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Reducing the dependence on fossil fuels and utilizing the renewable energy have become essential due to the global resource exhaustion and unfriendly environmental impact from coal, petroleum and natural gas. Therefore, the rising attention has been paid to wave energy characterized by sustainability, clean, high energy density and extensive distribution. As one of the most important parameters of wave energy, significant wave height (SWH) is difficult to forecast accurately due to the complex marine condition and ubiquitous presence of chaos in nature. In this research, a novel hybrid model called STL–CNN–PE which combines seasonal-trend decomposition procedure based on loess (STL) and one-dimensional convolutional neural networks (CNN) with positional encoding (PE) was proposed to forecast SWH efficiently and accurately. To evaluate the proposed model comprehensively, the hourly standard meteorology data at station 44007, 46087 and 51000 from NOAA’s National Data Buoy Center were selected for model training and testing. The experimental results indicated that STL–CNN–PE provided more reliable forecasting values than the single model. Meanwhile, STL–CNN–PE had enormous advantage on speed and similar precision compared with EMD-LSTM. Finally, the experimental results revealed that the models provided better forecasting metrics at deeper waters.

At home and abroad, this chapter carries out the first detailed investigation on the climate characteristics of wind energy resource along the Maritime Silk Road. A series of key parameters are defined: availability of wind energy (effective wind speed occurrence, EWSO), available level occurrence (ALO, occurrence of WPD greater than 100 W/m2) moderate level occurrence (MLO, occurrence of WPD greater than 150 W/m2) rich level occurrence (RLO, occurrence of WPD greater than 200 W/m2) excellent level occurrence (ELO, occurrence of WPD greater than 300 W/m2) superb level occurrence (SLO, occurrence of WPD greater than 400 W/m2), to describe the availability and richness of wind energy. Systematically considering the wind power density, energy availability, energy level occurrences, energy stability, monthly and seasonal variability of wind energy, energy storage, the temporal-spatial distribution characteristics of wind energy along the Maritime Silk Road are analyzed, to provide theoretical support for the energy classification, short-term forecast and long-term projection of wind energy.

The research on medium and long-term forecasting of wind energy is still extremely scarce until now, although this work is closely related to the medium and long-term planning of wind energy development and power dispatching. This chapter used the CMIP data to carry out the long-term wind energy projection along the Maritime Silk Road for the next 40 years, which includes a series of key indicators, such as: the wind power density, energy availability, energy level occurrences, energy stability, monthly and seasonal variability, energy storage for the next 40 years, to provide reference for the long-term planning of wind energy utilization.

Currently, the studies on the wind power along the Road area are still scarce, let alone those on its climatic trends. However, these studies are the theoretical basis which is crucial to improving the accuracy of the mid- and long-term forecast and could further impact the mid- and long-term planning of wind power exploitation. Besides, nowadays there is abundant research on the evolution trends of the meteorology and ocean, but little on that of the wind power. In this chapter, the annual trend, and regional and seasonal difference of the trends of a series of key indicators of wind energy resource are calculated and analyzed for the first time, to provide a theoretical foundation for the improvement of medium – and long-term projection capacity for wind energy projection.

Currently, the marine and meteorological raw data are relatively abundant. However, the offshore wind energy data is scarce. How to extracted the useful information about wind energy development from the original big data with large volume and low information density, and then building a wind energy resource dataset has become the key support to the industrialization and efficient deployment of wind energy. It is also a common challenge for global colleague. In this chapter, the first open-ended and non-profit dataset of spatial-temporal characteristics of wind energy resource for the Maritime Silk Road at home and abroad was established, to provide scientific reference and data support for offshore wind energy resource evaluation. A wind energy resource, which should include the temporal-spatial characteristics, energy classification, climatic variation of wind energy, long-term projection of wind energy, wind climate, etc., was prospected to be established to provide a systematic data support for power plant site selection, daily operation, long-term planning, environmental safety guarantee for resource development.

The short-term wind power forecasting is closely linked to the collection and transformation of resources and their applications such as unit scheduling and power trading. Previous researchers have done tremendous work on the short-term forecasting of offshore wind power across the globe. However, there are no such studies specifically targeting the countries and regions along the Maritime Silk Road. Besides, current forecasting products mainly focuses on parameters such as wind speed and density while key indicators like usability, ELO, and storage amount have not been covered. In this chapter, an all-element short-term forecasting system of offshore wind energy resource was designed, comprehensively including the wind field, wind power density, energy availability, energy level occurrences, energy storage, etc., as well as the forecasting of wind energy of key nodes (hourly wind power density and wind direction, wind energy rose, etc.), to provide reference for the daily operation of wind power generation and so on.

The offshore wind energy can provide strong power support to overcome the energy crisis, as well as good opportunity for international exchange and cooperation, an antidote to climate change and conventional energy shortage, and important support to achieve the carbon neutrality target. Evaluation of resources and planning should go first. However, such evaluations are still relatively few owing to the difficulties faced by marine observation and shortage of research resources, which has been a barrier to developing offshore wind power into a bigger scale as an industry. Firstly, this chapter discussed the research status and difficulties (detail research on the climatic characteristics of wind energy, macro and micro-scale energy classification, relationship between wind energy and key indexes, short-term forecast of wind energy, climatic variation of wind energy, mid-long term projection of wind energy, energy evaluation on key nodes). Then the countermeasures to deal with the difficulties are provided.

