Research development, current hotspots, and future directions of water research based on MODIS images: a critical review with a bibliometric analysis

The impact of Jürgen Habermas's scientific production: a scientometric review

The use of bibliometrics, based on statistical and mathematical tools, makes it possible to measure the contributions of researchers to science. This is a widely used tool to assess scientific production in several areas of knowledge. Such methodology analyzes publication trends, author networks, structures of co-citation, journals and even the scientific contribution of renowned scholars in science. The precursor of bibliometrics, Eugene Garfield, who proposes the retrieval of information from the indexing of citations, was the object of a scientometric review aimed at assessing his impact on science. Given such relevance, this article presents the academic contribution of Jürgen Habermas based on a preliminary scientometric review of his studies. Jürgen Habermas is regarded not only as an active scholar in the social and political process, but also as a productive, controversial and influential contemporary author. The correct understanding of his works is a great challenge, as the bases of his thinking are so broad that they allow an interface between different approaches. We elaborated a design of his scientific work with the advancement to a connection between his main ideas through the use of bibliometric software. Bibliometrics, of the scientometric type, allows the understanding of how recognized patterns in citations can develop information relevant to the scientific field. The results confirm the multidisciplinary contribution of Habermas's studies and highlight his main fields of research and works, which serve as a foundation for clearly understanding and applying his concepts.

Farmers' beliefs and concerns about climate change, and their adaptation behavior to combat climate change in Saudi Arabia

Climate change threatens the existence of humankind on the planet Earth. Owing to its arid climate and poor natural resources base, Saudi Arabia is particularly susceptible to the negative impact of ongoing climate change. Farmers' understanding of this global phenomenon is extremely important as it may help determine their adaptation behavior. This study was designed to analyze farmers' beliefs and concerns about climate change as well as their views about adaptation different obstacles. Data were collected from 80 randomly farmers of the Al-Ahsa region in Eastern Province using structured interviews. The findings revealed that farmers believed that climate change is mainly occurring due to anthropogenic activities. Drought, insects, crop diseases, and heat stress were their main concerns regarding adverse impacts of climate change. Lack of knowledge about adaptation practices, and poor government and financial support are perceived as the major obstacles to adaptation. The results of non-parametric analysis identified no significant differences in farmers' climate change beliefs and concerns, and their views about obstacles to adaptation in relation to their demographic characteristics. Based on the findings, we suggest that capacity building programs should be undertaken by the government for enhancing the adaptive capacity of the farmers as well the provision of financial incentives wherever deemed necessary for promoting the adoption of sustainable agricultural practices and building a resilient national food system.

A bibliometric review of vegetation response to climate change

Global assessment of vegetation response to climate change (VRCC) studies was conducted to reveal the research evolution, current research hotspots and better understanding of dominant themes in VRCC areas of research from 1992 to 2019 through the use of bibliometrics. A total of 186 articles with the search term "Vegetation response to Climate change" were retrieved using the Web of Science (WOS) database. The annual growth rate of 10.3% connotes that research on VRCC has been increasing over time during the survey period. Average citations per article experienced many fluctuations over the years rather than maintaining the same growth rate, which connotes that this field of research reached was unstable in terms of average total citation per document. Results show that China ranked first followed by the USA and the UK, and this shows the dominance of these countries on VRCC studies over the years in review. Results from corresponding authors' nationalities show that multiple-country publications are relatively low compared to articles from single-country publications which showed a dominant trend. Hence, we can infer that most studies on VRCC were sustained by single-country publications. Results from this study revealed top-cited articles, the top global distribution of documents, academic collaboration, most relevant keywords and Word TreeMap of high-frequency keywords. The findings of this study show that "temperature" is in a central position in all keywords with the largest significant appearance in the field. In conclusion, the findings from this study may be applicable for planning and managing vegetation and forest ecosystem research and provide hints for future development.

