1 Introduction

Drought is a frequent feature of most parts of the world’s climate. It is characterized by drier-than-normal conditions that can last for days, months, or years [1, 2]. Its consequences are classified as environmental, economic, and social. Dryer wetlands, wildfires, biodiversity loss, disruption of municipal water supplies, lower agricultural, forest, and fishery outputs, increased food production costs, and concerns about water supply for the energy sector are among the environmental consequences [3, 4]. Currently water shortages, and low water levels are all economic and health consequences [5,6,7,8]. Drought is caused by geophysical processes as well as a human activity, and it is becoming more often as the climate warms [9, 10].

A drought is a period of abnormally dry weather that generates water-related problems. It is classified into three types: meteorological, agricultural, and hydrologic. It is unusual for one type of drought to be more severe than another during a period of water constraint. A prolonged dry season throughout the summer may impair agricultural production while having no influence on groundwater storage replenished the previous spring [11, 12]

The presence of water influences the hydrology of the soil, changing its chemical composition, quantity, and microbiological interactions [13, 14]. Global climate systems have undergone an unparalleled transformation. Each of the last three decades has seen a warmer climate on the surface of the world. Climate change can have an influence on the water level, as well as the biogeochemistry and function of the land.

Water is the biggest terrestrial organic carbon reservoir, and its severity has a substantial influence on drought severity. Forecasting dammed water levels is critical for evaluating dam concerns such as water quality, biodiversity conservation, flood control, and hydropower generation optimization. Time-regular handling, symmetrical observational functions, error adjustment-based anticipating, multivariate techniques, and outfit-based algorithms are examples of computational procedures [15].

Groundwater is a significant natural resource, accounting for 33% of the global water supply. When there is less rainfall than usual, the flow of streams and rivers decreases, water levels in lakes and reservoirs drop, and the depth of water in wells increases. Droughts, seasonal fluctuations in rainfall, and pumping all have an impact on groundwater levels. Water levels in a well can be reduced if it is pumped faster than the aquifer surrounding it [16]. It is refilled by precipitation or another subsurface movement [17, 18]. A well is considered to be dry when the water level falls below the pump input. The absence of rain has a more direct effect on wells screened in unconfined water table aquifers than on those screened in deeper, confined aquifers [19]. Flooding is the most common natural catastrophe in the United States, and it is produced by rain, snow, coastal storms, storm surges, and dam overflows.

Climate change, drought, temperature, rainfall intensity, and extreme weather events all have an effect on water levels, modifying wetland biogeochemistry and function while also influencing hydrology and temperature [20]. Wetlands may become carbon sources due to greater microbial activity, quicker photosynthesis, and higher rates of nitrification and denitrification, potentially making important services inefficient [21].

Droughts and water levels are predicted to become major global challenges, affecting climate change and people all over the world. Their connection and influence on one another is of tremendous scientific interest [22, 23]. Droughts and water shortage have a substantial influence on the global economy, impacting consumer prices and energy expenditures. They have the ability to stymie economic progress, promote migration, and spark war. Droughts destabilize communities, provoke civil upheaval, and exacerbate water shortages and food hardship. The destruction of vegetation and tree cover exacerbates soil erosion and lowers groundwater recharge, creating water shortages and food poverty [24, 25].

This review of the scientific literature aims to identify gaps in the present research and give recommendations to future scientists. It will examine articles on drought and water levels topics and evaluate the decade’s strengths and shortcomings in institutions, keywords, authors, journals, and collaboration. It also provides future study areas. It would assist programmers, researchers, and institutions in identifying particular areas for collaboration and cooperation to address global drought and water level challenges.

2 Methodology

2.1 Data collection method

For this bibliographic study, the fundamental data collection was done at the Web of Science database at Nanjing University of Information Science and Technology [20, 26]. The search topic was set to ((“drought”) AND (“water level” OR “water shortage”)). Search results in 961 at ((“drought”) AND (“water level”)) (Topic)—961—All Databases (webofscience.com). The study was started early, in 1969 (1 article). Invalid items, such as conference documents, government documents, news, and other language articles were removed. The time range of data was “2012–2022” “English” was the language, and “Article” was the document type selected (Table 1). The Web of Science database returned 742 articles after filtering ((“drought”) AND (“water level”)) (Topic)—742—All Databases (webofscience.com). The findings were saved as “plain text files” and analyzed by Citescpce software (v.6.1. R6) as web of science.

