scholarly journals Seasonal and aridity influences on the relationships between drought indices and hydrological variables over China

2021 ◽  
Vol 34 ◽  
pp. 100393
Author(s):  
Hao-jie Xu ◽  
Xin-ping Wang ◽  
Chuan-yan Zhao ◽  
Shu-yao Shan ◽  
Jin Guo
Keyword(s):  
Drought Indices ◽  
Hydrological Variables

Evaluation of drought indices via remotely sensed data with hydrological variables

2013 ◽  
Vol 476 ◽  
pp. 265-273 ◽  
Author(s):  
Minha Choi ◽  
Jennifer M. Jacobs ◽  
Martha C. Anderson ◽  
David D. Bosch
Keyword(s):  
Remotely Sensed ◽  
Drought Indices ◽  
Remotely Sensed Data ◽  
Hydrological Variables

scholarly journals Novel Drought Hazard Monitoring Framework for Decision Support Under Data Scarcity

10.29007/1l5w ◽  
2018 ◽  
Author(s):  
Roberto A. Real-Rangel ◽  
Adrián Pedrozo-Acuña ◽  
J. Agustín Breña-Naranjo ◽  
Víctor H. Alcocer-Yamanaka
Keyword(s):  
Early Warning Systems ◽  
Drought Indices ◽  
Risk Governance ◽  
Data Scarcity ◽  
The Road ◽  
Drought Hazard ◽  
Direct Observations ◽  
The World ◽  
Hydrological Variables

Droughts are among the weather-related disasters, which affects most people around the world. Its large spatial extent and slowly, creeping onset, makes it difficult to define its start and end. Indeed, monitoring and early warning systems for drought hazards are recognized as critical activities of risk governance. Nevertheless, in many regions of the world, the scarcity of direct observations of climatological and hydrological variables, hinder an adequate follow-up and investigation of this phenomenon. This paper introduces a novel framework to generate drought hazard maps and time series, at national and regional levels, based on univariate and multivariate standardized drought indices. Notably, we utilize freely and globally available, gridded datasets of hydrological variables derived from remote sensing and data assimilation systems (e.g., rainfall, soil moisture, streamflow), which are verified against in situ measurements. A good performance of the framework is documented through the comparison of results against observed drought events in Mexico. This paves the road towards its use in other regions of the world, where data scarcity is an issue for drought monitoring activities.

scholarly journals Water Level Reconstruction and Prediction Based on Space-Borne Sensors: A Case Study in the Mekong and Yangtze River Basins

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3076 ◽  
Author(s):  
Qing He ◽  
Hok Fok ◽  
Qiang Chen ◽  
Kwok Chun
Keyword(s):  
Remote Sensing ◽  
Yangtze River ◽  
River Basins ◽  
Remotely Sensed ◽  
Weighted Averaging ◽  
Drought Indices ◽  
Surface Conditions ◽  
Enso Events ◽  
Hydrological Extremes ◽  
Hydrological Variables

