The Paradigm Shift in Scientific Interest on Flood Risk: From Hydraulic Analysis to Integrated Land Use Planning Approaches

Abstract

Floods are natural hazards that have the greatest socioeconomic impact worldwide, given that 23% of the global population live in urban areas at risk of flooding. In this field of research, the analysis of flood risk has traditionally been studied based mainly on approaches specific to civil engineering such as hydraulics and hydrology. However, these patterns of approaching the problem in research seem to be changing in recent years. During the last few years, a growing trend has been observed towards the use of methodology-based approaches oriented towards urban planning and land use management. In this context, this study analyzes the evolution of these research patterns in the field by developing a bibliometric meta-analysis of 2694 scientific publications on this topic published in recent decades. Evaluating keyword co-occurrence using VOSviewer software version 1.6.20, we analyzed how phenomena such as climate change have modified the way of addressing the study of this problem, giving growing weight to the use of integrated approaches improving territorial planning or implementing adaptive strategies, as opposed to the more traditional vision of previous decades, which only focused on the construction of hydraulic infrastructures for flood control.

1. Introduction

Floods are the most frequent natural hazards that result in the greatest socioeconomic impact worldwide. In the first two decades of this century, an average of 163 high-impact urban floods have been recorded globally per year, affecting some 172 countries across all continents [1,2,3]. Currently, around 1800 million people—23% of the world’s population—live in areas at risk of flooding, whether of fluvial, pluvial, or coastal origin, due to rising sea levels [4].

In the UN Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), both Working Group I [5] and Working Group II [6] confirmed what previous reports had already indicated [7]: climate change means that floods are expected to become more severe as a result of the increase in the frequency of extreme rainfall events. In fact, while 1389 significant floods were recorded in the 1980s, their number reached 3254 in the last decade [1].

Flood-related problems are amplified in urban environments. An ever-increasing proportion of the world’s population is concentrated in large cities [8]; it is expected that one-third of the world’s population will live in cities of more than half a million inhabitants by 2030 [9]. According to the UN, in 2007, the world’s population was roughly divided 50/50 between urban and rural areas; by 2021, 56.6% lived in urban settings, and it is estimated that 68% of the global population will reside in urban agglomerations by 2050 [10]. This trend towards the growth of large cities and urbanized areas makes the increasing impact of flood-related disasters inevitable. However, as the UN itself indicates in its recent reports [8], in reality, ‘natural disasters’ do not exist [11].

While many hazards cannot be prevented, disasters can be. Earthquakes, droughts, floods, storms, landslides and volcanic eruptions are natural hazards. They lead to deaths and great economic damage because of what humans do or fail to do rather than an act of nature [12]. Many disasters actually result from the combination of natural hazards and social and human vulnerability, including development activities that are ignorant of local hazardous conditions [13] or that hide legal and administrative problems [14].

The growing urban development of cities, both in urban and surrounding periurban areas associated with sprawl phenomena, affects water infiltration into the ground through what is known as the ‘sealing effect’, whereby large surfaces are impermeabilized, increasing runoff and worsening flood-related impacts [15]. It is estimated that a 1% increase in impervious surfaces in a basin increases the annual flood magnitude by 3.3% [16], or even by 5%, according to Kaspersen [17] in a study of some European cities.

This phenomenon is especially complex to gauge in dispersed urban environments or in areas partially anthropized by human beings, in what are called ‘diffuse territorial anthropization’ phenomena. In this context, urban planning and land use management approaches can be highly effective tools to reduce urban vulnerability to floods and also to mitigate their effects, as highlighted by various authors [15,18,19,20].

This has led to a change in trend in a large part of the research ecosystem on this subject, modifying the patterns of approach to this phenomenon in recent years. This issue has been the subject of debate in the scientific community in recent years, with researchers maintaining the need to address the problem from the pre-eminence of civil engineering solutions over others who are committed to an approach more based on urban planning and territorial management, with a varied scale of gray in the scientific ecosystem at the level of opinions. Furthermore, relevant studies recognize the effectiveness of an integrated approach to mitigate/prevent flood events: both civil engineering solutions and sound urban planning and territorial management should be adopted synergically to address flood mitigation and prevention [21,22].

