Displays

Despite billions of dollars of investments in disaster risk reduction (DRR), data over the period 1994- 2013 show natural disasters caused 1.35 million lives. Science respond with more timely and accurate information on the dynamics of risk and vulnerability of natural hazards, such as floods. This information is essential for designing and implementing effective climate change adaptation and DRR policies. However, how much do we really know about how the main agents in DRR (individuals, businesses, government, NGO) use this data? How do agents behave before, during, and after a disaster, since this can dramatically affect the impact and recovery time. Since existing risk assessment methods rarely include this critical ‘behavioral adaptation’ factor, significant progress has been made in the scientific community to address human adaptation activities (development of flood protection, reservoir operations, land management practices) in physically based risk models.

This presentation gives an historic overview of the most important developments in DRR science for flood risk. Traditional risk methods integrate vulnerability and adaptation using a ‘top- down’ scenario approach, where climate change, socio economic trends and adaptation are treated as external forcing to a physically based risk model (e.g. hydrological or storm surge model). Vulnerability research has made significant steps in identifying the relevant vulnerability indicators, but has not yet provided the necessary tools to dynamically integrate vulnerability in flood risk models.

However, recent research show novel methods to integrate human adaptive behavior with flood risk models. By integrating behavioral adaptation dynamics in Agent Based Risk Models, may lead to a more realistic characterization of the risks and improved assessment of the effectiveness of risk management strategies and investments. With these improved methods, it is also shown that in the coming decades, human behavior is an important driver to flood risk projections as compared to other drivers, such as climate change. This presentation shows how these recent innovations for flood risk assessment provides novel insight for flood risk management policies.

How to cite: Aerts, J.: Limits to natural disasters management: the influence of human behavior, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-5551, https://doi.org/10.5194/egusphere-egu2020-5551, 2020.

Floods are one of the costliest natural hazards worldwide, affecting millions of people every year. To plan flood risk reduction strategies, there is a need to understand how risk changes over time. In traditional flood risk assessment, vulnerability is often unrealistically considered constant in time, which does not reflect patterns observed in the real world. The coupled human and natural flood system is complex and determined by two-way interactions between the two subsystems. Floodplain dynamics may affect human behavior (e.g. by triggering the implementation of protection measures at different scales) which changes exposure and vulnerability, while they are also in turn influenced by human activities (e.g. land-use changes or flood protection structures). Here we explore how these two-way interactions influence changes in flood risk over time, with a focus on the role of individual and governmental decision-making, by developing a coupled agent-based and hydraulic modelling framework.

In our framework, household agents are located in a floodplain protected by a levee system. Individual behavior is based on Protection Motivation Theory and it comprises (as a response to floods) the options to do nothing, invest in private flood protection measures, or file a complaint to the government. The governmental decision making process about the implementation of technical flood protection measures, i.e. reinforcing the levee system, is a compromise between a Cost-Benefit-Analysis and relative number of filed complaints from the households. The agents take decisions at every time step of a long time series of annual maximum water levels: in case of levee breach, the floodplain water level is estimated by the LISFLOOD 2D hydraulic model, which is dynamically coupled into the agent-based model.

We show that this coupled model is capable of replicating adaptation and levee effects, which have been empirically observed by several scholars in numerous floodplains around the world. Thus, our framework provides a useful explanatory tool for assessing different spatial and temporal dynamics of flood risk in a socio-hydrological system. Moreover, the new modelling approach can explicitly simulate the spatial distribution of flood risk which allows for the analysis of conflicting interests in neighbouring communities. First, efforts have been made to include farmer agents into the model to simulate conflicts between urban and rural areas. Further, we exploit data from the real word in order to assess the credibility of our model and, lastly, use the model to investigate the effects of different climate scenarios on these types of conflicts.

How to cite: Michaelis, T., Brandimarte, L., Di Baldassarre, G., and Mazzoleni, M.: Capturing flood risk dynamics with a coupled agent-based and hydraulic modelling framework, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-2659, https://doi.org/10.5194/egusphere-egu2020-2659, 2020.

Even though there has been a move towards a more integrated approach to flood risk management, with a stronger focus on property level measures to reduce flood risk, the uptake of property level measures remains low. Experience has been found to influence the uptake of measures, but even property owners with experience do not always take measures to prepare for future flooding. In this paper we investigate the variations in the relationship between experience and preparedness (i.e. the uptake of property level measures) for the different regions of England. We use survey data collected among the population at risk in the years 1996 to 2004 and perform a hierarchical beta regression to determine the differences between the seven regions. We find that the South West and Southern regions have a higher increase in preparedness with increasing experience compared to other regions. In the Thames, Midlands and North West the preparedness increases less with increasing experience. Based on an analysis of additional data sources (e.g. surveys and maps of structural protection and population) we provide a possible explanation as to why the behaviour of property owners in these regions could be different.

How to cite: Barendrecht, M. H., McCarthy, S., and Viglione, A.: A comparative analysis of property level flood mitigation behaviour in the regions of England, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-16099, https://doi.org/10.5194/egusphere-egu2020-16099, 2020.

What implications do societies’ risk perceptions have for flood losses? This study uses a stylized, socio-hydrological model to simulate the mutual feedbacks between human societies and flood events. It integrates hydrological modelling with cultural theory and proposes four ideal types of society that reflect existing dominant risk perception and management: risk neglecting, risk monitoring, risk downplaying and risk controlling societies. We explore the consequent trajectories of flood risk generated by the interactions between floods and people for these ideal types of society over time. Results suggest that flood losses are substantially reduced when awareness raising attitudes are promoted through inclusive, participatory approaches in the community. In contrast, societies that rely on top-down hierarchies and structural measures to protect settlements on floodplains may still suffer significant losses during extreme events. This study illustrates how predictions formed through social science theories can be applied and tested in hydrological modelling.