Water level (WL) measurements denote surface conditions that are useful for monitoring hydrological extremes, such as droughts and floods, which both affect agricultural productivity and regional development. Due to spatially sparse in situ hydrological stations, remote sensing measurements that capture localized instantaneous responses have recently been demonstrated to be a viable alternative to WL monitoring. Despite a relatively good correlation with WL, a traditional passive remote sensing derived WL is reconstructed from nearby remotely sensed surface conditions that do not consider the remotely sensed hydrological variables of a whole river basin. This method’s accuracy is also limited. Therefore, a method based on basin-averaged, remotely sensed precipitation from the Tropical Rainfall Measuring Mission (TRMM) and gravimetrically derived terrestrial water storage (TWS) from the Gravity Recovery and Climate Experiment (GRACE) is proposed for WL reconstruction in the Yangtze and Mekong River basins in this study. This study examines the WL reconstruction performance from these two remotely sensed hydrological variables and their corresponding drought indices (i.e., TRMM Standardized Precipitation Index (TRMM-SPI) and GRACE Drought Severity Index (GRACE-DSI)) on a monthly temporal scale. A weighting procedure is also developed to explore a further potential improvement in the WL reconstruction. We found that the reconstructed WL derived from the hydrological variables compares well to the observed WL. The derived drought indices perform even better than those of their corresponding hydrological variables. The indices’ performance rate is owed to their ability to bypass the influence of El Niño Southern Oscillation (ENSO) events in a standardized form and their basin-wide integrated information. In general, all performance indicators (i.e., the Pearson Correlation Coefficient (PCC), Root-mean-squares error (RMSE), and Nash–Sutcliffe model efficiency coefficient (NSE)) reveal that the remotely sensed hydrological variables (and their corresponding drought indices) are better alternatives compared with traditional remote sensing indices (e.g., Normalized Difference Vegetation Index (NDVI)), despite different geographical regions. In addition, almost all results are substantially improved by the weighted averaging procedure. The most accurate WL reconstruction is derived from a weighted TRMM-SPI for the Mekong (and Yangtze River basins) and displays a PCC of 0.98 (and 0.95), a RMSE of 0.19 m (and 0.85 m), and a NSE of 0.95 (and 0.89); by comparison, the remote sensing variables showed less accurate results (PCC of 0.88 (and 0.82), RMSE of 0.41 m (and 1.48 m), and NSE of 0.78 (and 0.67)) for its inferred WL. Additionally, regardless of weighting, GRACE-DSI displays a comparable performance. An external assessment also shows similar results. This finding indicates that the combined usage of remotely sensed hydrological variables in a standardized form and the weighted averaging procedure could lead to an improvement in WL reconstructions for river basins affected by ENSO events and hydrological extremes.

scholarly journals Using an integrated hydrological model to estimate the usefulness of meteorological drought indices in a changing climate

2016 ◽  
Vol 20 (10) ◽  
pp. 4159-4175 ◽  
Author(s):  
Diane von Gunten ◽  
Thomas Wöhling ◽  
Claus P. Haslauer ◽  
Daniel Merchán ◽  
Jesus Causapé ◽  
...  
Keyword(s):  
Drought Index ◽  
Hydrological Model ◽  
Meteorological Drought ◽  
Future Climate ◽  
Drought Indices ◽  
Small Catchment ◽  
Hydrological Impacts ◽  
Hydrological Variable ◽  
Semi Arid ◽  
Hydrological Variables

Abstract. Droughts are serious natural hazards, especially in semi-arid regions. They are also difficult to characterize. Various summary metrics representing the dryness level, denoted drought indices, have been developed to quantify droughts. They typically lump meteorological variables and can thus directly be computed from the outputs of regional climate models in climate-change assessments. While it is generally accepted that drought risks in semi-arid climates will increase in the future, quantifying this increase using climate model outputs is a complex process that depends on the choice and the accuracy of the drought indices, among other factors. In this study, we compare seven meteorological drought indices that are commonly used to predict future droughts. Our goal is to assess the reliability of these indices to predict hydrological impacts of droughts under changing climatic conditions at the annual timescale. We simulate the hydrological responses of a small catchment in northern Spain to droughts in present and future climate, using an integrated hydrological model calibrated for different irrigation scenarios. We compute the correlation of meteorological drought indices with the simulated hydrological time series (discharge, groundwater levels, and water deficit) and compare changes in the relationships between hydrological variables and drought indices. While correlation coefficients linked with a specific drought index are similar for all tested land uses and climates, the relationship between drought indices and hydrological variables often differs between present and future climate. Drought indices based solely on precipitation often underestimate the hydrological impacts of future droughts, while drought indices that additionally include potential evapotranspiration sometimes overestimate the drought effects. In this study, the drought indices with the smallest bias were the rainfall anomaly index, the reconnaissance drought index, and the standardized precipitation evapotranspiration index. However, the efficiency of these drought indices depends on the hydrological variable of interest and the irrigation scenario. We conclude that meteorological drought indices are able to identify years with restricted water availability in present and future climate. However, these indices are not capable of estimating the severity of hydrological impacts of droughts in future climate. A well-calibrated hydrological model is necessary in this respect.

