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• Anticlockwise hysteresis type was the dominating hysteresis type. • Complex hysteresis type generated more sediment than either of three other types. • Antecedent rainfall dominated clockwise type, along with time lag for complex type. • Intraday rainfall and sediment separately dominated clockwise and anti-clock types. • Largest patch index and grassland separately dominated complex and other types. This study aims to quantitatively evaluate the effects of hydrological and landscape characteristics on suspended sediment concentration and discharge (SSC-Q) hysteresis. Runoff and sediment data of 405 flood events were collected from 10 basins in Wudinghe River basin on the Loess Plateau of China. Hysteresis analysis is a key tool for the interrogation of transport of sediment, which have been shown to be important within catchments. It can provide insight into catchment function, allowing the development and testing of process-based hypotheses. The principal components and corresponding explanatory power were extracted quantitatively from hydrological and landscape characteristics via principal component analysis (PCA) and redundancy analysis (RDA), respectively. The most common hysteresis type was anticlockwise. The proportions of the total event sediment loads for different hysteresis types were not always generally correlated to the frequency of the corresponding events. Furthermore, the composition and explanatory power of controlling principal components varied among clockwise, anticlockwise, figure-of-eight, and complex hysteresis types. For hydrological principal components, the antecedent precipitation, intraday precipitation, and sediment principal components controlled clockwise, anticlockwise, and figure-of-eight hysteresis types, which had explained 47.03%, 58.82% and 52.05% of the variation of hysteresis index, respectively; the antecedent precipitation and time lag principal component controlled complex hysteresis type and accounted for 28.22% and 34.65% of the variation of hysteresis index, respectively. For landscape principal components, grassland principal component dominated clockwise, anticlockwise, and figure-of-eight hysteresis types, and accounted for 95.00%, 69.70%, and 92.00% of the variation of hysteresis index, respectively. Largest patch index principal component controlled complex hysteresis type and accounted for 100% of the variation of hysteresis index. Therefore, within this catchment, whereas hysteresis patterns varied due to all of the hydrological and landscape variables to some extent, precipitation, suspended sediment, area of grassland, and the largest patch area had stronger impact on hysteresis dynamics. [ABSTRACT FROM AUTHOR]

Annual atmospheric nitrogen (N) deposition in China increased approximately 8 kg N ha−1 from the 1980s to the 2000s, which may have greatly affected soil respiration (R s) and its temperature sensitivity (Q 10). Although numerous individual studies have been conducted, the responses of R s to simulated N deposition remain controversial. To reconcile the conflicting results of R s and expand our knowledge about the response of Q 10 to N addition, a dataset with 333 independent observations in China was compiled, and a meta-analysis was performed. Our results showed that N addition increased R s by 7.1% (P < 0.05) across all biomes. The positive response degree of R s in croplands (27.0%, P < 0.05) was significantly greater than those in the grassland and forest biomes, which indicated that R s in anthropogenic ecosystems might be more sensitive to N enrichment. In contrast to low and medium N levels (≤20 g m−2 yr−1), high N addition levels (>20 g m−2 yr−1) inhibited R s due to a decrease in plant fine root biomass (RB). Compared with ammonium nitrate, urea is more likely to stimulate the release of soil C. Regression models showed that the R s response ratio (RR) was positively correlated with pH and the RR s of microbial biomass carbon (MBC) and RB. Increases in both plant roots and microbial biomass induced by N addition directly promoted R s , and N enrichment likely increases R s in soil with a high pH. The temperature sensitivity parameter, Q 10 , decreased by 3.7% (P < 0.05) across all biomes and showed an overall negative response for different biomes (except wetlands and deserts), N addition levels and N types. The Q 10 response ratio was positively correlated with the RR of pH. Soil acidification induced by proton release during N fertilizer transformation might accelerate the decomposition of recalcitrant organic matter and further decrease the Q 10 value. Our study provides valuable information to Chinese environmental policy- and decision-makers in their attempts to evaluate the effects of N deposition on terrestrial ecosystem C cycle. • N addition increased R s by 7.1% and decreased Q 10 by 3.7% across all biomes. • Relative to grassland and forest, R s of cropland was more sensitive to N addition. • Contrary to low and medium N addition levels, high N addition levels inhibited R s. • Soil acidification induced by N addition increased R s and decreased the Q 10 value. [ABSTRACT FROM AUTHOR]

