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Introduction: Climate change presents weighty challenges globally, with Nigeria particularly vulnerable to its multifaceted impacts. This review explores the effects of climate change-induced droughts and floods on food security in Nigeria, where agriculture is central to economic stability and livelihoods. Methods: The analysis integrates a comprehensive metadata evaluation, identifying trends, thematic gaps, and regional disparities in existing research. A systematic review of 2,500 publications, following PRISMA criteria, narrowed the focus to 450 studies, with 104 high-quality studies undergoing in-depth analysis. Results: Metadata analysis revealed an increase in research interest post-2010, a lack of longitudinal studies, and an underrepresentation of semi-arid northern regions in the literature. Findings indicate a growing threat to Nigeria's food security, as frequent flooding destroys infrastructure, erodes topsoil, and reduces agricultural productivity, leading to lower food output and increased costs. At the same time, droughts, particularly in the semi-arid north, drastically reduce crop yields and worsen food insecurity by depleting vital water resources. These challenges disproportionately affect smallholder farmers and pastoral communities, waning poverty and hunger. Discussion: The review highlights the complexity of Nigeria's food insecurity, shaped by factors such as geography, socioeconomic status, and adaptive capacity. Despite advancements in adaptation strategies, issues like fragmented policies and inadequate infrastructure continue to hinder effective responses. However, the review identifies key opportunities to enhance food security and resilience, including greater stakeholder engagement, increased investment in climate adaptation, and the use of digital technologies. By addressing these challenges and leveraging the opportunities, Nigeria can build a more resilient and sustainable food system capable of withstanding the increasing threats posed by climate change. [ABSTRACT FROM AUTHOR]

The Three Gorges Reservoir (TGR) is one of the world's largest hydropower projects and plays an important role in water resources management in the Yangtze River. For the sake of disaster prevention and catchment management, it is crucial to understand the regulation capacity of the TGR on extreme hydrological events and its impact on flow regime in a changing climate. This study obtains historical inflows of the TGR from 1961 to 2019 and uses a distributed hydrological model to simulate the future inflows from 2021 to 2070. These data are adopted to drive a machine learning‐based TGR operation model to obtain the simulated outflow with TGR operation, which are then compared with the natural flow without TGR operation to assess the impact of TGR. The results indicate that the average flood peaks and total flooding days in the historical period could have been reduced by 29.2% and 53.4% with the operation of TGR. The relative declines in drought indicators including duration and intensity were generally less than 10%. Faced with more severe extreme hydrological events in the future, the TGR is still expected to alleviate floods and droughts, but cannot bring them down to historical levels. The impact of TGR operation on flow regime will also evolve in a changing climate, potentially altering the habitats of river ecosystems. This study proposes feasible methods for simulating the operation of large reservoirs and quantifying the impact on flow regime, and provides insights for integrated watershed management in the upper Yangtze River basin. Plain Language Summary: The Three Gorges Reservoir (TGR) is located in the upper Yangtze River basin and is one of the world's largest hydropower projects. This study combines hydrological modeling and machine learning methods to quantify the effects of TGR operation on flow regime in the historical and future periods. The results indicate that the operation of TGR could play an important role in mitigating historical droughts and floods. Specifically, the flood peak in 1998 could have been reduced by 24.7% if the TGR was in operation. In the future, the extreme hydrological events will become more severe. While the TGR will continue to play a significant role, it cannot fully control floods and droughts to the same extent as it did in the historical period. In a changing climate, the Yangtze River basin will still face higher flood and drought risks with the operation of TGR. Under future climate scenarios, the operation of TGR will also alter the flow regime metrics and have new implications on the river ecosystem environment. Key Points: An ensemble learning model based on two neural networks is constructed to simulate Three Gorges Reservoir (TGR) operationsTGR can mitigate floods and droughts, but this capability might be weakened by more severe future extreme eventsTGR can offset most flow regime changes caused by climate change, but adaptive operation strategies are still needed [ABSTRACT FROM AUTHOR]

Although many large-N quantitative studies have evidenced the adverse effects of climatic extremes on social stability in China during the historical period, most of them rely on temperature and precipitation as major explanatory variables, while the influence of floods and droughts on social crises is rarely measured. Furthermore, a comparison of the climate-society nexus among different geographic regions and at different temporal scales is missing in those studies. To address this knowledge gap, this study examines quantitatively the influence of floods and droughts on internal wars in three agro-ecological (rice, wheat, and pastoral) regions in China in AD1470-1911. Poisson regression and wavelet transform coherence analyses are applied to allow for the non-linear and non-stationary nature of the climate-war nexus. Results show that floods and droughts are significant in driving internal wars in historical China, but are characterized by strong regional variation. In the rice region, floods trigger internal wars at the inter-annual and multi-decadal time scales. In the wheat region, both floods and droughts cause internal wars at the inter-annual and multi-decadal time scales. In the pastoral region, internal wars are associated with floods only at the multi-decadal time scale. In addition, the multi-decadal coherence between hydro-climatic extremes and internal wars in all three of the agro-ecological regions is only significant in periods in which population density is increasing or the upper limit of regional carrying capacity is being reached. The above results imply that the climate-war nexus is mediated by regional geographic factors such as physical environmental setting and population pressure. Hence, we encourage researchers who study the historical human-climate relationship to boil down data according to geographic regions in the course of statistical analysis and to examine each region individually in follow-up studies. [ABSTRACT FROM AUTHOR]