Climate Change Concerns of Saudi Arabian Farmers: The Drivers and Their Role in Perceived Capacity Building Needs for Adaptation

Climate change is a serious threat to the sustainability of global agriculture and food supply that necessitates taking appropriate action for building resilient food production systems and preserving rural economies. In this regard, farmers’ beliefs and concerns about the effects of climate change on agriculture may influence their adoption of adaptation and mitigation practices to address this emerging issue. This work was undertaken to evaluate farmers’ level of concern about climate change in the Jazan province of Saudi Arabia. The study also explored the role of various socioeconomic indicators in shaping farmers’ concerns and highlights various capacity-building initiatives that can be applied at the community level for effective adaptation. Ordered logistic regression was used to study the relationship between farmers’ level of concern and their need for capacity-building initiatives to tackle climate change. Results indicated that insect infestation is the farmers’ top concern, followed by higher crop-diseases incidence and drought. Regression analysis revealed that farmers’ income is a major factor that reduces their concern for insect infestation and crop disease while increases concern for drought. Credit access and information availability have a mixed impact on the farmers’ concern level. Capacity-building initiatives deemed necessary included establishing frequent contacts with extension personnel, timely warnings on droughts and other natural hazards, the training of farmers and extension workers, easy credit facilities, improvement in rural infrastructure and creation of awareness to address specific concern stimulus.

Research Trends in the Remote Sensing of Phytoplankton Blooms: Results from Bibliometrics

Phytoplankton blooms have caused many serious public safety incidents and eco-environmental problems worldwide and became a focus issue for research. Accurate and rapid monitoring of phytoplankton blooms is critical for forecasting, treating, and management. With the advantages of large spatial coverage and high temporal resolution, remote sensing has been widely used to monitor phytoplankton blooms. Numerous advances have been made in the remote sensing of phytoplankton blooms, biomass, and phenology over the past several decades. To fully understand the development history, research hotspots, and future trends of remote-sensing technology in the study of phytoplankton blooms, we conducted a comprehensive review to systematically analyze the research trends in the remote sensing of phytoplankton blooms through bibliometrics. Our findings showed that research on the use of remote-sensing technology in this field increased substantially in the past 30 years. “Oceanography,” “Environmental Sciences,” and “Remote Sensing” are the most popular subject categories. Remote Sensing of Environment, Journal of Geophysical Research: Oceans, and International Journal of Remote Sensing were the journals with the most published articles. The results of the analysis of international influence and cooperation showed that the United States had the greatest influence in this field and that the cooperation between China and the United States was the closest. The Chinese Academy of Sciences published the largest number of papers, reaching 542 articles. Keyword and topic analysis results showed that “phytoplankton,” “chlorophyll,” and “ocean” were the most frequently occurring keywords, while “eutrophication management and monitoring,” “climate change,” “lakes,” and “remote-sensing algorithms” were the most popular research topics in recent years. Researchers are now paying increasing attention to the phenological response of phytoplankton under the conditions of climate change and the application of new remote-sensing methods. With the development of new remote-sensing technology and the expansion of phytoplankton research, future research should focus on (1) accurate observation of phytoplankton blooms; (2) the traits of phytoplankton blooms; and (3) the drivers, early warning, and management of phytoplankton blooms. In addition, we discuss the future challenges and opportunities in the use of remote sensing in phytoplankton blooms. Our review will promote a deeper and wider understanding of the field.

Hotpots and trends of covalent organic frameworks (COFs) in the environmental and energy field: Bibliometric analysis

