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Groundwater level (GWL) prediction is important for ecological protection and resource utilization; it helps in formulating policies for artificial groundwater recharge, modifying the number of extraction wells, etc., and can support sustainable human development as well as inform water resource management decisions. However, climate change, anthropogenic impacts, and the complex coupling between surface water and groundwater increase the difficulty of predicting groundwater levels. The model proposed in this paper combines external data as well as multiple models. The method leverages long and short-term memory (LSTM) and convolutional neural network (CNN) models, combined with secondary modal decomposition and slime mould algorithm (SMA), together with an adaptive weight module (AWM). The study applies this method to predict GWL for three different hydrological conditions in China, specifically for the Jinan Baotu Spring, Heihu Spring, and Zhongtianshe watershed of Taihu Lake. A comparison of metrics such as mean absolute error and Nash efficiency coefficient for single and hybrid models shows that the model in this paper is more advantageous than the single model and other hybrid models. The interpretability of the model is enhanced by SHAP values that demonstrate the degree of contribution of the input variables. This paper uses SHAP analyses to identify the key drivers affecting groundwater levels. These factors must be detected in order to develop groundwater resource protection measures. [Display omitted] • Multivariate fusion data including hydrology and meteorology are used as model input. • A secondary modal decomposition module for historical groundwater level data was utilized. • The neural network hyperparameters are optimized using the slime mould algorithm. • Aggregate subsets of prediction with adaptive modules rather than linear summation. • The interpretable SHAP model measures the degree of influence of external variables. [ABSTRACT FROM AUTHOR]

Human impact on the coastal plain of Southeast China has been well studied over late Holocene timescales; however, an understanding of anthropogenic impact in mountainous regions is still lacking. In this paper, we present records of vegetation, fire, and human impact, spanning the past 4000 years, with a resolution of ∼40 years, obtained from an upland peatland in Southeast China. The results reveal that climate change (dominated by the evolution of the East Asia Monsoon) was the most critical factor controlling vegetation before 1.0 cal kyr BP, while human impact gradually emerged as the primary driver after 1.0 cal kyr BP in the mountains of Southeast China. As such, the record of anthropic impact in mountainous regions lagged behind the signal from the coastal plains by some 2000–4000 years. As the population migrating from northern China dispersed into the mountainous regions of Southeast China, demand for agricultural land promoted slash-and-burn cultivation and the destruction of broad-leaf forest. • Three climatic stages identified spanning 4.0 cal kyr BP based on pollen and charcoal analysis. • Significant anthropogenic impact on mountain vegetation of Southeast China occurred in 1.0 kyr BP, lagged coastal plains by 2000–4000 years. • The population migrating from northern China dispersed into the mountainous regions of southeastern China in 1.0 kyr BP, urgent demand for cultivated land. [ABSTRACT FROM AUTHOR]

Discriminating the provenance of fine-grained sediments is crucial for reconstructing paleogeography, sedimentary processes, and paleoclimate. In this paper, we investigate the South Bohai Coast to better understand source-to-sink systems in East Asia. This region is influenced by both distant sources such as the large-scale Yellow River and small local river sources flowing from the Luzhong Mountain area. Two Holocene sedimentary cores, dated using optically stimulated luminescence (OSL) and accelerator mass spectrometry (AMS) 14C chronology, were used to investigate the provenance of the fine-grained sediments over the last 7 kyrs. Clay mineralogy and relevant non-linear modeling were employed for provenance discrimination. The results show that the fine-grained sediments along the South Bohai Coast were mainly derived from the Yellow River during the periods of 7.0–5.4 ka and 4.5–2.6 ka, respectively, while the input from the Luzhong Mountain-derived rivers was greater during 5.4–4.5 ka and 2.6–0.2 ka, respectively. Fluvial activities and marine-terrestrial interaction driven by climate factors such as East Asian winter monsoon, temperature, and precipitation in river basins, dominantly influenced the provenance of fine-grained sediments from 7.0 to 2.6 ka. Anthropogenic impact on provenance increased after 2.6 ka. The chronology of the two cores showed extremely rapid sedimentation rate transitions at 5.2 ka and 1.5 ka, respectively, very likely attributed to anthropogenic-induced rapid progradation. Our study provides a model for better understanding the paleoenvironmental and paleogeographic evolution of a coastal area where multiple sources exist. • Anthropogenically high sedimentation rate in the South Bohai Coast in late Holocene. • Provenance discrimination of the fine-grained sediments in the South Bohai Coast since the mid-Holocene. • The major source of the fine-grained sediments in the South Bohai Coast changed episodically. [ABSTRACT FROM AUTHOR]

