As a new type of coastal ecological protection measure, ecological buffer zone formed by woody plants in coastal areas has attracted more and more attention in coastal engineering projects. It is an urgent problem to be solved that how to carry out the research on the protection effect of woody plants. The numerical simulation method is used in this paper. Firstly, a theoretical model of surface wave attenuation for wave climbing along a slope under the protection of woody vegetation is proposed by including the drag forces of branches and trunks in the N-S equation. Next, the MAC method is used to track the trajectories of water particles on the free surface. Then, taking the wave climbing along a slope of 1/30 as an example, the wave propagation process along an inclined beach with or without vegetation is discussed. The validity of the numerical model is verified by comparing the numerical result and those of the previous experiments. Finally, influences of the vegetation characteristics, such as height, density and tilt angle of plant branches and those of wave factors on wave dissipation are discussed and analyzed, respectively. Additionally, the rules of wave dissipation are summarized. The calculation results of this model can also be applicable to the design of revetment structures and ecological landscape.

Based on the buoys data over the China offshore area during July 1, 2018 to August 6, 2018 collected by the Ministry of Natural Resources, three SST reanalysis products (OISST, OSTIA SST, RTG SST) were validated and compared through analyzing the mean bias, root mean square error (RMSE), correlation coefficient and standard deviation bias. The comparison results show that in the whole time, three SST reanalysis products we used are comparable to the buoys data. The mean bias and correlation coefficient between OSTIA SST dataset and buoy SST data is 0.12℃ and 0.94, better than OISST dataset (−0.85℃, 0.90) and RTG SST dataset (−0.17℃, 0.86). Compared with 80% buoys, the reliability of OSTIA SST dataset is higher than OISST dataset and RTG SST dataset significantly. During typhoon transit periods, absolute values of mean bias and RMSE (correlation coefficient) between OSTIA SST dataset and buoy SST data are smaller (larger) than RTG SST dataset and OISST dataset, which means that OSTIA SST dataset can capture the basic characteristics of SST over the China offshore area more accurately in severe sea conditions.

Although the length of short array multi-channel streamers is limited,the absence of equipment for positioning and depth fixing, e.g., birds, magnetic compass, tail mark, etc., will bring some problems, such as inaccurate seismic geometric definition, to the subsequent procedure of data processing. In addition, different sinking depths without correction of depth fixing at different receiving sections along the short towing cable will destroy the relationship of the theoretical hyperbolic curve between time and distance. As to the short-array multi-channel seismic reflection data, therefore, we utilize the surveying navigation data to calculate the real shot track points, and then the interpolation algorithm weighted with inverse ratio of distance is employed to estimate the trajectory coordinates of the receiving points, which aids in obtaining the authentic geometric parameters of the total array. In order to resolve the distortion of time-distance curve caused by inconsistent depth of receiving cable, we calculate the theoretical reflecting positions of common mid-point (CMP) with hyperbolic curve and gauge the static correction of receiving arrays with different sinking depths. Finally, distortions of the reflection event caused by the non-uniform sinking depths of receiving array are eliminated by the fitting algorithm of static correction. The application of above processing processes to the short-array seismic reflection data collected in the Ross Sea, West Antarctica produces high-resolution stacked seismic reflection profiles, which provides great technical assistance for following work of geological interpretation.

As tidal waves propagate into the estuary, they are featured by significant longitudinal variation in seasonal scale due to the nonlinear interactions between tide and river discharge. In this study, the variations of tide-river dynamics in terms of tidal damping rate, wave celerity and residual water level slope were explored based on long-term time series of tidal water levels from 2002 to 2014 along the tidal reach of the Changjiang River (including the Tianshenggang, Jiangyin, Zhenjiang, Nanjing, Maanshan and Wuhu stations) in together with the monthly averaged river discharge observed at Datong hydrological stations. Subsequently, the underlying controlled factors that influence the tidal wave propagation were discussed. It was shown that the seasonal difference in tide-river dynamics was gradually reduced in the seaward direction. We identified a transitional zone located between the Tianshenggang and Jiangyin stations, where the seasonal differences in tidal range are 0.01 m and −0.04 m, respectively. Generally, upstream from Jiangyin Station the dynamics character was river-dominated, while in the lower reaches it was mainly controlled by the tidal forcing. In addition, we show that there exists a threshold in river discharge in the upper reaches of the tidal reach of the Changjiang River due to the increase of residual water level and hence water depth caused by the residual water level slope. This phenomenon was particularly true in the upstream reach between Maanshan to Wuhu stations, where the threshold of river discharge was approximately 33 000 m³/s. The results obtained from this study can enhance our understanding of tide-river interaction, and will, hopefully, provide guidelines for water resources management in the tidal reach of the Changjiang River.

