scholarly journals A Spatially Transferable Drought Hazard and Drought Risk Modeling Approach Based on Remote Sensing Data

2020 ◽  
Vol 12 (2) ◽  
pp. 237 ◽  
Author(s):  
Maximilian Schwarz ◽  
Tobias Landmann ◽  
Natalie Cornish ◽  
Karl-Friedrich Wetzel ◽  
Stefan Siebert ◽  
...  

Drought adversely affects vegetation conditions and agricultural production and consequently the food security and livelihood situation of the often most vulnerable communities. In spite of recent advances in modeling drought risk and impact, coherent and explicit information on drought hazard, vulnerability and risk is still lacking over wider areas. In this study, a spatially explicit drought hazard, vulnerability, and risk modeling framework was investigated for agricultural land, grassland and shrubland areas. The developed drought hazard model operates on a higher spatial resolution than most available drought models while also being scalable to other regions. Initially, a logistic regression model was developed to predict drought hazard for rangelands and croplands in the USA. The drought hazard model was cross-verified for the USA using the United States Drought Monitor (USDM). The comparison of the model with the USDM showed a good spatiotemporal agreement, using visual interpretation. Subsequently, the explicit and accurate USA model was transferred and calibrated for South Africa and Zimbabwe, where drought vulnerability and drought risk were assessed in combination with drought hazard. The drought hazard model used time series crop yields data from the Food and Agriculture Organization Corporate Statistical Database (FAOSTAT) and biophysical predictors from satellite remote sensing (SPI, NDVI, NDII, LST, albedo). A McFadden’s Pseudo R² value of 0.17 for the South African model indicated a good model fit. The plausibility of the drought hazard model results in southern Africa was evaluated by using regional climate patterns, published drought reports and a visual comparison to a global drought risk model and food security classification data. Drought risk and vulnerability were assessed for southern Africa and could also be spatially explicit mapped showing, for example, lower drought vulnerability and risk over irrigated areas. The innovative aspect of the presented drought hazard model is that it can be applied to other countries at a global scale, since it only uses globally available data sets and therefore can be easily modified to account for country-specific characteristics. At the same time, it can capture regional drought conditions through a higher resolution than other existing global drought hazard models. This model addressed the gap between global drought models, that cannot spatially and temporally explicitly capture regional drought effects, and sub-regional drought models that may be spatially explicit but not spatially transferable. Since we used globally available and spatially consistent data sets (both as predictors and response variables), the approach of this study can potentially be used globally to enhance existing modelling routines, drought intervention strategies and preparedness measures.

2020 ◽  
Author(s):  
Maximilian Schwarz ◽  
Tobias Landmann ◽  
Natalie Cornish ◽  
Karl-Friedrich Wetzel ◽  
Stefan Siebert ◽  
...  

<p>This study presents a new methodology for spatially explicit and globally applicable drought hazard, vulnerability and risk modelling. We focused on agricultural droughts since this sector affects the food security and livelihood situation of the often most vulnerable communities especially in developing countries. Despite recent advances in drought modeling, coherent and spatially explicit information on drought hazard, vulnerability is still lacking over wider areas. In this study a spatially explicit inter-operational drought hazard, vulnerability and risk modeling framework was investigated for agricultural land, grassland and shrubland areas. The developed drought hazard model operates on a higher spatial resolution than most available global drought models while also being scalable to other regions. Initially, a logistic regression model was developed to predict drought hazard for rangelands and cropland in the USA. The model results showed a good spatiotemporal agreement within the cross-verification with the United States Drought Monitor (USDM), using visual interpretation. Subsequently, the explicit and accurate drought hazard model was transferred and calibrated for South Africa and Zimbabwe, where a simplified drought risk indicator was calculated by the combination of drought hazard and drought vulnerability. The drought hazard model used time series crop yields data from the Food and Agriculture Organization Corporate Statistical Database (FAOSTAT) and biophysical predictors from satellite remote sensing (SPI, NDII, NDVI, LST, albedo). The McFadden’s Pseudo R² value of 0.17 indicated a good model fit for drought hazard in South Africa. Additionally, the plausibility of the model results in Southern Africa was evaluated by using regional climate patterns, published drought reports and through visual comparison to a global drought risk model and food security classification data. Drought risk and vulnerability were also assessed for Southern Africa and could be mapped in a spatially explicit manner, showing, for example, lower drought risk and vulnerability over irrigated areas. This developed modeling framework can be applied globally, since it uses globally available datasets and therefore can be easily modified to account for country-specific conditions. Additionally, it can also capture regional drought patterns on a higher spatial resolution than other existing global drought models. This model addressed the gap between global drought models, that cannot accurately capture regional droughts, and sub-regional models that may be spatially explicit but not spatially coherent. The approach of this study can potentially be used to identify risk and priority areas and possibly in an early warning capacity while enhancing existing drought monitoring routines, drought intervention strategies and the implementation of preparedness measures.  </p>


