Water-related Hazards Research Articles

Impact of Human Activities on Net Anthropogenic Nitrogen Inputs (NANI) at Township Scale in Erhai Lake Basin

Excessive nitrogen inputs from human activities have become the main cause of water eutrophication and related ecological hazards. In order to study the impact of human activities on nitrogen in the basin, and based on statistical data of administrative units in 16 towns and villages, this study used the NANI model to calculate net anthropogenic nitrogen inputs (NANI) at township scale in Erhai Lake basin. Results show that the total amount of NANI in Erhai Lake basin was 29.81×103 t in 2014, and nitrogen input intensity per unit area was 10986 kg·(km2·a)-1, significantly higher than the national average. The input of nitrogen from food by the local tourist population was 0.26×103 t, accounting for 8% of local food nitrogen input. Nitrogen input from chemical fertilizer is the largest NANI input source, accounting for 47% of net nitrogen input in the basin, followed by net nitrogen input of food and feed. The spatial distribution of NANI at township scale shows evident regionalization, with higher values in the north and lower values in the south of the basin. The intensity of NANI in towns with cropland or population is high. The corresponding risk of nitrogen pollution in Erhai Lake basin is therefore a primary concern, and will remain so in the near future.

Serious gaming for participatory planning of multi-hazard mitigation

ABSTRACTCollaborative, holistic, and proactive planning for basin-wide water management solutions addressing multiple water-related hazards is challenging. Shared vision planning (SVP) and decision support systems (DSSs) are two approaches that have been used to address the challenges described. SVP is a participatory planning process. DSSs can efficiently support the integration of multiple and vast amounts of information and interactively illustrate the trade-offs between alternative mitigation plans. While SVP and DSS have been previously used to help stakeholders to better understand watershed processes and how to arrive at collaborative basin-wide decisions, coupling these tools with serious gaming is an emerging effort. The multi-hazard tournament (MHT) framework is an example of the integration of serious gaming, DSS and SVP. The MHT is based on the premise that almost all cultures and individuals understand and enjoy sports, teams and structured games. This paper first introduces a new approach called the MHT which couples serious gaming via the use of DSS with the traditional SVP concepts of (1) collaborative computer modelling, (2) traditional water resources planning, and (3) structured public participation through a case study of the Cedar Rapids, Iowa MHT. Second, it examines and discusses the effectiveness of this combined approach in achieving objectives often established in collaborative, watershed scale: decision-making, social learning, and relationship building. An analysis of the Cedar Rapids MHT survey results show that the integration of the Iowa watershed decision support system, SVP, and serious gaming framework served as a valuable tool for examining trade-offs between mitigation options and their impacts. The Cedar Rapids MHT survey results indicated this was also an adequate means of capacity building, social learning, and meaningfully engaging the community in mitigating hazards posed in their watersheds. The paper also explores how the integration of SVP, DSS, and serious gaming with some refinements could be used to practically support watershed scale planning and decision-making processes.

Human impact parameterizations in global hydrological models improve estimates of monthly discharges and hydrological extremes: a multi-model validation study

Human activity has a profound influence on river discharges, hydrological extremes and water-related hazards. In this study, we compare the results of five state-of-the-art global hydrological models (GHMs) with observations to examine the role of human impact parameterizations (HIP) in the simulation of mean, high- and low-flows. The analysis is performed for 471 gauging stations across the globe for the period 1971–2010. We find that the inclusion of HIP improves the performance of the GHMs, both in managed and near-natural catchments. For near-natural catchments, the improvement in performance results from improvements in incoming discharges from upstream managed catchments. This finding is robust across the GHMs, although the level of improvement and the reasons for it vary greatly. The inclusion of HIP leads to a significant decrease in the bias of the long-term mean monthly discharge in 36%–73% of the studied catchments, and an improvement in the modeled hydrological variability in 31%–74% of the studied catchments. Including HIP in the GHMs also leads to an improvement in the simulation of hydrological extremes, compared to when HIP is excluded. Whilst the inclusion of HIP leads to decreases in the simulated high-flows, it can lead to either increases or decreases in the low-flows. This is due to the relative importance of the timing of return flows and reservoir operations as well as their associated uncertainties. Even with the inclusion of HIP, we find that the model performance is still not optimal. This highlights the need for further research linking human management and hydrological domains, especially in those areas in which human impacts are dominant. The large variation in performance between GHMs, regions and performance indicators, calls for a careful selection of GHMs, model components and evaluation metrics in future model applications.

