Drought, a natural disaster, possess a great threat to a nation as well as to human society by stressing the water availability, agricultural production and economy of the country. As per the studies, India is highly vulnerable to droughts, occurring once in every three years from the past three decades. India receives 70-80% of its annual mean precipitation brought by south-west summer monsoon. Monsoon failure leads to the acute deficiency of available water that ultimately causes droughts and water scarce conditions. This study is an attempt to analyse the spatio-temporal variations of meteorological drought and to investigate the effect of topographical variable (elevation) on Indian summer monsoon drought characteristics over Indus River Basin. Indian extent of Indus River basin has been considered as a case. Heterogeneity of the elevation spread over the basin makes it suitable for the study. Therefore, to serve the purpose, daily gridded precipitation and temperature data at a spatial resolution of 0.12⁰ x 0.12⁰ for a time period of 42 years (1979-2020) is utilized to analyse the drought characterization. Modified Mann-Kendall method and Sen’s slope estimator have been used to detect significant trends in the study region. Standardized Precipitation Evapotranspiration Index (SPEI) has been employed to identify the dry events on the basis of climatic water-balance. Indian summer monsoon lasts for four months (June-September), thus SPEI-4 has been computed to characterize the summer monsoon droughts. Results revealed that around 18% (5%) of the stations shows wetting (drying) trends for the monsoon time series analysis. Additionally, in relation to SPEI trends, larger area (25%) of the basin depicts increasing precipitation and decreasing Potential Evapotranspiration (PET) trends. Moreover, the study region experiences 1-10% and 1-5% severe and extreme drought frequency (percentage) respectively over the time period 1979-2020. Further, the relationship of SPEI trend with respect to elevation is explored because highlands are more vulnerable to climate change as compared to low altitude regions. In case of altitude up-to 2000 m, Sen’s slope exhibits positive magnitude thus, wetting trend is observed. A very minimalistic drying trend is seen between 2000-3000 m elevation and beyond that almost no trend pattern is followed. The possible causes of this certain behaviour of SPEI trend with elevation is determined by further analysis of trend of meteorological parameters (precipitation and PET) that were used to calculate SPEI. Both precipitation and PET trends are found to be responsible for the SPEI trends.

How to cite: Dubey, A., Swami, D., Gupta, V., and Joshi, N.: Characterization of Indian Summer Monsoon Drought and its Elevation Dependance over Indus River Basin, India, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-521, https://doi.org/10.5194/egusphere-egu23-521, 2023.

Drought is typically induced by the extreme water deficit stress that cascades through the atmosphere, hydrosphere, and biosphere. However, identifying individual cascade connections remains challenging due to the nonlinear interactive loops within drought cascades initiated by numerous physical elements, which hinder the emergent patterns of droughts cascade from being explored further.

In this study, we establish a statistical framework for characterizing the dynamic space-time behaviour of droughts to track the droughts cascade. We investigate four typical droughts: precipitation (PCP), evapotranspiration (ET), Runoff, and root-zone soil moisture (SM) throughout Central Asia, the typical arid and semi-arid area of the world. Then, this method extracts 15 emergent patterns of droughts cascading corresponding to the different temporal orders. Moreover, the 15 emergent patterns of droughts cascade are categorized further as two-phase, three-phase, and four-phase drought cascading patterns in keeping with the appearance of hydrological parameters.

The result shows the highest occurrence in the four-phase cascading pattern, manifesting that the drought in PCP, ET, Runoff, and SM are expected predominantly to occur consecutively across the study area. Additionally, we find that four variations coefficients of duration, intensity, severity, and area reveal a positive linear relationship during cascading processes. Furthermore, the distribution range and magnitude of four metrics (duration, intensity, severity, and area) of PCP droughts increase with the rising of phase number in all cascading patterns.

Traits of the drought cascade provide another perspective for the drought early-warning and impact forecast in Central Asia, which could support the decision-making on drought mitigation in the arid region under exacerbated water deficit stress from global warming.

Keywords: group behaviour of droughts, cross-temporospatial scale, arid region, water management

How to cite: Tian, L., Huang, J., and Disse, M.: Emergent pattern analysis of multiple-phase droughts cascade in Central Asia from a dynamic perspective, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9711, https://doi.org/10.5194/egusphere-egu23-9711, 2023.

Drought impacts monitoring is conducted on the ground in much of Brazil by local observers at monthly and municipality scale. The monitoring was established to contribute towards the Brazilian Drought Monitor (https://monitordesecas.ana.gov.br/, established in 2014) with a multichoice questionnaire principally aimed at ground truthing the monthly map of drought condition, but with additional questions, including an open question, about drought impacts.