Accurate information on crop type spatial distributions is crucial for yield estimation, agroecological modeling, and agrarian policy development. In comparison with moderate resolution (10–30 m) satellite images, very high-resolution (VHR, ≤ 1 m) images are superior at describing the spatial details and complex texture features of agricultural land. However, VHR images generally suffer from insufficient spatiotemporal coverage and high spectral variation in crop type, making fine-scale crop type mapping at regional or larger scales challenging. In this study, we developed a novel data-driven residual attention U-shape network (RAUNet) to identify crop types at the regional scale based on VHR images. RAUNet was adapted from UNet by introducing a residual module and a gated attention mechanism to strengthen the multilevel representation of crop features from VHR images. We selected rice-crayfish fields (RCFs) in Hubei Province, China, as the case crop type and area to test the performance of RAUNet. Seven models, including RAUNet pan , ResUNet, AttnUNet, UNet, DeepLabV3 + and random forest at the pixel and object levels, were adopted for comparison with RAUNet. Moreover, the model transferability was evaluated over regions with different agricultural landscapes. Our results showed that RAUNet-derived RCF maps obtained an average F1-score and MCC of 0.90 and 0.85 at different cultivation stages, which significantly outperformed other methods. Additionally, RAUNet had good spatiotemporal transferability, with an average F1-score and MCC of 0.93 and 0.88 in four transfer areas. The visualization results of the attention weights indicated RAUNet's prominent capability in combining useful and relevant information from different feature levels to produce refinement predictions for the target crop type. Furthermore, the high-level features derived from RAUNet can well separate RCFs and non-RCFs over different landscapes, which were also consistent across different cultivation periods. These encouraging results suggest that RAUNet works well for fine-scale crop type mapping in smallholder farming systems, and it is an efficient method for land cover mapping based on VHR images at the regional scale. [ABSTRACT FROM AUTHOR]

Cropland soil erosion is primarily caused by agricultural production and indirectly altered by consumption patterns. A well-developed grain trade system transfers grain products to distant locations, away from their place of origin where soil erosion may have occurred. Evidence-based policies to control soil erosion can be developed by holding consumers responsible for the soil erosion caused by their consumption. However, there have been few systematic studies on cropland soil erosion that is embodied in grain trade. In this study, we estimated the soil erosion intensity (SEI) of grain production in each province of China from 1990 to 2020 by combining the Revised Universal Soil Loss Equation and socio-economic statistics. We also constructed an interprovincial grain trade network using linear programming techniques and analyzed the cropland soil erosion associated with the interprovincial grain trade. The results showed a rise in national cropland soil erosion attributed to grain production from 5.36×108 t in 1990 to 7.56×108 t in 2020. In particular, those embodied in interprovincial grain trade increased from 0.94×108 t in 1990 to 3.52×108 t in 2020. Nationally, about 10.72% of soil erosion exports in 2020 was from provinces with lower-than-average SEI, compared to 18.42% in 1990, indicating that current patterns of grain production and consumption are unfavorable for erosion control. Accordingly, measures have been proposed to build a soil erosion control system that includes consumers, such as changing farming practices, optimizing agricultural layout, promoting technology export and establishing a provincial compensation mechanism. [Display omitted] • Trade was prominent and insufficiently explored driver for cropland soil erosion. • RUSLE and grain trade network were utilized to estimate embodied soil erosion. • Mismatch between production and consumption increased embodied soil erosion. • Soil erosion burden mainly shifted from south with high SEI to north with low SEI. • Current provincial grain trade patterns were not conducive to soil erosion control. [ABSTRACT FROM AUTHOR]