Compared with shore-based GNSS-R technology, the airborne GNSS-R has the advantages of high spatial resolution, wide monitoring range, high-resolution monitoring of specific areas, and flexible height and azimuth adjustments. This paper mainly studies the airborne GNSS-R altimetry model, based on the shore-based GNSS-R code altimetry principle, corrects the atmospheric delay, antenna distance, etc., optimizes the airborne altimetry model, and uses the DTU10 global sea level average height and tide. The model verifies the accuracy of the onboard GNSS-R altimetry model. By analyzing the GNSS-R airborne data of the CSIC-IEEC in the Baltic Sea in Finland on November 11, 2011, the inversion of the experimental data at different elevation angles was successfully carried out, and the inversion of the sub-meter airborne sea surface height was successfully achieved. The conclusion that the elevation angle has a great influence on the accuracy of the altimetry results qualitatively analyzes the error range caused by the elevation angle. The results of this paper demonstrate the feasibility of sea level altimetry for airborne GNSS-R.

Salinity linear trends and their contributed dynamics processes in the tropical Pacific Ocean were investigated with the Argo salinity and temperature fields, current assimilations and atmospheric reanalysis datasets. The robust salinity anomaly event (SAE) occurred in the tropical Pacific Ocean during 2015−2017, which resulted possibly in the reversing of Argo salinity long-term trends. Such SAE was characterized as distinct regional discrepancies and vertical structures. Significant surface freshening occurred in the northern tropical Pacific (NTP) and Southern Ocean Convergence Zone (SPCZ), whose remarkable freshening maximum could reach 0.71−0.92 and covered the upper mixed layer. Another subsurface salinification in the southern tropical Pacific (STP) with the maximum of 0.46 was found around thermocline layer. Moreover, the salinity anomalies in SAE can expand from west to east along the isopycnal layers. Salinity advection and entrainment were exhibited as the fundamental dynamic processes to the SAE event in the tropical Pacific Ocean, while advection term acted as the major contribution to salinity variability. Both of the dynamic factors played important role on SAE features during the whole event in the NTP and later period in the SPCZ and STP. The surface freshwater flux and subsurface mixing induce by density compensation were also supplements to the SAE events in the NTP freshening and STP salinification respectively.

Kinetic dissolution and the reactive continuum model were combined to characterize the reactivity of iron (Fe) and phosphorus (P) in surface sediments of the Changjiang (Yangtze) River Estuary and the adjacent East China Sea. Two kinetic parameters, i.e., theoretical amounts (m ₀) and apparent rate constant (k) of reactive Fe, were extracted by fitting kinetic dissolution data to the reactive continuum model. Results showed that Fe(Ⅱ) phases occurred in all surface sediments studies, which could be ascribed to rapid reduction of highly reactive organic-bound Fe(Ⅲ) flocculated/precipitated to the sediments. It is inferred that Fe(Ⅱ) occurs mainly as FeCO₃ in both the Changjiang (Yangtze )River Estuarine sediments and the adjacent East China Sea sediments. The m ₀ and k values of Fe(Ⅱ) were controlled mainly by total organic carbon (TOC) contents and clay fractions. Simultaneous release of Fe(Ⅱ) and associated P (mainly exchangeable P and authigenic P) resulted in similar pattern of dissolution kinetics. Relative to P adsorbed on surfaces of Fe(Ⅱ) solid phases, coprecipitated P with Fe(Ⅱ) phases has higher m ₀ but lower k. In fine-grained sediments with high TOC contents, Fe(Ⅲ) oxides have lower m ₀ values but higher k in comparison with those in coarse-grained sediments with lower TOC contents, which is caused by different processes of Fe redox cycling. Overall, the dissolution reactivity of P associated with Fe(Ⅲ) phases is largely controlled by the reductive reactivity of Fe(Ⅲ) phases. Our kinetic characterization indicates that flocculation/precipitation has caused reactive Fe enrichment in the estuarine sediments, occurring mainly in a narrow zone of low salinity, but the enrichment could not be revealed by conventional Fe speciation.