Table 1 Data collection methods (updated)
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2.2 Bibliometric analysis

A quantitative analysis of articles on a particular topic is known as bibliometric analysis. To find emerging themes and potential trends, it may do quantitative statistical analysis on a large number of peer-reviewed publications, network analysis, temporal analysis of document citation bursts, and keyword co-occurrence analysis [20]. CiteSpace is a popular bibliometric analytic tool [27]. It visually maps, explores, examines, organizes, and exposes the knowledge domain at a macro level. This approach is critical for identifying hotspots, understanding the changing trend in this field of study, and shedding light on future research fields. Computer software has attracted the interest of academics in a variety of sectors and is widely used [20].

Bibliometric citespace analysis is widely used in literature research in certain fields. Among a series of visual analysis tools, the CiteSpace (V.6.1. R6). The internal relationship between documents can be intuitively displayed through constructing a knowledge map, which helps enhance the abstract cognition of the relevant research status [28].

The number of published articles in the web of science (WoS) databases on the topics of drought and water level from 2012 to 2022 was plotted to examine and summarized its change-related tendencies [29]. To identify how research domains are based on high-frequency terms, keyword co-occurrence analysis was employed. To summarize the frequency and intensity of collaboration, the research cooperation network was evaluated for the major research nations, institutions, authors and burst detection function was utilized to identify research trends and frontiers as well as to forecast future research development paths [30].

2.3 Bursts, trends, and their influence

Burstness is a measure of an entity’s pace of change over time [31]. Citation burst and occurrence burst are both supported in CiteSpace. A high burstiness node usually represents a potentially interesting work that has received a lot of attention in a short period of time. CiteSpace is intended to offload some of the previously time-consuming tasks to computer algorithms and interactive visualizations, allowing human users to focus on problem-solving and truth-finding [27]. To do this, we used the “multiple-perspective co-citation analysis” approach, which included structural, temporal, and semantic pattern analysis [32].

2.4 Nodes assortment

The g-index is the most commonly suggested strategy for node selection. The 1 year per slice technique utilized in this study picked the most cited articles from each slice to create a network based on the user-specified input value and node type [33]. We used k = 20 and several node kinds, so the top 20 most referenced things were presented and rated. The g-index per slice procedure indicated the proportion of most cited items based on a fixed value.

2.5 Network development

The web of science (WoS) dataset was used to construct co-citation networks for authors and publications for network development [27]. Following Chen et. [32], trend research publication (Fig. 1), countries analysis (Fig. 2), institute co-citation (Fig. 3), author co-citation analysis (Fig. 4) [34], document co-citation analysis (DCA), journal co-citation analysis (JCA) (Fig. 5), and keyword analysis (Fig. 6) were performed to cluster co-citing authors [30, 35], and dual map overlay (Fig. 7).

Fig. 1
figure 1

Trends, research area and publishers in drought and water level articles A. trends of articles per year from January 2012 to December 31, 2022, and citation B, major research areas studied in drought and water level tops C, Top 5 publishers on drought and water level from 2012 to 2022

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Fig. 2
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Countries or regions analysis result, N = 88, E = 351, Q = 0.4464, S = .8125, Density = 0.0917, cluster = 8, a. Top 10 Countries in publications numbers b. four highest publication countries 10 years’ trends, c, d. countries clustering

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Fig. 3
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Analysis of Major Research Institutions, N = 263, E = 198, Q = 0.8441, S = 0.982, Density = 0.0057, cluster = 131 [34]. a. Highest citation institutes, b. Institutions study cluster, c. Tree structure of institute trend rank

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Fig. 4
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Top 10 Cited authors with the strongest citation Bursts and clustering, N = 488, E = 2187, Q = 0.6904, S = 0.8577, Density = 0.0184. A. Top Author in B. tree ring history of authors, and cluster view of influential authors

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Fig. 5
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Sample publication bursts computed via journal co-citation analysis (JCA) Q = 0.4164; silhouette = 0.822), density 0.0811 [54] a. Top Journal Co-Citation Analysis (JCA) clustering and major journal citation b. tree time citation view

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Fig. 6
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Sample keyword cluster and time analysis Q = 0.3741; silhouette = 0.754), density 0.034, a keywords, b VOSview of key words and c tree citation on timeline

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Fig. 7
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The dual-map overlay generated by CiteSpace (Chen, 2016a)

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To explore network and cluster characteristics, temporal and structural metrics were used. The burstiness and degree of citations are temporal measures. It was critical for citation analysis to know if the citation count of a certain reference increased and when the increase happened. Burst detection identified whether or not the variations for a particular frequency function during a given time period were significant. We employed structural measures to quantify the level of uncertainty in a cluster, such as the average silhouette score [36, 37], and modularity Q [38]. These criteria are useful for discovering famous scientific articles since they signify potentially groundbreaking material.