In China, sloping farmland accounts for one-third of its total farmland, supporting ~330 million mountain people's livelihoods. Despite its long history of using soil conservation measures for reducing soil loss on sloping farmland, no comprehensive evaluation has ever been performed on their effectiveness. In this study, we reviewed the soil conservation measures on sloping farmland in China from ~2500 years ago to the present and examined their effectiveness under current and projected climate change scenarios based on 6909 plot-scale observations. For the sloping farmland across China, the average soil loss rate is 14.47 Mg ha−1 yr−1, with a quarter of the observed values exceeding the maximum tolerable soil loss rate (10 Mg ha−1 yr−1). Soil conservation measures can reduce soil loss by ~80%, with the highest effectiveness for the combination of biological and engineering measures (reduced by ~86%), followed by biological measures (reduced by ~84%) and engineering measures (reduced by ~82%) separately. However, the effectiveness of soil conservation measures shows a significant decrease in the farmland with a slope above 15° or a single rainfall event >25 mm. The effectiveness of currently applied soil conservation measures was also compared under the Shared Socioeconomic Pathways (SSP) 1, 2, and 5 in 2050, and their effectiveness is expected to decrease on over 27% of the sloping farmland. In particular, under the SSP1 scenario, the effectiveness of soil conservation measures is projected to diminish in 70%, 54%, and 54% of sloping farmland in Northeast China, Sichuan Basin and surrounding regions, and Yunnan-Guizhou Plateau, respectively, due to changes in rainfall, highlighting the need to consider the impact of climate change when implementing soil conservation measures. Overall, this study provides useful information for scientific strategies on the construction, management, and maintenance of soil conservation measures to control soil loss on sloping farmland. [ABSTRACT FROM AUTHOR]

Background and aims: Trait-based approaches are increasingly used to improve ecological restoration in degraded ecosystems. The aim of this study was to evaluate how vegetation controls soil detachment capacity (Dc) by concentrated flow based on the linkages between root traits and soil physics. Methods: We selected 60 plots along a land degradation gradient caused by long-term water erosion in a small catchment, central China. These plots consisted of woodlands, scrublands, grasslands and bare lands. And soil physical properties, root traits and Dc were measured in each plot. Results: Fine roots (0.2 mm < diameter < 2 mm) accounted for 51–93% of total root length in topsoil. Roots explained most of the soil variations in noncapillary porosity, aggregate stability and shear strength. Furthermore, our prediction model (R2 = 0.88, NSE = 0.85) showed that fine roots length density and soil shear strength were the primary factors reducing Dc. Conclusions: Vegetation restoration improves multiple soil physical properties key to mitigating Dc, and the root functional traits play a substantial role in this relationship. These findings could provide the basis for soil conservation, and for expanding the pool of species of interest, which can be used to provide erosion mitigation services in degraded ecosystems. [ABSTRACT FROM AUTHOR]

Soil erosion affects the redistribution of soil and associated soil organic carbon (SOC) from different landforms, and it has significant implications regarding the fate of eroded SOC and terrestrial carbon sequestration. Despite the importance of soil erosion, few studies have evaluated the sources and budget of eroded SOC in the Loess Plateau region, which suffers from severe soil erosion. Based on an 11.3 m check dam sediment profile, we used the 137 Cs activity and extreme rainfall events as dating methods to date sediment sequences. In addition, the natural abundance levels of the stable carbon isotope (δ 13 C) of bulk organic matter and a two-end-member mixing model were used to discriminate the sources of eroded SOC from different siltation stages retained by the check dam in an intensive agricultural catchment of the Loess Plateau, China. The eroded SOC captured by the check dam was compared to potential source materials from different landscape units, which included sloping cropland and gully surface soils (0–5 cm). The results showed that the check dam intercepted 98.5 Gg of eroded soil and 172.6 Mg of SOC. The eroded SOC was primarily sourced from sloping cropland, which contributed to 81.3% of the total SOC retained by the check dam, whereas the gully soils contributed to 18.7% during the entire siltation stage. Additionally, the contribution of sloping cropland to eroded SOC increased from 1960 to 1990 as a result of rainfall and anthropogenic activities. A total of 89.7 Mg SOC was lost during soil erosion processes at a rate of 0.17 Mg ha −1 yr −1 and accounted for approximately 30% of the total eroded SOC exported from the eroding areas. Our results indicate that the soil erosion process has been an important net source of SOC in the study catchment. The check dam served as a carbon storage and sequestration structure for the hilly loess region due to its beneficial conditions for carbon sequestration over broad temporal and spatial distributions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Accurate quantification of soil erosion sub-process by remote sensing and check dam. • Vegetation restoration significantly reduced soil erosion modulus. • Check dams effectively reduce sediment delivery on the watershed scale. • The variation of erosion and deposition changes the sediment delivery ratio. China has implemented a series of ambitious soil and water conservation (SWC) projects on the Chinese Loess Plateau, which have significantly changed the erosion, transport, and deposition of sediment. As a result, the sediment flux of the Yellow River, once the largest carrier of fluvial sediment worldwide, has been reduced by approximately 85 % in the past 60 years. However, the effects of SWC measures on erosion, transport, and deposition of sediment are still difficult to quantify, which greatly limits the further planning and adjustment of SWC measures. Here, we determined soil erosion, sediment deposition, and sediment yield at different historical stages in a 187 km2 hilly and gully watershed on the Chinese Loess Plateau using the unmanned aerial vehicle (UAV) photogrammetry technology combined with check dam surveying and hydrologic monitoring. The results show that the construction of check dams and vegetation restoration significantly reduced the soil erosion rate, from 21,144 t km−2 yr−1 at Stage-1 (1960–1969) to 13,819 ± 3,622 t km−2 yr−1 at Stage-2 (1970–1999) and further to 4,723 ± 1,278 t km−2 yr−1 at Stage-3 (2000–2018). The sediment deposition rate was estimated to be 5,989 and 2,582 ± 351 t km−2 yr−1 at Stage-2 and Stage-3, respectively. The variation in the erosion and deposition of sediment led to a significant change in the sediment delivery ratio, from 1 at Stage-1 to 0.57 at Stage-2 and 0.45 at Stage-3. Our research results provide an important reference for further SWC planning. [ABSTRACT FROM AUTHOR]