2018 ◽  
Author(s):  
Ismail Dabanli

Abstract. Drought has multiple impacts on socioeconomic sectors and it is expected to increase in the coming years due to non-stationary nature of climate variability and change. Here, we investigated drought hazard, vulnerability, and risk based on hydro-meteorological and actual socio-economic data for provinces of Turkey. Although, drought vulnerability and risk assessment are essential parts of drought phenomenon, so far, lack of proper integrated drought risk assessment in Turkey (and elsewhere) has led to higher socio-economic impacts. Firstly, the Drought Hazard Index (DHI) is derived based on the probability occurrences of drought using Standardized Precipitation Index (SPI) to facilitate the understanding of drought phenomenon. Secondly, the Drought Vulnerability Index (DVI) is calculated by utilizing four socio-economic indicators to quantify drought impact on society. Finally, the Drought Risk Index (DRI) is obtained by multiplying DHI and DVI for provinces of Turkey to highlight the relative importance of hazard and vulnerability assessment for drought risk management. A set of drought hazard, vulnerability, and composite risk maps were then developed. The outputs of analysis reveal that among 81 administrative provinces in Turkey, 73 provinces are exposed to the low drought risk (0 


2020 ◽  
Author(s):  
Veit Blauhut ◽  
Claudia Teutschbein ◽  
Mathias N. Andersen ◽  
Manuela Brunner ◽  
Carmelo Cammalleri ◽  
...  

<p>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. </p><p>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.</p><p>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.</p>


Author(s):  
Lei Zhang ◽  
Wei Song ◽  
Wen Song

Natural disasters worldwide regularly impact on human activities. As a frequently occurring natural disaster, drought has adverse impacts on agricultural production. The Lancang-Mekong River is a transnational river running through China and five Southeast Asian countries and it is a vital water resource for irrigation in the region. Drought in the Lancang-Mekong Region (LMR) has occurred frequently in recent years. Assessing the risk of drought in the region is essential for rational planning of agricultural production and formulation of drought relief measures. In this study, an assessment of drought risk has been achieved by combining the hazard and vulnerability assessments for drought. The assessment of the drought hazard depends mainly on the standardized precipitation index (SPI). The assessment of drought vulnerability takes into account various indicators such as climatic factors (e.g., crop water stress index), soil factors (e.g., available water capacity), and irrigation factors (e.g., irrigation support). The results reveal that: (1) Drought distribution in the LMR is characterized by a spreading of the drought to countries along the middle and lower reaches of the Mekong River. Countries located in the middle and lower reaches of the Mekong River are more prone to drought. Laos, Thailand, and Cambodia are the regions with higher and high-drought risk levels. (2) The spatial distributions for the drought hazard and the drought vulnerability in the LMR exhibit significant differences as evidenced in the mapping results. High-hazard and high-vulnerability areas are mainly distributed in the middle LMR, and the middle to higher hazard areas and the middle to higher vulnerability areas are mainly distributed in the south-central LMR, while the low-hazard areas and the low-vulnerability areas are mainly in the north. (3) The majority of planting areas for sugarcane, rice, and cassava are located in the high-hazard areas. The distributions of drought-prone and high-hazard areas also correspond to the main agricultural areas in the LMR.


2020 ◽  
Author(s):  
Isabel Meza ◽  
Stefan Siebert ◽  
Petra Döll ◽  
Jürgen Kusche ◽  
Claudia Herbert ◽  
...  