Even so, in this debate, there is a trend of change that is clearly appreciable at the qualitative level, but about which there is not so much information at the quantitative level. This makes it necessary to study how this phenomenon has evolved from the perspective of a review article on the state of the art on the subject, addressing it in all its theoretical and practical breadth.

To discuss this issue, a bibliometric meta-analysis was conducted to assess the scientific relevance of studying the relationship between urban planning and flood vulnerability and to estimate how and since when the scientific community has paid attention to the different aspects involved. This meta-analysis will focus on the existing scientific literature in this specific field, paying special attention to its historical evolution and how the technological development of new tools such as remote sensing and GISs have methodologically affected these studies. The emergence of new phenomena such as the current meteorological derivatives of climate change and the improvements in operational approaches such as nature-based solutions will also be addressed, since they have had a relevant impact on the proposal of possible solutions.

2. Methodological Approach for Analysis

A literature review on the subject was conducted in January 2025 using the Scopus database. The search formula used the terms “urban planning” AND “flood”, with the search executed across titles, abstracts, and keywords. A total of 2694 documents were retrieved, dating from 1970, most of which were journal articles. This sample was the result of cleaning a previous sample of more than 3000 documents, after subjecting the initial sample to a pre-screening operation. In this initial operation, publications of journals that had nothing to do with the area of knowledge addressed or whose inclusion was the result of the partial conjunction of the random appearance in the title, abstract or keywords of these words in contexts unrelated to the researched one were discarded (this part was performed manually, looking mainly for anomalous results from journals and serial publications that did not usually deal with the subject studied).

The first stages of sample cleaning were performed with automated processes, and the final screenings were performed more manually. Finally, 2280 records were used for the meta-analysis. A PRISMA flow diagram for bibliographic reviews which included searches of databases is provided in Figure 1 to summarize the process.

As can be seen in the figure, for the last step, in which 2694 analysis elements were changed to the 2280 finally entered into the software, more than 400 documents were deleted in a final manual review. In this last revision, some documents were eliminated: although they in theory met all the requirements at the formal level, after reading, it was found that the topic of flooding (or land use planning in this context) was rather not relevant. The “other reasons” discarding criterion included various minor reasons, generally related to issues detected after a manual review in which problems were sometimes observed such as that the publication was not really a scientific article or that the content was not exactly relevant to the subject of this study despite the fact that it included related keywords, duplications that had not been detected in the previous stages, etc.

As will be detailed later in the scientific discussion section, the methodological approach used has some limitations in the field of bibliometric analysis derived from the use of the Scopus database, which, although it is a single database, currently has more than 90 million records and a very heterogeneous historical background of more than 50 years. These limitations have been addressed in a simplified way from a methodological point of view, with the aim of not distorting the main purpose of this review. This qualitative and prospective approach to the work carried out is applied to focus the purpose of the article on opening an intellectual and scientific discussion on the phenomenon studied, beyond technical issues of a bibliometric nature.

On the other hand, to address the analysis of the inter-relation of scientific concepts and the development of relational maps, the VOSviewer software was used for data processing, analysis, and visualization. Scientific activity was characterized through relevance, co-occurrence, and keyword temporality analyses. The selected data included “citation information”, “bibliographical information”, and “abstract and keywords”. Additionally, it was required that both search terms (“urban planning” and “flood”) co-occurred at least 15 times in the analyzed documents; this value is considered as a reasonable approximation based on the observation of methodologically similar studies on other topics. This relatively high threshold was set to ensure that only documents thoroughly focused on the subject were considered, whilst those that only tangentially mentioned it or addressed a wide range of natural hazards or urban planning-related topics were excluded.

Following this methodological framework, graphical models were generated in which each node (keyword) represented a random variable, and the lines linking the nodes represented causal relationships [23,24].

3. Retrospective Analysis

As shown in Figure 2, from around 2010 onward, there was a clear sustained increase in the number of publications (mainly journal papers) addressing the relationship between urban planning and flood risk.

This increase suggests that although the topic attracts considerable scientific interest today, this interest is only relatively recent. A reasonable hypothesis in this regard about the cause of this phenomenon could obviously be the increase in the number of publications or different journals that has occurred in the scientific field in recent years. On this issue, it should be noted that, although it is possible that it may have some influence at the numerical level, the patterns of the temporal distribution of the growth of publications per year and the temporal distribution patterns of the number of journals in Scopus do not follow inertia similar to that observed for the phenomenon we study (see Figure 3).

