Spatial-temporal Changes Research Articles

A global multi catchment and multi dataset synthesis for water fluxes and storage changes on land

Water on land is essential for all societal, ecosystem, and planetary health aspects and conditions, and all life as we know it. Many disciplines consider and model similar terrestrial water phenomena and processes, but comparisons and consistent validations are lacking for the datasets used by various science communities for different world parts, scales, and applications. Here, we present a new global data synthesis that includes and harmonises four comparative datasets for main terrestrial water fluxes and storage changes, and the catchment-wise water balance closure they imply for the 30-year period 1980–2010 in 1561 non-overlapping hydrological catchments around the world. This can be used to identify essential agreements and disagreements of the comparative datasets for spatial variations and temporal changes of runoff, evapotranspiration, water storage, and associated water-balances around the global land area, e.g., for pattern recognition and hypothesis/model testing. The facilitated direct dataset comparison can advance a more coherent, realistic cross-disciplinary understanding of Earth’s water states and changes across regions and scales, from local and up to continental and global.

The spatial–temporal changes and driving factors of desertification in the Wuliangsuhai watershed based on remote sensing

The spatial–temporal changes and driving factors of desertification in the Wuliangsuhai watershed based on remote sensing

Spatiotemporal changes and management measure to enhance ecosystem services in the Mongolian Plateau

The eco-environment in many underdeveloped areas is vulnerable. Elucidating the changes and relationships in ecosystem services (ESs) is a fundamental basis for achieving sustainable development in these regions. Utilizing multiple data sources and models, we quantified water provision (WP), habitat quality (HQ), carbon fixation (CF), soil conservation (SC), and wind erosion prevention (WEP) on the Mongolian plateau during 1992-2018. We then analyzed the spatial-temporal changes, trade-offs/synergies, and bundles relationship of these ESs. The results indicated there was high spatial variability in five ESs across the plateau, with overall higher ESs in forested areas, and grassland and cropland areas had higher WEP values. The annual mean values of WP, HQ, CF, SC, and WEP in the plateau during 1992-2018 were 27.15 mm, 0.57, 176.17 gC·m2, 48.83 t·hm2, and 58.31 t·hm2, respectively. Due to fluctuations in precipitation, vegetation cover and land use, the five ESs decreased from 1992 to 2000s, but increased from 2000s to 2018, Notably, the HQ changed most significantly (p<0.01), while the WP changed insignificantly (p>0.05). The different ESs on the plateau overall exhibited synergistic effects, trade-offs between several pairs of ESs related to HQ, were observed in cropland areas. We further identified five distinct categories of ES bundles and proposed targeted recommendations for spatial planning and management of these ESs, tailored to their characteristics. The findings offer a valuable reference for high-quality environmental management, as well as the restoration and enhancement of ESs in arid inland areas in a warming climate.

Coastal vertical land motion across Southeast Asia derived from combining tide gauge and satellite altimetry observations

Vertical land motion (VLM) is complex in Southeast Asia because this region is subject to a range of natural processes (e.g., earthquakes) and anthropogenic activities (e.g., groundwater withdrawal) that can change land heights. To aid in coastal management, long-term observations of VLM are as crucial as observations for climate-induced sea surface height changes; however, such long-term observations are sparse for Southeast Asian coasts. To fill this observational gap, here we derive monthly VLM time series from 1993 to 2020 at 50 coastal sites across Southeast Asia by combining tide-gauge records and newly generated satellite altimetry observations. These altimetry observations are reproduced sea-level products using new altimetry standards and more accurate geophysical corrections. Our 27-year-long VLM dataset shows high spatial variability and non-linear temporal changes in VLM across Southeast Asia. We identify several major sources that dominate the regional land-height changes, which include large subsidence due to groundwater extraction in Manila and Bangkok, land uplift in Indonesia and subsidence in Thailand from postseismic deformation resulting from the sequence of large Sumatran earthquakes since 2004, and land subsidence as a result of sediment compaction in Malaysia. Those signals are quantitatively or qualitatively consistent with observations from other sources. This VLM dataset can be used to advance our understanding of the physical mechanisms behind land-height changes and to improve sea level projections in the region.