Our research focussed on Ceará State in drought-prone semiarid northeast Brazil. In Ceará, over 3600 questionnaires were completed by agricultural extension officers since February 2019 based on their visits to a wide area of the municipalities. These local reports about drought impacts have been under-exploited by the Drought Monitor yet represent a rich resource of impact information. We aimed to understand what drought impacts were reported and if there were differences between these local reports and the Drought Monitor maps.

We manually coded all the reports to deductively identify impacts and other useful information. Despite some spatial and temporal gaps, the data reveal: a catalogue of the most significant impacts experienced on the ground per municipality per month, impact drivers (including non-climatic drivers), and areas of greater/lesser vulnerability (i.e. where more/less impacts were reported despite matching drought condition).

Analysis shows that impacts still occur, and are often normalised during non-drought periods. The impact drivers are either non-extreme hydrometeorological conditions or socially constructed vulnerability such as a lack of water infrastructure or poverty. The normalisation of “impacts” includes, in particular: a level of crop losses that is considered usual (up to 50% losses are acceptable) and consistently low reservoir levels (around 10% of capacity) around which the agricultural and domestic systems are adapted. The frequent non-correspondence of Drought Monitor drought severity and experienced drought severity suggests the Drought Monitor, and other Drought Monitors around the world based on traditional hydroclimatic indices, are not optimal for triggering emergency response, which they are often (mis)used for, though are relevant for triggering discussion and action on drought preparation, as is usually their principal aim.

How to cite: Walker, D. W., Oliveira, J. L., Cavalcante, L., Kchouk, S., Ribeiro Neto, G., Melsen, L. A., Fernandes, F. B. P., Mitroi, V., Gondim, R. S., Martins, E. S. P. R., and van Oel, P. R.: It’s not all about drought: what “drought impacts” monitoring reveals about semiarid northeast Brazil, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13020, https://doi.org/10.5194/egusphere-egu23-13020, 2023.

The Horn of Africa Drylands are increasingly experiencing severe droughts, which imposes a thread on traditional livelihood strategies of pastoralist communities. Understanding adaptation behaviour in rural communities is essential to help reducing the impact of these droughts. In this study, we identify drivers and barriers of drought risk adaptation decisions in pastoralist communities, by analysing household survey data from 502 Kenyan households. To provide theoretically sound insights into adaptive behaviour, we have grounded our empirical research in four established economic and psychological theories on decision-making under risk: Expected Utility Theory (EUT), Rank Dependent Utility Theory (RDU), Protection Motivation Theory (PMT) and Theory of Planned Behaviour (PMT). The variables of all theories are measured by multiple survey questions and we have included an economic experiment in the survey to measure the risk aversion parameters of Expected Utility Theory and Rank Dependent Utility theory. With regression models, we analyse the relation between the theory variables and adaptation behaviour. To measure adaptation behaviour, we have selected 15 different adaptation measures for which we asked about current uptake and the intention to adopt these measures in the future. Regression analyses show that important factors in adaptation decisions are risk attitudes, financial constraints, perceives self-efficacy and adaptation by family and friends.  An analysis of adaptation intention for each adaptation measure separately shows that drivers and barriers of adaptation are different for different types of adaptation measures. Risk-averse pastoralists are more likely to implement adaptation measures that are adjustments to current pastoral practices, and less likely to implement adaptation measures that require a (partial) shift to other livelihood activities. A person’s belief in their own ability to implement an adaptation measure (perceived self-efficacy) is an important factor in explaining which measure people are going to adopt. Furthermore, we find that some measures are more likely to be taken by women and others more likely to be taken by men and we find significant effects for differences in education levels. Our analysis can help to gain more knowledge on the drivers of individual adaptation decisions of pastoralists, which can enhance policies promoting adaptation of dryland communities. Our results indicate that drivers and barriers of adaptation can be quite different for different groups, which suggests that policies should be carefully targeted at specific groups.

How to cite: Schrieks, T., Botzen, W., Haer, T., Wasonga, O., and Aerts, J.: Drivers and barriers of drought risk adaptation decisions by agro-pastoralists in Kenya, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-476, https://doi.org/10.5194/egusphere-egu23-476, 2023.

In Central Europe and Germany, climate change increases the risk of temperature anomalies, heat waves, and droughts. The most profound and direct impacts of such risk will be on agriculture and food systems. Climate change will adversely impact crop yields and jeopardize harvests, resulting in substantial crop production and economic losses. The expected increase in the frequency and severity of droughts in the future due to climate change can lead to significantly higher annual economic losses. To mitigate these impacts, cultivation regimes, crop rotation, and even the entire production patterns would need to be adapted. Hence, it is imperative to understand the management of risk in crop production and its role in drought adaptation in light of predicted impacts and contribute to evidence for adaptation policies.

