GIS-Based Groundwater Potential Assessment in Varied Topographic Areas of Mianyang City, Southwestern China, Using AHP

Mianyang City is located in the varied topographic areas of Sichuan Province in southwestern China and is characterized by a complex geological background. This area is prone to disasters and its varied topography is inconvenient for emergency water storage and supply. Groundwater is essential for alleviating the demand for water and post-disaster emergency water supply in this area. This study applied AHP to integrate remote sensing, geological and hydrological data into GIS for the assessment of groundwater potential, providing a plan for the rational exploitation of groundwater and post-disaster emergency water supply in the area. Nine factors, including the spring calibration related to groundwater, were integrated by AHP after multicollinear checks. As a result, the geology-controlled groundwater potential map was classified into five levels with equal intervals. All the results were validated using borehole data, indicating the following: the areas with yield rates of , 1–20 , and 20–400 accounted for 2.66%, 36.1%, and 39.62%, respectively, whereas the areas with yield rates of 400–4000 and accounted for only 20.88% and 0.75% of the overall area. The flexibility of this quick and efficient method enables its application in other regions with a similar geological background.

Characterizing the Deep Pumping-induced Subsidence Against Metro Tunnel Using Vertically Distributed Fiber-Optic Sensing

Continuous pumping of groundwater will induce uneven ground settlement, which may adversely affect the nearby metro tunnels. In this paper, taking Nantong Metro Line 1 crossing Nantong Port Water Plant as an example, the surface level measurement and subsurface deformation monitoring using vertically distributed fiber-optic sensing are implemented to acquire the surface and subsurface settlement of emergency water supply conditions. The fiber optic cable vertically buried in the constant-temperature layer is used to measure the subsurface strain field and deduce the deformation amount of each stratum. The monitoring results show that, during the pumping, the deformation of the aquifer and ground surface is linearly compressed with time; after the pumping, the ground surface continues to settle linearly at a slower rate for about 50 days, followed by a slow linear rebound, and the aquifer is logarithmically rebounded. In addition, deep pumping causes the deformation of the aquifers to be much greater than the surface settlement; the surface settlement lags behind the settlement of the aquifer by 1 to 2 months; the surface rebound recovery also exhibits a similar delay. Fitting models were derived to predict the maximum settlement and curvature radius of the site, which indicates that the adverse effects against the metro tunnel are not negligible once the continuous pumping exceeds 15 days. Those insights can be referred by the practitioners for the control of urban subsidence.

Public health without water? Emergency water supply and minimum supply standards of hospitals in high-income countries using the example of Germany and Austria

The drinking water supply is a core element of national regulations for normal and emergency supply as well as coping with crisis events. Particularly with regard to the interdependence of critical infrastructures means that water supply failures can have far-reaching consequences and endanger the safety of a society, e.g., by impairing hospital operations. In case of an emergency in the drinking water infrastructure, minimum supply standards, e.g., for patients in hospitals, become important for emergency management during crisis situations. However, wider recognition of this issue is still lacking, particularly in countries facing comparably minor water supply disruptions. Several international agencies provide guideline values for minimum water supply standards for hospitals in case of a disaster. Acknowledging these minimum standards were developed for humanitarian assistance or civil protection, it remains to be analyzed whether these standards apply to disaster management in countries with high water and healthcare supply standards. Based on a literature review of scientific publications and humanitarian guidelines, as well as policies from selected countries, current processes, contents, and shortcomings of emergency water supply planning are assessed. To close the identified gaps, this paper indicates potential improvements for emergency water supply planning in general as well as for supply of hospitals and identifies future fields of research.

Will There Be Enough Water? A System Dynamics Model to Investigate the Effective Use of Limited Resources for Emergency Water Supply

The increased probability of occurrence of various hazards to water supply systems due to climate change requires the strengthening of their resilience through effective emergency preparedness planning. This paper introduces a method for the assessment of the resilience of water supply systems, including emergency supply measures. With 20 uniquely defined emergency situations, the technical constellations for possible impairments of the water supply are documented. The system analysis developed for each emergency situation is then used to determine and prioritise all suitable supply measures to reduce the supply deficit. Based on the data of a water utility close to Frankfurt, Germany, the developed system dynamics model was used to examine the resource utilisation for the respective emergency situations and to estimate the amount of water provided. The model allows us to scrutinize and compare emergency water supply measures as well as to identify required resources. Furthermore, the method helps us to prioritize measures as well as to make decisions when planning and providing emergency water supply (EWS).

