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Hydrogeological effects of climate change will continue to affect water reservoirs worldwide. Some regions are experiencing and will experience severe decline in their water resources due to prolonged periods of drought. Since emergency practices such as the provision of emergency drinking water and forest firefighting depend on regional surface and groundwater resources, the safety of the hydro geosphere's of a region is of fundamental importance, especially in times of crisis. The study uniquely addresses the integration of emergency water management within broader sustainable practices, particularly in the German context where such an analysis has not been previously consolidated. Using the example of emergency drinking water management, the paper elaborates the extent to which measures of emergency response are currently recognised as part of sustainable water management. In an analysis, 79 documents addressing emergency drinking water management of both water supply companies and crisis management authorities in Germany were analysed. The findings revealed a general lack of documents addressing the long-term dependencies between water resources and emergency measures currently applied. Furthermore, the documents do not elaborate on how to implement these measures in a sustainable way recognising the distinctive characteristics of a region. Since response measures can potentially intensify water stress in a region, emergency water management must be consequently included in a holistic water management process to protect landscapes and communities for the future. This paper provides a first comprehensive compilation of essential documents dealing with emergency drinking water management in Germany. It furthermore introduces a new approach to emergency water management and identifies necessary research that could serve as a baseline for future crisis decision making to strengthen national and international initiatives on water resource protection. • Holistic water management must include water intense measures of emergency response. • Procedures of crisis management can intensify processes of regional water depletion. • Performance of emergency response can decline in times of long-term dryness. • The management of water emergencies requires adaptation to regional hydrogeography. [ABSTRACT FROM AUTHOR]

Global climate change has led to an increase in both the frequency and magnitude of extreme events around the world, the risk of which is especially imminent in tropical regions. Developing hydrological models with better capabilities to simulate streamflow, especially peak flow, is urgently needed to facilitate water resource planning and management as well as climate change mitigation efforts in the tropics. In view of the need, this paper explores the feasibility of improving streamflow simulation performance in the tropical Kelantan River Basin (KRB) of Peninsular Malaysia through coupling a conceptual process-based hydrological model − Soil and Water Assessment Tool (SWAT) with a deep learning model − Bidirectional Long Short-Term Memory (Bi-LSTM) in two ways. All SWAT parameters were set as their default values in one hybrid model (SWAT-D-LSTM), whereas three most sensitive SWAT parameters were calibrated in the other hybrid model (SWAT-T-LSTM). Comparison of daily streamflow simulation results have shown that SWAT-T-LSTM consistently performs better than SWAT-D-LSTM as well as the stand-alone SWAT and Bi-LSTM model throughout the simulation period. Particularly, SWAT-T-LSTM performs considerably better than the other three models in simulating daily peak flow. Based on the latest projection results of five GCMs from the Sixth Phase of the Coupled Model Intercomparison Project (CMIP6) under three emission scenarios (SSP1-2.6, SSP2-4.5, SSP5-8.5), the best-performed SWAT-T-LSTM was run to assess the potential impacts of climate change on streamflow in the KRB. Ensemble assessment results have concluded that both average and extreme streamflow is much likely to increase considerably in the already wet northeast monsoon season from November to January, which has surely raised the alarm for more frequent flood occurrence in the KRB. • Couple SWAT with Bi-LSTM to simulate daily streamflow in a tropical river basin. • Coupled model simulates streamflow much better than stand-alone SWAT and Bi-LSTM. • Use coupled model to assess impacts of climate change under multiple scenarios. • Both average and extreme streamflow is much likely to increase in monsoon season. [ABSTRACT FROM AUTHOR]

Understanding the changes in hydrological process is a key subject for water resource management of a high-diversity watershed. In this paper, through an establishment of a SWAT-based model, the effects of climate change and its induced vegetation change on hydrological process were analyzed in the East River Basin. The model could well simulate the hydrological processes of the basin including surface runoff (SURQ), groundwater (GWQ), lateral flow (LATQ), total water yield (WYLD), actual evapotranspiration (ET), and groundwater recharge (PERC). Under the vegetation change induced by temperature increase, the effects of the vegetation change on hydrological process were larger than that of the temperature change. Under the vegetation change caused by the increase of temperature and precipitation, the vegetation change enhanced the effects of climate change on annual SURQ, LATQ, GWQ, WYLD, and PERC of the basin. Under spatial scale, when the temperature and precipitation changed simultaneously, the increase of precipitation could promote the increase of annual ET in sub-watersheds. Also, the annual SURQ, WYLD, GWQ and ET in western sub-watersheds were more sensitive to the cumulative changes of vegetation and climate. This work can provide useful information to decision makers in water resource management of watersheds. • A SWAT-based model was established for a multi-level simulation. • Response of hydrological process to a climate-driven vegetation change was explored. • Effect of climate and vegetation changes on hydrological process was quantified. [ABSTRACT FROM AUTHOR]

