Exploring human-induced flood risks and sustainable urban resilience in Iwo Nigeria with focus on awareness drivers and mitigation pathways

Abstract

Urban flooding remains a persistent challenge in many cities in developing countries, often intensified by anthropogenic activities such as poor waste disposal, encroachment on waterways, and inadequate drainage maintenance. These practices undermine urban resilience and threaten progress towards Sustainable Development Goal 11 (SDG 11), which promotes sustainable and resilient cities and communities. Although existing studies largely emphasise the physical and infrastructural drivers of flooding, relatively little attention has been given to how residents’ awareness, perceptions, and everyday practices interact to influence urban flood vulnerability, particularly in medium-sized cities. Addressing this gap, this study investigates the determinants of residents’ awareness of flood risk, examines community perceptions of anthropogenic drivers of flooding, and identifies sustainable pathways for enhancing urban flood resilience in Iwo, Nigeria. By integrating behavioural and environmental perspectives, the study contributes to the growing discourse on community-centred approaches to flood risk management. Primary data were collected through household surveys and analysed using descriptive statistics, factor analysis (FA), and principal component analysis (PCA). The findings reveal that flood risk awareness is strongly associated with recognition of harmful environmental practices (0.891), knowledge of simple household preventive measures (0.924), and prior training on flood risk reduction (0.919). Residents’ perceptions of flood drivers clustered around five key issues: community behaviours contributing to flooding (0.828), inadequate emergency response (0.851), poor drainage infrastructure (0.876), deteriorating sanitation conditions (0.847), and disruption of transport services (0.862). PCA further identified three major pathways for enhancing flood resilience: engineering and structural interventions (31.3%), institutional and service-oriented measures (26.2%), and ecological and environmental strategies (16.8%), jointly explaining 74.3% of the total variance. Overall, the study underscores the need to integrate behavioural change, institutional strengthening, and ecological planning in order to promote sustainable and flood-resilient urban environments.

Introduction

Flooding has become a recurring environmental challenge in Iwo, Osun State, particularly during the rainy season when intense rainfall interacts with poorly maintained drainage systems, expanding built-up areas, and increasing impervious surfaces. In several neighbourhoods of the city, stormwater frequently accumulates, leading to temporary road inaccessibility, damage to residential properties, and disruption of local economic activities. Although these incidents often occur at a local scale, they reflect broader patterns of vulnerability associated with rapid urban growth and inadequate infrastructure provision in many medium-sized Nigerian cities¹. In this context, flooding in Iwo is not merely a hydrological phenomenon but a socio-environmental challenge shaped by human behaviour, governance systems, and patterns of urban development.

More broadly, flooding has emerged as one of the most significant urban environmental challenges of the twenty-first century^2,3. Flood events disrupt livelihoods^4,5, damage infrastructure⁶, and weaken the resilience of cities worldwide^7,8. Increasingly, flood impacts extend beyond coastal areas to inland urban centres due to the combined effects of climatic variability and human-induced environmental change⁹. According to Ebi et al.¹⁰, floods account for nearly half of all weather-related disasters recorded over the past two decades, resulting in economic losses amounting to hundreds of billions of dollars annually. While climate change has intensified rainfall patterns and altered hydrological processes^11,12, anthropogenic factors such as poorly planned urban expansion, land-use change, and inadequate drainage infrastructure have significantly amplified flood risks in rapidly growing cities^11,13.

The increasing frequency of flood events has prompted planners and policymakers worldwide to reconsider conventional urban development and flood management approaches^14,15. In Jakarta, Indonesia, recurrent flooding linked to uncontrolled urban expansion and excessive groundwater extraction has led authorities to consider relocating the national capital¹⁶. In Houston, United States, urban sprawl into natural floodplains has significantly increased community vulnerability to flooding¹⁷. Similarly, the Netherlands has implemented adaptive strategies such as the “Room for the River” programme, which integrates engineering solutions with ecological restoration to create space for floodwaters while protecting urban settlements¹⁸. These examples illustrate that effective flood management requires not only physical infrastructure but also governance mechanisms capable of regulating human activities that intensify flood risks.

Recent studies also highlight the role of nature-based and community-oriented approaches in strengthening urban flood resilience. Irvine¹⁹, for instance, demonstrate how nature-based solutions were incorporated into the development of a Smart District in Thailand through wetlands, green corridors, and interconnected waterways designed to manage both riverine and rainfall-driven flooding. Beyond mitigating flood risks, such ecological interventions contribute to ecosystem health and improve social well-being²⁰. These findings underscore the importance of integrating community-informed planning with natural infrastructure as a sustainable complement—or alternative—to traditional engineering-focused flood management strategies.

Across Africa, urban flooding has become an increasing concern as rapid population growth and rural–urban migration place unprecedented pressure on infrastructure and environmental systems²¹. Cities such as Accra in Ghana, Dar es Salaam in Tanzania, and Lagos in Nigeria have experienced severe flood events in recent years, often triggered by intense rainfall and limited drainage capacity^22,23. The causes are multifaceted, ranging from poor waste management practices that obstruct drainage channels²⁴ to the proliferation of informal settlements in flood-prone areas without adequate regulatory oversight^25,26. These challenges are further compounded by institutional constraints, insufficient investment in climate-resilient infrastructure, and weak integration of flood risk considerations into urban planning frameworks^25,23.