Cropland soil erosion is a major threat to global agricultural sustainability. Compared with the well-studied natural factors of soil erosion, socioeconomic factors have just begun to be considered. The major obstacle is that the soil erosion of different crops has not been accounted for and connected to socioeconomic activities. This study adopted the revised universal soil loss equation (RUSLE) and the environmentally extended multiregional input-output (EE-MRIO) model to account for soil erosion on cropland from the production, consumption, and income perspectives at the provincial and sectoral levels in China. The results showed the major responsible agents in a synthetic view. On the production side, the Yunnan-Kweichow Plateau and surrounding hills of the Sichuan Basin, the Chinese grain bases located in northeastern and central China, and the Loess Plateau were the major regions that caused the most cropland soil erosion. On the consumption side, the national final demand for Sichuan, Yunnan, Shandong, Henan, and other provinces with high production-based cropland soil erosion (PBE) values per se pulled remarkable cropland soil erosion. On the income side, the crucial provinces into which the national primary input enabled notable cropland soil erosion were still those areas with serious cropland soil erosion. From the industrial perspective, the direct effects of human primary inputs into agriculture and the demand for agricultural products played the dominant role. In addition, Cereal and BOP (beans, oil and potatoes) were the most important among the agricultural sectors. The effects of the nonagricultural sectors, especially the manufacture of foods and tobacco (MFT) and the chemical industry (CI), on cropland soil erosion also cannot be ignored. Our results indicated that accounting from multiple perspectives could inform the better management of cropland soil erosion from a more comprehensive perspective. To the best of our knowledge, this study is the first to consider the accounting of cropland soil erosion in China from multiple perspectives. Tailored packages of measures should be established based on different patterns of areas with serious cropland soil erosion. [Display omitted] • Cropland soil erosion accounting was based on a multi-regional input-output table. • Multiple perspectives' accounting shows the major responsible agents for soil loss. • Crops in different regions also were the key to tackle cropland soil erosion. • Cropland soil erosion control cannot just narrow down to four agricultural sectors. • Cropland soil erosion is not a local phenomenon but a macroscopic problem. [ABSTRACT FROM AUTHOR]