Monitoring flood and drought events - earth observation for multiscale assessment of water-related hazards and exposed elements

Disaster management is dependent on comprehensive information about the hazard’s nature and the elements exposed – independent of the location and extent of the hazard. This work explores methods to monitor water-related hazards and identify exposed elements based on multisensorial earth observation (EO) and auxiliary data in southern Africa. For the hazard-related perspective, we present methods to monitor fl oods based on radar data (Sentinel-1, TerraSAR-X) and droughts based on time series MODIS satellite data. For the exposure-related perspective, we classify exposed settlements from TerraSAR-X (TSX) and TanDEM-X (TDX) data. We assess people at risk and their respective locations, combining earth observation and census-based geoinformation. The datasets and methods are explored in two case studies investigating a flood in northern Namibia in 2011 and drought events in South Africa and Botswana in 2015 and 2016. The case studies show that the methods developed are crucial tools for hazard and exposure identification, assessment, and monitoring.

Comparative study on long term climate data sources over South Korea

Abstract Long term climate data are vitally important in reliably assessing water resources and water related hazards, but in-situ observations are generally sparse in space and limited in time. Although there are several global datasets available as substitutes, there is a lack of comparative studies about their suitability in different parts of the world. In this study, to find out the reliable century-long climate dataset in South Korea, we first evaluate multi-decadal reanalyses (ERA-20 cm, ERA-20c, ERA-40 and NOAA 20th century reanalysis (20CR)) and gridded observations (CRUv3.23 and GPCCv7) for monthly mean precipitation and temperature. In the temporal and statistical comparisons, CRUv3.23 and GPCCv7 for precipitation and ERA-40 for temperature perform the best, and ERA-20c and 20CR also indicate meaningful agreements. For ERA-20 cm, it has only a statistical agreement, but the mean has the difficulty in representing its ensemble. This paper also shows that the applicability of each dataset may vary by region and all products should be locally adjusted before being applied in climate impact assessments. These findings not only help to fill in the knowledge gaps about these datasets in South Korea but also provide a useful guideline for the applicability of the global datasets in different parts of the world.

Environmental sustainability control by water resources carrying capacity concept: application significance in Indonesia

This paper reviews the use of Water Resources carrying capacity concept to control environmental sustainability with the particular note for the case in Indonesia. Carrying capacity is a capability measure of an environment or an area to support human and the other lives as well as their activities in a sustainable manner. Recurrently water-related hazards and environmental problems indicate that the environments are exploited over its carrying capacity. Environmental carrying capacity (ECC) assessment includes Land and Water Carrying Capacity analysis of an area, suggested to always refer to the dimension of the related watershed as an incorporated hydrologic unit on the basis of resources availability estimation. Many countries use this measure to forecast the future sustainability of regional development based on water availability. Direct water Resource Carrying Capacity (WRCC) assessment involves population number determination together with their activities could be supported by available water, whereas indirect WRCC assessment comprises the analysis of supply-demand balance status of water. Water resource limits primarily environmental carrying capacity rather than the land resource since land capability constraints are easier. WRCC is a crucial factor known to control land and water resource utilization, particularly in a growing densely populated area. Even though capability of water resources is relatively perpetual, the utilization pattern of these resources may change by socio-economic and cultural technology level of the users, because of which WRCC should be evaluated periodically to maintain usage sustainability of water resource and environment.

Adaptive Governance for Building Urban Resilience: Lessons from Water Management Strategies in Two Indonesian Coastal Cities

Using a combination of vulnerability and resilience frameworks, this paper examines governance challenges and strategies to coastal and water-related resilience in two Indonesian cities. It compares the methods that local governments have used to engage different stakeholders and enact various policy solutions, in order to understand how multi-scalar elements of governance influence vulnerability and adaptive capacity to water-related hazards. After discussing shocks and stresses of note that span the social, economic and environmental realm, a comparative analysis will be carried out for two large coastal cities in Indonesia, Surabaya and Semarang. A combination of resilience frameworks as a basis for analysis reveals the different approach of each city to enhance resilience. While Surabaya centered on enhancing people participation and efforts internally, Semarang more focused on instituting comprehensive plans and external collaboration. These different approaches suggest that resilience can be built from different ways. A combination of adequate financing, technical capacity, excellent leadership, an understanding of the root causes and pressures, and long-term visions is necessary for impactful governance.