How to cite: Ridolfi, E., Albrecht, F., and Di Baldassarre, G.: Exploring the role of risk perception in influencing flood losses over time, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-659, https://doi.org/10.5194/egusphere-egu2020-659, 2020.

Increased urbanization is causing evident negative consequences on the hydrological cycle. In particular, the increase of impervious surfaces is having a strong impact on the water cycle, amplifying the risk of urban floods. These impacts can get even worse for potential climate change impacts. The urban areas of the Simeto Valley, the largest river valley in Sicily (Italy), has been repeatedly hit by heavy rains in the last decades that caused urban flooding causing several problems and, in some instances, threats to population. The threats seem to derive also from a low awareness of the population on the correct behavior to have in potentially dangerous situations. Hence, it seems of key importance that residents develop and internalize a “culture of risk awareness”. The Life SimetoRES Project represents an opportunity to stimulate the development of a responsible and resilient community and at the implementation of best practices for storm water management. In the Simeto River Valley community has started in the recent decades to formally have an identity (for instance, by signing a River Agreement) and has already supported initiatives in the responsible and participatory co-management of the territory. Thus, this Valley represents an excellent context to investigate this problem and to understand the involvement of the citizens in solving climate change and urban floods. In order to maximize the effectiveness of the communication campaigns and the actions to safeguard the community, a study through a survey on the climate change and risk perception in 11 municipalities has been carried out, collecting 1143 answers. Starting from the current hydrogeological risk, quantified by the Flood Risk Management Plan, the goal was to identify the perception and the awareness of the citizens. A section of the questionnaire involved the direct experience of the residents during rain events, their relationship with the alert system and their knowledge of the correct behavior in case of flood. Finally, the survey investigated the willingness of citizens to implement adaptation actions in their own municipality and in their homes. The results show that over 52% of citizens is not aware of the real use of the infrastructures devised for urban drainage and only the 30% feels responsible about mitigation of flooding risk. Inaccurate weather warnings can endanger more inhabitants who don't trust the alert system. The results show that it is necessary to make incisive actions to educate people, especially in school age, on the correct behavior to take in case of urban flooding, and encourage citizens to acknowledge themselves as an active part of the mechanism of their own and community safety.

How to cite: Nanni, P., Musumeci, R. E., Peres, D. J., and Cancelliere, A.: Community awareness of climate change and urban flood risk: the case of the Simeto River Basin, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-5764, https://doi.org/10.5194/egusphere-egu2020-5764, 2020.

Flooding is globally one of the most damaging natural hazards. Flood risk will most likely increase in the near future due to increases in flood frequency attributed to climate change and growth in population and wealth in flood prone areas. This growth in wealth and population is increasingly considered as a major driver for the increase in flood losses in the last decades. Floodplains are susceptible to floods, but historically people have always been settling in floodplains. The growth of population in floodplains, which is a substantial cause for increased flood risk, is essential to consider for decision making in floodplain development, as improper development increases flood exposure and aggravates flood risk. The science of socio-hydrology tries to capture the interaction between humans and floods in the floodplain, but it is necessary to identify these mechanisms on a broader scale. A way of doing this, is to look at the development of floodplain population density over the years, but population data is not available on a long temporal scale. Therefore, Nighttime light data was used to model the gaps in the availability of population data. Nighttime light data captures the illumination on earth and is available on a large temporal and spatial scale. It also has a high correlation with population data. However, the relationship between Nighttime light data and population data is not straightforward. This study tries to model a population proxy using Nighttime light data and explains when and why it does or does not work. Validation of the model shows that in some regions the predicted data is relatively precise, but ultimately, due to the lack of data, the accuracy is unknown. This study shows that understanding the behavior of NTL is valuable, because it has the potential to map Socio-Economic variables in data-scarce areas.

How to cite: Verschuren, L., Nardi, F., Bricker, J., Hoes, O., Ceola, S., and Pande, S.: Explaining the pitfalls of quantifying population in riverine floodplains using Nighttime Light, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21382, https://doi.org/10.5194/egusphere-egu2020-21382, 2020.

Surface water resources are severely affected by human activities and climate variability, and their rapid depletion is one of the main challenges for sustainable development. This situation is expected to worsen because of climate change, world population growth and the associated conversion of rural lands into urban areas. Since about 70% of global population is projected to be living in cities by 2050, it is necessary to shed light on the influence of climate and human dynamics on water occurrence variation to better understand their driving role.

Remote sensing is a key tool for monitoring the process of environmental change because it provides the advantages of global spatial coverage, high temporal resolution, and fast updating. Satellite data enable to record changes in climatic conditions, land use, and spatial allocation of human settlement and activities, which are major factors in altering water dynamics. However, the potential of such data has not been fully exploited.

Here, the interrelation between spatial and temporal distribution of water depletion, changes in precipitation, and human dynamics across the USA watersheds is investigated using remote sensing data. In particular, the contribution of urbanization and precipitation variation to surface water decrease in the last 35 years (from 1984 to 2018) is evaluated at the basin scale. Preliminary results highlight the presence of a positive correlation between surface water loss and urban area growth. On the other hand, a counterintuitive increasing trend of surface water decrease with growing annual precipitation is found. A multiple linear regression among surface water loss, urbanization, and annual precipitation change is calculated, showing that most of the surface water loss can be attributed to the urbanization process. A spatial and temporal clustering analysis is then performed to better understand the influence of anthropogenic factors on surface water losses. Results clearly show a high level of urbanization close to surface water loss hotspots.