Spatial–Temporal Differentiation and Driving Factors of Vegetation Landscape Pattern in Beijing–Tianjin–Hebei Region Based on the ESTARFM Model

Urbanization and industrialization have led to obvious changes in the ecological environment and landscape pattern in the Beijing–Tianjin–Hebei region. Therefore, it is crucial to clarify the spatial–temporal changes in vegetation cover and its landscape pattern and conduct its analysis with the driving factors for ecological preservation in the Beijing–Tianjin–Hebei region. This study combined AVHRR GIMMS NDVI and MODIS NDVI data based on the ESTARFM model to obtain a high spatial–temporal resolution for vegetation cover; it then analyzed the vegetation cover changes at the type and landscape scales using a landscape index and explored the driving factors of the landscape pattern through principal component analysis. The results show that (1) the vegetation is mainly of medium and higher coverage and is distributed in the northeast, the western part of the Taihang Mountains and the central plains in the study area. From 1985 to 2022, there was no statistically significant difference in the overall change in its coverage. (2) From 1985 to 2022, at the landscape level, the vegetation cover landscape exhibited the following characteristics: increased fragmentation, an increase in the complexity of the landscape shape, a decrease in connectivity, a discrete landscape and a decrease in species diversity. At the type level, the medium vegetation demonstrated the most significant degree of fragmentation. The high-vegetation-cover areas exhibited a more concentrated distribution. Additionally, the low, lower and higher vegetation types displayed an increase in complexity, shape, discreteness and heterogeneity within the landscape. (3) Meanwhile, the principal component analysis showed that the changes in the landscape pattern of vegetation cover were mainly the result of the combined effects of climatic and anthropogenic factors in the Beijing–Tianjin–Hebei region. The human factor played the dominant role; this was followed by larger contributions from climatic factors. In addition to offering pertinent scientific insights for the maximization of the ecological environment and the fostering of regional ecological and sustainable development in the Beijing–Tianjin–Hebei region, the aforementioned analysis and research could serve as the foundation for the sustainable management and planning of vegetation cover.

Spatio-Temporal Variation and the Associated Factor Analysis of Net Primary Productivity in Grasslands in Inner Mongolia

The grassland ecosystem in the Inner Mongolia Autonomous Region (IMAR) serves as a vital ecological barrier in northern China, and the vegetation productivity in the grasslands exhibits considerable temporal and spatial variations. However, few studies have examined the long-term variations in the NPP in the IMAR and quantified the effects of natural factors and human activities on the NPP. The study modeled the net primary productivity (NPP) of the IMAR’s grasslands using the Carnegie–Ames–Stanford approach (CASA) model and employed linear regression, trend analysis, and spatial statistics to analyze the spatio-temporal patterns in vegetation productivity and explore the impact on the NPP of natural and socio-economic factors over the past two decades. The results reveal that the average NPP value from 2001 to 2021 was 293.80 gC∙m−2 a−1, characterized by spatial clustering of a relatively high NPP in the east, a low NPP in the west, and an annual increase of 3.26 gC∙m−2 over the years. The NPP values varied significantly across different vegetation cover types, with meadows having the highest NPP, followed by typical steppe and desert grasslands. The spatial distribution pattern and temporal changes in the grassland productivity are the result of both natural factors and human activities, including topographical properties and socio-economic indicators such as gross domestic product, night-time light, and population. The results for the NPP in the IMAR were based solely on the CASA model and, therefore, to achieve improved data reliability, exact measurements in real field conditions will be conducted in the future. The findings from the spatial clustering and temporal trajectories of the NPP and the impacts from the factors can provide useful guidance to planning grassland vegetation protection policies for the IMAR.