Another important issue, which will surely have an influence in Europe, is possibly the approval in 2007 of the EU Flood Directive (2007/60/EC) [25], which encouraged studies with this approach despite the fact that the directive itself indicates in its own wording that there are previous studies and experiences collected in the last 2–3 decades that justify this regulatory approach. These issues, together with the fact that the analysis sample is focused on a single database such as Scopus, could be interpreted as a limitation of the study carried out. However, it is considered that the results obtained are sufficiently robust to introduce a debate on the topic, since they represent a large homogeneous sample and highlight some clear patterns of behavior at the numerical level.

Similarly, from 2010 (this date is not an exact point of change in inertia but rather the approximate beginning of the current phase of sustained growth; Figure 4), articles started appearing primarily in journals focused on sustainability, environmental issues, or urban planning, such as Sustainability, Water, Landscape and Urban Planning, and IOP Conference Series: Earth and Environmental Science. Before that time, the primary sources were journals such as the Journal of Hydrology, Water Resources Management, the ASCE Journal of Water Resources Planning & Management and Water Resources Research, indicating a more hydraulic and hydrological focus in earlier publications (see in Figure 4 the historical evolution of this type of publication on the eight journals that have the largest number of articles on the subject).

Below, various analyses will be presented that lead us to think that we are possibly facing a double phenomenon: On the one hand, it is true that, in recent years, numerous research journals have appeared that address the problem of flooding from a more multidisciplinary perspective (this issue being also possibly influenced by the proliferation of open access journals). On the other hand, it is also observed that journals that addressed this topic only from a more traditional perspective, only focused on fields of civil engineering such as public engineering and hydrology, have been progressively opening up to incorporate other approaches such as territorial planning and urban planning.

The co-occurrence analysis (Figure 5), which linked and clustered the main keywords used in the analyzed documents, revealed three main thematic axes: urban planning (the red cluster), floods (the green cluster), and urbanization (the blue cluster). Notably significant terms (based on node size) include the following:

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In the red cluster, flood control, water management, urban runoff, drainage network, watersheds, storm water, and hydrology.

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In the green cluster, land use, risk assessment, flood risk management, flood damage, vulnerability, hazards, and mapping.

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In the blue cluster, climate change, flooding, sustainability, economic and social effects, resilience, adaptation, green infrastructure, cities, and urban design.

Nevertheless, the more interesting thing about these figures is not simply about corroborating the current positive bibliometric relationship between urban planning and flooding but being able to analyze the spatial distribution of the ecosystem of concepts that exists in this topic, characterizing their levels of intensity. It is particularly noteworthy that topics in the blue cluster related to climate change—such as integrated flood management, risk evaluation, adaptation strategies, resilience and sustainability, nature-based solutions, and environmental policies—carry significant weight in publications discussing the relationship between flooding and urban planning (Figure 4). However, as seen in Figure 5, these topics have only recently begun to receive attention (yellow and light green nodes), which is in contrast to earlier studies that focused on watershed-related aspects, hydrology, hydraulic and hydrological modeling, runoff, or drainage (dark green and red nodes).

In fact, these terms appear among the most relevant in the bibliometric density map produced by the meta-analysis, shown in the red and yellow zones in Figure 6, which represent the highest and intermediate densities, respectively. Supporting this, it should be noted that two of the five most cited articles in the dataset were published relatively recently and address topics related to urban adaptation to climate change (with over 650 citations) [26] and the impacts of urbanization and climate change on flood risk (with over 460 citations) [27], the first corresponding to a rather generalist journal on the environment and the second to a journal specifically oriented to hydrology, both being located in the first positions of the impact indexes of their thematic areas.

An equally interesting issue is to look at the border areas between the various main categories. A relevant point in this is the level of intensity of connection creation of the green category regarding flood risk strategies in relation to the other two categories, red and blue. A higher level of intensity is observed in the generation of links with adaptive approaches or those that are associated with the management of the territory to make it more resilient compared to the more traditional approaches of generating flood mitigation infrastructures. On the other hand, a lower level of interconnection between these two second categories is also observed, which may reveal the existence of a certain deficit of integrative visions of these two fields in the scientific literature (Figure 7).