2.6 Visualization and labeling of clusters

To locate clusters and their interactions, we employed the multidimensional clustering approach. Two visualization approaches the timeline view and the cluster was utilized [39]. The cluster view allowed nodes to have vertical links with nodes in various time zones, whereas the timeline view was made up of vertical lines representing time zones chronologically sorted from left to right. We also used the log-likelihood ratio (LLR) technique to automatically extract cluster labels, which delivers the best results in terms of originality and coverage [32, 40].

2.7 The dual-map overlay

CiteSpace was utilized to create a dual-map overlay [41] in this study, which exhibited a first base map of citing journals and a second base map of citing journals in the same user interface [39]. Trajectories were then built from the citing and referenced journals to offer a more complete picture of the citations. The blondel technique [42] was used to allocate these journals to a cluster, allowing access to community networks with varied community detection resolutions [30] (Fig. 7). This enabled us to look into inter-specialty linkages and citation trends across a variety of publications [40].

3 Results

3.1 Analysis of research trend

Based on a review of 742 papers published between 2012 and 2022 on the topic of “drought and water level,” there were a total of 9,964 citations recorded in the Web of Science Core Collection (WoSCC) database [43].

The trend in changes in the number of published papers, including the number and the growth rate, reflects the relationship between the number of published papers and changes over time; it was an important indicator for measuring the attention of scholars to a particular research field. It also reflects the overall progress of research in this domain [29]. The annual volume of article publishing increased steadily from 2012 to 2021, then fell in 2022. Prior to 2020, there were less than a hundred publications every year. In 2021, the publishing volume was 106 articles per year, the greatest publication output per year which was lower than it had been in 2021. The number of references mentioned more than doubled from 2192 (2012) to 5821 (Fig. 1A). Despite the fact that the research fields are always shifting, environmental science (330) and water resources (200) have consistently accounted for more than 71% of the overall study over the past ten years. Among others subjects covered in this topic are geology (159), marine and freshwater biology (114), engineering (78), plant science (51), and agriculture (46) (Fig. 1B). The top three publishers of publications on drought and water levels were Elsevier (183), Springer Nature (171), and MDPI (77). About 58% of all publications on this topic were published by these publishers (Fig. 1C).

3.2 Network evaluation of researcher collaboration

3.2.1 An assessment of research countries

The Investigation of the national collaboration network has offered a fresh viewpoint on how nation’' academic effects might be quantified as a result of their research. CiteSpace was used to produce a map of national cooperative ties based on the time slice chosen for analysing the WoS literature data, and the node type was set to ‘‘country’’ 1 year was chosen as the time slice for examining the WoS literature data. It resulted in 88 nodes and 355 link lines, a network density of 0.0917, modularity of 0.3714, and Silhouette of 0.7503. This demonstrates that nations or regions are well connected. In research projects focusing on "drought and water level issues’’ 88 countries or regions (96%) contributed (Fig. 2).

The People’s Republic of China came in first place with 3245 citations in 2012, followed by the United States with 2913 citations (Fig. 2a). Over the course of the research period, the quantity of Chinese articles in the web of science (WoS) database has increased significantly. From 2012 to 2022, there was a rise in publication articles in China (30), with a peak in 2019 and the USA (16) in (2022). It illustrates the quick development of science. China and the United States produced the most notable research findings on drought and water level, which call for the active participation and collaboration of other countries or regions (Fig. 2b, c). Water level management and case study clusters were biggest cluster in countries keyword. It shows China and USA mostly focused on case study cluster. After 2020, there will still be a research shortage on themes related to water level and drought control (Fig. 2d).

According to the data shown below, Switzerland (2015) had the most bursts in 2018, with 3.36 bursts. England (2012) came in second with 3.04 brusts. Australia (2016) and Singapore (2014) continue to have the hottest bursts and longest burst durations (Table 2). In contrast, the highest degree rating was achieved by England (2012), with a degree of 31 in comparison to the rest of the world’s countries. In terms of citation China (2012) was the top ranked by 192 citations, followed by United States of America (2012) ranks second in the world by 135 citations (Table 3).

Table 2 Top 10 Countries with strength citation burst
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Table 3 Top 10 citation count and degree of countries
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3.3 Analysis of major research institutions

The number of publications and the collaborative network of research institutes are important markers. It directly reflects the academic focus and overall strength of research institutes. One year was chosen as the time slice. The node type "institution” was chosen, and the Pathfinder tool was used for trimming and merging [44, 45]. CiteSpace was used, and the result was an institution partnership graph with a network density of 0.0057 and link 198. Figure 3 depicts the discovery of 263 nodes, 198 lines, and 131 clusters. The silhouette was 0.9820 and the modularity was 0.8441. The link was quite strong. It demonstrates that research institutions commonly exchange and cooperate on various fields of study, but there is a gap in salinity variability investigations, attribution studies, and macro ecological patterns Islamic Azad University collaborates efficiently with Chinese universities [46] (Fig. 3a). The Chinese Academy of Sciences (2012) was the most cited item in this institution’s publications, with 71 citations and 32 degrees. University Chinese Academic Science (2014) came in second, with 28 citations and 10 degrees (Table 4).