As the world's largest carbon emitter, China is under great pressure to cut down carbon emissions. Understanding the evolution of carbon emissions across Chinese cities is important for policymakers when allocating carbon emission quota among these cities. This paper draws upon the Open-source Data Inventory for Anthropogenic CO2 to calculate city-level per capita carbon emissions in China from 2001 to 2016. Overall, we find that per capita carbon emissions of Chinese cities have been generally on the rise during the 2001–2016 period. However, there has been on average a modest decline in per capita carbon emissions of cities in China's Yangtze River Delta region and Pearl River Delta region from 2011 to 2016, after a remarkable increase during the 2001–2011 period. Besides, the average north-south gap has been enlarged, with northern cities having a relatively higher level of per capita carbon emissions. [ABSTRACT FROM AUTHOR]

In the past decades, continuous efforts have been made at a national level to reduce Nitrogen Dioxide (NO2) emissions in the atmosphere over China. However, public concern and related research mostly deal with tropospheric NO2 columns rather than ground-level NO2 concentrations, but actually ground-level NO2 concentrations are more closely related to anthropogenic emissions, and directly affect human health. This paper presents one method to derive the ground-level NO2 concentrations using the total column of NO2 observed from the Ozone Monitoring Instrument (OMI) and the simulations from the Community Multi-scale Air Quality (CMAQ) model in China. One year's worth of data from 2014 was processed and the results compared with ground-based NO2 measurements from a network of China's National Environmental Monitoring Centre (CNEMC). The standard deviation between ground-level NO2 concentrations over China, the CMAQ simulated measurements and in-situ measurements by CNEMC for January was 21.79 μg/m3, which was improved to a standard deviation of 18.90 μg/m3 between our method and CNEMC data. Correlation coefficients between the CMAQ simulation and in-situ measurements were 0.75 for January and July, and they were improved to 0.80 and 0.78, respectively. Our results revealed that the method presented in this paper can be used to better measure ground-level NO2 concentrations over China. [ABSTRACT FROM AUTHOR]

Exploitation of groundwater has greatly increased since the 1970s to meet the increased water demand due to fast economic development in China. Correspondingly, the regional groundwater level has declined substantially in many areas of China. Water sources are scarce in northern and northwestern China, and the anthropogenic pollution of groundwater has worsened the situation. Groundwater containing high concentrations of geogenic arsenic, fluoride, iodine, and salinity is widely distributed across China, which has negatively affected safe supply of water for drinking and other purposes. In addition to anthropogenic contamination, the interactions between surface water and groundwater, including seawater intrusion, have caused deterioration of groundwater quality. The ecosystem and geo-environment have been severely affected by the depletion of groundwater resources. Land subsidence due to excessive groundwater withdrawal has been observed in more than 50 cities in China, with a maximum accumulated subsidence of 2-3 m. Groundwater-dependent ecosystems are being degraded due to changes in the water table or poor groundwater quality. This paper reviews these changes in China, which have occurred under the impact of rapid economic development. The effects of economic growth on groundwater systems should be monitored, understood and predicted to better protect and manage groundwater resources for the future. [ABSTRACT FROM AUTHOR]