The importance of these aspects is additionally reflected in the fact that recent literature reviews, including those focused on sustainable approaches to urban flood risk management [2,28,29,30], urban flood risk assessment [3,31], urban resilience to floods [32,33,34], nature-based solutions, green infrastructure, and other urban implementation strategies to mitigate flood impacts in cities [33,35,36,37,38,39,40,41,42], urban adaptation to climate change [24,43,44,45], and the socioeconomic implications of protection measures against urban floods [46], have extensively addressed them.

Although this bibliographic review on the subject cannot be considered comprehensive because Scopus is a database limited to serial publications with an impact index, it can be established reliably that the evolution in flood analysis within the research field of urban planning reveals a significant paradigm shift that began around 2010, as seen by the increased scientific interest in urban planning aspects, rather than purely hydraulic or hydrological ones. In 1927, the flooding of the Mississippi River affected over 70,000 km² across ten U.S. states, resulting in more than 500 deaths and damages totaling approximately USD 10 billion (figure-to-current cost), and impacted over 600,000 people [47]. This disaster sparked interest in flood prevention and control in the United States [48] and in the challenges posed by urban and industrial development in flood-prone areas [49]. A key publication that marked a turning point in flood research was the book Human Adjustment to Floods by Gilbert F. White in 1945 [50]. This pioneering work examined how urban development decisions in flood-prone areas contributed to increased socioeconomic losses, despite the improved control and awareness of flood hazards [51]; this paradox was also highlighted decades later by Burby and French in the 1980s [52].

The UK was also at the forefront on the topic, with events/studies and publications that contributed to forming the early scientific literature on urban flood risk during the 1960s and 1970s, such as the book Liable to Floods: Village Landscape on the Edge of the Fens A D 450–1850 by J. R. Ravensdale [53]. Some of them note many historical examples of deaths arising from extreme rates of increase, especially when associated with severe peak flows such as at Lynmouth in 1952, deeply studied by Dobbie and Wolf [54].

However, during those years, only very few publications approached the issue from the urban planning perspective. Most research focused on improving hydrological models and hazard control through hydraulic infrastructure. Nevertheless, some authors did highlight the negative impacts of poorly planned urban development on flood severity, such as increased peak flows due to deforestation, vegetation removal, ground leveling, and surface impermeabilization [55]. Similar conclusions were drawn by Siler [56], who suggested that urban planning programs were an excellent solution to flooding issues, and also Leopold [57], who emphasized that territorial planning should be based on proper hydrological analysis that considers the effects of land urbanization.

This approach remained dominant through the end of the 20th century. For example, in the more than 800 pages of the two-volume book Floods, edited by Dennis J. Parker and featuring contributions from over 60 authors, planning approaches are referred to very sparingly [58]. Only one chapter is specifically dedicated to territorial planning as a method to reduce adverse flood impacts [59], with the author highlighting that local government planning efforts have proven to be an effective way to reduce flood-related losses in populated areas.

At the turn of the 21st century, some authors began to argue that urban planning was essential for preventing and mitigating flood-related problems in cities and urban environments and advocated for a stronger integration of flood risk considerations into urban development strategies [60,61,62]. According to Lu and Ran [63], poor urban planning was the main cause of the devastating impacts of floods in China, a conclusion also drawn by Pérez-Morales [64] regarding several municipalities in Spain.

In other cases, the rapid and unplanned expansion of metropolitan areas surrounding large cities has encroached on increasingly flood-prone land, such as in the Bangkok metropolitan region [65]. In more extreme scenarios, the total absence of planning in impoverished informal settlements surrounding large cities has been a source of severe flood-related problems [66,67]. Similarly, floods have posed major challenges in very poor and vulnerable populations lacking the capacity for local planning [68].

As illustrated in Figure 2, the number of publications addressing certain aspects of the relationship between flooding and urban planning has steadily increased since 2010, reflecting growing scientific and technical interest in the topic. One of the key areas receiving greater attention concerns the need to adapt land use planning processes to climate change phenomena in contrast to earlier publications that focused more on mitigating its consequences rather than adapting planning itself (Figure 5). A review of more than 150 publications conducted by Dhar and Khirfan highlighted this trend [69].