Table 4 Top 10 citation count and degree of institution
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3.4 Author co-citation analysis

The number of publications and collaboration networks reflect the expert’’ academic talent, level of cooperation, and overall academic importance. The author’' cooperation network graph had a network density of 0.0184, with 488 nodes and 435 connections. The ACA network's modularity Q score was 0.6904, indicating moderately well-structured networks and clusters. The average silhouette score was 0.8577, suggesting that the cluster was varied and frequently mentioned [40].

Deo RC, Zhang Q and Yang had the most publications in the water level and drought topics each of them has 7 (Fig. 4a). There are 38 clusters in the authors' citations, 10 of which are interesting and listed under. The most populous writers’ references cluster, with a silhouette value of 0.698, were Gorges dam containing Anonymous, IPCC, and Jeppesen E, who were the most often cited members. They also called shallow lake or salinity fluctuation team. In this cluster, Anonymous (2012) obtained the most citations and degree [47] which is the cluster's most cited publication with 251 citations and highest degree (43), But Cooker (2013) (strength = 4.43), whose business launched in 2013 and continues to expand in 2015, was the top-ranked item by bursts, followed by Allen R.G. (strength = 4.02, 2019–2022) (Table 5). Notably, Allen R. G. (2019) had the longest-lasting burst with a period of 4 years and is presently the most-cited The analysis indicates the gap of current study areas like decline water level, hydrological alternatives, lake water management and harmful cyanobacteria. The rapid fluctuations in the number of citations collected throughout the stipulated timeframe showed the writer’' writings and ideas becoming more relevant. Generally, Zhang Q (2012, 2014), Jeppesen E (2015), R Core Team (2014) were influential authors. water level variation was host study topic while there is gaps substratum and mobilising citizen scientist clusters (Fig. 4b).

Table 5 The top 10 ranking publications as sample author bursts of authors co-citation analysis
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3.5 Document co-citation analysis (DCA)

A cluster view and a timeline view were used to examine the document co-citation analysis (DCA) network. Clusters were rated in order of size, with cluster #0 being the biggest. The size of the circle represented the influence of the publication, with larger circles signifying more citations. The red tree rings denoted the author's publication's brevity [48]. The DCA analysis discovered 56 clusters, the biggest of which (#0) had 48 members and a silhouette value of 0.901. It is referred to as the Gorges Dam and the Subsequent Response. Zhang Q, Guo H, and Zhang ZX are the most mentioned members. Wang, J (2014) is the most frequently cited paper in the cluster [49, 50]. Zhang Q (2014) is the top-ranked author by degree (30). But he was second by a burst of 4.06 and citation) after Guo H’s (2012) strength of burst of 4.24 with citation counts of 24. A high degree of between ness suggested that the articles in the table linked two or more clusters. Since they connected multiple topics, they were also likely to be a synthesis of different concepts into a new one, and maybe revolutionary in offering this connection [51]. As previously stated, higher degree values indicated the novelty of these publications [40, 52]. Alizadeh-Choobari (2016) was current timely hot references from 2020 to 2022 (Table 6).

Table 6 Top 10 references with the strongest citation bursts
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3.6 Journal co-citation analysis (JCA)

According to the statistics, the most co-cited journals are Journal of Water (43), and Hydrology (29) (Fig. 5) [29]. It has 384 nodes and 3422 connections in 18 clusters. There were several high-frequency keyword nodes, and the network density was 0.0465. The network was thick, with many connections between nodes. Taking into account the quantity of phrases, frequency of recurrence, and centrality between them [40]. With modularity Q scores of 0.436 and an average silhouette score of 0.8297, the JCA network exhibits strong interaction and frequency. Science, water resources, hydrobiology, ecology, and freshwater biology are among the most referenced periodicals (Fig. 5a).

The biggest cluster (#0), identified as Poyang lake, and Brisbane Australia, has 136 members with a silhouette value of 0.833. It is mostly cited in the journals J. Hydrol, Water Resources, and Res and Science. With 107 members and a silhouette value of 0.82, the second biggest cluster (#1) is dongting lake [53]. Currently there is gap on topic natural science in northern Atlantic cluster (Fig. 5b). J Hydrol (2012) ranks top with 302 citations, Water Recourse Research (2012) has 223, and while Nature and Science (2012) has 344 and 337 highest degree (Table 7).