scholarly journals Using an integrated hydrological model to estimate the usefulness of meteorological drought indices in a changing climate

2016 ◽  
Author(s):  
Diane von Gunten ◽  
Thomas Wöhling ◽  
Claus P. Haslauer ◽  
Daniel Merchán ◽  
Jesus Causapé ◽  
...  
Keyword(s):  
Hydrological Model ◽  
Potential Evapotranspiration ◽  
Meteorological Drought ◽  
Future Climate ◽  
Drought Indices ◽  
Small Catchment ◽  
Hydrological Impacts ◽  
Hydrological Variable ◽  
Semi Arid ◽  
Hydrological Variables

Abstract. Droughts are serious natural hazards, especially in semi-arid regions. They are also difficult to characterize. Various summary metrics representing the dryness level, denoted drought indices, have been developed to quantify droughts. They typically lump meteorological variables and can thus directly be computed from the outputs of regional climate models in climate-change assessments. While it is generally accepted that drought risks in semi-arid climates will increase in the future, quantifying this increase using climate model outputs is a complex process which depends on the choice and the accuracy of the drought indices, among other factors. In this study, we compare seven meteorological drought indices that are commonly used to predict future droughts. Our goal is to assess the reliability of these indices to predict hydrological impacts of droughts under changing climatic conditions. We simulate the hydrological responses of a small catchment in northern Spain to droughts in present and future climate, using an integrated hydrological model, calibrated for different irrigation scenarios. We compute the correlation of meteorological drought indices with the simulated hydrological times series (discharge, groundwater levels, and water deficit), and we compare changes in the relationships between hydrological variables and drought indices. While correlation coefficients are similar for all tested land-uses and climates, the relationship between drought indices and hydrological variables often differs between present and future climate. Drought indices based solely on precipitation often underestimate the hydrological impacts of future droughts, while drought indices that additionally include potential evapotranspiration sometimes overestimate the drought effects. In this study, the drought indices with the smallest bias were: the rainfall anomaly index, the reconnaissance drought index, and the standardized precipitation evapotranspiration index. However, the efficiency of these drought indices depends on the hydrological variable of interest and the irrigation scenario. We conclude that meteorological drought indices are able to identify the timing of hydrological impacts of droughts in present and future climate. However, these indices are not capable of estimating the severity of hydrological impacts of droughts in future climate. A well-calibrated hydrological model is necessary in this respect.

scholarly journals A drought monitoring framework for data-scarce regions

2019 ◽  
Vol 22 (1) ◽  
pp. 170-185 ◽  
Author(s):  
Roberto A. Real-Rangel ◽  
Adrián Pedrozo-Acuña ◽  
J. Agustín Breña-Naranjo ◽  
Víctor H. Alcocer-Yamanaka
Keyword(s):  
Temporal Distribution ◽  
Probability Of Detection ◽  
Drought Monitoring ◽  
Drought Indices ◽  
Drought Severity ◽  
Drought Risk ◽  
Spatial And Temporal Patterns ◽  
Maize Production ◽  
Drought Hazard ◽  
Hydrological Variables

Abstract Drought monitoring is a critical activity for drought risk management; however, the lack of ground-based observations of climatological and hydrological variables in many regions of the world hinders an adequate follow-up and investigation of this phenomenon. This paper introduces a transparent framework for monitoring the spatio-temporal distribution of drought hazard based on uni- and multivariate standardized drought indices that use reanalysis datasets of hydrological variables available freely and globally. In the case study of the 2015–2017 East-Southwest drought in Mexico, the introduced framework successfully detected the spatial and temporal patterns of drought conditions, even in regions where a benchmark drought monitoring system failed to detect deficits. In addition, the ability of the introduced framework to detect drought impacts on the annual agricultural maize production in Mexico was evaluated using data of 1980–2018, yielding scores of the false alarm ratio =0.32, the probability of detection = 0.71, and the proportion correct = 0.68 for the analysis at the national scale. Currently, the framework provides a significant extension to the capabilities for national drought monitoring, and it is being used by the Mexican water authority in the decision-making process related to drought severity assessment.

