Reclamation projects are the main method of coastal exploitation, and the hydrodynamic environmental effect, together with the sediment transport response of the reclamation project, is important to the project’s site selection and environmental protection. Herein, a 3D numerical model based on the finite volume community ocean model (FVCOM) is applied to simulate the changes in the Meizhou Bay’s hydrodynamic environment and sediment transport after a reclamation project. The reclamation project greatly alters the shape of the shoreline and narrows the bay, leading to a significant change in its hydrodynamic environment and sediment transport. After the project, the clockwise coastal residual current in the corner above the Meizhou Island gradually disappears. An obvious counter-clockwise coastal residual current emerges around the rectangular corner. The tidal prism decreases by 0.65 × 10⁹ and 0.44 × 10⁹ m³ in the spring and neap tides, respectively. The residence time presents a major increase. These changes lead to the weakening of the water exchange capacity and the reduction of the self-purification capacity of the bay. Currents in the tidal channel weaken, whilst currents in the horizontal channel strengthen. The strength and scope of particle trajectories around the horizontal channel and the Meizhou Island enhance. The suspended sediment concentration (SSC) increases in the majority of the Meizhou Bay but decreases in the lateral bay. The eastern corner of Z2 shows a tendency to erode. The western region of the Meizhou Island, the upper portion of the rectangular corner and the western corner of Z4 show a tendency to deposit. The reclamation project increases the maximum storm surges by 0.06 m and decreases the maximum significant wave heights by 0.09 m.

Urban parks can function as a proper sink of noise pollution. However, lack of universally-agreed upon methodologies and differing urban conditions have fueled controversy surrounding the effectuation of this urban park function around the world. Hence, to address this controversy in narrow urban parks (with a mean width of ~109 m) in Isfahan City, Central Iran, noise levels (L_q30) were measured along two longitudinal transects placed along the interior northern river-and adjacent to the southern edge of the parks bordered by a heavily-conjected road. We used statistical tests and models to determine the association of noise levels measured along the northern transect with the distance to, and the intensity of noise emitted from, the road, vegetation biomass, and vegetation height within two 50 and 100 m buffer rings drawn around northern sites and the richness of bird species. The average L_q30 values differed significantly between the southern (~73.21 dB) and northern (~66.43 dB) transects and correlated negatively with species richness (r(98) = −0.324, p<0.01). Three variables including mean NDVIwithin the 100 m buffer ring, distance from the road and mean L_q30 values of the nearest three southern sites were included to build the best predictive multiple-linear regression model through the step-wise procedure with r² of 0.52. These findings suggest that further attempts aiming to alleviate the parks’ interior noise level should be attentive to distance to road, traffic at the nearest road part, and the interior vegetation characteristics.

Investigation of climate change impacts on food security has become a global hot spot. Even so, efforts to mitigate these issues in arid regions have been insufficient. Thus, in this paper, further research is discussed based on data obtained from various crop and climate models. Two DSSAT crop models (CMs) (CERES-Wheat and N-Wheat) were calibrated with two wheat cultivars (Gemiza9 and Misr1). A baseline simulation (1981-2010) was compared with different scenarios of simulations using three Global Climate Models (GCMs) for the 2030s, 2050s and 2080s. Probable impacts of climate change were assessed using the GCMs and CMs under the high emission Representative Concentration Pathway (RCP8.5). Results predicted decreased wheat grain yields by a mean of 8.7%, 11.4% and 13.2% in the 2030s, 2050s and 2080s, respectively, relative to the baseline yield. Negative impacts of climatic change are probable, despite some uncertainties within the GCMs (i.e., 2.1%, 5.0% and 8.0%) and CMs (i.e., 2.2%, 6.0% and 9.2%). Changing the planting date with a scenario of plus or minus 5 or 10 days from the common practice was assessed as a potentially effective adaptation option, which may partially offset the negative impacts of climate change. Delaying the sowing date by 10 days (from 20 November to 30 November) proved the optimum scenario and decreased further reduction in wheat yields resulting from climate change to 5.2%, 6.8% and 8.5% in the 2030s, 2050s and 2080s, respectively, compared with the 20 November scenario. The planting 5-days earlier scenario showed a decreased impact on climate change adaptation. However, the 10-days early planting scenario increased yield reduction under projected climate change. The cultivar Misr1 was more resistant to rising temperature than Gemiza9. Despite the negative impacts of projected climate change on wheat production, water use efficiency would slightly increase. The ensemble of multi-model estimated impacts and adaptation uncertainties of climate change can assist decision-makers in planning climate adaptation strategies.