Urban water security: Emerging discussion and remaining challenges

Human livelihood requires reliable water supply and protection from water-related hazards. Significant growth in population and anthropogenic activities along with unfolding effects of global environmental change have enormously increased the vulnerability of human systems to changes in water quantity and/or quality. Addressing such vulnerabilities has high management priority in urban regions due to the concertation of population and socio-economic activities. This has resulted into emerging various discussions around the concept of “urban water security”. Here we provide a brief overview on the water-related threats to human society and the context of water security, with a greater goal of recognizing operational and social challenges along with science needs in urban environments.

A water risk index for portfolio exposure to climatic extremes: conceptualization and an application to the mining industry

Abstract. Corporations, industries and non-governmental organizations have become increasingly concerned with growing water risks in many parts of the world. Most of the focus has been on water scarcity and competition for the resource between agriculture, urban users, ecology and industry. However, water risks are multi-dimensional. Water-related hazards include flooding due to extreme rainfall, persistent drought and pollution, either due to industrial operations themselves, or to the failure of infrastructure. Most companies have risk management plans at each operational location to address these risks to a certain design level. The residual risk may or may not be managed, and is typically not quantified at a portfolio scale, i.e. across many sites. Given that climate is the driver of many of these extreme events, and there is evidence of quasi-periodic climate regimes at inter-annual and decadal timescales, it is possible that a portfolio is subject to persistent, multi-year exceedances of the design level. In other words, for a multi-national corporation, it is possible that there is correlation in the climate-induced portfolio water risk across its operational sites as multiple sites may experience a hazard beyond the design level in a given year. Therefore, from an investor's perspective, a need exists for a water risk index that allows for an exploration of the possible space and/or time clustering in exposure across many sites contained in a portfolio. This paper represents a first attempt to develop an index for financial exposure of a geographically diversified, global portfolio to the time-varying risk of climatic extremes using long daily global rainfall datasets derived from climate re-analysis models. Focusing on extreme daily rainfall amounts and using examples from major mining companies, we illustrate how the index can be developed. We discuss how companies can use it to explore their corporate exposure, and what they may need to disclose to investors and regulators to promote transparency as to risk exposure and mitigation efforts. For the examples of mining companies provided, we note that the actual exposure is substantially higher than would be expected in the absence of space and time correlation of risk as is usually tacitly assumed. We also find evidence for the increasing exposure to climate-induced risk, and for decadal variability in exposure. The relative vulnerability of different portfolios to multiple extreme events in a given year is also demonstrated.

Mapping flood and flooding potential indices: a methodological approach to identifying areas susceptible to flood and flooding risk. Case study: the Prahova catchment (Romania)

Given that floods continue to cause yearly significant worldwide human and material damages, flood risk mitigation is a key issue and a permanent challenge in developing policies and strategies at various spatial scales. Therefore, a basic phase is elaborating hazard and flood risk maps, documents which are an essential support for flood risk management. The aim of this paper is to develop an approach that allows for the identification of flash-flood and flood-prone susceptible areas based on computing and mapping of two indices: FFPI (Flash-Flood Potential Index) and FPI (Flooding Potential Index). These indices are obtained by integrating in a GIS environment several geographical variables which control runoff (in the case of the FFPI) and favour flooding (in the case of the FPI). The methodology was applied in the upper (mountainous) and middle (hilly) catchment of the Prahova River, a densely populated and socioeconomically well-developed area which has been affected repeatedly by water-related hazards over the past decades. The resulting maps showing the spatialization of the FFPI and FPI allow for the identification of areas with high susceptibility to flash-floods and flooding. This approach can provide useful mapped information, especially for areas (generally large) where there are no flood/hazard risk maps. Moreover, the FFPI and FPI maps can constitute a preliminary step for flood risk and vulnerability assessment.

An Enhanced Effective Reconnaissance Drought Index for the Characterisation of Agricultural Drought

The drought phenomenon is directly associated to the agricultural production and it is considered as one of the major water-related hazards in this sector. Conventionally, the magnitude of drought impacts on crops, taking into account the susceptibility of the plants to the meteorological and hydrological conditions, is referred to as agricultural drought. The accurate and timely assessment of agricultural drought can provide the means for taking the appropriate proactive and relief measures for the protection of the farmers’ income and supporting food security. The Reconnaissance Drought Index (RDI), incorporating the key parameters of precipitation and potential evapotranspiration, has been widely and successfully used worldwide for drought characterisation during the last decade. In this paper, a modification of this index is proposed, namely the Effective Reconnaissance Drought Index (eRDI), aiming at improving the ability to assess agricultural drought. The main aspect of this modification consists in the substitution of the total precipitation with the effective precipitation, which represents more precisely the amount of water that is productively used by the crops. Further, the estimation methods of effective precipitation and the modification of other aspects of RDI, such as the selection of the appropriate reference period, are analysed and discussed.