Covalent organic frameworks (COFs) have attracted extensive attention due to their low density, adjustable structure, functionalization, and good stability. This paper systematically and comprehensively describes to qualitatively and quantitatively the progress, trends, and hotspots of COFs in the environmental and energy fields from the perspective of bibliometrics. Herein, based on the Web of Science database, a total of 2589 articles from 2005 to October 6, 2020, were collected. Thereafter, co-occurrence, co-citation analysis, and cluster analysis were conducted using CiteSpace and VOSviewer software. The results indicated that COFs research shows the characteristics of rapid growth. The active countries were mainly USA, Germany, Japan, China, and India. More than half of the top 20 active institutions were from China. The research hotspots in this field were systematically elaborated, including synthesis, adsorption, catalysis, membrane, sensor, and energy storage. Research has shown that various COFs are reasonably designed, synthesized, and used in different applications. For example, when COFs are used for photocatalysis, groups containing photocatalytic active sites are integrated into COFs to improve photocatalytic activity. Finally, some challenges were proposed, that are beneficial to the rapid and balanced development of the COFs field. For instance, the preparation methods still need to be further improved for mass production and there is an imbalance in environmental applications such as fewer sensor and membrane applications. We believe that this study provides a comprehensive and systematic overview of the environmental and energy applications of COFs for future investigations.

Water-Food Nexus Assessment in Agriculture: A Systematic Review

The Water–Food Nexus (WF) has been proposed to reach equitable, balanced, and sustainable access to water and food resources in the face of the growing population demand. Therefore, developing models to assess them has become more relevant. This work systematically reviews the literature on the tools used to evaluate water and food resources between 2002 and 2020. Furthermore, it reports a critical analysis of the software used to assess the WF Nexus quantitatively. The models analyzed were Life Cycle Assessment (LCA), Common Agricultural Policy Regional Impact (CAPRI), Global Food and Water System (GFWS), Soil and Water Assessment Tool (SWAT), Water Evaluation And Planning system (WEAP), and Soil Water Atmosphere Plant (SWAP). We deduced that the following are necessary in evaluating the WF Nexus: (1) the capacity to generate future scenarios, (2) a global application, and (3) the application in case studies. The present paper is the first review to provide an overview of the software applied to evaluate WF Nexus, including the advantages and disadvantages of the tools found. They can help build sustainability criteria when designing policies that reduce water and food security risks and promote efficient water and food use.

Sustainable Use of Wastewater in Agriculture: A Bibliometric Analysis of Worldwide Research

It is estimated that at least one quarter of the world’s population will be affected by water shortages in the coming years and by 2030 there will be a global water deficit of 40% if urgent action is not taken. Currently, the main consumer of water globally is agriculture. In addition, it has been estimated that to meet the demand for food by 2050, the water available for agricultural irrigation would have to increase by 70%. In this context, wastewater could become a relevant water resource to meet this growing demand. This article aims to show the state of the global research on sustainable use of wastewater in agriculture. To this end, a systematic qualitative analysis and a quantitative bibliometric analysis were conducted. The search was carried out for the period 2000–2019, and the analyzed sample comprised 1986 articles. The results show that this line of research is one of the most outstanding within agriculture and has gained special relevance during the last five years. Research has improved significantly at a technical level, but problems such as energy consumption, and the elimination of heavy metals and elements of chemical and pharmacological products, still need to be refined. There is a particular lack of contributions covering social aspects. This article can serve as a reference for both researchers and stakeholders interested in this topic.

Rockfall Research: A Bibliometric Analysis and Future Trends

Rockfall is one of the main phenomena in mountainous environments due to its fast and high speed of movement, its unpredictability, and, therefore, the difficulty of identifying signs of instability and detachment of the blocks. Compared to other types of sliding, the proportion of rockfall research is smaller and sometimes little known, but, in the last five years, rapid growth in this area has been shown. Therefore, this research aimed to review the intellectual structure of rockfall, through analysis of scientific production using bibliometric techniques that allow its analysis, knowledge, global evolution, and future trends in rockfall. The research methodology consists of three steps: (1) data compilation, (2) software and data cleaning, and (3) analysis, interpretation, and visualization. This analysis focuses on the period from 1975 to 2019. For the data, a total of 811 academic publications were retrieved from the Scopus database. The results indicate an increasing trend of annual publications on rockfall. This analysis reveals the main topics, countries, and most influential institutions in the world that have carried out relevant research in scientific publications; it also shows the journals that have the most publications. VOSviewer software was adopted to evaluate the co-occurrence of author keywords. Currently, the hotspots rockfall issues mainly include: hazard-risk assessment, remote sensing, and rockfall monitoring. Finally, this article analyzes the limitations of current research and proposes a future direction for the development of new research.

