Search

With global climate change and the rapid urbanization, urban flood and drought disasters are frequent and urban water supply systems are facing a sea of serious challenges. It is crucial to assess the resilience of urban water supply systems and develop corresponding disaster mitigation and improvement strategies. Urban water supply systems include many subsystems, but existing researches generally focus on a single subsystem. Therefore, this paper proposes a correlation analysis method and a factor analysis method for the resilience evaluation index system of urban water supply systems by combining each subsystem and applying grey system theory. The method can reflect the four dimensions of the water supply process (water source, water plant, supply and distribution network and users) and the five dimensions of the urban management system (society, natural environment, economy, physics and organization). Taking Qingdao as an example, a multi-level integrated evaluation model based on a cloud model is applied to simulate and analyze the resilience of Qingdao's water supply system. As a result, decision support is provided for planning and building resilience systems for urban water systems in the short and long term, based on four main factors. [ABSTRACT FROM AUTHOR]

Extreme weather events present environmental and social challenges across the Eurasian steppe. In Mongolia much attention is given to drought and dzud (severe winter conditions) impact on rural livelihoods, landscapes and governance. A link between the two events, fostered by international and state agencies, speculates that drought leads to dzud; this has become the widely accepted doctrine. However, the relationship between the two events is assumed rather than analysed. Whilst there may be natural links between climate events, causality is more difficult to establish yet often claimed post-event. This paper stresses Mongolia’s destructive dzuds of 1999-2001 and 2009-2010 in examining drought frequency before dzud events. Findings question the hazard connection as just 3 of 32 examined dzud events were preceded by drought. Investigation did not document a relationship between the disasters; linkages between extreme events were implied rather than established. The human role in disaster also needs to be assessed as preparation, and response are key factors for mitigation. Study results identified a lack of causality between the disasters, suggesting more assiduous investigation of hazards is needed in Mongolia. This can clarify causal factors, identify risk and improve disaster mitigation strategies in Mongolia. [ABSTRACT FROM AUTHOR]

Drought is an extreme climatic event that mostly occurs as a result of low rainfall, which leads to lack of water in various agro-ecological conditions of Pakistan. The condition could be further exacerbated by the prevailing dry weather. Therefore, accurate, timely, and efficient drought monitoring is crucial to ensure that its adverse effects are mitigated. In this study, Moderate Resolution Imaging Spectroradiometer (MODIS) and TRMM-based data were used together with remote sensing techniques to improve drought mitigation and disaster risk reduction strategies. In order to monitor drought mitigation and disaster risk reduction strategies in Pakistan, the crop water stress index (CWSI), vegetation condition index (VCI), normalized vegetation supply water index (NVSWI), vegetation health index (VHI), and temperature vegetation drought index (TVDI) were chosen as the instrument. Due to low rainfall and significantly low vegetation, CWSI, NDVI, TVDI, and VHI are useful in characterizing drought mitigation strategies in Pakistan. Monthly NDVI, NAP, NVSWI, TVDI, VCI, and VHI values and heat map analysis show that Pakistan suffered from drought in years 2001, 2002, and 2006. Seasonal CWSI, NDVI, VHI, and TVDI confirmed that Pakistan was affected by severe drought in 2001, which continued and led to severe drought in 2002 and 2006. We generate spatial correlation coefficients between NDVI and NVSWI, VCI, and VHI, and NVSWI and VCI and VHI, while the VCI and VHI values are significantly positively correlated. CWSI, NDVI, VHI, and TVDI show positive signs of effective climate change drought mitigation and disaster risk reduction strategies in Pakistan. Thus, these drought indices have been confirmed to be a complete drought monitoring indicator and reduce the risk of drought in Pakistan. [ABSTRACT FROM AUTHOR]