Table 7 Publication citation computed via journal co-citation analysis (JCA)
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3.7 Keywords co-citation analysis

The keywords indicate the articles' study themes, contents, theories, methodologies, points of view, and other features. Cite Space’s analysis function can successfully extract high-frequency keywords, as well as conduct co-occurrence, clustering, and emerging word recognition [27]. After that, the study field can acquire topic clustering, as well as its distribution, scope, and sub-clustering [55, 56]. To understand research hotspots and frontier advancements, publications is evaluated using keywords, emphasizing large clusters and citation-based indicators such as citation counts and bursts [57].

The clusters created influential ideas with high keyword strength. With a modality of 0.6998, a silhouette of 0.6835, and densities of 0.0345, the network comprises 352 nodes and 2131 linkages. The analysis produced keyword bursts [40]. The most frequently used key terms were climate change (181), drought (159), water level (125), impact (118), dynamic (101). There were gaps on keywords like land use, system and restoration diversity in this field (Fig. 6a, b).

The bibliography mentions 15 prominent clusters, the greatest was Yangtze river cluster, which has 76 persons and a silhouette value of 0.648. It is a water level, impact, and unpredictability heterocyst development [58]. Drought Stress is Cluster #1, with 67 members and a silhouette value of 0.728. It is classed as heterocyst development and involves drought, growth, and response. The tree citation on timeline show gaps on clusters like species-rich fen and ground water level in this field. There is a scarcity of research on biological terrestrial concerns, lake acidification, salinity changes, and attribution [59] (Fig. 6c). The most important bursts were ‘‘reservoir’’ (4.61) from 2019–2020, followed by ‘‘water quality’’ (3.72) and ‘‘restoration’’ (3.46) with a 4 year burst duration. The phrase ‘‘frequency and soil moisture’’ witnessed a 4 year hot burst from 2018 to 2022 (Table 8).

Table 8 Top 10 Keywords with the strongest citation bursts mean time ≥ 3
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3.8 Dual-map overlay

Created a dual-map overlay, where the citing papers are on the left, the cited journals are on the right, and the citation connections identify the source journal. An understanding of inter-specialty interactions may be gained from the trajectory of the citation linkages. A change in trajectory from one region to another would suggest that papers from one field had an impact on the other [40]. It was clear that the major areas at the beginning of the trajectory were ecology, earth, marline, molecular, biology, immunology, veterinary and animal science. In contrast, the final leg of the trajectory was dominated by plant ecology, earth, geophysics, zoology, molecular, biology, genetics, environmental taxology and economics. The Fig. 7 ring shows inter connection of the right and left items in CiteSpace (Chen, 2016a).

4 Discussion

4.1 The drought and water level

Drought is a global climatic concern defined by drier-than-normal conditions that linger for days, months, or years. It has environmental, economic, and societal implications, such as wetlands, wildfires, biodiversity loss, and water supply interruption [60, 61]. Droughts are produced by geophysical causes as well as human activities, and their frequency is increasing as the climate warms. Droughts have an impact on groundwater, a valuable natural resource, and wetlands may become carbon sinks. Droughts and water scarcity are serious global concerns that impact climate change and people all over the world. Their relationship piques scientific curiosity [62, 63].

According to several studies, water is the biggest terrestrial organic carbon storage [64]. Water supply change has a substantial impact on the severity of the drought. Water level changes are fundamental to many aspects, including climate change, environmental balance, and the necessary conservation measures that have been better taken. Deep learning methods have become increasingly important for predicting drought and water levels using remote sensing satellite imagery [65, 66].

Unexpected warming or cooling of sea surface temperatures can induce a shift in air temperature, which can modify the position of the convection currents that generate weather patterns [67, 68]. Heat draws moisture from the earth, causing it to form clouds and fall back to earth as rain. If weather patterns vary sufficiently to create a dry region, there is not enough moisture in the soil to pull up into the air and form clouds. Droughts can result, affecting crops, water supply, stream water quality, recreation, hydropower generation, navigation, and forest resources [69].

Water parts are very vulnerable to hydrological change, particularly when other sources of disturbance like climate change, pollution, urbanization, and land use accentuate this change [70, 71].Water levels will always fluctuate since wetlands are frequently situated in an Eco-region where an aquatic and a terrestrial ecosystem coexist. In terms of environmental science and water resources, water is the most valuable. Unawareness of the possible ecological disasters that effects on some organisms may bring has impeded efforts [72].

This review paper data gathered information on ‘drought and water level’ from 2012 to 2022 using the Web of Science database at Nanjing University of Information Science and Technology. The data was analyzed using CiteSpace software to spot emerging themes and prospective trends. The study also used a research collaboration network and keyword co-occurrence analysis to count the number of publications published on drought and water level. The g-index approach was used to identify nodes, while burstiness was utilized to examine citation bursts and their impact. Co-citation networks for authors and articles were built using the Web of Science dataset, which improved network development.