How to cite: Palazzoli, I. and Ceola, S.: Anthropogenic and climatic controls on surface water loss across USA, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-254, https://doi.org/10.5194/egusphere-egu2020-254, 2020.

As one of the major weather-driven natural disasters, droughts exhibit as the most frequent and widespread natural disasters in China. It is reported that the agriculture losses show continuously grown by following the increasingly severe droughts for the whole country. In order to investigate the impacts of drought on agricultural, we rechecked the functional relationship between the crop yield and climatic variables. Based on the meta-analysis from previous literature, we found a more stable statistical relationship between the yield and the precipitation and evapotranspiration. These results introduce a new drought index, indicated as Crop Water-Related Index for Drought (CWRID), which can be used as a reference index to approximate the drought impact on the loss of yield. Based on the climatic data in China during 1982-2015, several other drought indices (SPI, SPEI, CI, and SEDI) were compared with CWRID to identify the most appropriate agricultural drought index. The data of historical drought damaged area and drought damaged crop yield reduction were used to validate the performances of different indices. The CWRID reasonably predicted the drought damaged area as well as the drought damaged yield reduction during the past 30 years in China. As a contrast, the SEDI is proved to be no suit for quantifying drought. Also, the calculated values are stored in the dataset and can be shared with researchers by request. As a simple index, results indicated that CWRID can be used to quantify the impacts of drought on agricultural as it can reflect the variation of crop yields.

How to cite: sun, H. and Chen, J.: An index to quantifying the impacts of agricultural drought and its application in China, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1041, https://doi.org/10.5194/egusphere-egu2020-1041, 2020.

There are evidences that climate change as a result of both natural and anthropogenic processes has exacerbated the frequency and the severity of flood hazards over past decades across the world. Moreover, changes in the pattern of precipitation and temperature during the 21^st century are expected to induce region-specific impacts on floods, especially increase in local floods in some catchments. However, the future is hard to predict as there are strong discrepancies in how climate change is expected to affect runoff and river discharge at different places. Many studies have proven that not only climate, socio-economic and physical factors such as elevation and soil type are determinant for flood risk characterisation. Anthropogenic activities and impacts through land use and land cover degradation have substantial implication for hydrological processes. Moreover, catchment management play an important role in sustainable flood management which is generally based on technical knowledge. But it must also be socially and politically meaningful. This is especially relevant for transboundary catchments where riparian countries might offer different economic, social and political environment, and hence have distinct approaches of flood risk reduction and management. An effective cooperation between states sharing transboundary water resources must include a continuum comprised of data exchange, information sharing, collaboration and joint action. It is a search for cooperative management while respecting the sovereignty of each state. There is a variety of methods used for assessing transboundary management and identifying cooperative strategies. Among others, the following ones can be mentioned: the Water Cooperation Quotient, the multiobjective analysis, hydropolicy simulation models, the Multiobjective Evolutionary Algorithms (MOEAs) and a combination of the two later. Hence this study aims at exploring various approaches of transboundary management and analyses experienced over the world. Lessons will afterward be drawn in the context of climate and land use change in the transboundary Mono River catchment shared by the Republics of Benin and Togo.

How to cite: Houngue, R., Evers, M., and Almoradie, A.: Impacts of Climate and Land Use Change in the Management of a Transboundary Basin- Case Study of Mono River catchment, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1145, https://doi.org/10.5194/egusphere-egu2020-1145, 2020.

Abstract: Decrease of saline lakes, which comprises of 44% of all the available lake water, is a major concern. It additionally brings to desertification process to the region. Thus, various countries have taken different actions in protecting their lake’s water level. The aim of this paper is to assess different strategies directed to tackle the decreasing saline lake water levels. Lake Urmia and the Aral Sea which split into North Aral and South Aral were among the world's largest saline lakes and now have reduced to 10% of their original size. A thorough review of academic reports, official documents and databases were considered. Although the dry-up of the lake is a natural process, it has been sped up by human interventions in the hydrology cycle. Dust storms (strong winds) in the case of the Aral Sea, transmit the pollutants from dry lake surface which initially accumulated in the lakebed causing severe health issue. Various strategies were implemented to manage the socio-economic conditions caused due to the drying of lakes. The strategy implemented for the North Aral Sea was to restore the lake by reducing the water withdrawal from tributary rivers which leads to increased water level in the sea. The strategy implemented for Lake Urmia was to restore the lake by water transfer activities from neighbouring water sources which until now show no increase in water level. The strategy implemented for the South Aral Sea was to use a dry lakebed to diversify the economy by oil and mineral extraction which shows the adaptation to the environmental conditions with no restoration strategy. As a conclusion, it is found that there is no common best solution for this kind of problem. The best fit depends on the local context and it is strongly path dependent. 

Keywords: Drying saline lake; Dust storms; Aral sea; Health impacts; Lake Urmia; Restoration of saline lake; Strategies.

How to cite: Anchita, A., Tussupova, K., and Hjorth, P.: Drying Lakes: A Review on The Health Conditions and Restoration Strategies, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1207, https://doi.org/10.5194/egusphere-egu2020-1207, 2020.