Nigeria faces particularly acute flood risks due to rapid urbanisation, infrastructure deficits, and environmental degradation²⁷. The nationwide flood disaster of 2012 displaced millions and caused damages estimated at over ₦2.6 trillion. Since then, both riverine and urban flooding have become seasonal occurrences affecting cities of different sizes across the country²⁸. In many Nigerian urban centres, anthropogenic activities—including indiscriminate disposal of solid waste, sand mining along waterways, and encroachment on wetlands—further degrade natural drainage systems and intensify flood hazards^24,29. These practices undermine environmental sustainability and hinder progress towards Sustainable Development Goal 11 (SDG 11), which seeks to promote inclusive, safe, resilient, and sustainable cities²⁹.

Within southwestern Nigeria, Osun State has also experienced recurrent flooding, particularly during periods of intense rainfall. Although the state is inland and less exposed to large-scale riverine flooding, flash floods frequently occur in urban areas where rapid development outpaces infrastructure provision¹. Cities such as Osogbo, Ile-Ife, and Iwo have reported repeated flood incidents associated with poorly maintained drainage networks, the conversion of vegetated land into built-up surfaces, and weak enforcement of environmental regulations¹.

As one of the rapidly growing urban centres in the state, Iwo provides an important context for examining the relationship between anthropogenic activities and urban flood vulnerability. Rapid land-use transformation and the proliferation of impervious surfaces^30,31, combined with weak enforcement of urban planning regulations, have heightened the city’s susceptibility to flooding³⁰. Residents often adopt coping measures such as raising building plinth levels, constructing informal embankments, or clearing blocked drainage channels³². However, these responses are largely reactive and do not adequately address the underlying drivers of flood vulnerability¹.

Despite a growing body of literature on urban flooding in Nigeria and other developing regions, most studies focus primarily on the physical drivers of flooding, hydrological dynamics, or infrastructural deficiencies^33–36. Relatively little attention has been given to how residents’ awareness, perceptions, and everyday practices interact with flood risks to influence urban sustainability outcomes, particularly in medium-sized cities. This gap is important because anthropogenic behaviours—such as waste disposal practices, land-use decisions, and informal adaptation strategies—can significantly shape both the occurrence and severity of flooding. Moreover, empirical research that integrates community awareness, behavioural responses, and sustainability pathways for flood resilience remains limited in southwestern Nigeria, where rapid urbanisation continues to reshape environmental conditions.

This study addresses this gap by examining the relationship between human activities that contribute to flooding and urban sustainability in Iwo, while situating the city’s experiences within broader national, continental, and global contexts. By linking residents’ awareness of flood vulnerability with their perceptions and everyday practices, the study provides empirical insights into how community behaviours influence flood risks and resilience pathways in rapidly urbanising secondary cities.

Specifically, the study aims to:

1. assess the level and determinants of residents’ awareness of flood risks and urban vulnerability in Iwo;

2. examine residents’ perceptions of anthropogenic activities that contribute to flooding and urban environmental vulnerability in the city; and.

3. identify community-driven pathways and participatory strategies that can enhance flood resilience and promote sustainable urban living in Iwo.

By bridging the gap between environmental processes and community behaviour, the study contributes to the literature on urban flood governance, sustainability transitions, and community-centred resilience, while offering practical insights for policymakers, urban planners, and local stakeholders working towards safer and more sustainable cities.

Theoretical framework

This study adopts the Pressure–State–Response (PSR) Model and the Sustainable Livelihoods Framework (SLF) as complementary analytical frameworks for examining the linkages between human activities, flooding, and urban sustainability. These frameworks help conceptualise the study’s core variables-awareness, human drivers of flooding, and sustainable pathways—within a structured analytical system that explains how anthropogenic actions generate environmental pressures, alter urban environmental conditions, and stimulate responses aimed at mitigating flood risks. Their integration enables a multidimensional understanding of environmental challenges and the socio-economic vulnerabilities associated with flooding³⁷. The PSR model provides a systems-oriented perspective for analysing how human pressures contribute to environmental change and increased flood risks³⁸, while the SLF highlights the livelihood conditions and adaptive capacities of households exposed to environmental hazards such as flooding³⁹. Within this study, awareness is conceptualised as part of societal responses that influence behavioural change and public participation in mitigation efforts; human drivers represent pressures resulting from anthropogenic activities; and sustainable pathways refer to institutional, community, and household strategies aimed at reducing flood vulnerability and promoting long-term urban resilience. Together, these frameworks offer a holistic analytical approach that captures both environmental processes and the human consequences of flooding in Iwo.

Pressure-state-response (PSR) model

The Pressure-State-Response (PSR) Model, developed by the Organisation for Economic Co-operation and Development, provides a widely used framework for analysing environmental issues through the interaction between human activities, environmental conditions, and societal responses. The model explains how human pressures influence the state of the environment and stimulate responses from institutions and communities^40,41. Although the PSR framework is sometimes criticised for presenting environmental processes in a linear cause–effect sequence, many studies recognise that environmental systems involve dynamic feedback relationships in which responses can also reshape both human behaviour and environmental conditions.