Sri Lanka is located near the center of the main channel of the Indian Ocean. It is also an important place for the Maritime Silk Road initiative. This chapter carried out a technology of offshore wind energy evaluation on key island or vital region, with the Sri Lankan waters as a case study. Systematically considering the wind power density, energy availability, energy level occurrences, energy direction (co-occurrence of wind power density-wind direction), climatic variation of wind energy, wind class, the wind energy of Sri Lankan waters for the future and for the past are analyzed and compared, to provide reference for the long-term planning of wind energy development and technical approach for the mid-long term projection of wind energy resource.

How to extract useful and key information from the original big wave data with large volume and low information density and establish a wave climate datasets is still in a blank status, which is also urgently needed in the ocean navigation, deep sea development, marine resource development, offshore construction, and disaster prevention and mitigation, etc. Based on the ERA-interim wave data for 1979–2018 and ERA-40 wave reanalysis from the European Centre for Medium-Range Weather Forecasts (ECMWF), this study adopts the climate statistical analysis methods to establish the first open and public wave climate dataset for the Maritime Silk Road, systematically including the prevailing wave direction and significant wave height (SWH), wave period, swell index (SI), rough sea occurrence, wave direction occurrence, co-occurrence of wave height and wave direction, co-occurrence of wave height and wave period, and extreme wave height. It is hoped that the results can provide a data support for the safe and efficient deployment of marine development and construction.

Nowadays, the world is facing the dual crisis of the energy and environment, and renewable energy, such as wave energy, can contribute to the improvement of the energy structure of the world, enhance energy supply and improve the environment in the framework of sustainable development. Long-term prediction of the significant wave height (SWH) is indispensable in SWH-related engineering studies and is exceedingly important in the assessment of wave energy in the future. In this paper, the spatial and temporal characteristics of wave energy in the South China Sea (SCS), and adjacent waters are analyzed. The results show that there are abundant wave energy resources in the waters around the Taiwan Strait, the Luzon Strait, and the north part of the SCS with annual average SWH (SWH) of over 1.4 m and obvious increasing trend. Then, the SARIMA approach considers the relationship between the current time and the values, residuals at some previous time and the periodicity of the SWH series are proposed to forecast the SWH in the SCS and adjacent waters. The results obtained are promising, showing good performance of the prediction of monthly average SWH in the SCS and adjacent waters.

Wave energy development will help ease resource crises. The projection of wave energy has practical value for the long-term planning of energy development (implementation of power generation, trading strategies, and so on). This paper proposed a wave energy projection program. South China Sea (SCS) and the East China Sea (ECS) in 2019 were carried out as case studies using the Coupled Model Intercomparison Project Phase 5 (CMIP5) dataset to drive the WAVEWATCH-III (WW3) wave model. The multiyear average wave energy of the SCS and ECS was presented. A comparison of the projected values with multiyear averages of the wave energy could positively contribute to the planning of the wave energy development. The results show that the SCS possessed relatively rich energy for both the past and future and that January and October possessed the highest wave power density (WPD). The projected annual average WPD in 2019 was similar to the multiyear average WPD in the north and middle of the ECS, slightly higher than the multiyear average in the south of the ECS, and considerably greater than that in the SCS. The projected WPDs in January, April, and October 2019 were higher than the multiyear averages in the corresponding months. In July, the projected WPD in the SCS was smaller than the multiyear average, while the opposite was observed in the south of the ECS. The projected effective wave height occurrence (EWHO) and the occurrence of WPD >2 kW/m in 2019 were also superior to the multiyear average values.

Against a backdrop of increasing energy demand, the development of wave energy technology is a logical means of both meeting this demand and mitigating the environmental degradation associated with conventional power generation. Previous research has made considerable progress in the climatic characterization and short-term forecasting of wave energy. However, medium- to long-term predictions of wave energy resources, which are central to the development of future operating and trading strategies, remain scarce. This study provides an overview of long-term climatic trends and medium- to long-term predictions of wave energy, before discussing the focus of future predictions. Finally, a new method is proposed for predicting wave energy resources on a medium- to long-term basis that incorporates the swell index and propagation characteristics of swell energy. This model was developed with the aim of improving the precision of wave energy predictions, thereby providing a reference for the effective utilization of wave resources. The results of this study demonstrate that long-term climatic trend analysis should include not only variations in wave power density (WPD), but also long-term variability in wave energy stability, energy level occurrence, and variability in the occurrence of effective significant wave height (SWH). The medium- to long-term prediction of wave energy should also synthetically consider the above factors. We conclude that monitoring the propagation of swell energy and calculating the swell index constitutes a robust theoretical basis for predicting the WPD of mixed wave.