Channel evolution and depo-center migrations in braided reaches are significantly influenced by variations in runoff. This study examines the effect of runoff variations on the erosion-deposition patterns and depo-center movements within branching channels of the near-estuary reach of the Yangtze River. We assume that variations in annual mean duration days of runoff discharges, ebb partition ratios in branching channels, and the erosional/depositional rates of entire channels and sub-reaches are representative of variations in runoff intensity, flow dynamics in branching channels, and morphological features in the channels. Our results show that the north region of Fujiangsha Waterway, the Liuhaisha branch of Rugaosha Waterway, the west branch of Tongzhousha Waterway, and the west branch of Langshansha Waterway experience deposition or reduced erosion under low runoff intensity, and erosion or reduced deposition under high runoff intensity, with the depo-centers moving upstream and downstream, respectively. Other waterway branches undergo opposite trends in erosion-deposition patterns and depo-center movements as the runoff changes. These morphological changes may be associated with trends in ebb partition ratio as the runoff discharge rises and falls. By flattening the intra-annual distribution of runoff discharge, dam construction in the Yangtze Basin has altered the ebb partition ratios in waterway branches, affecting their erosion-deposition patterns and depo-center movements. Present trends are likely to continue into the future due to the succession of large cascade dams under construction along the upper Yangtze and ongoing climate change.

In this study, a storm surge model of the semi-enclosed Tokyo Bay was constructed to investigate its hydrodynamic response to major typhoon parameters, such as the point of landfall, approach angle, forward speed, size, and intensity. The typhoon simulation was validated for Typhoon Lan in 2017, and 31 hypothetical storm surge scenarios were generated to establish the sensitivity of peak surge height to the variation in typhoon parameters. The maximum storm surge height in the upper bay adjacent to the Tokyo Metropolitan Area was found to be highly sensitive to the forward speed and size of the passing typhoon. However, the importance of these parameters in disaster risk reduction has been largely overlooked by researchers and disaster managers. It was also determined that of the many hypothetical typhoon tracks evaluated, the slow passage of a large and intense typhoon transiting parallel to the longitudinal axis of Tokyo Bay, making landfall 25 km southwest, is most likely to cause a hazardous storm surge scenario in the upper-bay area. The results of this study are expected to be useful to disaster managers for advanced preparation against destructive storm surges.

It is of great significance to quantitatively assess the impact of mountain precipitation on inland river runoff in data scarce regions. Based on the corrected TRMM precipitation and runoff data, a variety of statistical methods were used to identify which areas of precipitation have an important impact on runoff in the Hotan River Basin, and to evaluate the effects that precipitation changes have on runoff at low, mid, high, and extremely high altitudes of mountainous areas. The results showed that: 1) From 1998 to 2015, the annual runoff showed a fluctuating upward trend with a rate of 11.21 × 10⁸ m³/10 a (P<0.05). Runoff in every season also had an increasing trend, with summer runoff the most significant at a rate of 6.09×10⁸ m³/10 a. 2) The annual runoff and precipitation changes had certain synchronization, with a correlation coefficient of 0.45 (P<0.05). Among them, the correlations between precipitation and runoff changes were highest at low and mid- altitudes, with coefficients of 0.62 and 0.55, respectively (P<0.05). 3) 65.95% of the regional precipitation at low altitudes and 48.34% at high altitudes were significantly correlated with runoff (P<0.05), while only 38.84% and 26.58% of regional precipitation levels at mid- and extremely high altitudes were significantly correlated with runoff. 4) The annual precipitation change in the basin was 1%, which would cause the annual runoff to change by 0.24%. In 1998–2015, the change of annual runoff caused by precipitation change at high altitudes was largest at a rate of −6.01%; the change rates of annual runoff caused by precipitation change in the low, mid-, and extremely high altitudes were −3.66%, −3.62%, and −3.67%, respectively. The results have significant scientific guidance for water resource management in arid basins.

The Laowan deposit is a large gold deposit in the Qinling-Dabie orogenic belt where pyrite is the main Au-bearing mineral phase. We present results from the occurrences of gold, trace elements and sulfur isotopes of pyrite, and hydrogen and oxygen isotopes of quartz and calcite to elucidate the sources of ore-forming fluid; the genesis of pyrite and the ore-forming process.