To achieve this objective, we develop a spatial multi-agent system (MAS) model, DroughtMAS, using an Econometric Mathematical Programming (EMP) approach. The model simulates land-use adaptation to drought conditions, estimate the damages of droughts, and assesses risk management tools and strategies. The MAS model captures the biophysical and agro-economic heterogeneity of German agriculture through individually parameterized 401 land-user agents at a sub-national scale. Cropping behavior is calibrated with land-use data from high-resolution remote sensing analyses and public records. The economic parameters ground the model in a policy-relevant context while the statistical functions capture the impacts of biophysical factors on crop production. These yield functions enable the model to respond to soil moisture changes from observed data or projections from hydrological models.

The current modeling efforts are focused on extending the model to better reflect a farmer’s cropping decision at the time of planting. Specifically, using empirical data, we estimate the farmer’s expected yield factor at the planning/planting stage expressed as a function of previous drought-year yields for major agricultural crops in Germany. The aim is to explore how the dynamic interplay between the loss of income in previous droughts and resultant farmer cropping decisions affects adaptation to droughts in agriculture.  

We present the first analysis of the extension to demonstrate the ability of the model to capture farmer cropping decisions during drought and quantify their economic impacts on agriculture in Germany. The results provide bottom-up estimates of the economic damages of droughts accounting for much-needed short-run behavioral dynamics of adaptation. This provides a versatile validated cropping simulation model that can be used for realistic projections of future drought impacts of farm-specific changes aggregated at a national scale. The model also presents a spatiotemporal pattern of these impacts, showing the potential for this model to inform targeted policy interventions. The DroughtMAS provides a platform to capture additional adaptation behaviors (e.g. drought-resilient crops, irrigation systems) and integrate with other models that require empirically validated inputs about various agricultural decision-making conditions.

How to cite: Nagpal, M., Klassert, C., Klauer, B., and Gawel, E.: Simulating economic impacts of droughts on agriculture using DroughtMAS, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13372, https://doi.org/10.5194/egusphere-egu23-13372, 2023.

In recent years, research on drought risk has expanded to include multiple types of drought hazards, various exposed elements and a multitude of factors that determine the vulnerability of a given system or sector. This has resulted in a call from the scientific community to adopt a systemic risk perspective on drought. However, a thorough understanding of how drought risks manifest, cascade and interact across different systems and sectors is still lacking, and methodological guidance on how to analyse and represent these interdependencies does not yet exist.  In order to explore these gaps, we have developed conceptual models of drought risks for key selected systems and sectors in the European Union. 

For each system and sector considered (rain fed and irrigated agricultural systems, forest ecosystems, freshwater ecosystems, public water supply, inland water transport and the energy sector), a conceptual model was constructed to depict how drivers and root causes interact to create drought risk. The models are based on the impact chains methodology and are informed by literature review and multiple expert consultations (including a series of validation workshops). Subsequently, the system-specific models were used to build an overarching conceptual model of the critical interdependencies that exist between all the systems and sectors considered. 

The analysis has revealed that, in each system, drought risks manifest through a complex web of interactions between drivers of risk, which are in part system-specific and in part shared across the systems considered. From this, multiple considerations for drought risk assessment and management can be derived. In particular, special attention should be placed in defining and representing what drought risk is in each system, as the underlying characteristics might greatly differ. Additionally, the use of conceptual models can constitute an important first step for risk assessment, as they contribute to addressing the complexity of drought risks. Finally, the existence of commonalities and interdependencies between systems implies that interventions can and must be designed so as to consider multiple systems at once, thus avoiding maladaptive solutions. In this sense, the conceptual models can serve as entry points for the identification of risk reduction and adaptation measures which go beyond the single-risk and single-sector perspective, thus contributing to a more systemic view on drought risk management and adaptation, as well as highlighting persisting knowledge gaps.

How to cite: Cotti, D., Sabino Siemons, A.-S., Naumann, G., Wens, M., de Moel, H., Blauhut, V., Stahl, K., Rossi, L., Maetens, W., Toreti, A., and Hagenlocher, M.: Conceptual models of drought risks for Europe: a step towards a systemic perspective on drought, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7991, https://doi.org/10.5194/egusphere-egu23-7991, 2023.

Climate change is increasing the frequency and intensity of droughts across drylands, with negative consequences on local communities. Small water infrastructure (e.g. wells, ponds and small dams) are increasingly supported by many NGOs and national governments to increase water availability and help pastoralists cope with the effects of climate change. However, as opposed to large dams, very little is known about the potential cumulative impact of small water infrastructures and their cascading effects on the resilience of pastoral communities. Pastoralists of drylands across the world, who constitute large, marginalized groups in many low-income countries, practice mobility as one of the main adaptation strategies to water variability and uncertainty. Here we show that while developing fixed water points in dryland can provide additional water to pastoral communities, these short-term benefits can be offset by counterintuitive long-term effects such as the erosion of mobility practices and over-reliance on agriculture, thus decreasing resilience to climate change. Combining system dynamics and resilience thinking approaches, we explain the complex consequences of different water resource development strategies and their long-term cascading effects on the resilience of pastoral communities. We then show how our model can capture early signals of resilience loss in Angolan drylands, where water infrastructures are being planned at a large-scale in the pursuit of increasing climate resilience, with unclear long-term understanding of the effects of socio-hydrological dynamics on communities’ resilience.

