Reference crop evapotranspiration database in Spain (1961–2014)

Abstract. Obtaining climate grids for distinct variables is of high importance to develop better climate studies, but also to offer usable products for other researchers and to end users. As a measure of atmospheric evaporative demand (AED), reference evapotranspiration (ETo) is a key variable for understanding both water and energy terrestrial balances, being important for climatology, hydrology and agronomy. In spite of its importance, the calculation of ETo is not very common, mainly because data of a high number of climate variables are required, and some of them are not commonly available. To solve this problem, a strategy based on the spatial interpolation of climate variables previous to calculation of ETo using FAO-56 Penman-Monteith was followed to obtain an ETo database for Continental Spain and Balearic Islands covering the 1961–2014 period at a spatial resolution of 1.1 km and at weekly temporal resolution. In this database, values for the radiative and aerodynamic components as well as the estimated uncertainty related with ETo are also provided. This database is available to download in Network Common Data Form (netcdf) format at https://doi.org/10.20350/digitalCSIC/8615 (Tomas-Burguera et al., 2019), and a map visualization tool (http://speto.csic.es) is also available to help users to download data of one specific point in comma-separated values (csv) format. A relevant number of research ares could take advantage of this database. Providing only some examples: i) the study of budyko curve, which relates rainfall data with evapotranspiration and AED at watershed scale; ii) the calculation of drought indices using AED data, such as SPEI or PDSI; iii) agroclimatic studies related with irrigation requirement; iv) validation of Climate Models water and energy balance; v) the study of the impacts of climate change in AED.

Download Full-text

Reference crop evapotranspiration database in Spain (1961–2014)

Earth System Science Data ◽

10.5194/essd-11-1917-2019 ◽

2019 ◽

Vol 11 (4) ◽

pp. 1917-1930 ◽

Cited By ~ 4

Author(s):

Miquel Tomas-Burguera ◽

Sergio M. Vicente-Serrano ◽

Santiago Beguería ◽

Fergus Reig ◽

Borja Latorre

Keyword(s):

Climate Models ◽

Severity Index ◽

Important Variable ◽

Drought Indices ◽

Drought Severity ◽

Climate Variables ◽

Evaporative Demand ◽

Research Areas ◽

Climate Studies ◽

Reference Crop

Abstract. Obtaining climate grids describing distinct variables is important for developing better climate studies. These grids are also useful products for other researchers and end users. The atmospheric evaporative demand (AED) may be measured in terms of the reference evapotranspiration (ETo), a key variable for understanding water and energy terrestrial balances and an important variable in climatology, hydrology and agronomy. Despite its importance, the calculation of ETo is not commonly undertaken, mainly because datasets consisting of a high number of climate variables are required and some of the required variables are not commonly available. To address this problem, a strategy based on the spatial interpolation of climate variables prior to the calculation of ETo using FAO-56 Penman–Monteith equation was followed to obtain an ETo database for continental Spain and the Balearic Islands, covering the 1961–2014 period at a spatial resolution of 1.1 km and at a weekly temporal resolution. In this database, values for the radiative and aerodynamic components as well as the estimated uncertainty related to ETo were also provided. This database is available for download in the Network Common Data Form (netCDF) at https://doi.org/10.20350/digitalCSIC/8615 (Tomas-Burguera et al., 2019). A map visualization tool (http://speto.csic.es, last access: 10 December 2019) is available to help users download the data corresponding to one specific point in comma-separated values (csv) format. A relevant number of research areas could take advantage of this database. For example, (i) studies of the Budyko curve, which relates rainfall data to the evapotranspiration and AED at the watershed scale, (ii) calculations of drought indices using AED data, such as the Standardized Precipitation–Evapotranspiration Index (SPEI) or Palmer Drought Severity Index (PDSI), (iii) agroclimatic studies related to irrigation requirements, (iv) validation of climate models' water and energy balance, and (v) studies of the impacts of climate change in terms of the AED.