Spatiotemporal Variability and Trend of Ozone Pollution from Satellite Data (2003- 2021) in Iraq

Ozone (O3) occurs naturally in the Earth's upper atmosphere, and at ground level is a dangerous pollutant hurts plants and lung tissue and it’s a major component of smog. The purpose of this study to analyze the time series, trend, and spatial-temporal changes of monthly Relative Humidity (RH), Outgoing Longwave Radiation (OLR), and O3 in Iraq using the Atmospheric Infrared Sounder (AIRS) ascending AIRS3STM data during 2003 - 2021. The time series over six stations (Mosul, Sulaymaniyah, Khanaqin, Rutba, Baghdad, and Basra) have been analyzed and showed similar changes and fluctuation in O3 and OLR. The results of the study obtained were: minimum (decreasing, January–December) and maximum (increasing, May–August), and the mean and standard deviation were (0.044±0.003 ppmv) for O3 and (298± 22 Wm-2) for OLR during the study period. During December to February, the highest RH values were recorded, while the lowest RH values occurred from June to August. The monthly mean and standard deviation of RH was (28.66±29.54 g/kg). Further O3 trends revealed negative results in their annual series over all stations, except for Khanaqin and Basra, which had a positive trend. The O3 concentrations were consistently connected with other meteorological variables (the O3 has a negative correlation with RH and a beneficial correlation with temperature). The O3 spatiotemporal maps showed recorded the highest values recorded in April and May over Mosul and Sulaymaniyah (0.055–0.057), and in December, at middle and southern regions (Baghdad and Basra), there were the lowest O3 value (0.033). These results were due to meteorological and geographical factors. The results showed the efficient use of AIRS data to analyze the variations and distributions of atmospheric factors over different regions. In addition, AIRS observations can be used to obtain atmospheric, climatic, and environmental scientific reports and analyses for large, regional, and global regions and for long, continuous periods.

Time Series Clustering of Sea Surface Temperature in the Mediterranean and Black Sea Marine System

ABSTRACTSea surface temperature (SST) is a significant climatic variable that affects the climate of the Earth. Monitoring a location's SST pattern is useful for several research areas, including weather forecasting and climate change. In this study, the emerging hot spot and cold spot patterns of SST in the Mediterranean and Black Sea Marine System (MBMS) were examined, the spatial distribution characteristics and temporal changes of SST in the sub‐basins were analysed, and future predictions were made. A distinctive aspect of the research lies in the introduction of novel techniques, specifically the application of space time cube and evolving hot spot analysis, for visualising and evaluating SST in the MBMS. This approach sets the study apart by pioneering the utilisation of these methods in this particular context. In the examined region, SST demonstrates a decreasing trend from east to west and from south to north. The forecast suggests that this spatial distribution pattern will persist in 2033, further accentuated by the intensification of the warming effect. Nine different time series clusters are defined within this distribution pattern. Although it changes seasonally, the prevailing statistically significant hot spots in the study area are primarily characterised by new hot spots, intensifying hot spots, sporadic hot spots and oscillating hot spots. The trends of hot and cold spot clusters, along with SST values, were assessed for all sub‐basins in the MBMS. Conversely, the observed clustering category among statistically significant cold spots is identified as persistent cold spots, diminishing cold spots, sporadic cold spots, oscillating cold spots and historical cold spots. The spatiotemporal analysis in this research has provided notable insights, offering a spatial context to the previously explored temporal trends of SST in the MBMS.

Spatial-Temporal Changes in Ecosystem Service Value and Its Overlap with Coal Mining Intensity in the Yellow River Basin, China, During 2000–2030

Understanding the ecosystem services and their interaction with coal resource development is crucial for formulating sustainable development policies. In this study, we focused on the Yellow River Basin, characterized by both rich coal resources and ecological fragility. The key findings are that (1) the ecosystem service value (ESV) in the Yellow River Basin exhibited significant spatial heterogeneity during 2000–2030, decreasing from the southeast to northwest, and decreasing the most notably in the southern part of the upper reaches of the river basin; (2) the high-high clustering area of the ESV shifted from the upper-middle reaches in 2000 to the middle-lower reaches in 2020, while the low-low clustering area remained within Inner Mongolia. By 2030, the high-high clustering area is expected to stabilize in southern Shaanxi Province, and the low-low area will potentially spread eastward; (3) the overall ESV is low, and it experienced a significant decline from 2000 to 2020, with water supply emerging as a major limiting factor, although some policy-supported counties had better ecological service values and trends. (4) From 2000 to 2020, the coal mining intensity (CMI) was concentrated in the upper and middle reaches, particularly at the junctions of Shanxi, Shaanxi, and Inner Mongolia, and the pattern remained stable, but local areas experienced increased mining intensity; (5) the overlap of the CMI and ESV primarily exhibited a low-high clustering pattern in the middle and upper reaches of the Yellow River Basin and eastern Ordos City, and a high-high clustering pattern in the middle reaches of the basin in Shanxi Province, which remained stable and slightly expanded from 2000 to 2030; (6) the trade-off between the ecosystem services in the overlap area intensified, especially between the provisioning and support services, and was significantly impacted by the coal mining activities. The findings indicate that the area that overlaps with the coal mining area in the Yellow River Basin has expanded and has had an increasing negative impact on the ESV. It is also essential to address the trade-offs between the provisioning and support services and to implement ecological restoration measures to mitigate the risk of ESV loss. Future efforts should focus on the regions where the CMI and ESV overlap and have poor coordination and the adverse effects of resource extraction on ecosystem services are becoming more pronounced. The results of this study demonstrate that spatial overlap analysis is effective in identifying the hotspots and provides a foundation for developing sustainable and high-quality policies for ecologically fragile basins.

