The reductions of exposures to hazards, attenuating vulnerabilities of the populace and property, sustainable management practices of land and the environment, as well as improved forewarned preparatory ventures against adverse events constitute disaster risk reduction. Climate change and extreme hydrologic events, such as droughts and floods exacerbate vulnerabilities in biodiversity, the environment and health, precipitating a plethora of risk reduction processes ¹⁰. This ecological framework expounds the pattern of extreme hydrological events and climate change in the alterations of ecosystem services and dynamics, influencing species spread, community aggregation, and consequentially the affect on biodiversity, environment and human health as depicted in water scarcity, food security, and disease dissemination. The determinants of risk reduction concerning environmental and health vulnerabilities to extreme hydrological events and climate change are associated with decreasing exposure, augmenting vulnerability, and creating resilience. Instances of these determinants inculcated land use planning, enhanced infrastructure, improved adaptive capacity, and sustainable disaster risk management enforcement. These determinants pave the practice, capacity, capability and concept of the populace, communities, and ecosystems to confront and survive the untoward impacts of climate change. Climate change and the modifying patterns of extreme weather can expunge or suppress the sustainability of public health .

Prevailing challenges in sustainable land and water management, such as environmental and land degradation ¹¹, water deprivation ¹² and climate change provide opportunities for novel sustainable development. The instant challenges to be focused on are the trade-offs of the cost-benefit analysis in the short-run and long-run, respectively, or sustainable approaches and funding acquisition for projects, especially in the private sector. Opportunities correlate with the development of innovative business models, water resource integration and management within land use planning, and community-dependent strategies promotion. Potable water, food and energy security, climate change, water-borne diseases, water-associated hazard management, sustainable environmental quality and land use management are present and future challenges ^{12, 13}. The ongoing challenge for sustainable land and water management, climate change adaptation and mitigation projects is proper acquisition of Sustainable Land Management (SLM) concerning land degradation rates, and preventative measures against desertification in coordination for greener and more sustainable future, and aggregated efforts to obviate distortions, such as water unavailability, pollution, ecosystem cadastral ¹⁴ degradation and anomalous environmental health trajectories ¹⁵.

Understanding the associated characterizations with these extreme hydrological events is pertinent for precise risk assessment in the design and operation of water infrastructures. Inappropriate assessment of design floods leads to material and human life disruption. Thus, extreme weather events incessantly augment, and are correlated to global warming. The dissipation of biodiversity incorporates land-use change, suppressed habitat, excessive exploitation, pollution, species invasiveness or inhibition and climate change. These weather events are ostensibly contributory to, and enhance risks for expansive spectra of vector- and non-vector-borne diseases and infestations to fauna and flora with concomitant anomalous complications. As these pivotal determinants are placed on focus, individuals and communities are positioned to ameliorate vulnerabilities to extreme hydrological events and climate change, with resultant improvement of biodiversity, environment and health.

The hydrologic vulnerability correlates with the response of the natural and anthropogenic which depict aspects of geographical precincts to the impact of extreme hydrological phenomena. Hydrologic perturbations are extreme events ⁹ associated with water occurrence, motion, hazards, flooding, droughts and related events, such as landslides, river scour and deposition. These function as a framework for resourceful and safe drinking water and health in endpoint characterization variables concerning water usage on human health ¹³. The hydrological cycle has been profoundly affected by climate change. Climate-induced hydrological extremes, such as floods and droughts, have been overwhelming in past decades, with the trajectory and trend prominently unabated into the future. Droughts and floods are both extreme weather events associated with climate change, presenting extensive repercussions for communities, biodiversity, ecosystems, economies and health. Droughts result in water scarcity, with adverse effects on agriculture, energy production, and ecosystem health. The devastating impacts of floods include contamination and pollution of water sources, infrastructure degradation, and displacement of persons. The World Health Organization (WHO) is concerned that flood is a risk factor in cholera transmission of cholera but drought is not explicitly given due cognizance ^{13, 16, 17}.