It also reviews of prominent research institutes, as well as their publications and collaboration networks, demonstrates their academic concentration and strength. The Chinese Academy of Sciences (2012) received the most citations and degrees. Islamic Azad University works well with Chinese universities, with the Chinese Academy of Sciences being the most frequently mentioned. The author’s cooperation network graph had a low network density. The Gorges Dam cluster has the highest density of writers’ references. The results show gaps in current research areas such as declining water levels, hydrological alternatives, lake water management, and hazardous cyanobacteria.

4.2 Influential countries, institution authors, documents, keywords journals and dual-map overlay

This study used a variety of co-citation methodologies to investigate published articles to verify links and collaborations among countries, institutes, authors, journals, and keywords. The findings looked into how the number of authors, publication type, and journal choice affected the number of citations for “Drought and Water Level.” The most relevant variables were evaluated using generalized boosted regression tree (BRT) modelling and bibliometric network visualized [40]. The link between ‘Drought’ AND ‘water level’ and increase understanding in this subject. Moreover, show relevant research on the measurement and assessment of hydrologic models provides theoretical advice for countries to establish and improve frequency and co-operation of countries, institutions, authors, journals as well as accelerate the advancement of governmental and non-governmental organizations to show gap of study on these keywords [29]. This bibliographic review investigates the topic of "drought and water level" literature review. It emphasizes the significance of incorporating the complex interaction between Institution, countries, authors, references, and publishers [73].

We considered 742 works published between 2012 and 2022 in this study, with 9964 citing articles without self-citations, 9748 citing articles with self-citations, and 11,606 time of cited with self-citations. From 2012 through 2021, the number of papers produced each year increased steadily. The number of reference citations has more than doubled in the previous two years, from 2192 (2012) to 5821 (Fig. 1a). According to our data, China and the United States lead the world in terms of publication volume and citations. However, their articles in this subject are of insufficient quality (Table 2). whereas Switzerland, England, Greece, Germany, and Brazil emphasized the quality of publications. Many European countries’ periodicals and institutions were confident and had high degree in quality of articles [74]. For the last 10 years, environmental science and water resources researches have regularly accounted for more than 71% of total researches (Fig. 1b). Elsevier, Springer Nature, and MDPI were the top three publishers of works on drought and water levels. These publishers published around 58% of all articles on this topic (Fig. 1c).

The country's study revealed 81 clusters, biggest cluster of country nodes was water level management. China and USA were most cited (Fig. 2). China is the most often mentioned nation members of the water level management cluster, which is the biggest by nation. Estuaries are essential for preventing climate change, protecting the shore, sequestering carbon, and purifying water. They are particularly vulnerable to extreme river flows and the sea level rising brought on by climate change. Sea level rise would worsen estuary hydrodynamics, having an influence on water level, currents, and salinity, according to the Yangtze River Estuary simulation performed utilizing integrated modeling approach [75, 76]. Estuaries are crucial for climate change mitigation, coastal protection, water purification, and carbon sequestration. The paper ‘‘Integrated modeling analysis of estuarine responses to extreme hydrological events and sea-level rise’’ was ranked first by citation [77, 78]. Switzerland (2015) had the highest burst, 3.36, and was the most significant. Second-placed was England. Australia and Singapore now host this industry. Knowledge gaps were examined with regard to monitoring drought attribution and microbial necromass input to soil organic carbon clusters [27]. In the institutional clustering, the first cluster (Case study) comprises 24 members. Most cited papers included ‘‘Salinity changes in the southern Australian Coorong lagoon,’’ ‘‘macroecological patterns of adaptability deduced from a global, coordinated experiment,’’ and ‘‘Integrated modeling analysis of estuarine responses to intense hydrological events and sea-level rise.’’ The impact of decreased water levels on phytoplankton dynamics in tropical semi-arid shallow lakes is covered in these studies [79].

The first cluster with 136 members in the author citation is Gorge Dam, the biggest cluster. Most papers in the cluster that received the most citations were "decrease in fishery yields in response to hydrological alterations in the largest floodplain lake (Poyang Lake) in China," and Mosley, LM (2014), ‘‘acidification of lake water due to drought.’’ These are three papers that discuss the effects of water level reduction on the dynamics of phytoplankton functional groups in tropical semi-arid shallow lakes. It is also called the ‘‘biogeochemistry of Mediterranean wetlands.’’ It includes J Hydrol (302), Water Resource Research (223), Science (207), and Hydrobiologia (209). The most cited article was ‘Estimation of renewable energy and built environment-related variables using neural networks.