How to cite: Piemontese, L., Terzi, S., Di Baldassarre, G., Castelli, G., and Bresci, E.: Over-reliance on water infrastructure can erode resilience of drylands pastoralists, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-198, https://doi.org/10.5194/egusphere-egu23-198, 2023.

Impacts of a drought on society and hydrological processes cover a wide range of issues such as environment, economy, management and water structures. Here we present a case study addressing challenges in water management under drought conditions and human influence by focusing on developing a storyline for future reflections. With rich and fertile lands, the Seyhan River Basin in Turkey has an international importance for agricultural production as large quantities of vegetables are exported globally. The basin was exposed to an extreme drought at various intensities in the year 2008 when the river basin received the lowest precipitation ever recorded. The drought reduced total water availability throughout the river basin by triggering a series of cascading impacts such as reducing agricultural yield, increasing food prices, adversely affecting farmers’ income, leading a migration of regional farmers from rural regions toward urban centers. The migration caused population growth in big cities, alterations in water consumption habits by increasing socioeconomic development, and growth in urbanization and water-dependent sectors. These cascading impacts of the drought showed that the event indirectly fed back to affect the river basin hydrology as well. In order to avoid or minimize drought impacts, decision-makers and water managers implemented a number of water supply techniques and adopted temporary management policies, which resulted in increasing and unsustainable water demand under drought conditions. The paradoxical intervention can only mitigate negative effects of drought at short term but we need long-term drought mitigation measures. In addition, we understood that such short-term interventions should be avoided in the absence of an effective water management plan under drought conditions. An effective management plan requires that water managers, city planners, and all related governance levels interpret solutions together without challenging the entire system.

How to cite: Cavus, Y., Aksoy, H., and Stahl, K.: Human intervention against drought in Seyhan River Basin, Turkey, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-484, https://doi.org/10.5194/egusphere-egu23-484, 2023.

Since the turn of the 21st century, the capacity of many terrestrial ecosystems to withstand pressures is being eroded, with severe water stress in summer being one of the significant causes and consequences. With droughts projected to become more frequent, and to have more severe impacts, coping strategies must be in place. Some effects of droughts on human water and food systems and from ill-adapted human use of water can be mitigated through the implementation of early warning systems (EWS), which can predict the severity and duration of a drought. However, these systems should also elicit a response, delivering timely information to decision makers, including all involved in land and water management. This will allow for proactive risk management measures and appropriate emergency response programs. To comprehensively deal with such complex problems, innovative and integrated governance approaches are necessary. An approach put forward to manage complex social-environmental problems such as droughts is adaptive governance, which calls for more flexible and learning-based collaborations and decision-making processes involving all relevant actors and stakeholders across different governance levels.

Here we present the concept for an integrated drought EWS that provides prestructured accessible data and actionable knowledge across actors at different levels of governance. We propose the development of an accessible multiple-source-design web platform with a structure to cater for different user groups. The monitoring and associated EWS would allow data and scenario visualisation, along with ongoing networked and collaborative experimentation with adaptation and mitigation measures. The platform would also include an interactive blogging domain. In co-designing the EWS with stakeholders the project aims to create a sense of co-ownership to encourage active engagement, bringing together interest groups in agriculture and water to prioritize future challenges concerning resilience of ecosystems involving water, soil and agriculture.

The concept is developed based on the case of Luxembourg as a small country, but the innovative approach to co-creating knowledge for action across different scales is relevant in diverse contexts. The proposed EWS would function across scales, offering access to different spatial and temporal scales of representations of circumstances relating to drought risks, accessible to various actors across different levels of governance. For contiguous spatial representations relating to the entire territory of the nation state (and surroundings), remote sensing data from satellites would be used, such as EU and national data on land cover and land use and satellite based soil moisture. Official measurement stations and monitoring programmes on river levels and precipitation levels provide additional information at the spatial scale of individual larger rivers at the catchment level. With decreased spatial scales, municipalities or individual plots of land of farmers become the focus. The remote sensing and modelled data would need to be supplemented with ground truthing to increase the levels of accuracy, precision, and geographic scale, to reflect the real drought impacts on the ground. Citizen science can provide these data sets necessary to complement the official ones. The various levels are not intended to be discrete, but to form elements of a complete system.

How to cite: Stankiewicz, J., König, A., and Weiss, S.: Developing drought resilience through Early Warning System with knowledge for action in multi-level governance, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13476, https://doi.org/10.5194/egusphere-egu23-13476, 2023.