Water supply in large cities has challenged governments and water authorities because of the complexity involved in meeting water demands. The traditional challenges stem from the seasonality of precipitation and population growth. Although water resources management strategies assume potential scenarios for water demand growth to design water infrastructure, unexpected changes in the hydrological cycle may cause shocks to urban water supply systems and generate unanticipated patterns of consumption, such as occurred during the water crisis experienced by the São Paulo Metropolitan Area (SPMA) from 2014 to 2016. This work explores the coevolution of the coupled human-water system variables associated with the water supply system within the SPMA, from the late twentieth century to the present, to explain how water demand has influenced water availability, and vice-versa, in particular for the Cantareira Reservoir System. The challenges facing the human-water system in the region are of critical importance, given that it supplies water to more than 9 million people, and it supports economic activities that represent 12% of Brazil’s Gross Domestic Product. The analysis reveals that hydrological shifts are responsible for major structural transformations and they also have led to changes in domestic consumption. We conclude that modelling the interactions and feedbacks between water availability and consumption can provide more realistic storylines to implement strategies to address water scarcity than merely considering long-term demand scenarios, as it is normally done. In addition, policies implemented to promote water savings can have different responses at sub-regional scales and this can be explored also in the context of long-term scenarios.

How to cite: Souza, F., Gesualdo, G., Sivapalan, M., and Mendiondo, E.: Interactions and feedbacks between water availability and domestic consumption in São Paulo Metropolitan Area, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-6201, https://doi.org/10.5194/egusphere-egu2020-6201, 2020.

The presented paper examines current dilemmas in transboundary water interaction and debates about the reconceptualization of the Transboundary Water Interaction Nexus (TWINS). The new TWINS framework provides a theoretical alternative how to (1) evaluate the interstate relations between two or more actors regardless their legal status; (2) calculate the transboundary water interaction based on process tracing analysis rather than milestone analysis; (3) distinguish more intensities of cooperation and conflict, (4) clarify broader hydropolitical context in transboundary water interaction, and (5) debate about dual water event phenomenon where one event may possess both cooperation and conflict features. Currently, the new TWINS model serves as an indicator for evaluating cooperation and conflict intensity of water-related events in the Lancang-Mekong River Basin. The data are then recorded in the Lancang-Mekong Cooperation and Conflict Database (LMCCD) designed by authors which already comprise more than 1600 water-related events in the last 30 years (1990-2020). To proof the viability of the presented concept, we will illustrate the new TWINS model on a case study related to the Xayaburi hydropower dam. Although there are still several methodological limitations, the new TWINS model can be adapted to any interstate water-related issue and be able to fill the information gaps about the interdisciplinary understanding of the transboundary water interaction.

How to cite: Grünwald, R., Feng, Y., and Wang, W.: Lost in the waters: contemporary dilemmas in examining transboundary water interaction, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7040, https://doi.org/10.5194/egusphere-egu2020-7040, 2020.

Transboundary river basins share a complex network of environmental, economic, political, social and security interdependencies. Consequently, transboundary river systems are characterized by evolving conflict and cooperation dynamics between riparian states. The current literature on transboundary watersheds does not identify the key feedback loops between interconnected political, cultural, institutional and socioeconomic factors. This work compares sociohydrological models of three transboundary rivers (Nile River, Columbia River, and Lancang-Mekong River) with distinct characteristics in terms of hydrological processes and socioeconomic conditions. Conflict/cooperation dynamics within these three models were found to be driven by hydrological regime, economic benefits, power imbalance and institutional capacity. By comparing the contextual factors of the emergent conflict/cooperation dynamics across these three river basins, our synthesis study aims to present a general framework that explains how conflict/cooperation dynamics emerge from the interaction between human and hydrological systems.

How to cite: wei, J., Ghoreishi, M., Souza, F., Lu, Y., and Tian, F.: Socio-hydrological approach to understand conflict and cooperation dynamics in transboundary rivers, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-7148, https://doi.org/10.5194/egusphere-egu2020-7148, 2020.

The river Maltsch / Malše is an interesting waterbody from a historical, hydrological and ecological perspective. As a border river between Austria and the Czech Republic, it has had an eventful history. With the political separation into “East” and “West” in the middle of the 20th century, a region that initially had a similar land use structure was completely changed. On the Czech side, villages and settlements were removed and the land expropriated. In the course of the fall of the Iron Curtain, the land was mostly sold to large landowners. Changes also took place on the Austrian side. Agriculture and forestry have been intensified over decades.

This leads to the situation that on both sides of the river, under very similar geological and hydrological conditions, the effects of very different land use developments and changes on the water household and erosion can be documented. Thus, a transboundary, mainly EU-funded INTERREG project was launched to investigate this variability in general and to address the implications for the sediment regime in such river systems (concerning e.g. flood protection control, sedimentation of reservoirs) in specific. Moreover, it is examined how mitigation measures for water retention, erosion control and climate change adaption can be planned under these variable boundary conditions. Especially droughts and heavy rainfall events must be considered as threats in the region in the future.

In addition to the changes described above, the political situation in the border region has left a refuge for nature. The Maltsch is part of the so-called Green Belt that stretches across the whole of Europe. A key species of the region is the Freshwater Pearl Mussel (Margaritifera margaritifera), which is characterised by its very high demands on the environment. It, therefore, serves very well as an indicator / umbrella species and thus also as a condensation nucleus of the different topics of the project.

In summary, the following aspects will be presented: (1) documentation of historic, political driven land use changes and land use differences on GIS basis, (2) effects on soil erosion by means of modelling via USLE, (3) estimation of the effects on the landscape hydrology and (4) effects on the aquatic fauna, especially the key species Freshwater Pearl Mussel.

How to cite: Höfler, S., Ringler, G., Gumpinger, C., and Hauer, C.: Land use changes at the former “Iron curtain” and their implications for catchment hydrology, erosion and ecology – a transboundary project between Austria and Czech Republic, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-9012, https://doi.org/10.5194/egusphere-egu2020-9012, 2020.