The number of papers produced and the research institution collaboration network are important markers of a research institute's academic concentration and overall strength [80]. According to the findings of institution-partnership research, there are gaps in network density and links that are indicative of the institute's academic emphasis and overall strength. This demonstrates that many institutions are not working with one another and have minimal interaction with one another (Fig. 3). The Chinese Academy of Sciences (2012) was the most cited item in this institution's publications, with 71 citations and 32 degrees, followed by the University of Chinese Academy of Sciences (2014), with 28 citations and 10 degrees (Table 3) [81]. United States Department of the Interior and United States Geological Survey are top-rank strength institutes in our topic (by 3.98 burst). Even if collaboration of institute in this topic is weak Chinese institutes and Islamic Azad University were most co-operated in the studies areas of temporal dynamic drought interaction, case study, and changing environment. There is now a deficit in institution partnership research on salinity variation, micro ecological patterns, and attribute investigations (Fig. 3A).

The authors' cooperation network graph depicts author connections. The network density of the author’s collaboration network graph was moderate while ACA network's modularity Q score was high because to its well-structured networks and clusters [82]. Author clusters shows the collaboration of writer at different field of studies. The most common writers were Zhang Q, (2012/14), R Core (2014) and Jeppesen E (2015) (Fig. 4a). whereas the top-ranked references with the most citation bursts were Guo H, Zhang Q, Zhang ZX, Jeppesen E, and the R Core Team [83, 84]. The frequent changes in the number of citations obtained within the time period specified indicated that writers' writings and ideas were becoming increasingly significant. Our analysis reveals gaps in current research areas such as declining water levels, hydrological alternatives, lake water management, and hazardous cyanobacteria (Fig. 4b). Cooker (2013) was ranked top by Bursts, followed by Allen R.G. Allen R. G. (2019) had the longest burst, which lasted 4 years (Tables 4).

Journals with the highest number of citations include Journal of Water, Hydrology, Hydrobiology, and Science of the Total Environment were top ranked. The network density was modest, and there were a handful of high-frequency keyword nodes. The modularity Q scores for the JCA network were 0.436, while the average silhouette score was 0.8297. Water resources, Hydrobiology, Ecology, and Freshwater Biology are some of the most cited journals (Fig. 5a) (Additional file 1: Table S1, S2, S3, S4, S5, S6, S7).

Results Found 384 nodes and 3422 linkage references to Citespace in the Nanjing University of Information Science and Technology Web of Science Core Collection Database on the topic of water level and drought. With a few high-frequency keyword nodes, the network density was medium. J Hydrol (2012) earned the most citations (302), while Nature (2012) received the greatest degree (344) in Poyang lake biggest claster (Fig. 5b; Tables 6) [85, 86].

The keyword climate change (139) and drought (129) highest citation keywords (Fig. 6a) while ‘restoration’ had the greatest impact in Yangtze river cluster, followed by ‘water quality’ in shallow Mediterranean cluster in terms of burst (4.61, 3.71 respectively) (Fig. 6b, Table 7). But. Furthermore, bibliographic coupling and citation networks exhibit a continental pattern [87].

George’s dam is the biggest cluster in document clustering. it has 136 members and a silhouette value of 0.833. The most cited paper is De Vicente I (2021), ‘‘Biogeochemistry of Mediterranean Wetlands’’ 302 J Hydrol, 223 Water Resource Res, 207 Sciences, 209 Hydrobiological, 167 Ecologies, 164 Freshwater Biology, 59 Drought Stress, 91 New Phytol, and 81 Plant Soil, are the most referenced members in this cluster. also reference cluster #0, designated as gorges dam, with 48 members. the most cited article being Rodrigues, E. (2018). Estimation of renewable energy and built environment-related variables using neural networks (Table 8) [88].

CiteSpace’s analytical tool gathers high-frequency keywords and conducts co-occurrence, clustering, and emerging word detection. This review considered topic clustering, distribution, breadth, and sub-clustering [89]. Keywords are used to identify topics, concepts, theories, techniques, and points of view in research. Gorges Dam has the most people, with 76 people and a silhouette value of 0.648. Drought Stress has a silhouette value of 0.728 and 67 persons. Keyword analysis identifies high-frequency phrases, summarizes, and enhances the literature in an effective manner. Reservoir (2019) has the longest burst time, followed by water quality, with a burst length of five years. Drought, climate change, and water level were all rated highly in 2012 (Tables 9) [90]. Keywords that currently has gap were shallow Mediterranean, species rich fen and drought stress (Fig. 6) [91].

Table 9 Most cluster of keywords analysis
Full size table

The dual-map overlay was created to provide a map of WoS and its links to other academic areas. The left and right base maps shared subjects such as molecular biology and genetics on the right and molecular biology and immunology on the left, suggesting that these areas were connected. Publications in important subjects such as ecology, earth science, marine science, molecular biology, immunology, veterinary medicine, and animal science may have an impact on studies in other fields [92,93,94].