For instance, a study by Rahaman [70] involving interviews with urban planning stakeholders from six Canadian municipalities and five European ones concluded that research should be directed toward adapting land use planning processes to climate change; a transition that should be implemented as quickly as possible. Similarly, other authors [71,72], after analyzing the potential economic impacts of climate change in urban areas, also emphasized the urgency of adapting the urban design of cities.

In China, Yang et al. [73] highlighted the need to innovate in urban development planning systems to better suit a reality in which floods were already frequent and were likely to continue to become more so. Comparable conclusions were drawn for a municipality in Victoria, Australia [74], and for Dutch cities [75]. Tennekes et al. [76] also studied how institutional responsibilities and costs for implementing adaptation measures should be distributed.

However, Hetz and Bruns [77] were skeptical about whether the full potential of planning is being utilized to counter rising flood risks driven by climate change, citing the disorganized urban sprawl in Johannesburg that disregarded existing planning frameworks. Likewise, Sciulli et al. [78], in a study in which municipal officials from seven Italian towns were interviewed regarding the factors that supported or hindered urban flood resilience, found pre-existing poor planning to be the main obstacle. This contrasts sharply with the increasing social and institutional demand for cities to adapt to current and future natural hazards, as noted by Porta-Sancho et al. [79] in the case of Spain.

Increasingly sophisticated tools are being developed to identify and quantify the factors influencing flood risk [80] to improve urban planning and make cities and other human settlements less susceptible to flooding—and more resilient to its impacts—with numerous studies devoted to this subject throughout the 2010s. Dynamic GIS-based models for analyzing the effects of flash floods caused by torrential rainfall have been widely proposed as essential instruments for land management and urban planning [81,82,83].

The continuous improvement of GIS tools and Digital Elevation Models has marked a major advance in zoning for planning purposes [84]. The development of mixed two- and three-dimensional GIS technologies has enabled more realistic representations of urban scenarios [85,86]; these are extremely useful for enhancing urban design. In turn, remote sensing models offer more accurate estimates of flood damage, which is fundamental for optimizing investments in flood risk management in large areas all over the planet [87]. Cano [88] also used advanced GIS approaches through geostatistics to integrate disaster evacuation routes into urban planning, considering walking speeds based on terrain slope and other physical characteristics. These 3D models have been further refined using AI algorithms and advancements in remote sensing, such as LIDAR (Light Detection and Ranging) technology, which provides highly accurate three-dimensional data of the Earth’s surface, enabling more detailed planning [81,89].

In this context, the use of high-resolution maps that integrate flood risk and heat stress—a phenomenon increasingly prevalent in many cities worldwide—has proven to be an effective tool for urban planning decisions [90]. A study conducted in Taiwan, Thailand, and the Netherlands demonstrated its usefulness in identifying the areas that are most vulnerable to climate change and highlighted the effectiveness of parks and shaded green areas in jointly mitigating both issues [91].

Similarly, the use of high-resolution satellite imagery provides essential, up-to-date information for effective urban management and planning. For example, De Pinho et al. [92] used images from the IKONOS II satellite to assess and classify land occupation by favelas in planning flood prevention strategies. Furthermore, researchers analyzed the projected urban expansion of São Paulo up to the year 2030 using Landsat TM 7 satellite images and ArcGIS Pro geoprocess predictive tools and estimated that over 4% (800 km²) of new development would occur in flood-prone areas [67]. Patel and Srivastava [93] also used high-resolution satellite imagery and a GIS to produce flood hazard zoning maps for incorporation into the city planning framework of Gujarat, India.

On the other hand, the development of increasingly accurate mathematical models in the field of land use planning has enabled urban planning to be more precisely tailored to future flood hazard projections. Integrated hydrological/hydraulic and urban sprawl models have been refined [94,95] and used, for example, to study the role of impervious surfaces in flood processes, confirming their significant impact. Reduced infiltration leads to increased runoff and consequently greater flood damage [96,97], which is a critical insight for guiding both urban planning and flood management [98,99]. The use of Internet of Things technologies and big data also provides a continuous interesting stream of information to feed these models, which, according to Rathore et al. [100], will make them indispensable tools for urban planning in the future.