The research trends of metal-organic frameworks in environmental science: a review based on bibliometric analysis

Metal-organic frameworks, an emerging class of porous material, have developed rapidly in recent years. In order to clarify the application of metal-organic frameworks in the field of environmental science, 1386 articles over the last 20 years were obtained from Scopus and analysed by the bibliometric method. And the collaboration between countries, institutions and authors and the co-occurrence of keywords were also conducted using VOSviewer. The results indicated that this area of research has entered a fast-developing stage. The number of articles published has grown from 7 articles in 1999 to 378 articles in 2018. The most productive country was China with 626 articles published. The most productive institution was the Chinese Academy of Sciences, and the most productive author was Jhung SH from Kyungpook National University of South Korea. Although metal-organic frameworks have been widely used in adsorption and catalytic degradation of pollutants from the environment, the removal mechanism of pollutants by MOFs, the stability improvement and the cost reduction of metal-organic frameworks are still the main challenges for their practical applications.

Remote Sensing Applications in Monitoring of Protected Areas: A Bibliometric Analysis

The development of remote sensing platforms and sensors and improvement in science and technology provide crucial support for the monitoring and management of protected areas. This paper presents an analysis of research publications, from a bibliometric perspective, on the remote sensing of protected areas. This analysis is focused on the period from 1991 to 2018. For data, a total of 4546 academic publications were retrieved from the Web of Science database. The VOSviewer software was adopted to evaluate the co-authorships among countries and institutions, as well as the co-occurrences of author keywords. The results indicate an increasing trend of annual publications in the remote sensing of protected areas. This analysis reveals the major topical subjects, leading countries, and most influential institutions around the world that have conducted relevant research in scientific publications; this study also reveals the journals that include the most publications, and the collaborative patterns related to the remote sensing of protected areas. Landsat, MODIS, and LiDAR are among the most commonly used satellites and sensors. Research topics related to protected area monitoring are mainly concentrated on change detection, biodiversity conservation, and climate change impact. This analysis can help researchers and scholars better understand the intellectual structure of the field and identify the future research directions.

Text Mining in Remotely Sensed Phenology Studies: A Review on Research Development, Main Topics, and Emerging Issues

As an interdisciplinary field of research, phenology is developing rapidly, and the contents of phenological research have become increasingly abundant. In addition, the potentiality of remote sensing technologies has largely contributed to the growth and complexity of this discipline, in terms of the scale of analysis, techniques of data processing, and a variety of topics. As a consequence, it is increasingly difficult for scientists to get a clear picture of remotely sensed phenology (rs+pheno) research. Bibliometric analysis is increasingly used for the study of a discipline and its conceptual dynamics. This review analyzed the last 40 years (1979–2018) of publications in the rs+pheno field retrieved from the Scopus database; such publications were investigated by means of a text mining approach, both in terms of bibliographic and text data. Results demonstrated that rs+pheno research is exponentially growing through time; however, it is primarily considered a subset of remote sensing science rather than a branch of phenology. In this framework, in the last decade, agriculture is becoming more and more a standalone science in rs+pheno research, independently from other related topics, e.g., classification. On the contrary, forestry struggles to gain its thematic role in rs+pheno studies and remains strictly connected with climate change issues. Classification and mapping represent the major rs+pheno topic, together with the extraction and the analysis of phenological metrics, like the start of the growing season. To the contrary, forest ecophysiology, in terms of ecosystem respiration and net ecosystem exchange, results as the most relevant new topic, together with the use of the red edge band and SAR (Synthetic Aperture Radar) data in rs+pheno agricultural studies. Some niche emerging rs+pheno topics may be recognized in the ocean and arctic investigations linked to phytoplankton blooming and ice cover dynamics. The findings of this study might be applicable for planning and managing remotely sensed phenology research; scientists involved in such discipline might use this study as a reference to consider their research domain in a broader dynamical network.