Extreme dry conditions occurred over the summer of 2018 in the Netherlands. This severe drought event led to very low groundwater  and surface water levels. These impacted several sectors like navigation, agriculture, nature and drinking water supply. Especially in the Pleistocene uplands of the Netherlands, the low groundwater levels had a large impact on crop yields and biodiversity in nature areas. Projections show that droughts with this severity will occur more often in the future due to changes in climate. To mitigate the impact of these drought events, water management needs to be altered.

In this study, we evaluated the 2018 drought event in the sandy regions of the Netherlands and studied which measures could be most effective to mitigate drought impact. We have included meteorological, soil moisture and hydrological drought and the propagation of the drought through these types. Droughts were determined with standardized indices (e.g. Standardized Precipitation Index) and the variable threshold level method. Investigated measures were, for example, higher water levels in ditches, reduced irrigation from groundwater, and increased water conservation in winter. We also studied the timing of these measures to determine the potential for mitigating effects during a drought versus the effectiveness of long term adaptation. The measures were simulated with the agro-hydrological Soil–Water–Atmosphere–Plant (SWAP) model for several areas across the Netherlands for both agricultural fields and nature sites.

As expected, decreasing irrigation from groundwater reduced the severity of the hydrological drought in the region. Severity of the soil moisture drought also decreased in fields that were never irrigated due to the effects of capillary rise from the groundwater, but, as expected, increased in currently irrigated fields. Increasing the level of a weir in ditches had a relatively small effect on the hydrological drought, provided water was available to sustain higher water levels. This measure is, therefore, better suited as a long term change than as ad hoc measure during a drought. The effectiveness of the measures depended on the characteristics of the regions; for some regions small changes led to increases in groundwater levels for several months, whereas in other regions effects were lost after a few weeks. This study gives insight into the most effective measures to mitigate drought impacts in low-lying sandy regions like the Netherlands.

How to cite: van Huijgevoort, M. H. J., de Wit, J. A., and Bartholomeus, R. P.: Evaluation of 2018 drought and effectiveness of adaptation measures in the Netherlands, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-9166, https://doi.org/10.5194/egusphere-egu2020-9166, 2020.

It is widely recognized that urbanization has a significant impact on streamflow characteristics. However, the influences of economic development, increasing population and positioning of urban development on streamflow regimes is still not fully understood. This study aims to clarify these influences by analyzing 134 catchments in China and 1064 catchments in the United State. Urbanization metrics were derived from gridded GDP dataset, gridded population dataset and land use/land cover datasets, while the streamflow characteristics were calculated using annual streamflow and mean daily discharge data. The statistical analysis indicated that the rate of change in rainfall-runoff ratio is positively related to the growth rate of GDP and urban area both in China and the U.S., but this relationship was not found in population growth rate. Increasing the extent of urbanized area increased high and low flow frequency in Kansas metropolitan region as well as San Antonio metropolitan region, while reduced low flow frequency in Atlanta metropolitan region. In addition, urban expansion also enhanced streamflow flashiness. Compared to down-stream development, up-stream development increased high flow volume in Atlanta metropolitan region and Kansas metropolitan region, while decreased high flow volume in San Antonio metropolitan region and low flow volume in all study metropolitan regions. The findings in this study provide a sight for future researches in hydrological variation due to urbanization.

How to cite: Shen, Q. and Cong, Z.: Analyzing the Impacts of Urbanization on Watershed Streamflow Characteristics, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-9245, https://doi.org/10.5194/egusphere-egu2020-9245, 2020.

The Columbia River Treaty, signed in 1961, solidifies cooperation between the United States and Canada to manage the operation of the Columbia River’s extensive dam network jointly to optimize benefits for the whole system. Under the treaty, Canada operates dams to provide flood protection and maximize hydropower potential downstream. In exchange, the U.S. compensates Canada with half of the estimated benefits of the treaty, which provides an economic incentive to cooperate not seen in many other transboundary basins. However, since the treaty was established, this highly-managed system has responded to unanticipated external social and environmental factors. For example, mounting social pressure in the 1990s to protect the aquatic environment resulted in operational changes to U.S. dams to accommodate flows for fish migration, which ultimately resulted in financial losses for hydropower producers. These changes affected the relative benefits each country receives from cooperation. Utilizing a range of hydrological, economic, social, and environmental datasets, a socio-hydrological model was developed that simulates system operations using historical data to mimic operational changes, shifts in flood control and hydropower production, and cooperation dynamics.

Renegotiations of the Columbia River Treaty started in 2018, and the new treaty in 2024 must include provisions for environmental protection that were, originally, not considered. The purpose of this study is to use the established model to envision how changing conditions such as climate change, spring fish flows, and First Nation rights would affect each country’s willingness to cooperate. For example, how would changes in snowpack upstream or seasonal changes in precipitation alter the hydrology of the basin and, in turn, the benefits each country receives from cooperation. This scenario analysis provides insight into how a revised treaty that takes future uncertainties into account would affect the balance of benefits to maintain or disrupt cooperation on the Columbia River.

How to cite: Cherry, C., Souza, F. A. A., Park, S., Shrestha, A., Yang, L., Barendrecht, M., Garcia, M., Yu, D., Wei, J., and Tian, F.: Scenario Analysis of Cooperation Dynamics on the Columbia River under Changing Conditions using Socio-Hydrological Modelling , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-12073, https://doi.org/10.5194/egusphere-egu2020-12073, 2020.