4. Discussion of Current Situation

Focusing on recent years, it can be seen that many countries are located in the most worrisome areas of the five continents in which case studies have been carried out on the relationship between urban planning and flooding. In Africa, these studies cover Egypt [31], Ghana [101], Nigeria [102], and some sub-Saharan African countries [36]. In the Americas, the most relevant case studies are cited in Brazil [103,104], Canada [105] and the United States [106,107]. Likewise, an interesting recent study has been carried out in Australia [108]. Asia will probably be the continent that suffers this phenomenon most in the forthcoming decades because of climate change, with China [37,109,110], India [111,112], Iran [113,114], Iraq [115], Japan [30,116], Korea [117], Malaysia [118], Oman [119], and Sri Lanka [18] being some of the most affected countries today. In Europe, the large rate of urbanization of its land, established centuries on rivers or urban wadis, means that we find a varied catalog of places at risk in many countries, such as Denmark [17], France [120], Germany [121], the Netherlands [122], Poland [123], Spain [15,124,125], and the United Kingdom [126], and it is especially relevant in several countries of the Mediterranean arc due to various phenomena associated with climate change [127].

Nonetheless, it must be stressed that this is a planetary phenomenon that will ultimately affect all countries all over the world to a greater or lesser extent and that cases can even be found in mostly desert or highly depopulated countries such as Australia [19] in Oceania. Most of these studies stress that their results are useful for urban planning and that land use management may be the most viable measure for flood risk reduction since structural civil engineering measures such as dams or hydraulic channels are either too costly for poor economies, have unacceptable environmental implications, or may have unexpected derivatives causing several kinds of future complications [28,128].

Finally, we must not forget the derivatives that exist in this problem in coastal areas, which sometimes do not share the same patterns of behavior as in the previous cases. For coastal flooding, the publications mainly address aspects related to urban adaptation to climate change because of rising sea levels [127,129] and that the measures used should mitigate its effects [6,130]. The effects of rising sea levels will have a great impact on many coastal cities around the world, which, as they also have river environments in their territory, will force them to adopt composite approaches to address this problem [18].

Storm floods are currently being given the most attention compared to the previous ones since they generate the greatest socioeconomic risk in urban areas and they are, due to their very nature, more difficult to forecast and monitor, according to Schanze [131]. However, we must not lose sight of the growing impacts in this area associated with phenomena derived from the rise in sea levels. This will make it necessary to study new mixed different models, depending on precipitation intensity, to assess their flood risk in a way that is useful for urban planning [132].

The urban growth of cities that has occurred in recent decades, and that will continue to occur in the coming decades, combined with the greater tendency towards extreme events caused by climate change, will cause this problem to become increasingly pressing in the coming years. This issue has already become salient in many of the developed countries, where numerous strategic regulatory frameworks have been introduced in the field of urban planning to manage flood risk (see, for example, Directive 2007/60/EC of the European Parliament and of the Council of 23 October 2007 on the assessment and management of flood risks that has already been transposed in most countries of the European Union [25]).

Other regions of the world also have regulations on flood zone management. In Asia, flood zone management varies significantly between countries, reflecting different approaches and levels of institutional development. China has developed, during last decade, a provincial-level flood risk zoning system, classifying regions according to flood risk and intensity indices to guide territorial planning and emergency management [133]. Japan has adopted a flood risk management strategy that combines structural and non-structural measures. The Flood Control Act, amended in 2005, assigns responsibilities to municipal governments to designate flood risk areas and develop integrated watershed management plans [134].

Other countries such as India or Vietnam have tried to develop regulatory frameworks without them being fully implemented. In the case of India, it has guidelines for floodplain zoning issued by the National Disaster Management Authority (NDMA), which seek to regulate land use in flood-prone areas. However, their implementation has been limited due to the lack of enforcement mechanisms and clear demarcation of zones [135]. Vietnam has enacted laws such as the Natural Disaster Prevention and Mitigation Act that establish frameworks for flood management and national strategy planning. However, their effective implementation has been hampered by constraints on the country’s finances and the government’s institutional capacity to act [136].