Download Full-text

Flash Drought in CMIP5 Models

Journal of Hydrometeorology ◽

10.1175/jhm-d-20-0262.1 ◽

2021 ◽

Author(s):

David Hoffmann ◽

Ailie J. E. Gallant ◽

Mike Hobbins

Keyword(s):

Soil Moisture ◽

Land Surface ◽

Climate Models ◽

Standardized Precipitation Index ◽

Rapid Onset ◽

Stress Index ◽

Cmip5 Models ◽

Drought Indices ◽

Similar Proportion ◽

Evaporative Demand

Abstract‘Flash drought’ (FD) describes the rapid onset of drought on sub-seasonal times scales. It is of particular interest for agriculture as it can deplete soil moisture for crop growth in just a few weeks. To better understand the processes causing FD, we evaluate the importance of evaporative demand and precipitation by comparing three different drought indices that estimate this hazard using meteorological and hydrological parameters from the CMIP5 suite of models. We apply the Standardized Precipitation Index (SPI); the Evaporative Demand Drought Index (EDDI), derived from evaporative demand (E0); and the Evaporative Stress Index (ESI), which connects atmospheric and soil moisture conditions by measuring the ratio of actual and potential evaporation. The results show moderate-to-strong relationships (r2 > 0.5) between drought indices and upper level soil moisture on daily time scales, especially in drought-prone regions. We find that all indices are able to identify FD in the top 10-cm layer of soil moisture in a similar proportion to that in the models’ climatologies. However, there is significant inter-model spread in the characteristics of the FDs identified. This spread is mainly caused by an overestimation of E0, indicating stark differences in the land surface models and coupling in individual CMIP5 models. Of all indices, the SPI provides the highest skill in predicting FD prior to or at the time of onset in soil moisture, while both EDDI and ESI show significantly lower skill. The results highlight that the lack of precipitation is the main contributor to FDs in climate models, with E0 playing a secondary role.

Download Full-text

Drought monitoring incorporating precipitation and climate variables and its application for future drought projection

10.5194/egusphere-egu2020-13511 ◽

2020 ◽

Author(s):

Jeongeun Won ◽

Sangdan Kim

Keyword(s):

Drought Index ◽

Potential Evapotranspiration ◽

Standardized Precipitation Index ◽

Management Program ◽

Drought Monitoring ◽

Drought Indices ◽

Drought Severity ◽

Climate Variables ◽

Evaporative Demand ◽

Monitoring Method

In drought monitoring, it is very important to select climate variables to interpret drought. Most drought monitoring interprets drought as deficit in precipitation, so drought indices focused on the moisture supply side of the atmosphere have been mainly used. However, droughts can be caused not only by lack of rainfall, but also by various climate variables such as increase in temperature. In this regard, interest in potential evapotranspiration(PET), which is an moisture demand side of the atmosphere, is increasing and a PET-based drought index has been developed. However, complex droughts caused by various climate variables cannot be interpreted as a drought index that only considers precipitation or PET. In this study, we suggest a drought monitoring method that can reflect various future climate variables, including precipitation. In other words, copula-based joint drought index(CJDI), which incorporate standardized precipitation index(SPI) based on precipitation and evaporative demand drought index(EDDI) based on PET, is developed. CJDI, which considers both precipitation and PET, which are key variables related to drought, is able to properly monitor the drought events in Korea. In addition, future Drought severity &#8211; duration - frequency curves are derived to project future droughts compared to various drought indices. It is shown that CJDI can be used as a more reasonable drought index to establish the adaptation policy for future droughts by presenting the pattern of future droughts more realistically.Acknowledgment: This study was funded by the Korea Ministry of Environment (MOE) as Smart Urban Water Resources Management Program. (2019002950004)Keywords: Climate change; Copula; Drought; CJDI; Drought severity-duration-frequency curve

Download Full-text

Future drought analysis using SPI and EDDI to consider climate change in South Korea