In the context of this study, pressures refer to anthropogenic activities in Iwo, including uncontrolled urban expansion, indiscriminate waste disposal, and the encroachment of built-up structures into wetlands and natural drainage channels. These activities increase the likelihood and severity of flooding within the urban landscape. The state describes the prevailing condition of the urban environment, particularly the functionality of drainage systems, land-use patterns, and the frequency and intensity of flood events. The response component captures actions undertaken to address these challenges, including government policies, infrastructural improvements, community-based initiatives, and household coping strategies aimed at reducing flood vulnerability.

Importantly, these responses may generate feedback effects by improving environmental management practices, strengthening public awareness, and encouraging behavioural changes that reduce anthropogenic pressures over time. Thus, the PSR model enables the study to identify human drivers of flooding (pressures), assess environmental conditions that heighten flood risks (state), and evaluate awareness, policy measures, and community interventions designed to mitigate flood vulnerability (responses)^40,41.

Sustainable livelihoods framework (SLF)

While the PSR model emphasises environmental processes, the Sustainable Livelihoods Framework (SLF) provides a broader perspective on the socio-economic consequences of flooding⁴². Flood events often extend beyond physical damage, affecting livelihoods, weakening social networks, and disrupting the economic stability of affected communities⁴. The SLF therefore focuses on how households rely on five key livelihood assets—human, social, physical, financial, and natural capital—to withstand environmental shocks and maintain their well-being. Although the framework was originally developed for rural development contexts, its asset-based approach has increasingly been applied to urban settings to examine how households respond to environmental risks, livelihood disruptions, and infrastructure deficits^43,44.

Applying the SLF in the context of Iwo, Osun State, is particularly relevant because the town exhibits characteristics of many rapidly growing secondary cities in developing countries, where urban expansion, limited infrastructure, and livelihood dependence on informal economic activities heighten vulnerability to environmental hazards. In such settings, household resilience is closely tied to access to livelihood assets and social support systems. While the SLF does not explicitly address urban governance or planning structures, its strength lies in capturing how households experience and respond to environmental shocks within these broader institutional conditions.

From this perspective, resilience is understood not only in terms of infrastructural capacity but also through the ability of households and communities to mobilise available assets to cope with and recover from flood events. Consequently, the SLF strengthens the analysis of sustainable pathways in this study by explaining how residents of Iwo utilise livelihood resources and community networks to adapt to flood risks and enhance urban resilience.

Integrating the PSR model and SLF

Integrating the PSR model and the SLF provides a comprehensive analytical perspective linking the drivers of flooding to environmental conditions and societal responses. While the PSR model explains how human pressures transform the urban environmental state and trigger institutional responses, the SLF highlights how households experience these changes and adapt through their livelihood assets. Through this integration, the study connects awareness (societal understanding and engagement), human drivers (anthropogenic pressures contributing to flooding), and sustainable pathways (adaptive responses and resilience-building strategies) within a coherent framework for evaluating flood resilience in Iwo. This approach ensures that both ecological processes and socio-economic realities are considered in analysing flood impacts and promoting resilient and sustainable urban development.

Method of study

Study area

his study was carried out in Iwo, a rapidly expanding urban centre in Osun State, Southwestern Nigeria. The town lies along the busy Ibadan–Oshogbo highway, serving as a strategic link between major regional cities. Geographically, Iwo is positioned between latitude 7°38′–7°67′ North and longitude 4°07′–4°27′ East. In 2006, the population was approximately 191,000, but rapid growth driven by natural increase, migration, and the expansion of commercial and educational opportunities has pushed the population as at 2022 well beyond 248,400 (City Population, 2022). This demographic pressure has intensified demand for land, housing, and infrastructure, compounding environmental vulnerabilities.

Iwo experiences a humid tropical climate with two distinct seasons: a rainy season from April to October and a dry season from November to March. Annual rainfall ranges from 1200 to 1400 mm, and temperatures generally vary between 25 and 28 °C⁴⁵. Historically, the town has experienced recurrent flooding during the peak rainy months, often resulting in overflowing rivers, submerged streets, and damaged properties¹. According to Ogunbode and Oyebamiji, flood events have been reported nearly every year over the past two decades, with some years, such as 2012, 2016, and 2020, witnessing severe flooding that destroyed crops on adjacent farmlands displaced hundreds of residents, and disrupted transport networks. These events highlight both the frequency and magnitude of flood risks, providing a clear rationale for focused investigation. However, there is no official records on the details associated with flooding in Iwo as at the time of this research.

The town’s terrain is gently undulating, but unregulated construction, wetland reclamation, and blocked drainage channels have amplified flood vulnerability⁴⁶. Flooding is particularly common along rivers and streams such as the Ponyan, Aiba, Odo-Ori, and Odo-Oba, which frequently overflow during heavy rainfall events, forming part of the larger Osun River Basin. Historical records and local accounts indicate that low-lying areas near these waterways are most affected, with damages ranging from structural losses to disruption of livelihoods and public services.