Through the work of this book, a series of core challenges in wave energy assessment of Maritime Silk Road have been solved, such as the climate background characteristics of the wave energy resources (spatial-temporal distribution of a series of key parameters of wave energy), the historical trend of each key parameters, the short-term forecast of wave energy, the long-term projection of wave energy, wave energy assessment and proposals for maritime key points, etc. Planning to build a wave energy resource dataset of the Maritime Silk Road, and the results can provide a scientific basis for the site selection, daily operation, and long-term planning of wave power generation, seawater desalination and other wave energy projects. In the future, it is necessary to strengthen study on the following aspects: wave energy classification, propagation characteristics of swell energy and swell monitoring and warning, risk assessment of marine environment, the construction of a comprehensive application platform for wave energy resources, to improve the support capability for wave energy development.

The application and sharing of scientific data has become an important indicator of the national science and technology level. With the rapid development of observation methods and numerical models, ocean data has also exploded, and “big data” has entered people’s sight. How to extract useful information of energy assessments from large ocean data with low information density, and establish the marine energy dataset is the key to rational and efficient development of wave energy. At present, the global marine energy dataset is rare, and the dataset of wave energy of the Maritime Silk Road is still in blank. Based on the previous research results, this chapter propose to build the wave energy resource dataset of Maritime Silk Road, which is close to actual demand, convenient to query and perfect in theoretical system. The data is also the first wave energy resource dataset of Maritime Silk Road at home and abroad. In the future, the program can be widely used in the construction of marine new energy datasets of offshore wind energy and ocean current energy, to provide data support for researchers and engineers actively participating in the marine new energy development of the Maritime Silk Road.

The maritime key points are important support for marching into the deep blue. They are usually based on the remote islands and reefs, and the power dilemma has always been a worldwide difficulty. Carrying out the wave power generation will help the islands and reefs to achieve electricity self-sufficiency. Evaluation always goes first, followed by resource development. Previous researchers have made great contributions to the study of wave energy in various sea areas around the world. But so far, the wave energy research on the maritime key points of the North Indian Ocean is almost blank. This chapter uses the ERA-interim wave data from the ECMWF to conduct a systematic analysis of the wave energy resources in the Sri Lankan waters (an important node of the Maritime Silk Road), comprehensively including the monthly WPD, monthly available rate, monthly energy level frequency, energy direction and sea state contribution in representative months, monthly energy stability, monthly exploitable storage and long-term trend of wave energy, to provide scientific and technological support and proposal for marching into the deep blue.

Lots of research on the long-term trends of meteorological and oceanic factors has been conducted. However, the research on the climatic trend of wave energy is extremely scarce, which is closely related to the medium- and long-term planning of resource development and predictive ability of wave energy. And the traditional analysis on long-term trends of resources was mainly concerned with the trend of WPD. In the actual wave energy development, energy stability (Cv, Mv, Sv) can affect acquisition and conversion efficiency, as well as equipment life. The EWHO reflects the available rate of wave energy, and the energy level frequencies (ALO, MLO, RLO) reflects the energy enrichment. This chapter analyzed the climatic trends of a series of key parameters of wave energy along the Maritime Silk Road for the first time at home and abroad, comprehensively including the trends of WPD, Cv, Mv, Sv, EWHO, ALO, MLO, RLO, etc. The analysis content of climatic trend includes the overall trend, seasonal difference and regional difference of the trend, dominant season and region of the trend, to lay a theoretical foundation for improving the medium- and long-term planning ability of wave energy development and predictive ability of wave energy.

Previous researchers have made a lot of accumulation and contribution to the analysis of short-term forecast of oceanic and meteorological parameters and wind energy resource. However, researches on short-term forecasts of wave energy resources are extremely scarce, which is an urgent need in the business operation of wave energy engineering. In this chapter, based on the current international advanced wave model WW3, by comparing different boundary conditions, a short-term forecast scheme of wave energy that can fully consider the influence of swells generated from other oceans and is suitable for the Maritime Silk Road was proposed, which can provide scientific evidence for the business operation of wave energy development. The forecast parameters in this chapter are more abundant than the existing forecast scheme. It systematically covers the hourly significant wave height, wave period, WPD field, weekly availability, weekly richness, weekly energy storage, energy direction characteristics, sea state contribution to the wave energy, and wave energy forecast of key nodes, etc.

The liver cancer has become the sixth most common cancer and the second leading cause of cancer deaths worldwide. The incidence of liver cancer has characteristics of the geographical distribution, which vary from region to region. Based on the data from Cancer Incidence in Five Continents, this study analyzed the spatial distribution of liver cancer globally and explored the effect of meteorological factors of surface temperature and wind field on incidence of liver cancer, to find the geographical distribution characteristics of liver cancer and the impact of geographical environmental factors on the incidence of liver cancer, which will be of great significance to the epidemiological study of liver cancer and the prevention of liver cancer. The results show that the humid and hot oceanic climate may be conducive to the development of liver cancer. The environmental factors play an important role in the occurrence of liver cancer.