Water Science & Technology Water Supply ◽

10.2166/ws.2020.209 ◽

2020 ◽

Vol 20 (8) ◽

pp. 3266-3280

Author(s):

Jeongeun Won ◽

Sangdan Kim

Keyword(s):

Climate Change ◽

Climate Models ◽

Standardized Precipitation Index ◽

Drought Indices ◽

Drought Severity ◽

Climate Change Scenarios ◽

Climate Data ◽

Evaporative Demand ◽

The Standardized Precipitation Index ◽

The Impact

Abstract Prediction of drought is important for efficient water management, as the occurrence of droughts affects large areas over a long period. According to various climate change scenarios, it is reported that in the future, Korea's climate is likely to increase in temperature with increasing rainfall. This increase in temperature will have a big impact on evapotranspiration. The occurrence of drought begins mainly with two causes: lack of rainfall or an increase in evapotranspiration. Therefore, in this study, the impact of climate change on future droughts is revealed through the Standardized Precipitation Index (SPI) and the Evaporative Demand Drought Index (EDDI). These two drought indices with different characteristics are used to examine the trend of future drought, and a drought Severity-Duration-Frequency (SDF) curve was derived to quantitatively analyze the depth of future drought. Future droughts are projected by applying future climate data generated from various climate models.

Download Full-text

Distributed climate change impacts and uncertainty throughout mountainous catchments

10.5194/egusphere-egu2020-13364 ◽

2020 ◽

Author(s):

Jorge Sebastián Moraga ◽

Nadav Peleg ◽

Simone Fatichi ◽

Peter Molnar ◽

Paolo Burlando

Keyword(s):

Climate Change ◽

Climate Models ◽

Climate Model ◽

Climate Change Signal ◽

Similar Amount ◽

Climate Variables ◽

Distributed Hydrological Model ◽

Space And Time ◽

Mountainous Catchments ◽

Impacts Of Climate Change

A combination of high-resolution models in space and time was used to evaluate the impacts of climate change on streamflow statistics and their uncertainties throughout three mountainous catchments in Switzerland (Thur, K. Emme and Maggia). The two-dimensional AWE-GEN-2d model was used to simulate ensembles of gridded climate variables at an hourly and 2-km resolution based on ground and remote-sensing observations. The model was re-parametrized using the &#8220;factors of change&#8221; approach, calculated from regional climate models, and it was used to simulate ensembles of climate data until the end of the 21st century. These ensembles were subsequently used as inputs into the fully distributed hydrological model Topkapi-ETH, which is suitable for simulating streamflow over complex terrain, and considers all the relevant hydrological processes. Based on large ensembles of simulated hydrological variables, the changes of the hydrological components in space and time were evaluated along with their uncertainty due to the internal variability of the climate and the climate model selection. Results indicate a rather uniform increase in temperature for all catchments, characterized by high uncertainty toward the end of the century (with strongest increases of over 5&#176;C). On the other hand, the magnitude and spatial patterns (namely, mountain vs valley) of change in precipitation differ between catchments, and the uncertainty of changes in extreme events is of larger magnitude than the climate change signal. The changes in climate are foreseen to affect the hydrological components in the catchments: evapotranspiration is projected to increase, while snowmelt contribution to the streamflow is expected to decrease by 50% at the end of the century. Model results indicate a decrease in streamflow at the outlet during the summer months and an increase in winter as early as the 2020-2049 period. Conversely, changes in extreme discharge show an uncertainty greater than the change signal for most climate models. Spatially heterogeneous changes in temperature and precipitation lead to elevation-dependent hydrological responses: e.g., streamflow annual means would decrease 20% in the upper reaches of the Thur catchment, while decreasing a similar amount in the downstream reaches. Correspondingly, hourly extremes are expected to decrease 20% in the upper reaches and increase up to 50% in the lowest part of the catchment. However, the signals of the change for extreme streamflow, compared to their uncertainty, are stronger for the upper parts of the river network. These results illustrate the benefit of using stochastic downscaling of climate variables to capture climate variability and assess uncertainty, and emphasize the importance of investigating the distributed impacts of climate change in mountainous areas, which may differ between high and low elevation reaches.&#160;