• A UAV-based method estimating sediment deposited behind check dams was developed. • Errors of the optimal model for single and regional check dams are 12–13% and 2–3%. • This method avoids limitations of tedious field surveys and historical records. • This method can evaluate sediment retained by check dams in areas as large as 211,800 km2. The estimation of sediment deposited behind dams and reservoirs is of great significance for quantifying soil erosion rate and sediment flux. However, existing methods of sediment volume estimation often require detailed field measurements and historical topographic data, limiting the broader application of these methods. In this paper, focusing on the region that suffers the world's most severe soil erosion, we combine unmanned aerial vehicle (UAV) photogrammetry and simulate submerging analysis to propose a novel method for estimating sediment silted by check dams under complex topography. We obtained 1339 groups of topographic factors and ascertained the corresponding volumes of sediment deposited behind check dams in the loess hilly region of China (LHRC), and established five different models combined with regression analysis. Two different sets of data were used for method validation and optimal model determination. The results showed that the error of the optimal model in the volume estimation of single check dam and regional check dams is 12–13% and 2–3%, respectively. Additionally, the area-volume model has the potential to evaluate the sediment retention capacity of check dams (in the order of billions of cubic meters) in the whole LHRC, because the variables are easy to obtain and the model accuracy is relatively high. The further application of this method will help to evaluate the watershed sediment yield and regional soil and water conservation benefits, and is of great significance for explaining the future changes in water and sediment in the Yellow River basin. [ABSTRACT FROM AUTHOR]

Abstract: Controlling soil hydrological processes and combating soil erosion on agricultural fields are high priorities for crop production and ecological environments. In this research, the effect of land application of rock fragments on surface runoff, subsurface runoff, infiltration and soil loss on Regosols had been investigated under field conditions using a portable rainfall simulator. Experimental twin-plot (two subplot with 1-m wide by 2-m long, 32% slope) with different rock fragment covers ranging from 0–40% were exposed to three rainfall intensities, low (57±2mmh-1), medium (91±3mmh-1), and high (122±5mmh-1). Fifteen treatments were conducted in the experiments in duplicates. Surface runoff, subsurface runoff, soil moisture and sediment were measured. Results show that surface rock fragment cover retarded surface runoff, increased infiltration and subsurface runoff, and diminished sediment concentration and soil loss. The final infiltration rates, which increased with increasing rock fragment covers, were 16.5–42.7mmh-1 at low intensity, 19.7–50.8mmh-1 at medium intensity and 23.8–56.4mmh-1 at high intensity. Compared with bare soils, surface runoff rates were reduced to 24%, 51% and 64% in soils with 40% rock fragment cover at low, medium and high intensity rainfall, respectively. Subsurface runoff volume was significantly higher and time to start subsurface runoff was shorter as surface rock fragment cover increased. Compared with bare soils, subsurface runoff coefficients increased to 3.5, 3.3 and 2.9 times in soils with 40% rock fragment cover at low, medium and high intensity, respectively. Sediment concentrations increased from 9.8gL-1 for 40% rock fragment cover under high intensity rainfall to 51.5gL-1 for bare soils with rain falling at high intensity. The erosion rate was <12gm-2 min-1 for soils with 40% rock fragment cover, even when rainfall intensity was high, while it was >15gm-2 min-1 for bare soils under low intensity. The relationship between rock fragment cover and soil loss ratio can be expressed by an exponential function with a high degree of reliability, regardless of rainfall intensities. Overall, results indicate the surface rock fragments can be influential in shaping hydrological processes and soil loss from sloping farmland. [Copyright &y& Elsevier]

Abstract: Soil thickness exerts a first-order control on the hydrological processes of the hillslopes. However, from a hydropedological perspective, the knowledge of soil thickness effect on hydrological and erosion characteristics under sloping lands is limited. Based on a comprehensive survey of an experimental watershed in the Three Gorges Area of China, five typical sloping land plots (2m×1m) with different soil thickness were selected along a hillslope to investigate their hydrological processes and erosion response under three rainfall intensities (60, 90 and 120mmh−1) using a portable rainfall simulator. The results can be summarized as follows: (1) The surface flow coefficient was increased with increasing soil thickness, especially under the event of 60mmh−1. (2) The subsurface flow of the 23, 31 and 45cm plots mainly took the form of preferential flow. Conversely, the 59 and 76cm plots mainly took the form of matrix flow. (3) A prolonged low intensity rainfall is much more likely to facilitate deep percolation and subsurface flow than a short high intensity rainfall regardless of soil thickness. (4) Soil thickness and rock fragment cover were the most important factors than other soil properties in determining the hydrological and erosion behaviors. Thin soils showed higher infiltration capacity than thick soils due to their more distinct hydrological processes of subsurface flow and deep percolation. Rock fragment cover enhanced infiltration and served as a shield to protect the soil surface from detaching. Due to the synergies between thin soil thickness and high rock fragment cover, thin soils displayed significantly lower erosion rates than thick soils in all rainfall events, which increased from 211gm−2 h−1 for the 23cm plot with rainfall of 60mmh−1 to 4220gm−2 h−1 for the 76cm plot with rainfall of 120mmh−1. Our study suggested that the emerging interdisciplinary field of hydropedology promotes synergistic integration of pedology (e.g. watershed scale soil thickness investigation and soil profile description) and hydrology (e.g. rainfall simulation, subsurface flow and deep percolation) to enhance the holistic study of soil–water interactions in the sloping lands with different soil thickness. [Copyright &y& Elsevier]