Under the background of energy crisis, the development of renewable energy will significantly alleviate the energy and environmental crisis. On the basis of the European Centre for Medium-Range Weather Forecasts (ECMWF) interim reanalysis (ERA-interim) wind data, the annual and seasonal grade divisions of the global offshore wind energy are investigated. The results show that the annual mean offshore wind energy has great potential. The wind energy over the westerly oceans of the Northern and Southern Hemispheres is graded as Class 7 (the highest), whereas that over most of the mid-low latitude oceans are higher than Class 4. The wind energy over the Arctic Ocean (Class 4) is more optimistic than the traditional evaluations. Seasonally, the westerly oceans of the Northern Hemisphere with a Class 7 wind energy are found to be largest in January, followed by April and October, and smallest in July. The area of the Class 7 wind energy over the westerly oceans of the Southern Hemisphere are found to be largest in July and slightly smaller in the other months. In July, the wind energy over the Arabian Sea and the Bay of Bengal is graded as Class 7, which is obviously richer than that in other months. It is shown that in this data set in April and October, the majority of the northern Indian Ocean are regions of indigent wind energy resource.

China is now the world’s largest user of coal and also has the highest greenhouse gas emissions associated with the mining and use of coal. Under today’s enormous pressures of the growing shortage of conventional energy sources and the need for emission reductions, the search for clean energy is the most effective strategy to address the energy crisis and global warming. This study utilized satellite remote sensing technology, geographic information system (GIS) technology, and simulated wave data for the South China Sea. The characteristic features of the wave energy were obtained by analysis through the wave resource assessment formula and the results were stored in a GIS database. Software for the evaluation of wave energy in the South China Sea was written. The results should provide accurate, efficient references for wave energy researchers and decision-makers. Based on a 24-year WW3 model simulation wave data and GIS technology, this study presented the characteristic of the wave energy in the SCS; results demonstrated that the SCS has the feasibility and viability for wave energy farming.

This study presents the climatic trend of the North Atlantic wind energy using cross-calibrated, multiplatform (CCMP) wind data for the period 1988–2011. Results show the following. (1) The North Atlantic WPD exhibited a significant increasing trend of 4.45 (W/m2)/yr over the past 24 years. (2) The variation in the North Atlantic Ocean WPD shows a noticeable regional difference. More than half of the North Atlantic Ocean has a significantly increasing trend in WPD. The increasing trend in the mid-high latitudes is stronger than that in the low latitudes, and the trend is stronger in the west than in the east. The area with the strongest increasing trend is located along the southern coast of Greenland of 35 (W/m2)/yr. (3) There is a noticeable seasonal difference in the variation of WPD. The strongest increasing trend occurs in December-January-February (DJF), followed by September-October-November (SON) and March-April-May (MAM), and the weakest occurs in June-July-August (JJA). The increasing trend in different areas is dominated by different seasons. (4) There is no leading or lagging correlation between WPD and the North Atlantic Oscillation (NAO). However, there is a noticeable negative correlation between the Niño3 index and WPD in most of the North Atlantic.

Gao, C.; Zheng, C.W.; Zhang, G.; Han, Y.; Tian, F.; Liu, X.; Wang, L.; Zhang, D., and Xiao, Z., 2020. Long-term projection of wind potential in the China seas. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 396–403. Coconut Creek (Florida), ISSN 0749-0208.This study conducts the mid-long term predictions and assesses the multi-year average offshore wind energy in the China seas for the next five years based on CMIP5 wind data, in hope of providing reference for the long term prediction of wind energy. Results show that (1) large areas with multi-year average wind power densities (WPD) greater than 350 W/m2 are mainly found throughout the Ryukyu Islands and the Taiwan and Luzon Straits in the southeastern area of the Indo-China Peninsula. (2) From 2015-2019, the WPD in the Bohai Sea, Taiwan Strait and Beibu Gulf will be lower than the multi-year average level and thus will be similar to the multi-year average in the Yellow Sea and Gulf of Thailand but greater than the multi-year average in the East China Sea and South China Sea. (3) The predicted occurrences of exploitable wind speeds of the East China Sea and South China Sea are promising for the next five years, exceeding 60%. A value above 40% is predicted for the Yellow Sea, and a lower value is anticipated for the Bohai Sea. (4) The predicted occurrences of WPD > 50 W/m2 are more promising for the next five years.

The marine key points are usually far away from the mainland. The dilemma of the electricity, insufficiency of the fresh water, fragility of the ecological environment, etc. cause the construction of marine key points become a worldwide challenge. Rational developing the marine new energy resources will help solve these problems. This Chapter presented the comparison among new energy resources, prospect of wave energy and wind energy, introduction of wave energy conversion system, contribution to enhance the viability ability of marine key points, to exhibit the advantages of the wave energy and wind energy resources, especially on the marine key points construction. We also pointed out that the full assessment of energy should be carried out before the resource development, to realize the efficient and safety development and utilization of the wave and wind energy.