Global Water-Related Risk Indicators: Meta-Analysis of Indicator Requirements

Despite a long developmental history of water-related disaster risk indicators, there is still no consensus or reliable system for selecting objective data, no methodological system for choosing and verifying the relevancy of water-related disaster risk indicators, and no linking results back to root causes or addressing possible impacts on policies or actors to instigate change.Global policy documents such as the Sendai Framework for Disaster Risk Reduction (DRR) 2015–2013 [1] emphasize the urgent need for indicators capable of measuring risk reduction. However, developing and determining risk indicators faces many issues. Most disaster risk indices published do not yet include a basic overview of what data was used and how it was collected, let alone provide a systematic explanation of why each indicator was included, and why others were not. This consequently complicates linking the findings to their potential policy impacts. It also complicates the providing of clear-cut recommendations for improving resilience, which is a common intent of disaster risk indices.This study, which focuses on water-related hazards, aims to provide disaster managers with a set of criteria for evaluating existing datasets used in disaster risk indices, index construction methods, and the links back to policy impacts. So far, there has been no comprehensive overview of indicator requirements or scoring systems. Previous studies concerning indicator evaluating metrics [2] have fewer metrics and have not yet addressed the different tiers of requirements, namely objective indicator data quality, methodological/epistemological aspects of index composition, and, most importantly, policy and actors of change (impact requirements). Further testing of these metrics in local studies can lead to the greatly needed scientific justification for indicator selection and can enhance index robustness.The results aid in developing an evaluation system to address issues of data availability and the comparability of commonly used indicator sources, such as the World Bank. Once indicators can be scientifically linked to impacts through policy devices, national governments or other actors can become more likely to claim ownership of the data management of indicators. Future studies should expand this evaluation system to other natural hazards and focus on investigating the links between indicators and DRR in order to further validate indicator selection robustly.

Ensuring A Better Water Future for Malaysia

Human overuse of water resources and diffuse contamination of freshwater are stressing the water resources in the terrestrial water cycle. As a consequence, the ecological functions of water bodies, soils and groundwater in the water cycle are hampered and being further exacerbated by threats from impending climate change. Though Malaysia is blessed with fairly abundant rainfall it still has its fair share of water woes, such as occasional droughts, looding and pollution of its rivers and water bodies. Only recently, the country was faced with water related hazards of fairly disastrous proportions. Recurring potable water shortages that occurred in 2014 and 2015 in several states had led to water rationing. Malaysia has since the early 1990s set its vision to become a fully developed country by the year 2020 (Vision 2020). The transformation of the water sector must also evolve in tandem to meet sustainable development goals beitting a developed nation status by 2020. The National Water Resources Policy (NWRP), launched in March 2012, is based on the 3 essential principles i.e. water resources security, water resources sustainability and collaborative governance. This paper will review the various water-related issues and challenges whilst proposing the implementation of the Integrated Water Resources Management (IWRM) Road Map including the measures to be undertaken to effect the transformation of the water sector in pursuit of Vision 2020 and to achieve the post 2015 Sustainable Development Goals (SDGs). The indings and recommendations are largely based on several in-depth studies undertaken by the Academy of Sciences, Malaysia (ASM) pertaining to the water sector and the IWRM agenda.

Ensuring A Better Water Future for Malaysia

Human overuse of water resources and diffuse contamination of freshwater are stressing the water resources in the terrestrial water cycle. As a consequence, the ecological functions of water bodies, soils and groundwater in the water cycle are hampered and being further exacerbated by threats from impending climate change. Though Malaysia is blessed with fairly abundant rainfall it still has its fair share of water woes, such as occasional droughts, looding and pollution of its rivers and water bodies. Only recently, the country was faced with water related hazards of fairly disastrous proportions. Recurring potable water shortages that occurred in 2014 and 2015 in several states had led to water rationing. Malaysia has since the early 1990s set its vision to become a fully developed country by the year 2020 (Vision 2020). The transformation of the water sector must also evolve in tandem to meet sustainable development goals beitting a developed nation status by 2020. The National Water Resources Policy (NWRP), launched in March 2012, is based on the 3 essential principles i.e. water resources security,water resources sustainability and collaborative governance. This paper will review the various water-related issues and challenges whilst proposing the implementation of the Integrated Water Resources Management (IWRM) Road Map including the measures to be undertaken to effect the transformation of the water sector in pursuit of Vision 2020 and to achieve the post 2015 Sustainable Development Goals (SDGs). The indings and recommendations are largely based on several in-depth studies undertaken by the Academy of Sciences, Malaysia (ASM) pertaining to the water sector and the IWRM agenda.