Urbanisation has significantly altered Iwo’s landscape. While some traditional settlement patterns remain, new neighbourhoods often lack proper planning. Deforestation, wetland encroachment, and indiscriminate waste disposal further exacerbate flood risks. Economically, Iwo is a vibrant hub of commerce, agriculture, and education, hosting markets, small-scale industries, and institutions such as Bowen University, which attracts students and staff nationwide. However, recurring floods threaten both livelihoods and urban sustainability, demonstrating the tension between growth and resilience.

Given the historical recurrence, frequency, and impact of flooding, Iwo presents a critical case for examining how human activities exacerbate flood risks and identifying pathways for sustainable urban development. Lessons from Iwo have relevance not only locally but also for other rapidly growing tropical cities seeking to achieve SDG 11 - inclusive, safe, resilient, and sustainable urban environments (Fig. 1).

Fig. 1.

River networks in Iwo, Osun state, Nigeria.

Data collection

The study employed a purposive sampling approach to identify households located within the long-established flood-prone zones along Iwo’s three main river corridors—the Ponyan, Aiba, and Odo-Ori streams—which are historically the most affected by flooding. No official records exist for the total number of households or residents in these areas. However, field reconnaissance indicated approximately 75 residential buildings (Ponyan-20, Aiba- 28 and Odo-Ori- 27), housing around 500 residents ((Ponyan-140, Aiba- 200 and Odo-Ori- 180), within these floodplain corridors. This information provided a basis for assessing the representativeness of the sampled households. Following the delineation of the flood-prone zones, simple random sampling was used to select participants, resulting in 164 respondents: 55 along the Ponyan stream, 42 along the Aiba stream, and 67 along the Odo-Ori stream as shown in Fig. 2. The distribution of respondents reflected both the relative lengths of the streams within the town and the spatial concentration of residences along the riverbanks. Data were collected through face-to-face administration of structured questionnaires at respondents’ homes, with all 164 questionnaires successfully retrieved, yielding a 100% response rate.

Fig. 2.

Flow chart illustrating data collection processes.

While purposive sampling along these high-risk corridors may introduce spatial bias and limit the generalisability of findings to the broader urban population, it was deliberately chosen to focus on areas where flood impacts are most frequent and severe. Households outside the riverbanks, particularly those affected by pluvial flooding, were not included; therefore, the results primarily apply to communities along the three rivers and should not be extrapolated to all parts of Iwo without caution. Nevertheless, concentrating on these critical flood zones allows the study to capture detailed dynamics of flood vulnerability, adaptive behaviours, and responses, providing valuable evidence for targeted interventions, river corridor management, and local policy development for flood resilience.

The study adhered strictly to established ethical standards. Ethical clearance was obtained from the Bowen University Research Ethics Committee, and informed consent was secured from all participants prior to data collection. Participation was entirely voluntary, without coercion or inducement, and respondents were assured of the confidentiality of their identities and responses. All procedures complied with relevant institutional and national ethical guidelines.

Data analysis

Descriptive statistical tools such as tables, percentages, and graphical illustrations were first employed to present the socio-demographic characteristics of respondents and other basic attributes. This provided a clear overview of the dataset and helped to establish patterns that guided further analysis.

Beyond description, two inferential statistical techniques—factor analysis and principal component analysis—were applied for deeper exploration. Factor analysis was used to condense the numerous perceived drivers of flood disaster into a smaller group of underlying factors, thereby identifying the key dimensions that explained the greatest variance in respondents’ views. This was necessary given the interrelated nature of many of the variables.

The preference for the PCA is to reduce the complexity of the dataset by grouping interrelated variables into a smaller number of components, thereby highlighting the underlying dimensions of flood mitigation strategies. This approach not only identifies the most significant measures but also provides a structured framework through which interventions can be categorised into engineering, institutional, and ecological pathways. Such categorisation offers clarity for policy formulation, ensuring that actions are evidence-based, integrated, and capable of addressing both immediate flood risks and long-term sustainability challenges in Iwo. Moreso, the dataset showed that it is factorable with KMO of 67.9 significant at p ≤ 0.005.

Results and discussion

Basic attributes of respondents

Respondents’ age

As shown in Fig. 3, the majority of respondents were aged between 18 and 49 years (49.7%), followed by those aged 50–69 years (37.2%). Only 6.6% of respondents were younger than 18 years, and a similar proportion were over 70 years. This distribution indicates that the surveyed population is largely composed of middle-aged adults, who are typically the most active and responsible for managing household affairs, including flood preparedness and response. Their predominance suggests that the study captures the perspectives of the demographic group most directly exposed to flood risks and most likely to engage in mitigation and adaptive strategies, highlighting their central role in shaping household and community-level flood resilience⁴⁷.

Fig. 3.

Respondents ‘age distribution.

Gender distribution of respondents

Figure 4 shows a pronounced gender disparity, with males comprising 74.3% and females 25.7% of respondents. This likely reflects cultural norms in Iwo, where men are often household heads and more available to participate in surveys, particularly those concerning environmental management and flood risk. Often, men are also perceived to play a more prominent role in decision-making and coping with flood-related challenges in local communities⁴⁸. Nonetheless, the underrepresentation of women highlights the need for more inclusive approaches in future studies to ensure that both men’s and women’s experiences and perspectives inform flood risk management and adaptation strategies.

Fig. 4.