Assessing the conservation status of Mediterranean coastal ponds: Checklist, ecological and functional diversity of diatom communities

Coastal ponds are peculiar and threatened habitats, considered biodiversity hotspots. In many ecosystems ponds can be a valuable resource for the conservation of freshwater biodiversity. The Castelporziano Presidential Estate is a Mediterranean protected area hosting numerous ponds which are suffering severe droughts and a general decline in number and hydroperiod length. Hydroperiod changes can be particularly relevant for biodiversity inhabiting ponds, in particular diatom communities. Here, for the first time, we evaluate the conservation status of Mediterranean ponds inside the Castelporziano Reserve. The aims of this research are to i) investigate the influence of environmental variables on diatom communities of ponds; (ii) analyse diatom community structure in function of species richness and competitive interactions; (iii) highlight the potential and effectiveness of diatom ecological guilds in supporting the interpretation of the ecological status of threatened small waterbodies. Overall, 122 diatom taxa in the 29 ponds were described. Nitzschia (18 species) was the most species-rich genus, followed by Gomphonema (14) and Navicula (13). 17 species were included in the Red List of endangered species. Intra-pond distance and anthropogenic impacts didn't influence diatom assemblages. On the contrary, diatom communities were influenced by altitude and the distance from the sea. Furthermore, temporary ponds showed the lowest values for Shannon, evenness and Simpson indexes Considering Beta-diversity, both Bray-Curtis and Jaccard dissimilarity matrices highlighted a large dissimilarity between sampling sites. Inter-variability between sites and intra-variability within the sites resulted both very low. Our results highlight that diatom species are not influenced by hydroperiod length. Moreover, a structured diatom community emerged, where segregation processes predominating over aggregation ones. Finally, the average water quality of the ponds, calculated using the EPI-D index, was described as “good”. This study represents the most complete checklist of diatom communities inside coastal ponds of Castelporziano, providing valuable insights into the effects of natural and anthropogenic influences on ponds conservation and management activities. However, spatial-temporal changes and anthropogenic impacts should be deeply investigated.

Spatial-temporal variations of cultivated land compensation and its compensation mechanism in mainland China

Cultivated land compensation can alleviate the conflict between cultivated land protection and socio-economic development. Exploring the spatial-temporal trends of cultivated land compensation, and formulating a scientific and reasonable compensation mechanism are important to achieve sustainable development. To analyze the spatial-temporal changes of the area, comprehensive non-market value, and compensation amount of cultivated land in mainland China, this paper constructed a comprehensive non-market value evaluation framework including positive ecological, negative ecological, and social values, and designed a feasible cultivated land compensation model. In terms of cultivated land area, the cultivated land area indicated an overall surplus condition, and the total net surplus area during 2000–2021 was 54.4 million hectares per year. On a spatial scale, the net surplus districts were concentrated in the north and the center of China, while the net deficit districts were in the developed areas along the southeast coast. In terms of comprehensive non-market value, except for negative ecological value, all other non-market values had increased. On a spatial scale, the coupling relationship between comprehensive non-market value and regional economic development was obvious, presenting a higher value observed in the southeastern coastal developed provinces, and a lower one in the developing inland provinces. In terms of compensation amount, the total payment amount of the payment districts was difficult to cover the total compensation amount of the compensated districts, a certain compensation gap between the two appeared, averaging 6.03 trillion RMB during 2000–2021. On a spatial scale, the payment districts were mainly distributed in the southeastern coastal area, and the number of the payment districts was smaller than that of the compensated area. It is suggested that we should clarify the subject of cultivated land compensation and identify its rights and responsibilities, highlight the leading role of the central government and give full play to the main role of all levels of government, adopt diversified market financing instruments according to local conditions, and formulate relevant supporting security systems.