DEVELOPMENT OF STREAMFLOW DROUGHT INDICES IN THE MORAVA RIVER BASIN

2020 ◽  
Author(s):  
Ondrej Ledvinka ◽  
◽  
Pavel Coufal ◽  
Keyword(s):  
Time Series ◽  
Kendall Test ◽  
Drought Indices ◽  
Drought Period ◽  
Left Hand ◽  
Low Flows ◽  
Current Period ◽  
Catchment Size ◽  
Morava River ◽  
The Stability

The territory of Czechia currently suffers from a long-lasting drought period which has been a subject of many studies, including the hydrological ones. Previous works indicated that the basin of the Morava River, a left-hand tributary of the Danube, is very prone to the occurrence of dry spells. It also applies to the development of various hydrological time series that often show decreases in the amount of available water. The purpose of this contribution is to extend the results of studies performed earlier and, using the most updated daily time series of discharge, to look at the situation of the so-called streamflow drought within the basin. 46 water-gauging stations representing the rivers of diverse catchment size were selected where no or a very weak anthropogenic influences are expected and the stability and sensitivity of profiles allow for the proper measurement of low flows. The selected series had to cover the most current period 1981-2018 but they could be much longer, which was considered beneficial for the next determination of the development direction. Various series of drought indices were derived from the original discharge series. Specifically, 7-, 15- and 30-day low flows together with deficit volumes and their durations were tested for trends using the modifications of the Mann– Kendall test that account for short-term and long-term persistence. In order to better reflect the drivers of streamflow drought, the indices were considered for summer and winter seasons separately as well. The places with the situation critical to the future water resources management were highlighted where substantial changes in river regime occur probably due to climate factors. Finally, the current drought episode that started in 2014 was put into a wider context, making use of the information obtained by the analyses.

Drought indices and prediction models for winter wheat

2011 ◽  
Vol 19 (4) ◽  
pp. 860-865
Author(s):  
Xi-Yan KANG ◽  
Guang-Qin GU ◽  
Yin-Shan SHI ◽  
Guo-Qiang TIAN ◽  
Yong-Li GU
Keyword(s):  
Winter Wheat ◽  
Prediction Models ◽  
Drought Indices

scholarly journals Documentary data and the study of past droughts: a global state of the art

2018 ◽  
Vol 14 (12) ◽  
pp. 1915-1960 ◽  
Author(s):  
Rudolf Brázdil ◽  
Andrea Kiss ◽  
Jürg Luterbacher ◽  
David J. Nash ◽  
Ladislava Řezníčková
Keyword(s):  
Large Scale ◽  
State Of The Art ◽  
Drought Indices ◽  
Documentary Evidence ◽  
Climatic Trends ◽  
Instrumental Observations ◽  
Spatio Temporal ◽  
Epigraphic Evidence ◽  
Administrative Evidence

Abstract. The use of documentary evidence to investigate past climatic trends and events has become a recognised approach in recent decades. This contribution presents the state of the art in its application to droughts. The range of documentary evidence is very wide, including general annals, chronicles, memoirs and diaries kept by missionaries, travellers and those specifically interested in the weather; records kept by administrators tasked with keeping accounts and other financial and economic records; legal-administrative evidence; religious sources; letters; songs; newspapers and journals; pictographic evidence; chronograms; epigraphic evidence; early instrumental observations; society commentaries; and compilations and books. These are available from many parts of the world. This variety of documentary information is evaluated with respect to the reconstruction of hydroclimatic conditions (precipitation, drought frequency and drought indices). Documentary-based drought reconstructions are then addressed in terms of long-term spatio-temporal fluctuations, major drought events, relationships with external forcing and large-scale climate drivers, socio-economic impacts and human responses. Documentary-based drought series are also considered from the viewpoint of spatio-temporal variability for certain continents, and their employment together with hydroclimate reconstructions from other proxies (in particular tree rings) is discussed. Finally, conclusions are drawn, and challenges for the future use of documentary evidence in the study of droughts are presented.

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