Respondents’ gender distribution.

Respondents’ level of education

As shown in Fig. 5, educational attainment among respondents varied considerably. The majority, 62.8%, had completed secondary education, followed by 11.5% with tertiary education. Respondents with primary education accounted for 8.7%, while 5.5% reported having no formal education. The predominance of individuals with secondary and tertiary education suggests that the community has relatively strong educational exposure, which can enhance awareness, understanding, and responsiveness to flood risks. Higher levels of education may enable residents to access information on disaster preparedness, adopt safer practices, and make informed decisions during flood events^49,50, thereby potentially reducing vulnerability and supporting more effective adaptation strategies.

Fig. 5.

Respondents’ levels of education.

Respondents’ occupation

Figure 6 shows that 43.2% of respondents are farmers, 30.6% are technicians or traders, and 26.2% are civil servants. This distribution indicates a mix of formal and informal livelihoods, with a large proportion engaged in semi-formal or informal occupations. Such livelihoods are often sensitive to flooding, as agricultural losses or disruptions to trading can directly affect income stability. Civil servants, with regular salaries, may be less immediately affected financially but can still experience property damage or indirect economic impacts. Wang⁵¹, revealed that differences in occupation highlight the variable capacity of households to cope with and recover from flood events.

Fig. 6.

Respondents’ occupational distribution.

Residents’ house tenure

Figure 7 presents the distribution of house tenure among respondents. The analysis indicates that 38.3% of residents owned their homes, 36.6% were tenants (renters), and 25.1% did not provide information on their tenure status. This pattern suggests that most residents lived in relatively stable housing arrangements, either as owners or renters, while a smaller segment either withheld information or potentially occupied less secure tenure. Such variations in housing security may influence vulnerability during flood events, as households without stable tenure arrangements are often less able to implement protective measures or recover effectively after flood-related damage⁵².

Fig. 7.

Respondents’ different house tenure.

Respondents’ displacement days in last major flood

The experience of displacement during the most recent major flood in Iwo varied considerably among residents, as illustrated in Fig. 8. Approximately 43.7% of respondents reported being displaced for one to three days, while 36.6% experienced displacement lasting four to seven days. A smaller proportion, 13.1%, were displaced for more than seven days, and 6.6% of respondents indicated that they had not experienced any displacement due to flooding. These findings highlight that, although a substantial number of residents faced only short-term disruption, a notable segment of the population endured prolonged displacement. This variability underscores differences in both exposure and adaptive capacity within the community⁵³, reflecting how resilience to flood impacts is unevenly distributed across households along the three river corridors.

Fig. 8.

Respondents’ displacement days in the last major flood.

Determinants of residents’ awareness of flood events in Iwo

The suitability of the data for factor analysis was first assessed using the Kaiser–Meyer–Olkin (KMO) measure of sampling adequacy and Bartlett’s test of sphericity. The KMO value of 0.799 exceeded the minimum recommended threshold of 0.70, indicating that the sample size and data structure were adequate. Bartlett’s test of sphericity produced a Chi-Square statistic of 893.658 with 36 degrees of freedom and was significant at p < 0.001, confirming that correlations among the variables were sufficient for factor analysis. These preliminary tests justified the application of factor analysis. Using common factor extraction with Varimax rotation, four factors with Eigenvalues greater than one were identified, together explaining 78.1% of the total variance. The rotated factor structure revealed meaningful clusters of variables that explain the dimensions of residents’.

The factor analysis conducted to assess residents’ awareness of flood risk in Iwo, Nigeria, produced four significant variables with strong loadings, which together accounted for 78.1% of the total variance explained as shown in Table 1. The first variables, with high loadings on practices that increase flood risk (0.891) suggests that awareness in the community is strongly linked to the recognition of human activities that exacerbate flooding. Elum and Lawal⁵⁴, noted that most of their respondents demonstrated limited knowledge of flood risks, which translated into weak adaptive capacity, as they had taken few or no actions to address potential flood disasters. This, according to Iqbal and Nazir⁵⁵, implies that when residents observe or experience the consequences of poor environmental practices, their awareness of flood risks becomes more pronounced.

Table 1.

Significant determinants of residents’ awareness of flood events by FA.

Factor	Significant variable	Loading	Eigenvalue	% Variance	Cumulative %
1.	Practices that increase flood risk	0.891	2.073	23.031	23.031
2.	Government policies aimed at reducing urban flooding	0.880	1.766	19.625	42.656
3	I am aware of simple household measures to control flooding	0.924	1.625	18.059	60.715
4	I have been trained on how to reduce household flood risk	0.919	1.563	17.371	78.087

Another key dimension of awareness emerged through household-level knowledge, as shown by the very high loading on awareness of simple household measures to control flooding (0.924). This highlights that residents’ understanding of basic preventive practices, such as clearing gutters, safe waste disposal, and adopting local flood-control measures, significantly enhances their awareness of risks within their immediate environment⁵⁶. Similarly, the high loading on training received on how to reduce household flood risk (0.919) demonstrates the role of structured education and sensitisation programmes in improving awareness. Training interventions provide residents with the practical knowledge needed to anticipate and mitigate flood risks at the household level^57,58. Overall, the analysis indicates that residents’ awareness of flood risks in Iwo is shaped by a combination of recognition of human contributions to flooding, practical household knowledge, and training programmes. Together, these factors suggest that effective awareness-raising must integrate policy enforcement, community sensitisation, and continuous education to improve preparedness and resilience against flood events.