Sustainable Irrigation in Agriculture: An Analysis of Global Research

Irrigated agriculture plays a fundamental role as a supplier of food and raw materials. However, it is also the world’s largest water user. In recent years, there has been an increase in the number of studies analyzing agricultural irrigation from the perspective of sustainability with a focus on its environmental, economic, and social impacts. This study seeks to analyze the dynamics of global research in sustainable irrigation in agriculture between 1999 and 2018, including the main agents promoting it and the topics that have received the most attention. To do this, a review and a bibliometric analysis were carried out on a sample of 713 articles. The results show that sustainability is a line of study that is becoming increasingly more prominent within research in irrigation. The study also reveals the existence of substantial differences and preferred topics in the research undertaken by different countries. The priority issues addressed in the research were climatic change, environmental impact, and natural resources conservation; unconventional water resources; irrigation technology and innovation; and water use efficiency. Finally, the findings indicate a series of areas related to sustainable irrigation in agriculture in which research should be promoted.

Rainwater Harvesting for Agricultural Irrigation: An Analysis of Global Research

Within a context of scarce water resources for agriculture, rainwater harvesting constitutes a promising alternative that has been studied by different disciplines in recent years. This article analyses the dynamics of global research on rainwater harvesting for agricultural irrigation over the last two decades. To do this, qualitative systematic analysis and quantitative bibliometric analysis have been carried out. The results reveal that this line of research is becoming increasingly important within research on irrigation. Environmental sciences and agricultural and biological sciences are the most relevant subject areas. Agricultural Water Management, Physics and Chemistry of the Earth, and Irrigation and Drainage are the journals that have published the most articles on the subject. India, China, the United States (USA), South Africa, and the Netherlands are the countries that lead this line of research. Although significant progress has been made in this subject area, it is necessary to increase the number of studies on the capacity of rainwater harvesting systems to cover irrigation needs in different farming contexts, the factors that determine their adoption by farmers, the economic and financial feasibility of their implementation, and their contribution to mitigating global climate change.

Scientific Coverage in Water Governance: Systematic Analysis

In this article, the results of the bibliometric analysis applied to research on “Water Governance” are presented in order to observe behavior patterns in the key areas of this field of knowledge (progression, most productive authors, etc.). This research is complemented with a co-citation analysis. When considering two databases, a comparative study is carried out between both databases through coverage, overlap, dispersion, or concentration indicators. The results indicate that this area of knowledge has evolved rapidly and has gained popularity and importance among researchers, especially since 2009, when the real boom of the discipline took place, with about two-thirds of the papers being published in the last five years. The main authors, the most relevant articles based on the citation criterion, the institutions, and countries with the highest number of investigations and the journals where this topic is published are also identified. Scopus is the database that performs better coverage by collecting a higher number of articles and obtaining a greater number of citations.

Forest Ecosystem Services: An Analysis of Worldwide Research

The relevance of forests to sustain human well-being and the serious threats they face have led to a notable increase of research works on forest ecosystem services during the last few years. This paper analyses the worldwide research dynamics on forest ecosystem services in the period from 1998 to 2017. A bibliometric analysis of 4284 articles was conducted. The results showed that the number of published research articles has especially increased during the last five years. In total, 68.63% of the articles were published in this period. This research line experiences a growing trend superior to the general publishing trend on forest research. In spite of this increase, its relative significance within the forest research is still limited. The most productive subject areas corresponded to Environmental Science, Agricultural and Biological Sciences and Social Sciences Economic topics are understudied. The scientific production is published in a wide range of journals. The three first publishing countries are United States, China and the United Kingdom. The most productive authors are attached to diverse research centres and their contributions are relatively recent. A high level of international cooperation has been observed between countries, institutions and authors. The findings of this study are useful for researchers since they give them an overview of the worldwide research trends on forest ecosystem services.