The seventh facet of uncertainty: wrong assumptions, unknowns and surprises in the dynamics of human–water systems

ABSTRACTThe scientific literature has focused on uncertainty as randomness, while limited credit has been given to what we call here the “seventh facet of uncertainty”, i.e. lack of knowledge. This paper identifies three types of lack of understanding: (i) known unknowns, which are things we know we don’t know; (ii) unknown unknowns, which are things we don’t know we don’t know; and (iii) wrong assumptions, things we think we know, but we actually don’t know. Here we discuss each of these with reference to the study of the dynamics of human–water systems, which is one of the main topics of Panta Rhei, the current scientific decade of the International Association of Hydrological Sciences (IAHS), focusing on changes in hydrology and society. In the paper, we argue that interdisciplinary studies of socio-hydrological dynamics leading to a better understanding of human–water interactions can help in coping with wrong assumptions and known unknowns. Also, being aware of the existence of unknown unknowns, and their potential capability to generate surprises or black swans, suggests the need to complement top-down approaches, based on quantitative predictions of water-related hazards, with bottom-up approaches, based on societal vulnerabilities and possibilities of failure.Editor D. Koutsoyiannis; Associate editor S. Weijs

Reducing Social Vulnerability to Environmental Change: Building Trust through Social Collaboration on Environmental Monitoring

Abstract The occurrence of natural and socially driven catastrophic events has increased in the last few decades in response to global environmental changes. One of the most societally relevant challenges in managing the effects of these events is the establishment of risk management strategies that focus on managing vulnerability, particularly in disfavored countries, and communities among them. Most cases of enhanced vulnerability occur in, but are not limited to, developing countries, where the combination of social inequity, inappropriate use of natural resources, population displacement, and institutional mistrust, among other factors, make risk management particularly challenging. This paper presents a vulnerability-centered risk management framework based on social cohesion and integration principles that, combined with scientific, technical, and popular knowledge, lead to the development of social networks of risk reduction. This framework is intended as a strategy to strengthen early warning systems (EWS), where the human-related factor is among their most challenging components. Using water-related hazards as a case study, this paper describes the experience of the conformation of a social network for environmental monitoring using this model example on vulnerability reduction in the rural areas of the central Andes in Colombia. This experience allowed the effective conformation of a social network for environmental monitoring in 80 municipalities of Colombia, where communities developed a sense of ownership with the instrumentation and the network, strengthening links with local authorities and contributing to more efficient EWS. More generally, the authors highlight the need to develop vulnerability-centered risk management via community-building strategies, particularly for areas where little can be done to decrease the occurrence of catastrophic events.

Multifunctional Roads

Rural roads are built to improve people’s mobility and to enhance access to markets, administrative centres, schools and health posts, and are credited with important socio-economic changes. A less studied aspect is the impact of roads on hydrological resources, as roads interact with existing surface and groundwater flows, redistributing water-related hazards and resources across space with significant consequences on people and their livelihoods. In Ethiopia, the government has embarked on a massive road construction programme over the last decade, mainly to serve the needs of an essentially rural population and agrarian economy. In parallel, the government has also been investing significantly in water harvesting and conservation measures and irrigation to serve the needs of a population whose livelihoods depend heavily on rain-fed agriculture. Based on fieldwork conducted in 2014 in the semi-arid region of Tigray, Ethiopia, this article explores the opportunities and potential for multifunctional infrastructures. We argue that the two distinctive objectives of improving road connectivity and water availability for irrigation are interlinked and can be served by the same infrastructure, which we call multifunctional roads.

Urban vulnerability and resiliency over water-related risks: a case study from Algiers.