The marine key points that based on the important remote islands and reefs are the pivotal support for human society to step into the deep sea. A serial of marine key points will make positive contribution to enhance the capabilities of oceangoing voyage, integrated supplies, ship maintenance, marine observation, anti-piracy escort, anti-terrorism cruises, humanitarian assistance, medical aid, etc., to improve the navigation capability, marine construction capability, sea power maintenance capability, etc. However, the remote islands and reefs are usually far from the mainland. During the construction, it confronted with lots of difficulties such as the rational selection and risk evaluation of the key point, urgent demand of electricity and fresh water, fragility of the ecological environment, terrible survival and medical condition, complicacy dispute on marine rights and interests, which makes the construction of marine key points to be a worldwide difficulty for a long time. This Chapter firstly presented the functions, necessity and difficulties of the construction of marine key points; then provides corresponding countermeasures.

The Gwadar Port that located in southwestern Baluchistan province, Pakistan, grip the throat of the Persian Gulf, is a deepwater port. It is the key node of both the “21st century Maritime Silk Road” and the “Silk Road Economic Belt”. The construction of the Gwadar Port can benefit the countries and regions along the Maritime Silk Road, such as energy supply, cargo transport, and so on. The infrastructure construction of the Gwadar Port is important, especially the electricity supply. The development of clean and renewable energy will effectively improve the ability of sustainable development. Resource assessment should be carried out before the resource development. Previous scholars have made great contributions to the evaluation of wind energy resources. However, about the evaluation of wind energy resource in the Gwadar Port is still in blank. This chapter utilize the ERA-interim wind production from the ECMWF to evaluate the climate characteristics of the wind energy resources in the Gwadar Port. The analysis contents mainly includes the value size of the wind power density, effective wind speed occurrence (EWSO), richness of wind energy (energy level occurrence), wind energy rose diagram (co-occurrence of wind energy direction and wind power density value size), long term trends of wind energy resources, wind class occurrence, etc., to provide scientific reference for the development of wind energy, thus to contribution to promote the sustainable development of Gwadar Port. We hope the method and scheme formed in this book can be popularized in the construction of remote islands and reefs in global oceans, especially the Maritime Silk Road.

The Maritime Silk Road belongs to the tropical cyclone prone seas, and is in the monsoon transformation zone. The islands and reefs are numerous and the wind and wave characteristics are complex. An internsive study of the wind climate and wave climate of the Maritime Silk Road is a prerequisite for the efficient and safety development and utilization of the ocean and for disaster prevention and reduction. Due to the scarcity of data, temporal-spatial resolution, precision and other issue, there are very few studies on the remote islands and reefs. The chapter takes an important remote island as the object of researching. Using the CCMP wind data to drive the WW3 wave model, thus to obtain the wave filed in the China seas. Then the wind climate and wave climate of the important remote island were analyzed, based on the CCMP wind data and hindcast wave data, in hope of providing reference for the ocean navigation, development and utilization of marine resources, ocean engineering, disaster prevention and reduction, and so on.

This chapter presents the feasibility of wind power and wave power generation in the South China Sea, and a remote island was selected as a case study. Using the CCMP wind data, the wind energy characteristic of the selected remote island is analyzed. In addition, we also use the CCMP wind data to drive the WAVEWATCH-III (WW3) numerical wave model. Then the wave energy characteristic of the selected remote island is also analyzed based on the hindcast wave data. The research results can provide scientific guidance for wave power generation and offshore wind power generation. The scheme formed in the chapter can also be popularized in the Maritime Silk Road.

As a marine corridor between the Pacific Ocean and the India Ocean, about more than 40,000 ships pass through the South China Sea. The importance of the South China Sea is evident. However, the shortage of electricity and fresh water severely restrict the marine construction of the South China Sea, which also increase the difficulty of construction of the Maritime Silk Road. Adjust measures to local conditions, rationally develop and utilize the offshore wind energy and wave energy resources can help the remote islands and reefs overcome the difficulties of electricity dilemmas and fresh water shortage. In this chapter, the 24 year Cross-Calibrated, Multi-Platform (CCMP) wind data and 24 year hindcast wave data are used to evaluate the wave and offshore wind energy of a key point of the South China Sea, to provide scientific reference for wave and offshore wind energy development.

The development of wind energy resource could make a positive contribution to the construction of the Gwadar Port, thus to contribute to the construction of the Belt and Road. In the actual development of the wind energy, it is necessary to pay attention to the climatic trend and future prediction of wind energy so as to provide scientific basis for mid-long term planning. Until now, the research on the climatic trend of oceanic and meteorology parameters are abundant. However, the research on the climatic trend of the wind energy is scarce. In addition, the research on prediction of oceanic and meteorology parameters are abundant. However, the research on prediction of wind energy is scarce until now, which is not benefit for the mid-long term planning of wind energy development. In this chapter, we use the ERA-interim wind field data for the past 36 years (1979–2014), to calculate the climatic trend of wind energy parameters in the Gwadar Port, and utilize two methods to make long term prediction of wind energy parameters in the Gwadar Port, which can provide the scientific basis for the long term planning of wind energy development, and provide scientific support for the construction of the Belt and Road.