Sustainable Water Use in Agriculture: A Review of Worldwide Research

Sustainability of water use in agriculture is a line of research that has gained in importance worldwide. The present study reviewed 25 years of international research on sustainable water use in agriculture. A bibliometric analysis was developed to sample 2084 articles. Results indicate exponential growth in the number of articles published per year, with research in this field having acquired a global scale. Environmental Science and Agricultural and Biological Sciences are the main categories. Three journals—Agricultural Water Management, Water Resources Management and Nongye Gongcheng Xuebao Agricultural Engineering—published the most of the articles. China, the U.S., Australia, India and Germany produced the most research. The three institutions that published the most articles were all Chinese (Chinese Academy of Sciences, China Agricultural University and Northwest A&F University). The most cited authors were Ridoutt, Hoekstra and Zhang. The keywords most frequently used include: water-use, irrigation, water-management, water-supply, and sustainability. A network map shows three clusters that focus on the environmental, agronomic and management aspects. The findings of this study can assist researchers in this field by providing an overview of research on the sustainability of hydric resources.

Advances in Water Use Efficiency in Agriculture: A Bibliometric Analysis

Water use efficiency in agriculture (WUEA) has become a priority given increasing limitations on hydric resources. As a result, this area of research has increased in importance, becoming one of the most prolific lines of study. The main aim of this study was to present a review of worldwide WUEA research over the last 30 years. A bibliometric analysis was developed based on the Scopus database. The sample included 6063 articles. The variables analyzed were: articles per year, category, journal, country, institution, author, and keyword. The results indicate that a remarkable growth in the number of articles published per year is occurring. The main category is environmental science and the main journal Agricultural Water Management. The countries with the highest number of articles were China, the United States of America, and India. The institution that published the most articles was the Chinese Academy of Sciences and the authors from China also were the most productive. The most frequently used keywords were irrigation, crop yield, water supply, and crops. The findings of this study can assist researchers in this field by providing an overview of worldwide research.

Benchmarking the scientific research on wastewater-energy nexus by using bibliometric analysis

With an exponential increase in urbanization and industrialization, water pollution is an inevitable consequence of relatively lagging wastewater treatment facilities. The conventional activated sludge process for wastewater treatment primarily emphasizes the removal of harmful substances to maintain increasingly stringent effluent discharged standards, which is considered an energy-intensive technique. Therefore, innovative and sustainable wastewater treatment should pay more attention to energy and resource recovery in dealing with fossil fuel depletion, global-scale energy security, and climate change. A bibliometric analysis was applied to trace wastewater-energy nexus-related research during the period 1991 to 2015, with respect to the Science Citation Index EXPANDED (SCI-EXPANDED) database. Journal of Hazardous Materials, ranking 1st in h-index (79), was the most productive journal (431, 4.5%) during the same time, followed by International Journal of Hydrogen Energy (422, 4.4%) and Water Research (393, 4.1%) journal, the latter owning a topmost journal impact factor. Though, China (2154, 22.5%) was the most productive country, while the USA with highest h-index (88) was the favorest collaborative country. The Chinese Academy of Sciences, China (241, 2.5%) produced the maximum publications. A novel method called "word cluster analysis" showed that the emerging sustainable processes and novel renewable energy application are applied in response to the desire for a net wastewater-energy nexus system. Based on different wastewater types, the emerging energy and sources recovery treatment processes of Anammox, anaerobic digestion, and microbial fuel cells gained extensive innovation. Evaluation indicators including sustainability, life cycle assessment, and environmental impact were appropriately used to dissert feasibility of the novel treatment methods in regard of renewable energy utilization, energy savings, and energy recovery. The transformation of the new concept of "broaden income source, economize on expenditures and exploit inner potential" should be generalized in order to achieve an environmentally sustainable development of wastewater-energy nexus system.