<p>Drought is a recurrent global phenomenon considered one of the most complex hazards with manifold impacts on communities, ecosystems, and economies. While many sectors are affected by drought, agriculture’s high dependency on water makes it particularly susceptible to droughts, threatening the livelihoods of many, and hampering the achievement of the Sustainable Development Goals. Identifying pathways towards more drought resilient societies by analyzing the drivers and spatial patterns of drought risk is of increasing importance for the identification, prioritization and planning of risk reduction, risk transfer and adaptation options. While major progress has been made regarding the mapping, prediction and monitoring of drought events at different spatial scales (local to global), comprehensive drought risk assessments that consider the complex interaction of drought hazards, exposure and vulnerability factors are still the exception.</p><p>Here, we present, for the first time, a global-scale drought risk assessment at national level for both irrigated and rain-fed agricultural systems. The analysis integrates (1) composite drought hazard indicators based on historical climate conditions (1980-2016), (2) exposure data represented by the harvest area of irrigated and rainfed systems, and (3) an expert-weighted set of social-ecological vulnerability indicators. The latter were identified through a systematic review of literature (n = 105 peer-reviewed articles) and expert consultations (n = 78 experts). This study attempted to characterize the average drought risk for the whole study period.</p><p>Results show that drought risk of rain-fed and irrigated agricultural systems display different heterogeneous patterns at the global level with higher risk for southeastern Europe, as well as northern and southern Africa. The vulnerability to drought highlights the relevance to increase the countries’ coping capacity in order to reduce their overall drought risk. For instance, the United States, which despite being highly exposed to drought hazard, has low socio-ecological susceptibility and sufficiently high coping capacities to reduce the overall drought risk considerably. When comparing irrigated and rain-fed drought hazard/exposure, there are significant regional differences. For example, the northern part  of Central Africa and South America have low hazard/exposure levels of irrigated crops, resulting in a low total risk, although high vulnerability characterize these regions. South Africa, however, has a high amount of rain-fed crops exposed to drought, but a lower vulnerability compared to other African countries. Further, the drivers of drought risk vary substantially across and within countries, calling for spatially targeted risk reduction and adaptation options.</p><p>Findings from this study underline the relevance of analyzing drought risk from a holistic and integrated perspective that brings together data from different sources and disciplines and based on a spatially explicit approach. Being based on open-source data, the approach allows for reproduction in varying regions and for different spatial scales, and can serve as a blueprint for future drought risk assessments for other affected sectors, such as water supply, tourism, or energy. By providing information on the underlying drivers and patterns of drought risk, this approach supports the identification of priority regions and provides entry points for targeted drought risk reduction and adaptation options to move towards resilient agricultural systems.</p>


2020 ◽  
Vol 12 (3) ◽  
pp. 752 ◽  
Author(s):  
Janna Frischen ◽  
Isabel Meza ◽  
Daniel Rupp ◽  
Katharina Wietler ◽  
Michael Hagenlocher

The devastating impacts of drought are fast becoming a global concern. Zimbabwe is among the countries more severely affected, where drought impacts have led to water shortages, declining yields, and periods of food insecurity, accompanied by economic downturns. In particular, the country’s agricultural sector, mostly comprised of smallholder rainfed systems, is at great risk of drought. In this study, a multimethod approach is applied, including a remote sensing-based analysis of vegetation health data from 1989–2019 to assess the drought hazard, as well as a spatial analysis combined with expert consultations to determine drought vulnerability and exposure of agricultural systems. The results show that droughts frequently occur with changing patterns across Zimbabwe. Every district has been affected by drought during the past thirty years, with varying levels of severity and frequency. Severe drought episodes have been observed in 1991–1992, 1994–1995, 2002–2003, 2015–2016, and 2018–2019. Drought vulnerability and exposure vary substantially in the country, with the south-western provinces of Matabeleland North and South showing particularly high levels. Assessments of high-risk areas, combined with an analysis of the drivers of risk, set the path towards tailor-made adaptation strategies that consider drought frequency and severity, exposure, and vulnerability.