Emergency water supply decision-making of transboundary river basin considering government–public perceived satisfaction

The emergency supply of transboundary water resources is a prominent problem affecting the social and economic development of basin countries. However, current water supply decisions on transboundary water resources may ignore the psychological perception of multi-stakeholders, and the evolution of emergencies increases the uncertainty of decision making. Both factors would lead to the low acceptance of water-related decisions. Utility satisfaction, perceived losses, and quantity satisfaction were selected in this paper to identify the perceived satisfaction of upstream governments, downstream governments, and the public, respectively, over multiple decision-making stages. A modeling framework combining prospect theory and the multi-stage multi-objective programming methodology was then developed to measure the perceived satisfaction of different stakeholders in a watershed under emergency. A two-stage NSGA-II and TOPSIS based approach was adopted to find the optimal compromise solution to solve the model. The framework was applied in the Lancang–Mekong River basin to provide suggestions to decision makers. Upstream decision makers must choose a moderate proportional fairness degree when making emergency decisions to maximize the perceived satisfaction of all stakeholders. Meanwhile, the perceived loss of downstream countries with low water demand should be considered first in the formulation of emergency water supply plans. Furthermore, although water supply from upstream countries can improve perceived water quantity satisfaction of downstream publics, additional actions must still be taken to change the traditional concepts of the public.

Determination of Proper Water Supply Rate for Emergency Interconnection Plan

The deterioration of water supply networks leads to frequent accidents, such as pipe failure, which result in water service interruptions. Depending on the type of accident, a large-scale water service interruption can occur. Therefore, an emergency interconnection plan has been established to prevent interruptions in water service. However, most emergency interconnection plans only consider whether water can be supplied to the region of water service interruption. The area that can actually supply water, emergency water supply area (EWSA), and the possible time required to supply water, emergency water supply time (EWST) are not usually considered. Furthermore, in cases wherein the adjacent local governments or adjacent water supply blocks have insufficient water for the region of water service interruption, it is a good practice to increase the possible water supply time by the reducing the water supply rate (WSR) in order to minimize the damage from the water service interruption. In this study, a method is suggested to determine the proper WSR required to minimize the damage when the amount of emergency water is insufficient. Since it is a case where the amount of emergency water is not sufficient, A-PDA is used to simulate EWSA and EWSA for each WSR. The simulation results are subsequently converted into the customer satisfaction index for each WSR. Through this procedure, the proper WSR can be determined, thereby improving both customer satisfaction and water supply time. Finally, this method is applied to a real water supply network to verify its applicability.

Numerical Simulation of Groundwater Flow of Emergency Water Source in Nanchang City

The source of water supply in Nanchang City is relatively single, and the safety of urban water supply is difficult to guarantee. According to the hydrogeological conditions of the study area, a threedimensional visualization numerical model of groundwater system was established. After the model identification and verification, combined with the target of emergency water supply in Nanchang city, the emergency exploitation of groundwater in Youkou emergency water source was simulated by using the model under different emergency exploitation schemes, respectively. The prediction results show that compared with scheme I and scheme II, scheme III is most suitable for the requirements of well layout, which has the advantages with the minimum drawdown of groundwater level, and the maximum exploitation. For scheme III, under the conditions that the dewatered aquifers are no more than 1/2 and 2/3 of the original aquifer, the emergency exploitation of 36.55×104m3/d and 49.45×104m3/d can be provided, which could meet the emergency water demands of 54.9% and 74.3% of the local residents, respectively.

Description of the targeted WASH response strategy implemented during the cholera outbreak of 2017-2018 in Kinshasa, DRC

Background Rapid control of cholera outbreaks is a significant challenge in overpopulated urban settings, and documented results on field interventions are scarce. During the 2017-2018 period, Kinshasa, the capital ofDemocratic Republic of the Congo, experienced a sharp increase in cholera cases that showed potential to quickly spread throughout the city. A novel targeted WASH (Water, Sanitation and Hygiene) strategy was implemented to quickly stem the cholera outbreak. Methods We carried out a descriptive study of the cholera outbreak in Kinshasa from 2017 to 2018. Cholera surveillance databases from the Ministry of Health were analyzed to assess the spatiotemporal dynamics of the cholera outbreak using epidemic curves and cartography. Weekly precipitation levels in Kinshasa were also assessed. We also described the targeted cluster grid WASH strategy, which was implemented to quickly target case clusters at the household and community level, carrying out interventions focused on emergency water supply, household water treatment and safe storage, home disinfection and hygiene promotion. We also examined the evolution of the outbreak following implementation of the response strategy. Results From January 2017 to November 2018, a total of 1,712 suspected cholera cases were reported in Kinshasa. During this period, the health zones most affected included Binza Météo, Limeté, Kokolo, Kintambo and Kingabwa. Following implementation of the response strategy, the weekly cholera case numbers in Binza Météo, Kintambo and Limeté decreased by an average of 57% in two weeks and 86% in four weeks. The total weekly case numbers throughout Kinshasa Province dropped by 71% at four weeks after the outbreak peak. Conclusion During the 2017-2018 period, Kinshasa experienced a sharp increase in cholera cases that showed potential to quickly spread throughout the city. To contain the outbreak, WASH response interventions targeted case households, nearby neighbors and public areas in case clusters using a grid approach. Following implementation of the WASH response, the outbreak in Kinshasa was quickly brought under control. A similar approach may be useful to quickly interrupt cholera transmission in other urban settings.