In this paper, the RIEMS 2.0 model, source emission in 2006 and 2010 are used to simulate the distributions and radiative effects of different anthropogenic aerosols over China. The comparison between the results forced by source emissions in 2006 and 2010 also reveals the sensitivity of the radiative effects to source emission. The results are shown as follows: (1) Compared with those in 2006, the annual average surface concentration of sulfate in 2010 decreased over central and eastern China with a range of -5 to 0 g/m³; the decrease of annual average aerosol optical depth of sulfate over East China varied from 0.04 to 0.08; the annual average surface concentrations of BC, OC and nitrate increased over central and eastern China with maximums of 10.90, 11.52 and 12.50 g/m³, respectively; the annual aerosol optical depths of BC, OC and nitrate increased over some areas of East China with extremes of 0.006, 0.007 and 0.008, respectively. (2) For the regional average results in 2010, the radiative forcings of sulfate, BC, OC, nitrate and their total net radiative forcing at the top of the atmosphere over central and eastern China were -0.64, 0.29, -0.41, -0.33 and -1.1 W/m², respectively. Compared with those in 2006, the radiative forcings of BC and OC in 2010 were both enhanced, while that of sulfate and the net radiative forcing were both weakened over East China mostly. (3) The reduction of the cooling effect of sulfate in 2010 produced a warmer surface air temperature over central and eastern China; the maximum value was 0.25 K. The cooling effect of nitrate was also slightly weakened. The warming effect of BC was enhanced over most of the areas in China, while the cooling effect of OC was enhanced over the similar area, particularly the area between Yangtze and Huanghe Rivers. The net radiative effect of the four anthropogenic aerosols generated the annual average reduction and the maximum reduction were -0.096 and -0.285 K, respectively, for the surface temperature in 2006, while in 2010 they were -0.063 and -0.256 K, respectively. In summary, the change in source emission lowered the cooling effect of anthropogenic aerosols, mainly because of the enhanced warming effect of BC and weakened cooling effect of scattering aerosols. [ABSTRACT FROM AUTHOR]

Recently, more and more poisoning accidents associated with toxic heavy metals have been reported throughout China, coal-fired power plants (CFPPs) sector is regarded as one of the most important source categories of anthropogenic atmospheric releases of heavy metals due to tremendous annual coal consumption (about 1785.3 Mt in 2012). In this paper, with the concept of whole process control, the co-benefit or synergistic removal efficiencies of different control measures used in CFPPs of China are evaluated, the combination of coal washing before burning plus post combustion cleaning of selective catalytic reduction (SCR) + electrostatic precipitator/fabric filters (ESP/FFs) + wet flue gas desulfurization (WFGD) configuration is identified to be the best available control technology for heavy metals abatement of CFPPs at present and in the near future. However, the widely application of special mercury control (SMC) technologies in Chinese CFPPs in future is greatly needed. Furthermore, three energy scenarios and three control scenarios were assumed to forecast the future trend of heavy metals emissions. Under the same control scenario, the change of the energy saving and energy structure will give rise to about 24.1% and 24.6% of abatement potential for heavy metals in 2020 and 2030, respectively. Whereas, under the current energy consumption pattern and air pollution control policies, the installation of SCR + SMC + ESP/FFs + WFGD will result in about 21.0–44.1% and 36.3–67.5% of reduction for heavy metals emissions in 2020 and 2030, respectively. Finally, integrated control suggestions are proposed to minimize the final toxic heavy metals discharges. [ABSTRACT FROM AUTHOR]

The farming-pastoral region of North China is a region that has suffered from serious desertification, and the multiple transitional characteristics in this region make it very difficult to link the progress of desertification to the driving forces behind it. This paper mainly focuses on the dynamics of desertification over the past 10 years and their relationship to climate change and human activity. According to the MODIS images in 2000 and 2010, the farming-pastoral region had experienced significant desertification dynamics over the past 10 years. The area of regions that had undergone desertification reversion and expansion were 186,240 km 2 and 199,525 km 2 respectively, and the spatial distribution of these regions showed great heterogeneity. The relationship between desertification dynamics and their driving forces was investigated by comparing the change in the NPP that was induced by climate change and human activity for each pixel that experienced desertification reversion and expansion. From 2000 to 2010, the coupling of climate change and human activity was the dominant factor behind desertification reversion. However, the human activity was the dominant factor that controlled the desertification expansion process between 2000 and 2010. The driving processes of desertification also had considerable spatial heterogeneity, and the dominant factors behind desertification reversion and expansion in each sub-region were not completely the same. So, the scale effect must be considered when explaining the results from similar studies. [ABSTRACT FROM AUTHOR]