2020 ◽  
Author(s):  
Ali Ahmadalipour ◽  
Hamid Moradkhani

<p>Drought risk refers to the potential losses imposed by a drought event, and it is generally characterized as a function of vulnerability, hazard, and exposure. Here, we assess drought risk at a national level across Africa by considering climate change, population growth, and socioeconomic vulnerabilities. Drought vulnerability is quantified using a rigorous multi-dimensional framework based on 28 factors from six different sectors of economy, energy and infrastructure, health, land use, society, and water resources. Various analyses are conducted to assess the reliability and accuracy of the proposed drought vulnerability index (DVI). A multi-model and multi-scenario framework is employed to quantify drought hazard using a multitude of regional climate models. Drought risk is then assessed for 2 climate emission pathways (RCP4.5 and RCP8.5), 3 population scenarios, and 3 future vulnerability scenarios in each country during 2010-2100. Drought risk ratio is calculated for each scenario, and the role of each component (i.e. hazard, vulnerability, and exposure) is identified, and the associated uncertainties are also characterized. Results show that drought risk is expected to increase in future across Africa with varied rates for different models and scenarios. Although northern African countries indicate aggravating drought hazard, drought risk ratio is found to be highest in central African countries as a consequent of unprecedented vulnerability and population rise in the region. Results indicate that controlling the population growth is imperative for mitigating drought risk since it improves socioeconomic vulnerability and reduces potential exposure to drought. Meanwhile, climate change will considerably exacerbate drought and heat-stress hazards. Our findings show that global warming will escalate heat-stress mortality risk across Central Africa to unprecedented levels. It is revealed that unfortunately, the poorest countries (that have least contribution to climate change) are expected to be most impacted, and they will experience markedly higher risk ratios compared to the wealthier nations.</p>


Water ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 359 ◽  
Author(s):  
Muhammad Azam ◽  
Seung Maeng ◽  
Hyung Kim ◽  
Ardasher Murtazaev

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2264 ◽  
Author(s):  
David Solomon ◽  
Bo-Christer Björk

Background.Open access (OA) publishing via article processing charges (APCs) is growing as an alternative to subscription publishing. The Pay It Forward (PIF) Project is exploring the feasibility of transitioning from paying subscriptions to funding APCs for faculty at research intensive universities. Estimating of the cost of APCs for the journals authors at research intensive universities tend to publish is essential for the PIF project and similar initiatives. This paper presents our research into this question.Methods.We identified APC prices for publications by authors at the 4 research intensive United States (US) and Canadian universities involved in the study. We also obtained APC payment records from several Western European universities and funding agencies. Both data sets were merged with Web of Science (WoS) metadata. We calculated the average APCs for articles and proceedings in 13 discipline categories published by researchers at research intensive universities. We also identified 41 journals published by traditionally subscription publishers which have recently converted to APC funded OA and recorded the APCs they charge.Results.We identified 7,629 payment records from the 4 European APC payment databases and 14,356 OA articles authored by PIF partner university faculty for which we had listed APC prices. APCs for full OA journals published by PIF authors averaged 1,775 USD; full OA journal APCs paid by Western European funders averaged 1,865 USD; hybrid APCs paid by Western European funders averaged 2,887 USD. The APC for converted journals published by major subscription publishers averaged 1,825 USD. APC funded OA is concentrated in the life and basic sciences. APCs funded articles in the social sciences and humanities are often multidisciplinary and published in journals such as PLOS ONE that largely publish in the life sciences.Conclusions.Full OA journal APCs average a little under 2,000 USD while hybrid articles average about 3,000 USD for publications by researchers at research intensive universities. There is a lack of information on discipline differences in APCs due to the concentration of APC funded publications in a few fields and the multidisciplinary nature of research.


2019 ◽  
Vol 11 (5) ◽  
pp. 1442 ◽  
Author(s):  
Mahiuddin Alamgir ◽  
Morteza Mohsenipour ◽  
Rajab Homsi ◽  
Xiaojun Wang ◽  
Shamsuddin Shahid ◽  
...  

Droughts are more damaging when they occur during crop growing season. This research assessed the spatial distribution of drought risks to crops in Bangladesh. Catastrophe theory-based weighting method was used to estimate drought hazard, exposure, and risk by avoiding potential human bias. Ten major crops, including eight different types of rice, wheat, and potato, were selected for evaluation of drought risk. Results showed that 32.4%, 27.2%, and 16.2% of land in Bangladesh is prone to extreme Kharif (May-October), Rabi (November-April), and pre-Kharif (March-May) droughts, respectively. Among the major crops, Hybrid Boro rice cultivated in 18.2% of the area is found to be highly vulnerable to droughts, which is followed by High Yield Varity (HYV) Boro (16.9%), Transplant Aman (16.4%), HYV Aman (14.1%), and Basic Aman (12.4%) rice. Hybrid Boro rice in 12 districts, different varieties of Aman rice in 10 districts, and HYV Boro rice in 9 districts, mostly located in the north and northwest of Bangladesh, are exposed to high risk of droughts. High frequency of droughts and use of more land for agriculture have made the region highly prone to droughts. The methodology adopted in this study can be utilized for unbiased estimation of drought risk in agriculture in order to adopt necessary risk reduction measures.


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