From field observations, five generations of pyrite are identified; one formed in a metamorphic-diagenetic epoch (PyI), and the others during four mineralization stages: 1) the coarse-grained pyrite-quartz stage (PyII), 2) the quartz and medium- to fine-grained pyrite stage (PyIII), 3) the polymetallic sulfide stage (PyIV), and 4) the carbonate-quartz stage (PyV). Gold mainly occurs in PyIII and PyIV. We find that Au, Ag, Pb, and Cu are incorporated into pyrite as micro-/nano-inclusions and that Co, Ni, As, and Se enter the pyrite lattice via isomorphous replacement.

The Co/Ni values and Se concentrations indicate that PyI formed from metamorphic hydrothermal fluids and that pyrites (PyII, PyIII, and PyIV) from the ore-forming stages typically reflect a hydrothermal genesis involving magmatic fluid.

The d³⁴S values of PyI (1.45‰–2.09‰) are similar to that of plagioclase amphibole schist, indicating that S was primarily derived from wall rock, while those of PyII, PyIII, and PyIV (3.10‰–5.55‰) suggest that S was derived from the Guishanyan Formation and the Laowan granite. The four mineralization stages show a systematic decrease in dD (from −77.1‰ to −82.8‰, −84.7‰, and −102.7‰), while the {\mathrm{\delta }}^{\mathrm{18}}{\mathrm{O}}_{{\mathrm{H}}_{\mathrm{2}}\mathrm{O}} values showed a gradual decrease from 5.7 to 2.7‰, 1.0‰, and −1.3‰. These data show that the ore-forming fluid was similar to a mixture of magmatic and meteoric waters. Thus, we conclude that the Laowan gold deposit is related to magmatic-hydrothermal fluid.

Remote sensing spatiotemporal fusion models blend multi-source images of different spatial resolutions to create synthetic images with high resolution and frequency, contributing to time series research where high quality observations are not available with sufficient frequency. However, existing models are vulnerable to spatial heterogeneity and land cover changes, which are frequent in human-dominated regions. To obtain quality time series of satellite images in a human-dominated region, this study developed the Modified Flexible Spatial-temporal Data Fusion (MFSDAF) approach based on the Flexible Spatial-temporal Data Fusion (FSDAF) model by using the enhanced linear regression (ELR). Multiple experiments of various land cover change scenarios were conducted based on both actual and simulated satellite images, respectively. The proposed MFSDAF model was validated by using the correlation coefficient (r), relative root mean square error (RRMSE), and structural similarity (SSIM), and was then compared with the Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model (ESTARFM) and FSDAF models. Results show that in the presence of significant land cover change, MFSDAF showed a maximum increase in r, RRMSE, and SSIM of 0.0313, 0.0109 and 0.049, respectively, compared to FSDAF, while ESTARFM performed best with less temporal difference of in the input images. In conditions of stable landscape changes, the three performance statistics indicated a small advantage of MFSDAF over FSDAF, but were 0.0286, 0.0102, 0.0317 higher than for ESTARFM, respectively. MFSDAF showed greater accuracy of capturing subtle changes and created high-precision images from both actual and simulated satellite images.

n-Fatty acids (n-FAs) are widely investigated in lake sediments, yet less attention has been given to soil sedimentary n-FAs primarily derived from terrestrial plants. In this study, we performed an analysis of n-FA distributions in modern plants on the Loess Plateau, China. It showed that n-FAs were generally dominated by n-C₁₆, and that short-chain (C₁₆–C₂₀), medium-chain (C₂₂–C₂₆) and long-chain (C₂₈–C₃₂) n-FAs accounted for 49.7%, 33.7% and 16.6%, respectively. The LTR (long-chain/total ratio), and medium-chain EOP (even/odd predominance) are likely to differentiate between dicots and monocots in modern plants. It is believed that this study will promote the paleo-application of soil sedimentary n-FAs on the Loess Plateau.