The American continent also presents a heterogeneous situation regarding the level of development of the regulatory framework for this problem. Flood zone management regulations vary significantly between countries, depending on factors such as geography, the frequency of extreme weather events, and institutional and socioeconomic development. In the United States, for example, flood zone management is highly institutionalized. The Federal Emergency Management Agency (FEMA) is leading these efforts through the National Flood Insurance Program (NFIP), which not only provides insurance to affected communities but also imposes strict land use regulations. Through FIRMs (Flood Insurance Rate Maps), risk areas are identified and classified, allowing local authorities to establish regulations that regulate construction in vulnerable areas [137]. In Latin America, the case of Colombia stands out, with legislation being quite advanced in terms of the integration of risk in territorial planning. Law 388 of 1997 requires municipalities to incorporate risk management into their Land Use Plans (POT), while Decree 1807 of 2014 reinforces this obligation. The Institute of Hydrology, Meteorology and Environmental Studies (IDEAM) produces detailed flood hazard maps, which serve as a basis for decision-making at the local level [138].

However, in many developing countries in Asia, Africa and Latin America, which are currently some of those in which the highest rate of accelerated urbanization is taking place on the planet, this debate is not even on the table, given that the country’s socioeconomic priorities are other more pressing. Even in the developed countries themselves, debates on this issue take place in crisis situations that do not lead to prioritizing scientific knowledge in this area over economic needs (see, for example, what happened recently in Spain, where after heavy flooding in various peripheral towns in the south of the metropolitan area of the city of Valencia, that ended the lives of more than 220 people who lived in areas declared floodable almost 20 years ago [139] but built some decades earlier, the administrations finally decided to repair and rebuild in the same areas in view of the economic difficulties of relocating the homes of all these populations to other safer areas and the social urgency to relocate those affected by the catastrophe; Figure 8).

In this regard, a calm reflection based on technical and scientific criteria on the limitations and possibilities of action that are also available at the social, economic and political level on these matters is also necessary. Urban planning and improvement in land management cannot be a magic solution to all these problems, but it is surely the most sustainable and viable solution for the future. Nor is it realistic to expect that tools such as nature-based solutions, more oriented towards ecological sustainability than risk reduction, will replace large civil engineering infrastructures against floods. In this context, a very interesting case is, for example, the expectations that are sometimes generated around the role of Sustainable Urban Drainage Systems (SUDSs) to mitigate flood risks related to urbanization. In Myanmar, they are proposed as instruments that may be key for the future in the mitigation of these phenomena, but studies limit their effectiveness to return periods of 10 years [140]. Other studies carried out as a review of the state of the art for the application of these technologies in prestigious publications highlight, for example, that research attention on technical performance indicates a continuing need for evidence of the effectiveness of SUDSs in this field [141].

However, a broad and multidisciplinary vision that introduces the urban variable with greater weight and combines it more effectively with the execution of flood lamination infrastructures is increasingly necessary. This will force the use of even more hybrid approaches to address the issue from a more comprehensive perspective in the future. Scientific knowledge and the use of new technologies must be the cornerstone on which to build a new model to address this problem. In this sense, there are already numerous studies that face this new approach in a very hopeful way. The aspects most frequently stressed in recent publications are those related to the greater exposure resulting from climate change derivatives [24,142,143,144] and the predicted risks of the urbanization of flood zones [30,145,146,147,148,149], combined with those related to risk mapping and AI event simulation [143,150,151], including more new sustainable approaches referring to comprehensive mitigation strategies through nature-based solutions combined with traditional approaches of civil engineering, but which are supported by new formulas called ‘soft infrastructures’ [35,36,37,152,153,154].

Finally, another issue that should be paid attention to is the subsequent monitoring of the effectiveness and efficiency of the measures implemented at the urban or territorial level, so that they do not remain pure theoretical frameworks, especially in the development of adaptive strategies for mitigating damage in the current context of climate change. An integrated approach combining traditional structures and nature-based solutions should be pursued, paying particular attention to the individual and cumulative effects of these practices in flood mitigation and prevention. This would give an answer to the practical problem of the phasing of construction due to cost constraints or scheduling interventions to fit in with climate change projections. On this question, more emphasis should be placed on the assessment of the performance of adaptive measures and actions for damage mitigation on issues such as the ventilation planning of cities, which are an important component of flood drainage systems, considering physical, socioeconomic and institutional settings [155,156,157].