Residents’ experience and perception of anthropogenic drivers of flood risks

The results of the factor analysis show that the dataset was well-suited for identifying key issues related to neighbourhood experiences during flooding in Iwo (Table 2). The Kaiser–Meyer–Olkin (KMO) measure of sampling adequacy was 0.749, which falls within the acceptable range and indicates that the sample size was sufficient for reliable analysis. In addition, Bartlett’s Test of Sphericity was highly significant (χ² = 1725.932, df = 91, p < 0.001), confirming that correlations among the variables were strong enough to justify the use of factor analysis. Together, these results provide a solid statistical foundation for interpreting the extracted factors.

Table 2.

Factors that explain residents’ perception of anthropogenic drivers of flood risks.

Factor	Significant Variable	Loading	Eigenvalue	% Variance	Cumulative %
1.	Link between local behaviour and flooding is known	0.828	3.708	21.984	21.984
2.	Emergency during flooding is inadequate in my area	0.851	2.251	16.081	38.065
3	Poor drainage contributes significantly to flood	0.876	1.909	13.637	51.702
4	Flood worsens environmental sanitation	0.847	1.849	13.204	64.905
5	Flood regularly disrupts transport and access services	0.862	1.773	12.666	77.571

The first factor, which explained 21.98% of the variance, was linked to the community’s recognition of the connection between local behaviours and flooding. With a high loading (0.828), this suggests that residents are aware of the ways in which their actions, such as indiscriminate waste disposal and construction practices, contribute to flood risks. Echendu²⁴, in supporting this finding revealed that a drastic shift in the neighbourhood behaviour, especially in waste disposal management, should be promoted to mitigate flood risks. Salami et al.²⁶, having significant correlation between residents’ flood awareness and having previous flood experiences, suggested that effective policies targeting adaptive measures rather than reactive measures after the occurrence of flood. This awareness is crucial, as it highlights the potential for behavioural and attitudinal change to reduce vulnerability.

The second factor, accounting for 16.08% of the variance, focused on the inadequacy of emergency response during flooding events. The strong loading (0.851) demonstrates a clear perception that institutional support and disaster preparedness mechanisms in Iwo are weak or ineffective. This gap underscores the need for improved local governance, investment in early warning systems, and the establishment of functional emergency response frameworks to minimise loss and damage. Mashi et al.⁵⁹, in corroborating this finding recommended early warning system, sound physical planning and effective urban governance among others to enhance flexibility in the management of flooding.

Poor drainage was identified as the third major factor, contributing 13.64% of the variance. With the highest loading (0.876), this variable reflects a consensus among respondents that inadequate drainage systems are a critical driver of flooding in the city. This finding is consistent with broader urban flooding literature, where blocked or poorly designed drainage channels often intensify flood risks. Addressing this challenge will require infrastructural upgrades, regular maintenance, and stricter enforcement of planning regulations^59,60.

The fourth factor, with a variance contribution of 13.20%, indicated that flooding worsens environmental sanitation in neighbourhoods. The strong factor loading (0.847) suggests that floodwaters exacerbate waste dispersal, sewage overflows, and general unsanitary conditions, which in turn create heightened risks of disease outbreaks. This dimension highlights the intersection between flooding and public health challenges, calling for integrated flood management and sanitation strategies. This is in support of the findings of Fowé et al.⁶⁰ which recommend putting in place executable adaption policies that will enhance urban resilience though awareness and vulnerability minimization.

Finally, the fifth factor, explaining 12.67% of the variance, was associated with the disruption of transport and access services during floods. The high loading (0.862) demonstrates how flood events regularly hinder mobility, restrict access to markets, schools, and workplaces, and create broader socio-economic impacts. This factor points to the need for flood-resilient infrastructure and transport systems that can withstand and adapt to such disruptions²⁷.

Overall, the five extracted factors collectively explained 77.6% of the total variance, which is a strong indication that they capture the central issues shaping community experiences of flooding in Iwo. The findings provide valuable insights for policymakers and urban planners, suggesting that interventions should target behavioural change, improved drainage systems, strengthened emergency response, enhanced sanitation, and resilient transport infrastructure.

Pathway strategies to subdue human-induced flood for sustainable urban living

To identify actionable measures for promoting sustainable and flood-resilient urban living in Iwo, Principal Component Analysis (PCA) was conducted on nine flood-related variables. The analysis revealed three significant components-engineering/structural interventions, institutional and service-oriented measures, and ecological/environmental strategies-that collectively form a structured pathway for reducing flood risks as shown in Fig. 9. While PCA provides the statistical basis for these dimensions, their interpretation is situated within both the PSR and SLF frameworks. The PSR perspective emphasises how anthropogenic pressures—such as inadequate drainage, unmanaged waste, and unplanned land-use changes—affect the urban environment (flood exposure, degraded infrastructure, and ecological stress), triggering responses in the form of engineering, institutional, and ecological interventions. The SLF framework, in turn, situates households’ adaptive capacity within these pathways, showing how residents’ knowledge, skills, and participation interact with institutional mechanisms, planning authorities, and infrastructural provisions to shape flood outcomes. Incorporating governance and institutional context is critical, as local policies, municipal planning structures, and the condition of urban infrastructure directly influence the effectiveness of flood risk interventions.