Pakistan has become a poster child for extreme weather events such as floods and droughts in recent years. The frequency and severity of these events are expected to increase in the future due to predicted climatic changes. This scenario suggests the likelihood of increased crop damage in flood- or drought-prone areas, and hence the need for risk-reducing mechanisms. This paper attempts to determine whether crop insurance is an acceptable tool against flood and drought events in rural Pakistan. It also analyses the factors influencing a farmer's willingness to pay insurance premiums. In a rural farm-household survey, farmers were asked about their willingness to pay for a hypothetical crop insurance programme employing a “double-bounded dichotomous contingent valuation method”. The results revealed that around 30% of the respondents accepted the idea of crop insurance as a tool to reduce and mitigate the financial risks associated with floods and droughts. Our findings suggest that the frequency and severity of the previous weather-related extremes, socio-economic settings, farm typology and the farming communities’ ability to pay need to be taken into consideration when introducing crop insurance programmes against flood or drought in Pakistan. Furthermore, disseminating awareness among farming communities about the future climatic changes and the associated risks of the occurrence of extreme weather events is imperative. The government's willingness to share/subsidize insurance premiums may increase the demand for crop insurance among smallholders in Pakistan and protect them from the negative repercussions of these extreme weather events in order to sustain their livelihoods. [ABSTRACT FROM PUBLISHER]

The Water Framework Directive sets out a series of deadlines for implementation that are proving hard to meet as a result of the economic recession. In addition to which, we also have to face the serious challenges affecting the Spanish water situation: floods, droughts, water shortages in Eastern Spain, without ignoring the need to conserve the wealth of waterworks in the country. This article discusses a series of points and measures concerning the stakeholders involved and covering different areas of action related to water These measures are all geared to stimulating this sector by productive investment which would help create employment. [ABSTRACT FROM AUTHOR]

The present study has been taken up to quantify the possible impact of the climate change on the water resources of Indian river systems within the constraints of the uncertainty of climate change predictions. The study uses the PRECIS daily weather data to determine the spatio-temporal water availability in the river systems. A distributed hydrological model, namely SWAT has been used to simulate all the river basins of the country. The analysis has been performed to evaluate the severity of droughts and floods and thus identify the vulnerable hotspots that may require attention in view of the climate change in various parts of the country. The analysis is also performed on the blue and green water so as to identify the climate change impacts on these sub-components of water that are responsible for environmental functions and biomass production. These results have been made available at http://gisserver.civil.iitd.ac.in/natcom for use by a large cross-section of users. [ABSTRACT FROM AUTHOR]

Floods and droughts are natural phenomena of difficult prevision. Awareness, mitigation and water resource management, depend upon timely information on the beginning of a dry or wet period and on their extension in time and space. This study predicts SPI steady state class probabilities in the Douro region, Portugal, through an empirical and Markov chain approach, expected residence time in each class of severity; expected first passage time, recurrence time and class prediction in a short-term basis. It was verified that all these variables are useful for water resources management. [ABSTRACT FROM AUTHOR]

The Weihe River Basin (WRB) in a monsoon transition zone of East Asia interacts with multiple weather systems and is susceptible to floods and droughts. We developed a framework based on the Empirical Orthogonal Function analysis, Complete Ensemble Empirical Mode Decomposition with Adaptive Noise analysis, and moving-average based Spearman rank correlation to identify the spatial patterns of the dry/wet conditions from 1470 to 2016, decompose the dry/wet index into the leading components with a period between 2 and 3 years and 100+ years, and discover their driving forces on multiple time scales. Results show that WRB can be divided into four distinguishable hydroclimatic subregions located in the southeast, west, central, and north. The East Asian summer monsoon and South Asian summer monsoon impact this region mainly on the inter-annual and inter-decadal scales, while the impacts of ENSO, PDO, AO, and NAO are dominant on the multi-decadal and centennial scales. [Display omitted] • Developed a new framework to attribute dry/wet spatiotemporal variability on multiple time scales. • Revealed four unique hydroclimatic subregions for the Weihe River Basin. • Identified the effects of monsoons, plateau circulation, westerly, and solar activities on Weihe. • Dry/wet conditions of the subregions show opposite responses to solar activity. [ABSTRACT FROM AUTHOR]