Developing an index that can assess the marked changes in water resources is necessary for drought/flood hazard prevention and water resource planning, particularly in the context of global climate change and intensified human activities. In this study, spatiotemporal variations of water resources variables, namely precipitation (P), evapotranspiration (ET), and runoff (R), regarded as water input, output, and storage, respectively, were systematically statistically analyzed. Following this, a comprehensive Copula-based Drought/Flood Index (CDFI) was constructed to identify the drought/flood hazards, and machine learning and game theory were then successively applied to quantify the influence of the Large-scale Climate Indices (LCIs) on drought/flood intensity. The results reveal that temporally, P, ET, and R present similar turning-point years in the 1990s, with values changing from significantly decreasing to insignificantly decreasing, significantly increasing, and insignificantly decreasing, respectively. Spatially, the water resources become drier in the arid area and wetter in the humid area. The CDFI results demonstrate an increased flood probability in the mountains and near-polar rivers, and drought in extremely arid areas. Moreover, the influencing factors of CDFI exhibited notable spatial heterogeneity. CDFI is controlled by the Arctic Oscillation in most regions of the world, and the influence of sea surface temperature on CDFI increases gradually with the decrease of latitude, and extreme events are generally linked to extreme LCIs. Notably, vegetation change (area, type, and growth) affects ET and R, thus enhancing the climate's impact on drought/flood hazards. The conclusions provide an essential basis for the identification and policy planning of drought/flood hazards caused by the spatiotemporal variations of water resource variables. [ABSTRACT FROM AUTHOR]

This study aimed to explore the rich tapestry of studies on drought disasters, drought vulnerability, drought severity and water shortage (DDVS_WS), taking into account the critical situation and circumstance posed by drought in line with the shortage in water supplies. In total, 1117 original articles were downloaded in a BibTeX format for further analysis. The downloaded information included, but was not limited to authors, title, year of publication, citations, author keywords, keywords plus, countries of publications, institutions, journals, citations. Published studies on DDVS_WS obtained from the web of science (WOS) and Scopus databases on 20 May 2020 were used in this study. The field of DDVS_WS experienced a drastic increase with an annual growth of about 12.7% in terms of continued publications output during the years under assessment. Considering the country level, China ranked first with the highest number of publications, and the USA has great academic influence with most top articles' citations emerging from the USA affiliated institutions and research centres. Based on the top keyword, drought and climate change are at the centre of issues related to drought and water shortage, this provides a hint on the relatedness of drought and climate change for further studies. This study offers a map to navigate the intellectual quandary of DDVS_WS research and guidance for further studies in this area of specialization. It is fundamental to stress that this study only covers the core area of DDVS_WS research, hence, it is expected that new empirical studies and potential solutions would offer new insight on drought and water shortage as new research evolves. [ABSTRACT FROM AUTHOR]

This study provides an overview of the drought situation in Northeast Brazil for the past, present, and future. Droughts affect more people than any other natural hazard owing to their large scale and long-lasting nature. They are recurrent in the region and while some measures have been taken by the governments to mitigate their impacts, there is still a perception that residents, mainly in rural areas, are not yet adapted to these hazards. The drought affecting the Northeast from 2012 to 2015, however, has had an intensity and impact not seen in several decades and has already destroyed large swaths of cropland, affecting hundreds of cities and towns across the region, and leaving ranchers struggling to feed and water cattle. Future climate projections for the area show large temperature increases and rainfall reductions, which, together with a tendency for longer periods with consecutive dry days, suggest the occurrence of more frequent/intense dry spells and droughts and a tendency toward aridification in the region. All these conditions lead to an increase in evaporation from reservoirs and lakes, affecting irrigation and agriculture as well as key water uses including hydropower and industry, and thus, the welfare of the residents. Integrating drought monitoring and seasonal forecasting provides efficient means of assessing impacts of climate variability and change, identifying vulnerabilities, and allowing for better adaptation measures not only for medium- and long-term climate change but also for extremes of the interannual climate variability, particularly droughts. [ABSTRACT FROM AUTHOR]