Climate change substantially alters the pattern of precipitation, resulting in both elevated intensity and frequency of extreme precipitation events and modifications in total quantities of precipitation. The augmentation of the atmospheric water holding capacity due to warming leads to exacerbated intense storms and enhancing flooding risk. Concomitantly, warming culminates in elevated evaporation, leading to drier states in certain ambientes with drought intensification. The scenario of respective superimposed wetness and dryness are evidenced in the effects of climate change on precipitation¹⁸. Invariably, alterations in precipitation or climate impact on health. Expansive wildfires tending to extreme temperatures, and decrement in precipitation can lead to rising ozone and particulate matter, exacerbating in cardiovascular threats or risks. However, certain populations exhibit more vulnerability to climatic health challenges ¹⁹.

Extreme precipitation events may induce aberrant effects on crop growth, soil quality, and agricultural productivity ^{20, 21}. On the other hand, climate change leads to higher temperatures, accelerated water evaporation, and decreased soil moisture, and subsequently affects the water use efficiency of crops. Dryland rivers and streams contribute significantly in the dynamics of dryland ecosystem food web, with impact on biodiversity and food security. Hydrologic variability that characterizes dryland areas, critically impacts these systems, by regulating both terrestrial and aquatic food webs and the dependent organisms. Climate change constitutes a veritable influence in the availability, quality and diversity of food, and nutritional crises. There are standard strategies to explicate and understand indicators for river health in variable systems ^{22, 23, 24}. Due to the extreme hydrological variability and opportunistic biotic responses to flood pulses, dryland rivers are accommodating to specific food webs. In these systems, primary productivity and heterotrophy are important for food web sustainability^{25, 26}. Flows provide rewetting and upstream delivery, accompanied by episodic particulate and dissolved resources, with frequent autochthonous formation, within a short period generating an expansive biomass²⁷. The biomass preponderance can result in high quantities of secondary production. It is suggestive that dryland river food webs depict resistant multiscale backbones²⁸ which undergird the persistence of the primordial and pivotal ecological functionalities in these systems in drought.

The tolerance of plants to flooding and submergence broadly varies, with certain species depicting high sensitivity, whereas other species exhibit thriving adaptability in flood-prone ambientes. The health of the root is important for crop survival and yield during flooding ²⁹. Pivotal adaptations incorporate structural and functional alterations, such as aerenchyma production, that propagates oxygen transport, and physiological adaptations as aggravated hypoxia tolerance. For instance, rice is a highly tolerant species, whereas a vast majority of crops exhibit elevated sensitivity. In rice, enhanced flooding tolerance requires a combined tolerance of submergence and stagnant flooding. Agricultural ambientes are susceptible to flooding and ponding due to the excessive precipitation and hydrologic extremes. Within this milieu, plant breeders profoundly identify and develop genetic technologies to augment crop productivity. Rice maintains a veritable position in breeding as regards crop tolerance ²⁹ to flooding. Numerous rice cultivars merely tolerate flooding for circa a week. However, a class of ethylene-response-factor-like genes is associated in flooding/submergence tolerance ³⁰. The accumulation of ethylene retards cytokine-mediated senescence and instigates dormancy in submergence. In addition, climate change aggravates the frequency and intensity of these events, culminating in elevated challenges for agricultural systems and production. Extreme weather events caused by the ENSO cycle or El Niño-Southern Oscillation can affect health via associated droughts, floods, heat waves, and distortions in food supply ³¹. Thus, extreme weather events associated with the El Niño-Southern Oscillation (ENSO) can remarkably affect public health. ENSO-related droughts, floods,, elevate the risk of exacerbating extant health vulnerabilities. The health risks of climate change emerge from interactions of the dangers associated with a changing climate, for instance, increased frequency and intensity of extreme weather events, the susceptible communities exposed to the hazards, the vulnerability of regions to adverse health impacts on exposure, and the potential to be aware against these events, and cope with the hazard ³¹.