Nearly one-sixth of US river basins are unable to consistently meet societal water demands while also providing sufficient water for the environment. Water scarcity is expected to intensify and spread as populations increase, new water demands emerge, and climate changes. Improving water productivity by meeting realistic benchmarks for all water users could allow US communities to expand economic activity and improve environmental flows. Here we utilize a spatially detailed database of water productivity to set realistic benchmarks for over 400 industries and products. We assess unrealized water savings achievable by each industry in each river basin within the conterminous US by bringing all water users up to industry- and region-specific water productivity benchmarks. Some of the most water stressed areas throughout the US West and South have the greatest potential for water savings, with around half of these water savings obtained by improving water productivity in the production of corn, cotton, and alfalfa. By incorporating benchmark-meeting water savings within a national hydrological model (WaSSI), we demonstrate that depletion of river flows across Western US regions can be reduced on average by 6.6%-23.5%, without reducing economic production. Lastly, we employ an environmentally-extended input-output model to identify the US industries and locations that can make the biggest impact by working with their suppliers to reduce water use “upstream” in their supply chain. The agriculture and manufacturing sectors have the largest indirect water footprint due to their reliance on water-intensive inputs but these sectors also show the greatest capacity to reduce water consumption throughout their supply chains.

How to cite: Marston, L., Lamsal, G., Ancona, Z., Caldwell, P., Richter, B., Ruddell, B., Rushforth, R., and Davis, K.: Reducing Water Scarcity by Improving Water Productivity, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-12550, https://doi.org/10.5194/egusphere-egu2020-12550, 2020.

Transboundary water problems are complex systems, which involve interdependence and interconnectedness between elements, uncertainty and feedbacks between processes, and emergence and adaptation through evolution of the systems. There is nearly no way to formulate transboundary water problems in an equation fitting-one-size-for-all. As nature-human coupled systems, transboundary water problems should consider actual stakeholders and parties in context-specific situations as well as natural conditions.

News media are good recorders for us to have an insight into the transboundary water problems down-to-earth. Local news media are the first-hand and direct reflections of societal values among the riparian countries and stakeholders, and are documentaries of what is going on in transboundary river basins. International news media are also good sources to know about how people in the world perceive transboundary river issues from the perspectives as “outsiders”. Therefore, text analysis of news articles concerning conflict and cooperation on transboundary river basins can tell us a whole story about the past history and on-going “real” life in the basins.

To uncover the patterns and dynamics of conflictive and cooperative events on a global scale, people usually read news articles, extract information manually in the past, which is tedious and time-commanding. In the era of big data, we collect large news media datasets automatically, and employ machine learning techniques to do data mining out of those news media data. The aim of our research is to minimize manual labor in searching, filtering, reading and understanding the related news media articles by computer, and to provide potent tools for researchers to retrieve useful information  in the related areas. To validate our methodology, we look Mekong River Basin and Brahmaputra River Basin as case studies into details. To apply our methodology in a global scale, we intend to draw a world map with a timeline to show how water conflict, and cooperation occurs, grows, and transforms. By capturing characteristics of the life cycles of water conflict and cooperation, we aim to throw light upon water management in transboundary river basins, provide some hints for water resources decision-makers, and enhance global water security.

How to cite: Guo, L., Tian, F., Wei, J., and Lu, Y.: Conflict and Cooperation Analysis on Transboundary River Basins Using News Media Text Mining Approach , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-13100, https://doi.org/10.5194/egusphere-egu2020-13100, 2020.

How to cite: Srinivasan, V., Khandekar, N., and Shinde, G.: Drivers of water conflicts in co-evolving human-water systems in Cauvery Basin, Southern India, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-13368, https://doi.org/10.5194/egusphere-egu2020-13368, 2020.

The Platform for Atlantic Geohazard Risk Management (AGEO) is a new project co-financed under the Interreg Programme for the Atlantic Area which aims to launch five Citizens’ Observatory pilots on geohazards according to regional priorities:

• Citizens’ observatory on rockfalls and rockfall-triggers in the Canary Islands, Spain
• Peat-slides and peat massmovement monitoring and control in Cuilcagh Mountain, Northern Ireland
• Multihazard Citizens’ Observatory in Lisbon, Portugal
• Citizens’ observatory of slope instability monitoring along the Cliffs of Moher, Ireland
• Citizens’ observatory of vulnerability to coastal Risks in Brittany, france

These will demonstrate how citizens’ involvement in geohazard risks prevention can strengthen regional and national risk management systems. Instituto Superior Técnico (Portugal) leads the consortium of AGEO that also counts with several other partners from Portugal, Spain, France, Ireland and the United Kingdom.

AGEO will engage with local communities to actively participate in risk preparedness and monitoring and incorporate local capacities into risk management systems. Experiences gained during the implementation of the Citizens’ Observatory pilots will be used to formulate recommendations for the creation of future observatories in response to the widest range of hazards (both natural and human-induced) faced in the Atlantic region.

The Observatories are part of the phenomenon of citizen science.  As defined by the EC, “Citizens' Observatories are community-based environmental monitoring and information systems. They build on innovative and novel Earth observation applications embedded in portable or mobile personal devices.  This means that citizens can help and be engaged in observing our environment.”

There are many other definitions, as it is still a novel concept, but for this project the one above will be used. It is an observatory in a sense that we need careful monitoring of the risks that will be defined per region in line with a set of parameters to be defined through engaging with participating citizens to be filled in by the participating citizens. This approach lends the opportunity of collecting large amounts of data for very little to no money with the added bonus of the territorial coverage such approach can grant. Additionally, spatial data infrastructures and services already in place, e.g. Copernicus, will support the assessment and monitoring of geohazards and risk management systems.