The collapse of the plastic waste trade (PWT) amplifies the threats of mismanaged plastic waste to the ecological system and human health, posing a risk as well as an opportunity to the global circular economy. Although trade barriers in the PWT continue to impact waste management systems, there are few analyses that propose global mitigation strategies in response to trade fluctuations. Here, we show that most countries have been overloaded with plastic waste compared to their ordinary capacity since China's import ban in 2017. We apply a cascading failure model to quantify the collapse process worldwide and find that 183 countries become overloaded as this collapse cascades, with nearly 6% of countries experiencing over 1.5 times their ordinary load. However, this overload could be greatly alleviated if leading countries were to sharply increase their capacity to treat plastic waste based on scenario analysis. Although waste exporters should take more responsibility and scenario analysis results show that top exporters could effectively mitigate global plastic waste levels by increasing their treatment capacity, cooperation between key exporters, importers, and intermediators has the best mitigation effects. Our analysis suggests that key countries should as soon as possible take responsibility for and cooperate in mitigating potential plastic waste pollution related to trade fluctuations. • Many countries show plastic waste overloading due to China's import ban. • Structural change of plastic waste trade could lead cascading failure worldwide. • Overload situation will be greatly alleviated, if leading countries work for it. • The cooperation strategy has the best mitigation effect. [ABSTRACT FROM AUTHOR]

Soil erosion on cropland is a result of the interaction between nature and human activities. The socioeconomic influencing factors of soil erosion have been less studied than the biophysical processes and previous studies have mainly focused on the impacts of local socioeconomic factors on soil erosion in the same region. However, since agricultural activities are densely connected to other socio-economic activities, the need for agricultural products from distant regions could potentially drive local soil erosion accompanying agricultural production. To the best of our knowledge, these telecoupling effects have not been studied. Here, we combined the Revised Universal Soil Loss Equation (RUSLE) and multiregional input-output analysis (MRIO) models to quantify the contribution of China's cross-provincial economic demand to local soil erosion at the provincial, sectoral, and supply chain levels. Our results show that a large amount of soil erosion in the southwest, northeast, and central regions is linked to the economic needs across provinces. Agriculture and food processing are the most important distant driving sectors. The driving effect of household consumption on soil erosion mainly occurs on shorter supply chains, while exports and capital formation drive soil erosion through longer chains. Our results indicate that local soil erosion management must consider the impact of distant agricultural product needs and coordinate food production and supply on a national scale to protect the ecological function of the land. [Display omitted] • Cropland soil erosion was linked to a multi-regional input-output table. • 28.19% of cropland soil erosion was driven by distant final demand. • Ten provinces had more than 1/4 of their soil erosion driven by other provinces' consumption. • Agriculture, Food Processing, and Construction contributed 72.28% telecouped erosion. • The telecoupled share increases along supply chains from 19.60% (tier 0) to 33.70% (tier 6). [ABSTRACT FROM AUTHOR]

