spaces. It plays a positive feedback role in the construction of social space. However, it has a low level of adaptability to the space of health seeking and consumption behavior spaces and has a negative feedback effect on the construction of social space. The 25 min life circle is the opposite. (3) The reorganization of facility layout, hierarchical structure, and service functions in the village life circle will lead to changes in the range, frequency, and purpose of villagers’ behavioral activities, resulting in a new social spatial pattern. These findings are important for formulating village development and construction plans, improving the settlement habitat, and reconstructing the order of social life.

Land use transition occurs through changes in land use morphologies. The decision-making and land use behavior of farmers is the main factor that causes changes in the land use system and subsequent transitions of land use. This study focused on the recessive morphologies of farmland based on the investment in agricultural production inputs by farmers, and established an analytical framework based on induced technological innovation theory and farmers’ behavior theory, which followed the pathway of “objective-willingness- behavior.” Using survey data for farming households in two counties (Shouguang and Yiyuan) in Shandong province, the main factors influencing farmers’ willingness to invest in agricultural production and their differences under the background of labor force changes were comprehensively analyzed with a binary logistic model and ordinary least squares (OLS) regression model. The aim was to provide decision-making guidance for promoting farmland use transition. There were three key results. (1) The scale management objectives of a farmer were limited, with 75% of farmers intending to maintain the current farmland management scale, and planning to retire at an advanced age, although there were regional differences in these phenomena. (2) Farmers’ willingness to invest in agricultural production inputs was closely related to agricultural production objectives, farmland use, and agricultural production, whereas the labor structure had no significant effect. Farmers’ behavior toward investment in agricultural production inputs was negatively related to their expected retirement age. Changes in the household labor structure were an important factor boosting farmers’ investment in agricultural production inputs. (3) It is essential to better understand the cognitive level and structure of farmers, and the characteristics of the labor structure and type of agricultural development could be combined to improve the farmers’ cognitive level and willingness to adopt scale management objectives and generate behavioral responses. Using the dual scale of “land + service” would overcome the structural obstacles faced by farmers, and effectively play the role of providing both policy incentives and regulation.

The integration of culture and tourism is conductive to the realization of urban-rural integration and rural revitalization. Taking 16 typical traditional villages in Beijing as cases, this study proposes an evaluation system and influencing factor model for the integration of culture and tourism in traditional villages. Based on the TOPSIS model supported by the entropy method, the level of culture and tourism integration in traditional villages is analyzed. Moreover, we discuss the main factors influencing the integration of culture and tourism in traditional villages and their paths by using fuzzy-set qualitative comparative analysis (fs/ QCA). The results can be summarized in four main areas. (1) The integration of culture and tourism in traditional villages is a dynamic process that continues to promote the comprehensive revitalization by deepening resource integration, advancing product cultivation and strengthening industry functions. (2) There are obvious differences in the development levels of the integration of culture and tourism among the case villages. Specifically, the levels of each village in the four dimensions present the characteristics of differentiation and imbalance. (3) No single factor can capture the necessary and sufficient conditions for the integrated development of culture and tourism. (4) There are three paths influencing the integration of culture and tourism in traditional villages, namely, the mature development path, the rapid development path and the progressive development path, which correspond to their respective combinations of influencing factors. The results of this study can provide theoretical inspiration and scientific guidance for the urban-rural integration and rural revitalization of traditional villages from the perspective of the integration of culture and tourism.

In the past 30 years, observational climate datasets reveal a significant a drying and warming trend over in North China. Understanding of climatic variability over North China and its driving mechanism in a long-term perspective is, however, limited to a few sites only, especially the lack of temperature reconstructions based on latewood density and blue intensity. In this study, we developed a 281-year latewood blue intensity chronology based on 45 cores of Picea meyeri in western North China. Based on the discovery that the warm season (May-August) mean maximum temperature is the main controlling factor affecting the change in blue light reflection intensity, we established a regression model that explained 37% of the variance during the calibration period (1950-2020), allowing to trace the mean maximum temperature up to 1760 CE. From the past 261 years, we identified seven persistent high temperature periods (1760-1773, 1778-1796, 1805-1814, 1869-1880, 1889-1934, 1984- 2000, 2004-2020) and three persistent low temperature periods (1815-1868, 1935-1963, 1969-1983) in North China. Comparisons of a nearby temperature reconstructions and climate gridded data indicate that our reconstruction record a wide range of temperature variations in North China. The analysis of links between large-scale climatic variation and the temperature reconstruction showed that there is a relationship between extremes in the warm season temperature and anomalous SSTs in the equatorial eastern Pacific, and implied that the extremes in the warm season temperature in North China will be intensified under future global warming.

Rainfall temporal patterns significantly affect variability of flash flood behaviors, and further act on hydrological model performances in operational flash flood forecasting and warning. In this study, multivariate statistical analysis and hydrological simulations (XAJ and CNFF models) were combined to identify typical rainfall temporal patterns and evaluate model simulation capability for water balances, hydrographs, and flash flood behaviors under various rainfall patterns. Results showed that all the rainfall events were clustered into three types (Type 1, Type 2, and Type 3) in Anhe catchment in southeastern China. Type 1 was characterized by small total amount, high intensity, short duration, early peak moment, and concentrated hourly distribution. Type 3 was characterized by great total amount, low intensity, long duration, late peak moment, and uniform hourly distribution. Characteristics of Type 2 laid between those of Type 1 and Type 3. XAJ and CNFF better simulated water balances and hydrographs for Type 3, as well as all flash flood behavior indices and flood dynamics indices. Flood peak indices were competitively simulated for all the types by XAJ and except Type 1 by CNFF. The study is of significance for understanding relationships between rainfall and flash flood behaviors and accurately evaluating flash flood simulations.

Road network expansion can result in the fragmentation of ecological landscapes due to the transformation of landscape processes and patterns. However, knowledge about these processes and patterns is scarce. In this study, the road network and landscape patterns in the Dongzhi tableland of the Chinese Loess Plateau (CLP) between 2005 and 2020 were characterized, and their spatial relationships were analyzed. The results showed that (1) the kernel density estimation (KDE) method is useful in characterizing road network density. When the bandwidth value is four, the boundary of the road network kernel can be distinguished clearly. (2) The road network in the tableland expanded greatly over the past 15 years, and the total area of road kernels in the Dongzhi tableland increased from 55.73 km² in 2005 to 223.55 km² in 2020. (3) High-density road networks were generally distributed on cultivated and constructed lands where the slopes were generally 0°-5°, while low- and medium-density road networks were mostly distributed in grassland areas where the slopes were greater than 5°. (4) Road network density is closely related to the coverage of cultivated and constructed lands. The results of this study are helpful in understanding the potential impact of road network evolution on the landscape at a regional scale.