5 Conclusion finding and recommendations

Using generalized boosted regression tree (BRT) modelling, the most essential variables were discovered and shown. Citespace is used in this bibliographic research to emphasize the need of understanding the complicated relationship between organizations, nations, writers, references, and publishers.

The yearly publishing volume of publications on ‘‘Drought and Water Level’’ climbed gradually from 2012 to 2021, with China and the United States placing first and second in terms of volume and citations, while Switzerland and England ranked top in quality respectively. Analyses of institutional collaboration indicated differences in network density and linkages, with the Chinese Academy of Sciences garnering the most citations and degrees. Collaboration research discovered network density and link gaps, suggesting the institute's academic focus and general strength. To increase comprehension of bursts of publications in various clusters, a document co-citation analysis (DCA) network was built. J Hydrol (2012) had the most citations (302), while Thesis (2016) received 10.97.

The keyword reservoir (2019), followed by water quality (2014) had the biggest influence by burst (4.61and 3.72) respectively, although the most cited phrases and highest degree used keywords were climate change(181) and drought (159). The document co-citation analysis (DCA) network was built to understand the frequency and amplitude of bursts of various publications in separate clusters. Guo H, Zhang Q, Zhang ZX, Jeppesen E, and the R Core Team were the top-ranked references in terms of citation bursts. CiteSpace acquired 384 nodes and 3422 linkages from the WoS core collection database of literary data. The most cited work was J Hydrol (2012), which garnered 302 citations, while Thesis (2016) received 10.97 citations.

The analytical tool from CiteSpace collects popular keywords and performs co-occurrence, grouping, and emerging word recognition. The highest silhouette value, 0.728 for Gorges Dam, is followed by Drought Stress. The most crucial word, reservoir (2019), has the longest burst duration and is followed by "water quality" which has a five-year burst period. The terms with a current study need include shallow Mediterranean, species-rich fen, and drought stress. Wu W. (2021) writings on China are the most popular, having the most mentions of any country. Estuaries are essential for preventing climate change, protecting the shore, sequestering carbon, and purifying water.

Using several co-citation methodologies, this study examined published publications on ‘‘Drought and water level’’ between 2012 and 2022. In terms of publication volume and citations, China and the United States were the top two countries. CiteSpace’s analytical tool was used to analyzed the frequency and amplitude of bursts from distinct publications in discrete clusters. The most referenced article had 302 citations, with the most often used phrases being climate change and drought. After Gorges Dam, the cluster with the biggest population was drought stress.

The use of keywords might improve and simplify text. The dual-map overlay highlights the relationships between WoS and other academic fields while highlighting how ecological, earth, marine, molecular, and immunological sciences have an impact on other fields. In terms of citations, bursts, and frequency, the paper emphasizes the significance of article clusters, authors, publications, journals, and keywords. The importance of "drought and water level" model papers should be discussed in future research, and article methodologies should be improved.

6 Finding

The quality and collaboration of articles on drought and water levels have changed over the past 10 years due to variations in research intensity and burst among countries, regions, institutions, study subjects, keywords, authors, journals, affiliations, and titles. Switzerland ranked top in terms of research strength and burst, whereas China and the United States were in first and second place in terms of publishing. Case studies, temporal dynamics, drought interpretation, gorge dams, survey recovery, and water level management are some of the hot issues in environmental science right now.

Salinity variation attribute study macro ecological processes hydrological drought, water level change, hydrologic modelling, and soil moisture call for more focused future research subjects as well as international cooperation between authors, institutions, and nations. Phytoplankton, temperature, wetland, time series, diversity, and carbon dioxide are a few of the most important words looked at. The phrases ‘‘climate change’’ and ‘‘water level’’ were often used, along with ‘‘gaps in biological teratology’’, ‘‘salinity changes’’, ‘‘shallow lakes’’, ‘‘lake water’’ and ‘‘attribution’’.

Zhang Q. (2012), the R Core team (2014), and Jappen E. (2015) were the top three contributions in terms of citations, references, and academic impact. In terms of frequency, Allen, R.G. (2013) and Cook, ER (2013) were placed first and second, respectively. The most often used terms were found to be ‘‘water quality’’ and ‘‘restoration’’ however other phrases like ‘‘climate change’’, ‘‘drought’’, ‘‘growth ’’ and ‘‘dynamic’’ were also regularly utilized.

6.1 Recommendations

Significant knowledge gaps are identified in the areas of microbiological dynamics, environmental factors, fen peat incubation, lake water, drought risk reduction, watershed management, biological ecology, lake acidification, salinity changes, and attribution control mechanisms in this study. Future academicians should concentrate on these and similar topics, while Chinese and American authors should concentrate on their talents rather than their publishing numbers.