AGEO is also organizing workshops in each participating region to ensure the citizens understand the role they play in preventing and mitigating natural risks by being part of the observatories and hopefully encouraging new members to join. These workshops will be held in the national language of the region and are to be tailored to the different audiences and will democratize the use of the observatories by listening to the people using them and taking into account their needs.

How to cite: Ortega Rodriguez, A., Carrilho Gomes, R., Telmo Jeremias, F., Santamarta Cerezal, J. C., Quental, L., Galindo Jiménez, I., Correia, V., Narciso Pinto, C., Le Dantec, N., Gouveia, F., Lemon, K., Hénaff, A., and O’Hare, G.: AGEO – Natural hazard prevention and awareness raising through citizen observatories., EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-13519, https://doi.org/10.5194/egusphere-egu2020-13519, 2020.

In many regions of the world, water supply is threatened by natural hazards such as floods and droughts, as well as by shocks induced by anthropogenic changes to water use. Lack of anticipation and/or preparation for these events can lead to delayed or insufficient responses to sudden or developing water crises, that sometimes can produce irrecoverable damage to the environment. In this work, a socio-hydrological approach to sustainable water resources management of the Alcantara River Basin in Sicily (Italy) is adopted that explicitly takes into account feedbacks between the natural and the human components that might arise from shocks to the water management system, including possible evolution of policy responses. The Alcantara River Basin is a groundwater-fed catchment which supplies many villages on the Ionian coast up to Messina city, mainly through the Alcantara aqueduct, but also agricultural areas and industries, including hydropower plants. It also hosts the Alcantara Fluvial Park, an important natural reserve. The Alcantara aqueduct also supplied the city of Messina during a temporary failure of its main aqueduct caused by a landslide in October 2015. The main purpose of the work is to use the socio-hydrological model as a “screening tool” to frame water resource management issues in a broad way and provide guidance to the community to identify aspects of societal behavior that need to evolve towards sustainable water resource management in order to withstand future shocks. This has been done by scenario simulations in conditions of a natural shock affecting the system (i.e. drought) and of a human-induced one (i.e. increase in groundwater extraction). Sensitivity analysis of the model social parameters revealed how the value attributed by the society to the environment and water resources use, its capacity to remember previous water crises and, in particular, its previous responses to shocks, can affect the system in a way that can produce paradoxical effects. Results show how a rapid decision-making strategy that may work in the short term, can be counter-productive when viewed over the long term and how a do-nothing decision during a water crisis could be highly damaging to the environment. For the above-mentioned reasons, this socio-hydrological approach can be considered as a useful tool to understand human-water dynamics and to support decision-makers in water resource management policies with a broad and long-term perspective.

How to cite: Borzì, I., Sivapalan, M., Bonaccorso, B., and Viglione, A.: Effects of Interactions Between Society and Environment on Policy in Water Resources Management: Exploring Scenarios of Natural and Human-Induced Shocks, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-17936, https://doi.org/10.5194/egusphere-egu2020-17936, 2020.

"When I first became aware of the destruction of the world through climate change, I felt very upset and angry, but also a little worried.  What was going to happen to my world? And what was everyone going to do about it, including me?” (Parsons, 2019).

The Earth is currently undergoing a sixth global scale ecological crisis. The available science almost unanimously positions human activity at the heart of the cause of this crisis, with anthropogenic emissions of greenhouse gasses, pollution, land degradation and deforestation, all contributing. Recent IPCC reporting has demonstrated a need to curb global warming at 1.5 degrees above the pre-industrial baseline and have highlighted a range of likely impacts of Climate Change should no action be taken, particularly in relation to reducing greenhouse gas emissions to net zero by 2050. Despite this need, policy-based action at a nation state level is largely lacking, with recent talks at COP25 failing to reach agreements. However, a significant global youth movement is now underway, with children and young people taking it upon themselves to highlight a need for climate and environmental action, calling for others to follow. Greta Thunberg and the Fridays For Future (#FFF) movement now regularly appears in mainstream media, highlighting the issues of Climate Change with an emotive narrative centred on the impact of future climate change on today’s children and their environments.

Whist there is growing literature that explores Youth Activism, to our knowledge, there is no investigation that has followed the emotional journey of a child whom has chosen to take environmental action. Here, we present Lucie Parsons, an 11-year old girl who, after watching BBC’s Blue Planet II back in 2017 and seeing the devastation plastic pollution was having on the marine environment and its wildlife, decided to take action and be a champion for positive environmental change. Since then, Lucie has spoken at international conferences, conducted her own research in her primary school, organised regional litter picks, and has become an Ambassador for the national charities iWill and Kids Against Plastic; amongst many other things. As her activism has gained momentum and as she has become more aware of wider environmental issues, her focus on plastic pollution has broadened to include the current climate crisis and environmental degradation as a whole. We will present the highs and lows of Lucie’s Environmental Activism and the role that emotion has played in her journey thus far; as well as what she believes to be the achievements in her own science communication and what you as scientists can do to help her in her fight against environmental and climatic change.

How to cite: Halstead, F., Parsons, L., and Parsons, K.: From Fear to Hope: The inspiring journey of an 11-year-old Environmental Activist, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-18711, https://doi.org/10.5194/egusphere-egu2020-18711, 2020.