Revealing the dynamic effects of land cover change on land surface temperature in global major bay areas

Comparative studies across national boundaries on urban heat islands (UHI) are lacking, especially comparative analyses among globally important bay area urban agglomerations at different levels of urbanizations. Bay areas around the world are currently experiencing different stages of urbanization, and the transformation of urban land cover into thermal environments varies significantly. This study investigated the spatial-temporal changes of land cover change (LCC) and the land surface temperature (LST) in four major bay areas (including the San Francisco Bay Area (SFBA), the New York Bay Area (NYBA), the Tokyo Bay Area (TBA), and the Guangdong-Hong Kong-Macao Bay Area (GBA)) from 2000 to 2020. Utilizing correlation analysis and the multiscale geographical weighted regression model (MGWR), the goal was to understand how LCC impact the thermal environmental regionally. The results showed that: (1) The main shift in land cover involved a decrease in forested and cultivated area and an increase in impervious surfaces, with deforestation and agriculture conversion being major factors in this increase. The GBA gave a significant 112% rise in impervious surface during this period. (2) The LST trended towards higher, medium LST zones, closely linked with urban impervious surface expansion. (3) The MGWR model highlighted the direct non-stationary relationship between land cover alterations and LST effects. It showed that conversion to impervious surfaces, particularly from water and cultivated lands, markedly intensified LST, whereas water bodies and forests demonstrated a substantial capacity to mitigate LST. Urban planners were advised to mitigate LST elevations stemming from the transformation of forest lands and aquatic environments into impervious areas, a change notably prevalent in highly urbanized regions. This study provides valuable perspectives on balancing the management of urban thermal environments and urbanization processes.

Spatial–Temporal Analysis of Greenness and Its Relationship with Poverty in China

Ecological environmental protection and poverty alleviation are of great significance for the study of human–land relationship coordination and sustainable development, and they have also been a focus of attention in China in the past few decades. In this study, we chose 13 contiguous poverty-stricken areas in China as the study area. Using MODIS Leaf Area Index (LAI) data from 2000 to 2020, the spatial–temporal changes in greenness were obtained using the Bayesian spatial–temporal model (BYM). Spatial autocorrelation was used to identify the spatial distribution of poverty using socio-economic statistical data. Driving factors, including natural factors, poverty factors, and the Grain for Green Policy (GTGP), and their influence on greenness were analyzed by using the Geodetector model for detecting spatial differentiation and factors’ interactions. The results showed the following: (1) In 13 contiguous poverty-stricken areas (CPSAs) in China, 59% of the area presented an increasing trend of greenness. (2) In 2000, the high poverty levels with larger MPI values were widely distributed. After 20 years, the overall MPI value was lower, except in some northwest regions with increased MPI values. The spatial autocorrelation of poverty, which relates to the mutual influence of poverty in adjacent areas, also decreased. (3) In the study area, 65.24% of the regions showed strong synergistic effect between greening progress and poverty reduction in the interaction between poverty status and green development. With the improvement of greenness level, the positive correlation between poverty alleviation and ecological environment improvement has become increasingly close. (4) The impacts of interaction factors with the highest q values changed from temperature interacting with precision to regional division interacting with the Grain for Green Policy. The conclusions are that from 2000 to 2020, the impact of natural factors, geographical division, and poverty status on greenness has shown a decreasing trend; The effect of the Grain for Green Policy is gradually increasing; At the same time, the interaction and overlapping effects between the Grain for Green Policy and poverty were increasing. Taking into account the needs of ecological environment, poverty alleviation, and rural revitalization, this research provides valuable reference for formulating and implementing relevant policies based on the actual situation in different regions to promote harmonious coexistence between human-land relationship.