Fig. 9.

A structured pathway to achieving flood-free and sustainable urban living in Iwo.

The first component, engineering and structural interventions, represents the city’s direct response to the physical pressures of flooding. Measures such as drainage desilting, installation of larger culverts, implementation of permeable pavements, and flood early warning systems improve the urban environment’s ability to cope with extreme rainfall events^54,61. These interventions are typically coordinated by municipal planning and public works authorities, reflecting institutional capacity in implementing and maintaining infrastructure. Beyond improving the state of the built environment, these measures foster behavioural adaptations, enabling residents to respond effectively to flood warnings and minimise losses to property and livelihoods^62,63.

The second component, institutional and service-oriented measures, underscores the governance and social structures that mediate responses to flooding. Retention ponds, improved waste management, relocation and compensation schemes, and community-based clean-ups exemplify the interaction between local policy instruments, municipal agencies, and civil society actors^64,65. These interventions reinforce structural solutions while enhancing social and institutional capital, allowing communities to actively participate in flood risk management. In Iwo, the effectiveness of such measures depends on clear delineation of roles among planning authorities, emergency response units, and community organisations, highlighting how governance structures shape both the design and uptake of adaptive strategies.

The third component, ecological and environmental strategies, addresses long-term sustainability by restoring natural systems. Riparian buffers, urban greenways, and integrated green infrastructure reduce flood intensity, enhance biodiversity, and provide co-benefits such as recreational spaces and improved air quality^{66,67,68–72}. When implemented alongside engineered solutions, these measures demonstrate the synergy between technical and ecological responses, aligning local interventions with SDG 11 goals for resilient and inclusive cities. Effective ecological strategies require institutional support in land-use planning, environmental regulation, and enforcement, ensuring that natural buffers are protected from encroachment and degradation.

By linking PCA-derived factors to these multidimensional pathways, the study bridges statistical findings with practical policy, governance, and behavioural interventions. This integrated framework highlights how pressures, infrastructural states, and institutional capacities collectively shape flood vulnerability in Iwo, offering a roadmap for enhancing urban resilience while promoting sustainable and inclusive development.

Table 3.

Pathway strategies to control human-induced flood for sustainable urban living.

Component	Eigenvalue	% of Variance	Cumulative %	Strongly loading variables
1. Engineering & Structural Measures	2.817	31.298	31.298	Drainage desilting (0.949), Bigger culverts (0.758), Permeable pavings (0.732), Early warning systems (0.555)
2. Institutional & Service-Oriented Measures	2.354	26.161	57.459	Retention ponds (0.839), Improved waste services (0.702), Relocation/Compensation (0.751), Community clean-ups (0.633)
3. Ecological & Environmental Measures	1.515	16.836	74.295	Greenway/Riparian buffers (0.941), Early warning systems (0.457), Bigger culverts (0.453), Relocation/Compensation (0.278)

Together, these three pathways provide a multidimensional approach to achieving flood-free and sustainable urban living in Iwo. Structural interventions offer immediate relief from flood hazards, institutional measures build long-term capacity and resilience through governance and community action, while ecological strategies secure environmental sustainability. By integrating these approaches, Iwo can move towards an urban future that not only controls flooding but also promotes liveability, resilience, and sustainable growth.

The results show that flood risk awareness is strongly associated with residents’ recognition of harmful environmental practices, knowledge of preventive household measures, and exposure to flood risk reduction training. Perceptions of flooding are primarily linked to community behaviours, weak emergency response systems, poor drainage infrastructure, deteriorating sanitation conditions, and disruptions to transportation. The analysis also highlights three major pathways for enhancing urban flood resilience: engineering and structural improvements, institutional and service-based interventions, and ecological and environmental strategies.

Integrated pathway strategies for sustainable flood management in Iwo

While the proposed pathways provide a detailed roadmap for flood mitigation, their successful implementation in Iwo must consider feasibility, resource limitations, and local socio-political dynamics. Municipal capacity, funding availability, coordination among state agencies, and community acceptance are critical factors that influence which interventions can be prioritised and scaled. Each pathway below incorporates these considerations, ensuring strategies are not only technically sound but also practically achievable within Iwo’s governance context.

1. Engineering and structural solutions

Policy Goal: Upgrade and maintain the city’s flood-control systems to cope with current and future risks.

• i.Regular Drainage Maintenance: Establish a routine, adequately funded programme to clear silt and debris from primary and secondary drainage channels. Local communities can support monitoring, but municipal budget constraints may necessitate phased implementation.
• ii.Larger Culverts and Storm Drains: Replace undersized culverts with larger, climate-informed designs. Implementation should be prioritised in high-risk zones first, taking into account available funding and technical capacity.
• iii.Porous Surfaces: Encourage permeable pavements in markets, car parks, and residential areas. Partnerships with private developers can offset municipal costs.
• iv.Flood Early Warning Systems: Develop affordable technology-based alert systems using SMS, radio, and social media. Maintenance and operation require local technical expertise and budgetary planning.