Landslides, seriously threatening human lives and environmental safety, have become some of the most catastrophic natural disasters in hilly and mountainous areas worldwide. Hence, it is necessary to forecast landslide deformation for landslide risk reduction. This paper presents a method of predicting landslide displacement, i.e., the improved multi-factor Kalman filter (KF) algorithm. The developed model has two advantages over the traditional KF approach. First, it considers multiple external environmental factors (e.g., rainfall), which are the main triggering factors that may induce slope failure. Second, the model includes random disturbances of triggers. The proposed model was constructed using a time series which consists of over 16-month of data on landslide movement and precipitation collected from the Miaodian loess landslide monitoring system and nearby meteorological stations in Shaanxi province, China. Model validation was performed by predicting movements for periods of up to 7 months in the future. The performance of the developed model was compared with that of the improved single-factor KF, multi-factor KF, multi-factor radial basis function, and multi-factor support vector regression approaches. The results show that the improved multi-factor KF method outperforms the other models and that the predictive capability can be improved by considering random disturbances of triggers.

This study performed a scenario-based land allocation in a mixed agriculture-forest landscape in northern Iran to investigate how different land use policies contribute to changes in carbon storage. In pursuit of this goal, a temporal profile of the trade-off between the region’s land use land cover (LULC) classes was produced using Landsat image of the year 2016. The weighted linear combination procedure was also used to map the suitability of land for agriculture, forest, urban, and rangeland based on ecological and socio-economic criteria. The suitability maps were analyzed through the Multi-Objective Land Allocation procedure under five scenarios with differing areas devoted to each LULC to generate different patterns of LULC distribution in the region. In addition, the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model was used to estimate the potential of LULC classes in carbon storage. The amount of carbon storage differed significantly between the scenarios, ranging from 1.29 tons/ha/year when the majority of the land was devoted to agriculture (76% of the area) to 5.40 tons/ha/year when the landscape was dominated by forest (77% of the area). The extreme conditions presented in this research may not be as likely to occur, but opens a dialog between different stakeholders and informs of a probable trend of ecosystem service loss due to agricultural land expansion.

The Linfen rift is a Cenozoic extensional rift with significant seismicity and seismic hazards. Studies of this rift shed light on deep dynamic processes and seismogenic mechanisms relevant to crustal structure and seismic activity. We first conducted a joint inversion of receiver functions and surface wave dispersion on waveform data collected from 27 broadband seismic stations to image the crustal S-wave velocity in the Linfen rift and its surroundings. We then relocated the source parameters for 10 earthquake events with depths>20 km and studied the relationship between crustal S-wave velocity and seismicity. The results show that low-velocity zones of different scales exist in the middle-lower crust, and that the depth of the seismogenic layer gradually increases from ~25 km in the south to ~34 km in the north, roughly corresponding to the bottom of the low-velocity zone. We found that most of the relocated earthquakes occurred in the low-velocity zone at depths of 18 km to 34 km, with the deepest at 32 km. Two of the greatest historic earthquakes, Linfen (Ms 7.75) in 1695 and Hongtong (Ms 8.0) in 1303, occurred at the bottom of the high-velocity zone at depths of 12 km to 18 km. Our results, combined with previous studies, suggest that the upwelling mantle material below the rift did not remarkably affect the velocity structure from the bottom of the seismogenic layer down to the uppermost mantle nor heat the crust. It is likely that neither crustal-scale faults nor mantle earthquakes exist in the Linfen rift.

The Universal Soil Loss Equation model is often used to improve soil resource conservation by monitoring and forecasting soil erosion. This study tested a novel method to determine the cover and management factor (C) of this model by coupling the leaf area index (LAI) and soil basal respiration (SBR) to more accurately estimate a soil erosion map for a typical region with red soil in Hetian, Fujian Province, China. The spatial distribution of the LAI was obtained using the normalized difference vegetation index and was consistent with the LAI observed in the field (R² = 0.66). The spatial distribution of the SBR was obtained using the Carnegie–Ames–Stanford Approach model and verified by soil respiration field observations (R² = 0.51). Correlation analyses and regression models suggested that the LAI and SBR could reasonably reflect the structure of the forest canopy and understory vegetation, respectively. Finally, the C-factor was reconstructed using the proposed forest vegetation structure factor (C_s), which considers the effect of the forest canopy and shrub and litter layers on reducing rainfall erosion. The feasibility of this new method was thoroughly verified using runoff plots (R² = 0.55). The results demonstrated that C_s may help local governments understand the vital role of the structure of the vegetation layer in limiting soil erosion and provide a more accurate large-scale quantification of the C-factor for soil erosion.