With the rapid development of human society, the demand for energy has accordingly increased, and along with this increasingly serious energy and environmental crises have developed. Many countries have been focusing on new energy resources to combat these crises, and offshore wind energy resources are especially attractive; they are safe, non-polluting, renewable, and widely distributed with large reserves, which has made them become the focus of developed countries. However, the distribution of wind energy has strong regional and seasonal differences, which determines the success and efficiency of wind energy developments. Therefore, there is a clear need for “resource evaluation and planning in advance” in the wind energy development. Previous research has made a great contribution to the evaluation of offshore wind energy resources, mostly through analysis of the climatic characteristics of wind energy. In the actual development process of wind energy resources, these analyses of the climatic characteristics of wind energy provide a reference for site selection. However, after constructing wind farms, to aid their operation, there needs to be a more comprehensive understanding of other factors, such as the short-term forecasting and medium- to long-term predictions of wind energy. This paper reviews the research progress of the wind energy resource evaluations, and then considers where future research needs to focus, for the evaluation of wind energy resources. This mainly includes further analyses of the climatic characteristics of wind energy, short-term forecasting, medium- to long-term predictions, early disaster warning systems, the establishment of a wind energy development index (WEDI) and an integrated application system, in hope of providing a reference for offshore wind power generation, seawater desalination and other wind energy resource developments, and accelerating the industrialization and utilization of offshore wind energy. Doing this will alleviate the energy and environmental crises, and promote the sustainable development of human society.

The sea surface wind field plays an important role in navigation, ocean engineering, disaster prevention and reduction, reef runway construction, take-off and landing of carrier planes, and so on. The Maritime Silk Road is located in the monsoon region, where there are obvious seasonal variations. It is also often invaded by tropical cyclones. Therefore, in-depth research on the wind climate of the Maritime Silk Road will make a positive contribution to the development of offshore wind energy as well as disaster prevention and reduction, which is presented in this chapter.

Under the background of a shortage of conventional resources (such as coal and oil) and overfishing of inshore fishery resources, countries all over the world are paying special attention to energy strategies. China has also been paying special attention to energy strategies, as realized through equal trade. In addition, China also actively promotes the development and utilization of renewable energy, which is undoubtedly an effective method to deal with climate change and ease the energy crisis. Since ancient times, the ocean has been the cradle of human life, and it is also a huge treasure house of resources, including the following: a wide range of biological resources, rich mineral resources, chemical resources, and inexhaustible power resources. Exploitation of marine resources can strongly guarantee the survival of human society and sustainable development during the 21st century. A thorough understanding of the resources involved in the relevant seas will be conducive to the efficient and rational exploitation and utilization of marine resources. In this chapter, the characteristics of marine resources in the South China Sea and the Indian Ocean are analyzed, which will contribute to the construction of the Maritime Silk Road, benefit international marine development and construction, and promote the sustainable development of human society.

Due to the lack of systematic basic theoretical support, there is no professional application system for the Maritime Silk Road either at home or abroad, which is urgently required by ocean navigation, remote islands and reefs construction, ocean engineering design, resource development, disaster prevention and mitigation, and so on. Since 2015, Zheng Chong-wei’s team has presented research on the management and plan for 21st Century Maritime Silk Road for the first time at home and abroad. This series of research systematically and finely analyzes the characteristics of the marine environment, as well as marine energy, important routes and port characteristics, geographical features, climate features, legal escort, and so on. Based on the previous research, we first analyze the importance and urgency of the construction of a comprehensive application platform for the Maritime Silk Road. We then propose to construct a professional application system for the Maritime Silk Road, covering the marine environment, resources, humanities, geography, economy, and legal cases to provide scientific reference for the national decision-makers, researchers, and marine engineering personnel related to the construction of the Maritime Silk Road.

The ocean wave has a significant impact on the safety and cost of navigation, wave energy resources development, seawall design, ocean engineering, island and reef construction, disaster prevention and reduction, air-sea interaction, global climate change and so on. Previous researchers have made a great contribution to the wave climate analysis of the China seas. However, there are few studies on the wave climate of the northern Indian Ocean, so there is no detailed reference for the construction of the Maritime Silk Road. In this chapter, the wave climate of the Maritime Silk Road is analyzed based on ERA-interim wave reanalysis data from the European Centre For Medium-Range Weather Forecasts (ECMWF) and WW3 hindcast wave data forced by the CMIP5 wind data, systematically including the seasonal characteristics of wave direction and wave height, wave rose (co-occurrence of wave height and wave direction), rough sea occurrence, the annual trend of significant wave height (SWH), extreme wave height, the future wave field, etc., to provide a reference for navigation, ocean engineering, wave energy development, disaster prevention and reduction, and so on.