Improving water use efficiency in agriculture is a key strategy in reducing water scarcity, especially during drought seasons. However, the benefits of these water saving strategies can be reduced if farmers switch to more profitable and water consuming crops or increasing irrigable area, i.e. rebound effects. These feedbacks will likely offset the water savings benefits and subsequently intensify agricultural water use. Here we propose a new system dynamic model that represents the interactions and feedback loops between hydrological and social processes to explore rebound effects by analysing competing water needs for both urban and agricultural allocation. The model is then used to explore the dynamics of different mitigation policy options to alleviate the phenomenon: (i) Restricting water allocation (ii) Limiting size of agricultural land (iii) Changing cropping patterns (iv) Deficit irrigation.

How to cite: Odongo, V., Di Baldassarre, G., and Mazzoleni, M.: Conceptualizing trade-offs of water conservation strategies and unintended consequences using a system dynamics approach, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19092, https://doi.org/10.5194/egusphere-egu2020-19092, 2020.

In recent years, the adverse effects of drought have been experienced and perceived more severely and frequently all over Europe. These impacts are a result of the drought hazard and the socio-economic and ecological vulnerability. Due to the heterogeneity of Europe’s hydro-climatology and its cultural, political, social and economic diversity , the socio-economic and ecological impacts vary not only with respect to the extent, duration and severity of the drought, but also with the characteristics of affected societies, economic sectors and ecosystems. 

The lack  of understanding the spatio-temporal differences in the drivers of drought risk hinders the successful mitigation of future impacts, and the design of suitable reactive and proactive drought action plans. Therefore, this study describes the European drought events of 2018 and 2019 beyond the hazard. The hypothesis to be proven is that similar hazard conditions result in different impacts due to national and sub-national differences in drought vulnerability, perception and drought-risk management. Based on research in 35 European countries, comparable national datasets on drought management and perception are established. For each of these countries, a uniform questionnaire was distributed to water management-related stakeholders at different administrative levels. A major focus of the questions was the perception and impacts of the recent droughts and current management strategies on a national and sub-national scale. The results of the questionnaires are also compared to country-scale profiles of past drought events for different drought types, i.e. meteorological, soil moisture, hydrological and vegetation drought, which were established based on information derived from the European Drought Observatory indicator system.

The results highlight a large diversity in the national perception of drought as a natural hazard and its impacts; but also a different spatial extent of 2018/2019 drought events At the same time,  existing drought management strategies are shown to increase national and sub-national resilience. The study, therefore, calls for international exchange and mutual learning to improve national and international drought governance and management.

How to cite: Blauhut, V., Teutschbein, C., Andersen, M. N., Brunner, M., Cammalleri, C., Cindrić Kalin, K., Finger, D. C., Huysmans, M., Manevski, K., Osuch, M., Romanowicz, R. J., Stahl, K., Stoelzle, M., Van Loon, A. F., Van Vliet, M. T. H., Wanders, N., Vogt, J., Vidal, J.-P., and Williams, P.: Perceiving and managing the 2018 & 2019 droughts in Europe: is there a need for macro-governance in Europe?, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19969, https://doi.org/10.5194/egusphere-egu2020-19969, 2020.

Intensive human interference, climate variability, and ongoing climate change affect the seasonality of runoff processes in rivers worldwide, which in turn may promote more frequent extreme flow events and cause irreversible damage to the ecological environment. Here we examine the global trend of the intra-year distribution of the seaward water discharge in 314 independent river basins, the total drainage area of which accounts for 2/3 of the total Earth land. The results show that the intra-year distribution of water discharge is homogenized between dry and flood seasons in 181 river basins, such as the Nile, Mississippi, Yangtze, Ganges, etc., but polarized in 39 basins, e.g. Amazon, Zaire, and Niger. Considering the primary factors affecting the intra-year distribution of water discharge, i.e. precipitation (P), evaporation (E), glacial runoff (G), and dam operations (D), the global river basins can be divided into GDEP, DEP, GEP, and EP types. Using the stepwise regression method, quantitative contributions of each factors to either homogenization or polarization phenomena are calculated. It is found that the homogenization of water discharge is mainly controlled by dam operations in GDEP and DEP river basins, but dominated by the homogenized precipitation in GEP and EP river basins. Homogenized evaporation and polarized precipitation are the major factors behind the polarization of water discharge. This work is of importance to flood/drought disasters control and sustainable riverine/coastal eco-system management.

How to cite: Yue, Y. and Chai, Y.: Intra-year distribution of water discharge in global rivers, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21060, https://doi.org/10.5194/egusphere-egu2020-21060, 2020.

Various satellite data are part of humanitarian decision-making workflows. The added value of daytime imagery is mostly obvious, contributing to damage and needs assessment or the monitoring of populations of concern among other applications. However, the development and practical humanitarian applications of night-time imagery are largely unexplored. New possibilities are emerging with the public release of NASA’s black marble dataset – a global nighttime lights product derived from the Visible Infrared Imaging Radiometer Suite (VIIRS) on-board the Suomi National Polar-orbiting Partnership (NPP) satellite. Emerging evidence demonstrates the added-value of the black marble dataset to assess disaster impact and displacement after cyclone Idai made landfall in Mozambique in March 2019. Similar data was used to monitor reconstruction efforts in Puerto Rico in the wake of hurricane Maria's landfall in 2017, uncovering socio-economic inequalities in electricity restoration efforts. This work is led by a unique collaboration between the Universities Space Research Association’s (USRA) Earth from Space Institute, NASA Goddard Space Flight Center, Harvard Humanitarian Initiative, the World Bank, logistics services companies, aid and development organizations. 

How to cite: Enenkel, M., Román, M., Stokes, E., Ranjay, S., and Patrick, V.: On the dark side of the earth – How the Black Marble Alliance supports humanitarian activities with satellite-derived night-time light observations, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21922, https://doi.org/10.5194/egusphere-egu2020-21922, 2020.