5. Conclusions and Future Lines of Research

5.1. Main Findings

This study reveals a clear evolution in the way flood risk in urban areas is conceptualized and approached. The field was historically rooted in hydrological and hydraulic perspectives of civil engineering (watersheds, dams, infrastructure, hydro-forestry interventions, drainage, mathematical models, etc.) but has undergone a significant paradigm in recent years, with urban planning and land use management becoming increasingly recognized as a central component in flood risk reduction. This change has been driven by growing problems linked to the accelerated sprawl of urban areas and the urgency of climate change derivatives, expressed in the socioeconomic impacts of more frequent and severe flood events. In this field, this study has shown quantitatively some interesting and specific issues:

(1)

The bibliometric meta-analysis carried out highlights a surge in academic research since 2010 approximately (this date is not an exact point of change in inertia but rather the approximate beginning of the current phase of sustained growth), with co-occurrence clustered search results showing a diversification of publication sources, which reflects a much broader, interdisciplinary understanding of flood risk. Research today emphasizes integrated, adaptive planning strategies that account for the dynamic relationship between urban growth phenomena and flood vulnerability.

(2)

Three main thematic clusters have emerged—hydrological control, urban development, and climate-related adaptation—with an increasing focus on sustainability, resilience, and nature-based solutions. These topics demonstrate a shift away from reactive flood mitigation toward proactive risk reduction embedded within urban planning frameworks. Advanced technological tools, including GISs, remote sensing, and urban design based on hydrological modeling, are now essential in urban flood risk analysis. These technologies enhance decision-making, improve hazard mapping, and enable more accurate scenario simulations, thus supporting better-informed planning practices.

(3)

Case studies from around the world illustrate the current global relevance of this issue. Many show that poorly planned or unregulated urban expansion significantly increases flood risk, particularly in vulnerable and rapidly urbanizing regions. In contrast, well-implemented planning policies can greatly reduce exposure and damage, even in areas of high vulnerability. The integration of flood risk assessment into city planning processes is increasingly viewed not only as an environmental necessity but as a social and economic imperative. In particular, storm flooding in urban areas has emerged as the most critical concern due to its increasing frequency and unpredictability because of climate change derivatives.

5.2. Future Lines of Research

Even so, it should be noted that, despite these advances, challenges remain in mainstreaming flood risk into planning policies, particularly in low-income regions or where institutional frameworks are weak. Adaptation strategies must be supported by strong governance, adequate funding, and public engagement.

Ultimately, the findings underscore the need to continue shifting away from merely civil engineering hard infrastructure solutions to take on comprehensive approaches and models that also incorporate urban planning and territorial management as a key variable. This should also include prioritizing climate adaptation, risk-informed land use, and resilient cities design. Strengthening this nexus between urban planning and flood risk management offers a path toward more sustainable and safer cities in an era of increasing environmental uncertainty. On this issue, this work does not start from dogmatic positions and raises the need to develop new balanced work models that implement hybrid and multidisciplinary frameworks for the risk analysis and evaluation of alternatives.

In this sense, it will be important that these new approaches are able to differentiate the different boundary conditions offered by the areas already built from the areas pending urbanization when addressing the problem. It will also be necessary to realistically address the different debates involved in making decisions about how to develop or build in areas with a greater or smaller risk of flooding since risk, after all, is still a statistical concept. In planned but currently undeveloped areas, or those with dispersed urbanization boundary conditions but with a certain risk of flooding, the variable of urban planning and the improvement of large-scale territorial land use management should be the key factor and be deeply supported by scientific knowledge. In addition, it is possible that in many of these cases, there are not sufficiently effective alternatives from the point of view of infrastructures or they are economically unviable because they do not pass the cost–benefit analyses required by public works.

However, in contexts in which we find areas currently declared floodable thanks to the numerous assessment tools that new spatial analysis technologies have provided us with in recent years, the debate is much more complex. In these cases, the importance of other social, legal or even political variables should also be considered, and in these cases, the need to implement flood lamination infrastructures based on traditional civil engineering approaches cannot be ignored.