Given the current background of ongoing environmental and resource issues, the increased exploitation of clean and renewable energy could help to alleviate the energy crisis, as well as contributing to emissions reduction and environmental protection, and so promote future sustainable development. This study explores to reveal the climatic long term trends of the China Sea wave power and significant wave height (SWH) for the period 1988–2011, using a WAVEWATCH-III (WW3) hindcast wave data. The regional difference and seasonal difference of the variation are also presented firstly. Results show that, (1) The China Sea exhibits a significant overall increasing trend in the wave power density (0.2012 (kW/m)/yr) and the SWH (1.52 cm/yr) for the period 1988 to 2011. (2) There is a noticeable increasing trend in most parts of the China Sea, of 0.1–0.7 (kW/m)/yr in wave power density and 0.5–4.5 cm/yr in SWH. Areas with strong increasing trend distribute in the Ryukyu Islands waters, Taiwan Strait and north of the South China Sea (SCS), especially in the Dongsha Islands waters. (3) There is a noticeable seasonal difference in the variation of both SWH and wave power density. The variation in different waters is dominated by the different seasons. The increasing trend of SWH in DJF and MAM is obviously stronger than that in JJA and SON. The increasing trend of wave power density in DJF is stronger than that in other seasons.

Fan, L.; Zheng, C.W.; Zhou, H.; Tang, H.; Zhang, G.; Gao, C.; Lang, F., and Gao, Y., 2020. Gust characteristic analysis of wind energy resource in the western Pacific Ocean. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 404–410. Coconut Creek (Florida), ISSN 0749-0208.As a key factor in the ocean energy development, particularly for preventing and reducing disaster, the analysis of gust characteristic is necessary. This study presents the characteristics of annual and seasonal wind speed, gust wind speed in the western Pacific region, using the CCMP wind data and ERA-interim gust data. Results show that, (1) There is a good consistency in annual variation between the averaged wind speed and averaged gust, while a great difference with the maximum gust. (2) The averaged wind speed for 35 years in the nearshore is smaller than that in the off-shore. There is a large value belt in Ryukyu Islands -- Taiwan Island -- the traditional South China Sea gale center, with two obvious large centers (about 7.5-8.0 m/s) located in the Taiwan Strait, the traditional South China Sea gale center. The large area of maximum annual mean gust (> 50 m/s) is mainly locates in the broad ocean of the east of Taiwan, (3) There is an obvious seasonal difference of the average wind speed, average gust and maximum gust. The average gust has noticeable monthly variation, the peak usually appears in November and the trough mainly appearing in summer. There is also a noticeable monthly variation for the maximum gust. In the middle and south of the South China Sea, the maximum gust is

Against the background of many countries and regions in the world facing energy crisis in the modern society, the development of renewable energy is an inevitable choice. As a non-polluting, renewable, large reserve, widely distributed energy, the development and utilization of renewable wave energy will become the focus. In order to cast a brick to attract jade, this article intends to a preliminary research on the advantage of wave energy, the evaluation on wave energy resource. At last, we also assess the characteristic of wave energy resource in the South China Sea. We hope this study can provide reference for the evaluation of developing wave energy, especially the sustainable development of remote islands.

Against a background of an environmental and resources crisis, the exploitation of renewable and clean energy can effectively alleviate the energy crisis and contribute to emission reduction and environmental protection, thus promoting sustainable development. This study aims to develop a grade classification map of the global ocean wind energy resource based on CCMP (cross-calibrated, multi-platform) wind field data for the period 1988–2011. We also calculate, for the first time, the total storage and effective storage of wind energy across the global ocean on a 0.25°×0.25° grid. An optimistic increasing long-term trend in wind power density was found. In addition, the global ocean wind energy resource was analyzed and regionalized by considering the temporal and spatial distributions of wind power density, wind energy levels, and effective wind speed, as well as through a consideration of wind energy storage and the stability and long-term trends of wind power density. This research fills a gap in our knowledge in this field, and provides a reference point for future scientific research and development into wind energy resources such as wind power generation, water pumping, and wind-heating.

Shadowing occurs for the groove zone plate when radiation origin from one zone of the zone plate must pass through another before reaching the focus point. Using the vector diffraction theory, we study the influence of the shadowing on the focusing properties of binary phase Fresnel zone plates (FZPs). The results show that a low-numerical-aperture (NA) FZP can be treated as an ideal in-plane FZP and the shadowing effect can be neglected. For a high-NA FZP, however, the shadowing effect from the etch depth has to be considered. Owing to the shadowing, the intensity of focusing spot decreases markedly and the size of focusing spot increases slightly in a high-NA FZP. The optimal etching depth of an actual FZP is smaller than that of an ideal FZP.

The propagation of elliptical Gaussian beam passing through paraxial optical systems with aperture is investigated analytically by using tensor method. The approximate formula for propagation of elliptical Gaussian beam through hard apertured optical systems is derived based on the fact that the circ function can be expanded into a finite sum of complex Gaussian functions. The derived formula provides a convenient tool for treating the propagation and transformation of elliptical Gaussian beam through apertured optical systems. As an application example, the propagation properties of elliptical Gaussian beam through apertured fractional Fourier systems are discussed.