Nature-Based Solution for Climate Change Adaptation: Coastal Habitats Restoration in Xiamen Bay, China

Nature-based solutions (NbSs) of biodiversity conservation and ecosystem restoration have been paid increasing attention as an essential approach to slow down climate change. However, to what degree an NbS approach will contribute to the combined effects of human intervention and climate change has not been well studied. From a habitat quality perspective, we set four NbS scenarios to analyze whether the NbS—mangrove restoration in particular—will be enough for climate change in Xiamen Bay of Fujian Province, China. The habitat quality module of the InVEST model (InVEST-HQ) and the Sea Level Affecting Marshes Model (SLAMM) were used to simulate the spatial-temporal changes in habitat types and habitat quality. Results show that (1) rising sea levels will cause coastal squeeze effects, impacting habitat quality due to erosion and inundation in the study area; (2) mangrove restoration is an effective way to mitigate climate change effects and to increase habitat quality; and (3) further analysis of the effectiveness of mangrove restoration shows that the consideration of mangrove fragmentation effects and sea-use impacts are necessary. The findings in this study will enrich the international discussion of NbSs to climate change in coastal areas.

Spatial-temporal Change and Driving Force of Carbon Storage in Three-River-Source National Park Based on PLUS-InVEST-Geodector Model

Exploring the spatial-temporal changes, driving forces, and future development tendency of the carbon sequestration service function of the Three-River-Source National Park ecosystem has great significance for regional ecological protection and sustainable development. Historical land-use data of Three-River-Source National Park from 1990 to 2020 were selected at five-year intervals, and based on the PLUS-InVEST-Geodector model, the spatial-temporal changes of historical carbon storage were analyzed, and the driving forces of spatial-temporal variation were explored combined with multiple factors. The carbon storage of Three-River-Source National Park in 2030 was predicted under the scenarios of natural development and ecological protection. The results showed that： ① The carbon storage of Three-River-Source National Park showed a fluctuating characteristic of increase-decrease-increase-decrease from 1990 to 2020, the carbon storage was increased by 41.85×106 t overall, and the grassland took the largest contribution. ② The spatial distribution characteristics of carbon storage in Three-River-Source National Park had little change between 1990 to 2020, and the evolution of the spatial distribution was relatively stable. The contribution ratio of the Yangtze River source park, Lancang River source park, and Yellow River source park was 7∶1∶2, which was roughly equivalent to the park area. ③ The major driving factors of the spatial-temporal variation of carbon storage in Three-River-Source National Park from 1990 to 2020 were： FVC, soil type, and annual precipitation. The interactive detection of each driving factor showed dual-factor enhancement and nonlinear enhancement. ④ The carbon storage of Three-River-Source National Park was predicted to decrease by 4.87% and 3.98% from 2020 to 2030 under the scenarios of natural development and ecological protection, respectively, and the carbon storage reduction under the ecological protection scenario had a significant inhibitory effect. The findings can provide data support for national spatial planning of Three-River-Source National Park and the enhancement of terrestrial ecosystem carbon storage.

Assessing the effects of soil and water conservation in gully land consolidation using the modified SWAT-Terrace model

To alleviate the competition for cropland between ecological restoration and agricultural production, a Gully Land Consolidation (GLC) project has been widely executed in the Chinese Loess Plateau. This project involves mechanically excavating slopes and filling gullies to expand cropland area. Therefore, in the context of climatic and topographical changes, an assessment of the impact of GLC as a key land use measure of water and sediment in space and time is urgently needed. However, due to scale effects, there is a lack of relevant assessments for the GLC. This study utilized the Soil and Water Assessment Tool (SWAT) and SWAT-Terrace model to analyze the temporal-spatial changes of water and sediment in the Yanhe watershed during 1985–1998 (R1) and 1999–2017 (R2). Additionally, it assessed the effectiveness of GLC in erosion control across different sub-basin clusters. The results showed that (1) at the temporal scale, the runoff and sediment decreased by 30.09 % and 72.73 % respectively, during R2 compared to R1; (2) at the spatial scale, 56 % and 71 % of the sub-basins located in the central and northern parts of the watershed showed a reduction in water and sediment yield, respectively, during R2 compared to R1, while the remaining sub-basins located in the southern part showed an increasing trend in water and sediment yield; and (3) the GLC can reduce 1.17 %-1.93 % of water yield and 0.94 %-1.91 % of sediment yield in the three clusters of sub-basins. The assessment of the soil and water conservation effects of the GLC is beneficial to policymakers in designing effective land management plans and the extension of the project to other regions.