Implementation Considerations: Coordination between the municipal council, state ministries, and private developers is essential. Resource constraints may require phased deployment and prioritisation based on risk mapping. Community engagement will ensure acceptance and sustainability.

• 2.Institutional and service-based approaches

Policy Goal: Strengthen institutions, improve waste management, and promote inclusive decision-making.

• i.Stormwater Retention Ponds: Construct multipurpose ponds that serve flood control during the rainy season and secondary uses during the dry season. Funding and land acquisition may present challenges, necessitating multi-stakeholder collaboration.
• ii.Enhanced Waste Services: Introduce door-to-door collection through public–private partnerships. Enforcement of anti-dumping laws may face political and compliance challenges, requiring strong institutional oversight.
• iii.Relocation and Compensation: Develop fair resettlement policies for high-risk households. Socio-political sensitivities around displacement necessitate transparent communication and adequate compensation.
• iv.Neighbourhood Sanitation Days: Institutionalise monthly community clean-ups, with incentives such as recognition or tax breaks. Success depends on sustained community participation and local leadership support.

Implementation Considerations: Collaboration between Iwo local government, OSEMA, NGOs, and community groups is essential. Political will, social acceptance, and long-term funding must be carefully managed to ensure continuity.

• 3.Ecological and environmental strategies

Policy Goal: Integrate green infrastructure and nature-based approaches into urban planning.

• i.Riverbank Buffers: Enforce setbacks and reforest riparian zones. Socio-economic pressures on land use may require compensation strategies and stakeholder negotiation.
• ii.Green Infrastructure: Promote rooftop gardens, urban tree planting, and bio-swales. Private sector participation and community ownership are key for feasibility.
• iii.Climate-Sensitive Urban Design: Incorporate ecological principles into the city master plan, preserving wetlands for natural drainage. Implementation may be constrained by technical capacity and regulatory enforcement.

Implementation Considerations: Collaboration between planning authorities, Ministry of Environment, universities, and international climate adaptation funders can address resource and expertise gaps.

Sustainable flood mitigation in Iwo requires inclusive, participatory planning, alignment with SDG 11 and SDG 13, and continuous capacity development. Training for engineers, urban planners, and municipal officials is critical to strengthen adaptive management skills. Measurable indicators should monitor drainage performance, waste management efficiency, ecological restoration, and community engagement.

By combining engineering solutions for immediate resilience, institutional reforms for governance and participation, and ecological strategies for long-term sustainability, Iwo can transition from reactive flood responses to proactive prevention. Consideration of feasibility, resources, and socio-political realities ensures that interventions are not only technically effective but also socially acceptable and sustainable, offering a replicable model of flood-resilient urban development in Nigeria.

Conclusion and recommendations

This study examined how anthropogenic activities exacerbate urban flooding and influence sustainable development in Iwo, Osun State, with implications for achieving SDG 11. Findings indicate that residents’ awareness and perceptions of flood risks are shaped by recognition of harmful practices, knowledge of household preventive measures, and prior training. Concurrently, poor drainage systems, weak emergency response mechanisms, deteriorating sanitation, and disrupted transportation underscore the multidimensional impacts of flooding. Three interrelated pathways—engineering, institutional, and ecological—emerged as critical for fostering proactive and sustainable flood management.

The study’s limitations should be acknowledged. The sample may not fully represent Iwo’s diverse urban population, as participation was voluntary and concentrated in accessible areas. Reliance on self-reported data introduces potential biases in residents’ perceptions of flood risk and preparedness. Additionally, unobserved socio-economic factors, seasonal variations, and local governance dynamics may affect the generalisability of the findings.

To enhance urban flood resilience, the study recommends integrated strategies that consider local feasibility and resource constraints:

1. Engineering interventions: Routine drainage desilting, culvert upgrades, permeable pavements, and flood warning systems are essential. However, implementation should prioritise high-risk zones, phased according to available municipal funding and technical capacity.

2. Institutional and governance measures: Improved waste management, stormwater retention ponds, fair relocation policies, and institutionalised community sanitation programmes can strengthen governance. Success will depend on multi-stakeholder coordination, political will, and sustained community engagement.

3. Ecological strategies: Enforcing riparian buffers, integrating green infrastructure, and incorporating wetlands into urban planning can enhance ecological resilience, though these require careful alignment with land-use regulations and potential compensation for affected stakeholders.

Cross-cutting actions should emphasise capacity-building for municipal officials, participatory decision-making, phased implementation according to available resources, alignment with SDG targets, and monitoring indicators sensitive to local conditions. By adopting these context-sensitive, resource-aware strategies, Iwo can move from reactive flood responses to proactive prevention, offering a replicable model of flood-resilient and sustainable urban living in Nigeria.

Author contributions

TOO: Conceptualization, validation, visualization, formal analysis, supervision, writing draft, edit and review; BAO, STA, EAA and IMA: Investigation, edit and review;

Funding

This research received no funding from any source.

Data availability

Data used in this study is available on reasonable request from the corresponding author.

Declarations

Competing interests

The authors declare no competing interests.