Based on the scattering theory and the Green function method, a dynamical theory is given for calculating the difiraction of deeply-etched gratings with a stratifled structure substrate. The key of our method is that the patterned grating structure is considered as a perturbation to the unpatterned stratifled structure rather than to vacuum. Using the flrst-order Born approximation and in the Fresnel difiraction region, we obtain a simple analytical expression, which can be used to calculating the scattering intensity of deeply-etched circular binary Fresnel zone plates with a stratifled substrate (MDECBFZPs). The numerical results show that the focusing intensity at the foci of the MDCBFZP changes periodically with the etching depth and the thickness of the substrate fllm. Our results are in good agreement with FDTD simulations.

State estimation plays an important role for both process control and fault detection. In this paper, a methodology of multi-group particle filter is proposed for the uncertainty problem of state initialization in the nonlinear process systems. The measurement test criterion is introduced to indirectly identify whether the state initialization is accurate. According to the result of identification, multi-group particle filter is selected to generate the initial particles under bad state initialization, which can increase the probability of generating correct initial particles. The rectified errors of observed variables are used for the selection of the optimal particles. Finally, reliable state estimation would be derived through iterative particles. The proposed methodology of multi-group particle filter is compared with the generic particle filtering method through two examples of nonlinear dynamic systems. The results demonstrate the effectiveness and robustness of the proposed methodology.

In this paper, the third-generation wave model WAVEWATCH-III (WW3) was used to simulate the wave field of the East China Sea and South China Sea from January 1988 to December 2009, with wind input of CCMP wind field. Then, the wind energy density and wave energy density were calculated by using the simulated 22-years wave-field data and CCMP data. By synthetically considering the size of energy density, the frequency of energy level and the stability of energy density, the resources of wind energy and wave energy in the East China Sea and South China Sea were analyzed and regionalized. The result can be a guide to searching location of wind & wave power plant.

Based on the definition of fractional Fourier transform (FRT) in the rectangular coordinate system, the FRT for off-axis circular and elliptical dark-hollow beams (DHB) is studied in detail, and analytical formulae are derived for the FRT for off-axis circular and elliptical DHB. The properties of off-axis DHB in the FRT plane are illustrated numerically by use of the derived formulae. The results show that the properties of the off-axis DHB in the FRT plane are closely related with the parameters of the beam and fractional order. The derived formula provides a convenient way for analyzing and calculating the FRT of off-axis DHBs.

The fractional Fourier transform (FRT) of an elliptical dark-hollow beam (EDHB) is studied in detail. Based on the definition of FRT in the rectangular coordinate system, analytical formulae are derived for the FRT of an EDHB with the help of a tensor method. The properties of an EDHB in the FRT plane are illustrated numerically by use of the derived formulae. The results show that the properties of the EDHB in the FRT plane are closely related to the parameters of the beam and to the fractional order. The derived formula provides a convenient way for analyzing and calculating the FRT of an EDHB.

Off-axis flat-topped multi-Gaussian beam is proposed as an extension of flat-topped multi-Gaussian beam. The electric field of off-axis flat-topped multi-Gaussian beam is expressed as a superposition of a series of off-axis Gaussian beams. Propagation formulae for off-axis flat-topped multi-Gaussian beam through aligned and misaligned optical system are derived. As a numerical example, propagation properties of off-axis flat-topped multi-Gaussian beam in free space and through a misaligned thin lens are discussed.

Based on the vectorial Rayleigh diffraction integral and the hard-edge aperture function expanded as the sum of finite-term complex Gaussian functions, an approximate analytical expression for the propagation equation of vectorial Gaussian beams diffracted at a circular aperture is derived and some special cases are discussed. By using the approximate analytical formula and diffraction integral formula, some numerical simulation comparisons are done, and some special cases are discussed. We find that a circular aperture can produce the focusing effect but the beam becomes the shape of ellipse in the Fresnel region. When the Fresnel number is equal to unity, the beam is circular and the focused spot reaches a minimum.

A new kind of laser beam named off-axis elliptical flat-topped beam is proposed. This beam is expressed as a finite series of off-axis elliptical Gaussian beams with different beam parameters. Analytical propagation formulas for the off-axis elliptical flat-topped beam through aligned and misaligned optical systems are derived. As a numerical example, the propagation properties of the off-axis elliptical flat-topped beam in free space are calculated and discussed.

The fractional Fourier transform (FRT) is applied to off-axis elliptical Gaussian beam (EGB). An analytical formula is derived for the FRT of off-axis EGB in terms of the tensor method. The corresponding tensor ABCD law for performing the FRT of off-axis EGB is also obtained. By using the derived formulae, numerical examples are given. The derived formulae provide a convenient way for analyzing and calculating the FRT of off-axis EGB.

An analytical expression describing the vectorial field distribution of Gaussian light beams diffracted by an axicon is obtained. The theoretical analysis and simulation calculation show that for the linearly x-polarized light incident on an axicon, the y-component of the diffraction field is very small and the x-component dominates. The intensity of the z-component along the propagation direction is related with the open angle and index of axicon. The open angle plays the more important role in determining the polarization than does the index. For a small open angle, the z-polarized effect can be neglected and the scalar method is simple and valid to evaluating the diffraction field distribution of axicon. However, the vectorial method has to be used for great open angle.