Climate change may induce disruptive healthcare access, and risk vulnerabilities to physical and mental health well-being and hygiene. The health impacts of the disruptions, such as increased cardiopulmonary disorders, wounds and premature mortality-associated extreme weather events, alterations in demographics of food- and water-borne morbidities and comorbidities, the emergence and reemergence of infectious diseases ^{32, 33} unravel expansive interventions in public policies and administration ³⁴. Climate change may disorient cardiovascular health via multiple pathways. Environmental stressor exposure causes physiological alterations, such as accelerated heart rate and altered plasma viscosity in association with extreme heat, local and systemic inflammation exposures from airborne particulate matter inhalation ^{35, 36}. Environmental temperature constitutes the most intensively researched phenomenon. The association between mortality, cardiovascular disorder incidence, and temperature depicts graphically as the "U" alphabet. The invariable association of cold, heat and heat wave exposures with elevated risk of acute coronary syndromes has been documented ³⁷. Extreme temperature exposure poses a significant impact on food intake and nutrient composition. Extreme temperatures impact on eating habits through enhancing the tendency to imbibe high-fat diets, although, the total calorie consumption is relatively unperturbed. This shift presents adverse health risks in obesity, diabetes, and cardiovascular diseases^{38, 39, 40}. It was observed in both hot and cold weather, persons are induced to consume more fat, especially with more impact on vulnerable groups, such as rural dwellers and the low-educated populace. As cooling fans and heating systems as adaptation resources, tend to ameliorate the effects, broader policy interventions are pertinent. In essence,, short-run exposure to extreme temperatures modifies dietary patterns by augmenting fat consumption, even with total calorie intake is constant. Driven by physiological appetite regulation, this shift augments the risk of high-fat diets and diet-associated disorders, particularly within the vulnerable population. These findings may correlate with short-term dietary modifications, and further research is pertinent to understand longer-run implications ⁴⁰.

The intensification of the hydrological cycle could result as global warming instantaneously escalates mechanisms associated with the hydrologic cycle with resultant intense droughts, floods and wet periods which impact health, environment, biodiversity and societal sustainability. Warmer temperatures and shifting weather patterns disrupt air quality which precipitate to cardiopulmonary health deficits and asthmatic presentations. Predictable increased severity, quantity and extent of wildfires with the concomitant smoke alongside climate change, including aberrant or health debilitating atmospheric pollutants. Extreme weather events invariably affect human health by causing injuries, dissipation of human lives, diseases, psychiatric disorders and comorbidities. There are geopolitical trends and convergence in health and environment of countries on the scientific parameters of climate change but variance and divergence sustain on which country is the most culpable, the ways and means to predict and track the decrement of the emissions regarding risk reduction, and the rationale for the compensation of vulnerable geopolitical areas.

Considering climate-driven dietary modification is pertinent to safeguard long-run public health in a global accelerating warming ambient. Climate vulnerabilities have ostensibly been principally induced by anthropogenic activities on climate change and global warming, with incessant exclusivity of superimposed threats due to carbon dioxide emissions, population growth and energy sources from stressors accrued from the emergence of global affluence ^{43, 44} and deplorable health conditions. It is crucial to evaluate all encompassing threats by employing the bottom-up model on sustainable food resources, ecosystems ¹⁴, energy, human health ^{45, 46}, through configuring water threats, exploring preventive measures and adaptations ⁵. The adaptation to extreme events necessitates a multi-dimensional approach by addressing risk management, health and hydrological issues. This requires investment in infrastructure, implementation of early warning systems, and promotion of community-based adaptation procedures. Health impacts of these events, necessitate cooperation between stakeholders, such as governments and communities, with appropriate healthcare facilities. Essentially, extreme weather events constitute health hazards ⁵.