This paper introduces a new methodology for quantifying the total resilience of water resources management scenarios. The climate change impacts on water supply and demand have been investigated using a calibrated soil and water assessment tool (SWAT) and a MODSIM water allocation model. Several criteria have been defined to measure five aspects of water resources systems resilience. The first aspect defines resilience as system strength against crossing a performance threshold (reliability). In the second aspect, if the system crosses the performance threshold, the recovery rate of the system after a disturbance is evaluated. The violation from the performance threshold has been measured as the third aspect (vulnerability), which considers the failure's severity. The fourth aspect is the resilience under extreme events with unknown occurrence probability, which includes four sub-criteria, namely rapidity, robustness, resourcefulness, and redundancy (4 R). Finally, the fifth criterion considers the ecological condition of the system (ecological index). To compare water resources management scenarios (alternatives), an analytical evidential reasoning-based (ER) approach has been used. To show the applicability of the proposed methodology, it has been applied to the Zarrinehrud river basin, which is the leading water supplier of Lake Urmia in Iran. As one of the largest saline lakes globally, this lake has been suffering from drastic desertification and salinization in the past two decades. The grade-based results of the performance criteria are synthesized into a grade-based total resilience criterion to facilitate the comparison of water resources management scenarios. It is shown that a scenario which results in 40% reduction in agricultural water demand until 2023 has the highest resilience and an acceptable construction and operational cost. • A total resilience criterion is proposed for assessing water resources systems. • This criterion can evaluate the resilience against events with known and unknown probability. • The grade-based values of performance criteria are estimated and combined using ER. • The previous resilience evaluations /have underestimated the critical conditions. • The total cost and resilience of the selected scenario are 1272.5 × 106 $ and 0.85. [ABSTRACT FROM AUTHOR]

Drought is a complex natural hazard. It occurs due to a prolonged period of deficient in rainfall amount in a certain region. Unlike other natural hazards, drought hazard has a recurrent occurrence. Therefore, comprehensive drought monitoring is essential for regional climate control and water management authorities. In this paper, we have proposed a new drought indicator: the Seasonally Combinative Regional Drought Indicator (SCRDI). The SCRDI integrates Bayesian networking theory with Standardized Precipitation Temperature Index (SPTI) at varying gauge stations in various month/seasons. Application of SCRDI is based on five gauging stations of Northern Area of Pakistan. We have found that the proposed indicator accounts the effect of climate variation within a specified territory, accurately characterizes drought by capturing seasonal dependencies in geospatial variation scenario, and reduces the large/complex data for future drought monitoring. In summary, the proposed indicator can be used for comprehensive characterization and assessment of drought at a certain region. • Comprehensive drought monitoring. • Save time and resources in the forecasting of future drought. • Systematic way to combine SDI by using a Bayesian network approach. • Easy in the calculation, save time and resources. [ABSTRACT FROM AUTHOR]

The present study reviews the overall perspectives of end-use studies on urban water crisis management by analysing their beneficial application in water conservation and wastewater recycling. The paper incorporates a critical review of water end-use consumption of 16 major countries from 3 major continents, i.e. Asia, Europe, and Australia. The study reflected a different trend between the water consumption of developed and developing nations, thereby implying a need for separate prospects of end-use results in these countries. Besides, the percentage of greywater generated varies from 54% to 86% of the total indoor household water consumption and thus can be a valuable water resource to solve the urban water crisis. There exists a strong correlation between the amount of greywater generated and the amount of water used for the shower (R2 = 0.69) and laundry (R2 = 0.50). The same, i.e. R2 values, for end-uses of the toilet flushing, dishwashing, and indoor taps with the amount of greywater, were found to be 0.30, 0.26, and 0.04, respectively. Further, except for the end-use pertaining to indoor taps, water consumption of all other end-uses has witnessed an upward spiral in developing countries with time, which may be attributed to the improved accuracy of collected end-use data or increased contribution of 'leaks/others' category. In developed nations like the USA, there is not a single end-use that has shown an absolute increase with time owing to a variety of measures such as increased awareness, education, retrofitting of appliances and several other factors like governmental restrictions. Change in attitude or/and behaviour of people towards water use driven by drought-like experience could also be a valid reason. After this extensive review of the end-use pattern, we proposed specific greywater recycling models that are expected to help engineers, governments, and policymakers in sustainable urban water management. Image 1 • Water end-use estimation can adequately support the urban water crisis management. • Greywater generated at household varies from 54% to 86% of total indoor water use. • Correlation (R2) of greywater with bath and washing was 0.7 and 0.5, respectively. • Water consumption of all end-uses witnessed a temporal shift in developing countries. • Specific greywater recycling models have been proposed based on end-use studies. [ABSTRACT FROM AUTHOR]