The ad hoc management of natural environmental features and inappropriate social interventions could cause vulnerability of thriving urban ecosystems. For instance sub-aerial exposure, water-related hazards, urban intrinsic sensitivity, urban adaptation ability or flexibility and urban transformability factors could contribute a potential danger. In spite of seasonal climatic changes, the exposure indicates a significant geographical determinism whereas the other factors express its antithesis. The present paper aims to adapt a vulnerability-resilience indicators' multicriteria analysis to show the variability and contribution rate with regard to local water-related risks. The municipality of al-Harrash from Algiers has been selected as a case study. The urban vulnerability-resilience closely tied up with a sum of relevant indicators confirmed by the diagnosis items, which are relevant to the local urban and hydro systems. The cumulative sums are obtained from a classification process referring to several criteria implied in the water-related risks. These were formulated here for the purpose of a multicriteria analysis with the objective of assessing the urban vulnerability-resilience index and subsequently orientating the preventive strategy towards different levels of sustainable measures. With this respect the exposure and sensitivity received a significant score while adaptation ability and transformability scored very low.

Novel Solution for Low-Lying Land Areas Safe from Natural Hazards—Toward Reconstruction of Lost Coastal Areas in Northeast Japan

The imminent fear of water-related hazards such as flooding hangs over low-lying areas, in particular now because climate changes have led to increased hazards, like storm surges, that could result in serious harm. This paper aims to provide a novel solution—namely “the floating platform”—that can transform dangerous low-lying areas into those safeguarded against potential hazards. Additionally, by utilizing this solution as a secure base for society to build atop this new artificial reservoir, we offer a better future role for such areas. Meanwhile, we propose adoption of our concept soon at two low-lying areas in northeast Japan hard-hit by the huge 11 March 2011 tsunami: Sendai’s Arahama coastal district and the still-devastated residential harbor area of Kesennuma, both cities in need of a fresh perspective.

Improving high-resolution quantitative precipitation estimation via fusion of multiple radar-based precipitation products

Summary For monitoring and prediction of water-related hazards in urban areas such as flash flooding, high-resolution hydrologic and hydraulic modeling is necessary. Because of large sensitivity and scale dependence of rainfall–runoff models to errors in quantitative precipitation estimates (QPE), it is very important that the accuracy of QPE be improved in high-resolution hydrologic modeling to the greatest extent possible. With the availability of multiple radar-based precipitation products in many areas, one may now consider fusing them to produce more accurate high-resolution QPE for a wide spectrum of applications. In this work, we formulate and comparatively evaluate four relatively simple procedures for such fusion based on Fisher estimation and its conditional bias-penalized variant: Direct Estimation (DE), Bias Correction (BC), Reduced-Dimension Bias Correction (RBC) and Simple Estimation (SE). They are applied to fuse the Multisensor Precipitation Estimator (MPE) and radar-only Next Generation QPE (Q2) products at the 15-min 1-km resolution (Experiment 1), and the MPE and Collaborative Adaptive Sensing of the Atmosphere (CASA) QPE products at the 15-min 500-m resolution (Experiment 2). The resulting fused estimates are evaluated using the 15-min rain gauge observations from the City of Grand Prairie in the Dallas–Fort Worth Metroplex (DFW) in north Texas. The main criterion used for evaluation is that the fused QPE improves over the ingredient QPEs at their native spatial resolutions, and that, at the higher resolution, the fused QPE improves not only over the ingredient higher-resolution QPE but also over the ingredient lower-resolution QPE trivially disaggregated using the ingredient high-resolution QPE. All four procedures assume that the ingredient QPEs are unbiased, which is not likely to hold true in reality even if real-time bias correction is in operation. To test robustness under more realistic conditions, the fusion procedures were evaluated with and without post hoc bias correction of the ingredient QPEs. The results show that only SE passes the evaluation criterion consistently. The performance of DE and BC are generally comparable; while DE is more attractive for computational economy, BC is more attractive for reducing occurrences of negative estimates. The performance of RBC is poor as it does not account for magnitude-dependent biases in the QPE products. SE assumes that the higher-resolution QPE product is skillful in capturing spatiotemporal variability of precipitation at its native resolution, and that the lower-resolution QPE product provides skill at its native resolution. While the above assumptions may not always be met, the simplicity and robustness observed in this work make SE an extremely attractive choice as a simple post-processor to the QPE process. Also, unlike the other procedures considered in this work, it is extremely easy to update the statistical parameters of SE in real time, similarly to the real-time bias correction currently used in MPE, for improved performance via self-learning.