According to the data collected from bottom-trawl surveys in Haizhou Bay and adjacent waters during spring and fall in 2011 and 2013–2016, generalized additive model (GAM) based on the Tweedie distribution was used to examine the relationship between the distribution of small yellow croaker (Larimichthys polyactis) and environment factors in different seasons and ontogenetic stages. Combined with the bottom sea water temperature (BSWT), bottom sea water salinity (BSWS), water depth, sediment types, and abundance of prey (Crangon affinis, Leptochela gracilis, Engraulis japonicus, Thrissa kammalensis), the conditional index k and Variance Inflation Factor (VIF) were used to measure the degree of multicollinearity between these factors. The results of multicollinearity indicated that all factors can be used as explanatory variables. The results of Tweedie-GAM show that the factors affecting the distribution of small yellow croaker and their deviance explained varied greatly with seasons (spring and fall) and ontogenetic stages (juvenile and adult). For example, the factors affecting the spring-juvenile small yellow croaker distribution were BSWT, BSWS, water depth and the abundance of C. affinis, which depth had the largest deviance explained (16.09%). In addition, the factors affecting the spring-adultl yellow croaker distribution were BSWT, BSWS, water depth and the abundance of C. affinis and E.japonicus, which BSWS had the largest deviance explained (13.56%). The distribution of small yellow croaker in different seasons and ontogenetic stages was found to be closely related to its ecological habits, environmental factors and distribution of prey in Haizhou Bay and adjacent waters.

Transient electromagnetic method (TEM) is an effective method for deep-sea polymetallic sulfide exploration. High-grade metal components in seafloor polymetallic sulfides cause extremely strong induced polarization effects and have a significant impact on transient electromagnetic response. In this paper, the inductive effects of deep-sea polymetallic sulfides were analyzed through laboratory measurement and numerical simulation. First, systematic electrical tests were carried out on rock ore samples from the hydrothermal vent fields on the southwest Indian Ocean Ridge. The complex resistivity of typical sulfides has a phase shift of up to 160 mrad in the frequency domain. The time domain and frequency domain measurements show that the polarizability parameter is a good indicator to distinguish sulfide minerals and surrounding rocks. Using the Cole-Cole model to interpret the complex resistivity to obtain the characteristic parameters of complex resistivity, the relationship between parameters and the composition and structure of the massive sulfide was analyzed, and the typical sulfides were classified based on the polarizability parameter. The induced polarization parameters of the typical sulfides were used to calculate the transient electromagnetic response of the layered medium, which show that the influence of induced polarization effect can be observed simultaneously in the best observation window of the TEM response of the deep-sea polymetallic sulfide deposit. Although the transient response is distorted in the late stage of the acquisition window, in the early stage of signal reception, the induced polarization effect effectively enhances the detection capability of the TEM for deep-sea polymetallic sulfides, which provides an explanation basis for the transient electromagnetic measurement data.

The technical bottlenecks of threshold determination and key parameter calibration in carrying capacity of resources and environment urgently need to be broken through, and then establish a standardized quantitative evaluation method. In the present study, several key parameters such as primary productivity, phytoplankton organic carbon content and trophic level were obtained through investigation and experimental analysis. The nutrition dynamic model and the Tait coastal energy flow model were used to estimate the total quantities of marine biological resources. Then, the threshold of carrying capacity of marine biological resources was calculated based on the “resource-consumption” model. For example, according to the survey results in 2016, the annual average primary productivity of sea area under Rizhao jurisdiction was 428.22 mg/(m²·d) and the annual production of phytoplankton was 9.19×10⁶ t. Meanwhile, the average trophic levels of fishes, shrimps and crabs, and cephalopods were 3.85, 3.92 and 3.90, respectively. The annual production of fishery resources (fish, shrimp and crab, and cephalopod) in the sea area was 38.9 thousand tons calculated by the “nutritional dynamic model”. In addition, the shellfish resources in shallow sea within 10 m depth contour was 55 thousand tons calculated by the Tait coastal energy flow model. Thus, according to the annual per capita intake of aquatic products of 21 kg, the total carrying capacity of marine biological resources in Rizhao coastal waters was 1.928 6×10⁶ people. Meanwhile, according to the annual per capita protein intake of 30 kg, the total carrying capacity of marine biological resources in Rizhao area was calculated to be 1.687×10⁵ people. Taken together, this paper describes a quantitative assessment technique with wide applicability for carrying capacity of marine biological resources. This will contribute to substantial utilization of the marine biological resources and establishment of the monitoring and early warning of resources and environment carrying capacity in a way of overall planning of land and sea.