Atmospheric Polycyclic Aromatic Hydrocarbons (PAHs) emissions cause non-negligible damage to human health and well-being. Effective regional cooperation is urgently required to mitigate PAHs emissions to maintain satisfactory air quality. This study quantified and tracked China's PAHs emissions flows embodied in interprovincial trade. A production-based emissions inventory of 16 U.S. EPA priority PAHs based on commercial energy consumption in China in 2012 was compiled using the emissions factor approach. Then, a multiregional input-output model was constructed to reveal consumption-based emissions and to track the PAHs emissions embodied in the trade of 27 major sectors across 30 regions in China. Key structural paths were also identified using structural path analysis (SPA). In 2012, the total industrial energy-derived PAHs emissions were estimated to be 47.7 tons of BaP-toxic equivalents (8032.7 tons of mass). Shandong, Hebei, and Hubei accounted for more than 24.0% of the production-side PAHs emissions in the whole country. Approximately 30.8% of China's PAHs emissions were embodied in goods consumed outside of the province in which they were produced. PAHs flow tended to start in the western regions and ended in the eastern regions along the coast. The results of the SPA showed that critical paths, such as from the Metallurgy sector to the Construction sector, embodied a large amount of emissions and had the potential to affect the performance of the entire system. By paying attention to the consumption-based accounting as well as the production-based accounting of emissions and by focusing on vital transfer paths, policymakers can devise effective and targeted environmental protection and sustainable development policies in China. • PBA and CBA of PAHs emissions were constructed to show a geographical disparity. • Construction and Other Service were key sectors driving embodied emissions. • Metallurgy, Transportation and Coal Mining were key sectors in production. • The coastal region was important sink. • Central and northern China was the most important source for PAHs flows. [ABSTRACT FROM AUTHOR]

Agricultural production in China is mainly decentralized, small in size, and involved by independent single households. Farmers are the main implementers of soil erosion control projects. Their willingness and abilities, which are crucial to the effectiveness of these projects, are closely related to their social networks. However, the relationship between farmers' social networks and soil erosion control remains unclear. Hengxi, a typical village in Jiangxi Province, China, was used as a case study. Traditional- and new-type of farmers' social networks were built according to the planting structures based on survey data. The results showed that both types of networks had the characteristics of small-world network and scale-free network. The ability to obtain and dispense information was the significant distinction between the two networks. The dealer was an influential key node in both networks. The government agencies were key nodes in the new-type network but not in the traditional-type network, which made it difficult for traditional farmers to obtain indispensable information about soil erosion control. The characteristics of farmers and their corresponding networks had significant influences on their awareness of soil erosion. Soil erosion management projects could be deployed smoothly by the key farmers and government agencies in the new-type social network, but difficultly in the traditional-type social network. To improve the effectiveness of soil erosion control projects, cooperation with dealers is important for government agencies. • Characteristics of farmers' social networks are distinct based on planting structure. • Information diffusion is more efficient in new-type social network. • Betweenness centrality affects farmers' awareness of soil and water conservation. • Government agencies should undertake proper roles in traditional-type social network. [ABSTRACT FROM AUTHOR]

• Afforestation projects have a positive effect on the increase of permanent water. • Dams construction is an important factor in controlling permanent water changes. • Vegetation changes have a greater impact on permanent water than climate factors. China is facing the challenge of the uncertain impacts of large-scale afforestation on regional water resources. However, the effects of vegetation cover changes on the variation in surface water at the regional scale are still controversial. Here, we focused on the 0.9 million km2 vegetation restoration region in China, where the highest significant vegetation cover changes on the earth. Multi-source remote sensing data were used to describe the characteristics of seasonality and transition of surface water and to analyse the causes of surface water changes from climate, vegetation cover and other human factors. Our results show that the annual maximum NDVI of Northeast region (NE) and Loess Plateau region (LP) increased significantly from 0.74 to 0.85 and 0.49 to 0.62 from 2000 to 2015, respectively. Meanwhile, permanent water, as a vital component of surface water, exhibited net increases of 695.6 km2 and 119.4 km2 in NE and LP from 2000 to 2015, respectively. The extension in permanent water and the implementation of ecological projects exhibited highly consistent spatiotemporal patterns. Statistical analysis indicated that vegetation cover is an important factor in controlling permanent water changes. Human activities such as building dams and reservoirs are also an important explanatory variable for permanent water increases. The newly built dams contributed 43% in NE and 25% in LP to the increase in permanent water. In addition, although climatic factors were not the main factor influencing permanent water, precipitation significantly affected the total surface water in NE. These findings have potential implications for understanding surface water and forest dynamics and formulating regional development plans in the vegetation restoration region in China. Image, graphical abstract [ABSTRACT FROM AUTHOR]