Reciprocal regulation between rural settlement expansion and human-elephant conflict in China's wild elephant range

Human-wildlife conflict (HWC) and its socioeconomic impacts are a pressing global issue. Accurately quantifying HWCs and their interaction with residential development is crucial for rural revitalization and biodiversity conservation efforts. This study investigates the interplay between rural residential expansion (RRE) with human-elephant conflict (HEC) in southern Yunnan Province using high-accuracy yearly land use/land cover data and Asian elephant accident data. A piecewise regression along with several metrics, including expansion intensity and rate of rural residential land, and residential density, were employed to analyze the spatial-temporal change characteristics of RRE. Then, a geographical detector and a bivariate spatial autocorrelation model were used to reveal the driving mechanisms of RRE, with particular emphasis on the spatial relations between RRE and HECs. The results indicate that HECs had a significant negative impact on RRE, exhibiting higher expansion intensity and rate of rural residential land in non-HEC areas than in HEC areas. High spatiotemporal consistency between accelerated RRE and intensified HECs occurred from 2010 onwards, which aligns with the year when the trend of settlement area expansion changed. RRE activities and ensuing land use conversions led to increased occurrences of HECs, which negatively affected the RRE. Compared to HECs, topography and locational factors exhibited a secondary effect on RRE activities. The findings underscore reciprocal feedback mechanisms between RRE and HECs and the elevated risk of adverse interactions between humans and elephants within the range of China's wild elephants, providing theoretical support for coordinating conservation initiatives for Asian elephants with rural revitalization in the border areas of Southwest China.

Prediction and spatial–temporal changes of soil organic matter in the Huanghuaihai Plain by combining legacy and recent data

Soil organic matter (SOM) is critical for soil fertility, crop growth, and plays an important role in the global carbon cycle and climate change. Therefore, spatial prediction of SOM is important to rational soil resource utilization, agricultural production, and ecological environment management. However, large-area SOM mapping research heavily relies on legacy soil data, and large-scale recent SOM mapping may not be possible or have lower accuracy due to limited or less recent data availability. In this study, we aimed to improve SOM prediction and mapping accuracy by combining legacy data with limited recent data. Three models, namely, partial least squares regression (PLSR), random forest (RF), and one-dimensional convolutional neural network (1D-CNN), were applied and compared. The results showed that combining legacy and recent data effectively improved SOM prediction accuracy compared to using only recent data. Among the three modeling methods, 1D-CNN exhibited superior performance, with an averaged determination coefficient of the prediction (R2) of 0.58, a root mean square error (RMSE) of 4.56 g/kg, and a ratio of performance to interquartile distance (RPIQ) of 2.05. The predicted SOM content for both legacy (1980 s) and recent (2010 s) periods showed similar spatial distribution patterns throughout the Huanghuaihai Plain. Generally, there was a noticeable trend of increasing SOM content from northwest to southeast, with higher values observed in Jiangsu and lower values concentrated in Henan, Hebei, and Shandong regions within the study area. Over time, SOM contents in the Huanghuaihai Plain showed an increasing trend, with an average increase of 5.90 g/kg from legacy to recent period. This study provides a promising approach for improving SOM prediction and mapping accuracy at large scales, particularly when recent data availability is limited.

Evaluation of Water–Carbon–Ecological Footprint and Its Spatial–Temporal Changes in the North China Plain

Evaluation of Water–Carbon–Ecological Footprint and Its Spatial–Temporal Changes in the North China Plain

Spatial–Temporal Changes and Driving Factor Analysis of Net Ecosystem Productivity in Heilongjiang Province from 2010 to 2020

Spatial–Temporal Changes and Driving Factor Analysis of Net Ecosystem Productivity in Heilongjiang Province from 2010 to 2020