Download Full-text

Climate-induced historical drift of reference evapotranspiration in Mymensingh region of Bangladesh

Journal of the Bangladesh Agricultural University ◽

10.3329/jbau.v17i2.41991 ◽

2019 ◽

Vol 17 (2) ◽

pp. 258-264

Author(s):

Khadiza Akhter Mousumi ◽

Md. Abdul Mojid ◽

Tanvir Ahmad ◽

Md. Zamil Uddin ◽

Md. Ferdous Parvez

Keyword(s):

Water Resources ◽

Irrigated Agriculture ◽

Climatic Data ◽

Climatic Parameters ◽

Evaporative Demand ◽

Irrigation Planning ◽

Reference Crop Evapotranspiration ◽

Planning And Management ◽

Reference Crop ◽

Saturation Vapor

Reference crop evapotranspiration (ETo) is essential for planning and management of irrigation to ensure optimum utilization of a region’s available water resources. ETo being an indicator of atmospheric evaporative demand provides a measure of the integrated effect of climatic parameters like solar radiation, wind, temperature and humidity. Variation of these climatic parameters over long period of time alters ETo. The modified ETo is crucial for periodic adjustment of irrigation planning and management. This study evaluated variation of ETo and contribution of the climatic parameters to ETo-variation in Mymensingh region of Bangladesh by analyzing climatic data of 28 years (1990–2017). ETo was determined by FAO Penman-Monteith method and trends of ETo and its governing climatic parameters were evaluated by MAKESENS trend model. The ETo-governing climatic parameters revealed contrasting trends, which also varied in different months of the year. Net radiation and wind speed showed decreasing trend, while temperature and saturation vapor pressure deficit showed increasing trend. In spite of contrasting contributions of the climatic parameters, their combined effect reduced ETo with a resulting decreasing trend of the monthly average daily ETo over the months of the year except July. These results enhance our understanding of the effects of climate change on ETo and can help correct-planning of water resources for irrigated agriculture. J. Bangladesh Agril. Univ. 17(2): 258–264, June 2019

Download Full-text

Hydrological droughts in the southern Andes (40–45°S) from an ensemble experiment using CMIP5 and CMIP6 models

Scientific Reports ◽

10.1038/s41598-021-84807-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Rodrigo Aguayo ◽

Jorge León-Muñoz ◽

René Garreaud ◽

Aldo Montecinos

Keyword(s):

Climate Models ◽

Physicochemical Characteristics ◽

Climate Impact ◽

Economic Consequences ◽

Cmip5 Models ◽

Southern Andes ◽

Weap Model ◽

Coastal System ◽

Hydrological Droughts ◽

Impacts Of Climate Change

AbstractThe decrease in freshwater input to the coastal system of the Southern Andes (40–45°S) during the last decades has altered the physicochemical characteristics of the coastal water column, causing significant environmental, social and economic consequences. Considering these impacts, the objectives were to analyze historical severe droughts and their climate drivers, and to evaluate the hydrological impacts of climate change in the intermediate future (2040–2070). Hydrological modelling was performed in the Puelo River basin (41°S) using the Water Evaluation and Planning (WEAP) model. The hydrological response and its uncertainty were compared using different combinations of CMIP projects (n = 2), climate models (n = 5), scenarios (n = 3) and univariate statistical downscaling methods (n = 3). The 90 scenarios projected increases in the duration, hydrological deficit and frequency of severe droughts of varying duration (1 to 6 months). The three downscaling methodologies converged to similar results, with no significant differences between them. In contrast, the hydroclimatic projections obtained with the CMIP6 and CMIP5 models found significant climatic (greater trends in summer and autumn) and hydrological (longer droughts) differences. It is recommended that future climate impact assessments adapt the new simulations as more CMIP6 models become available.

Download Full-text