Agricultural Drought Trends on the Iberian Peninsula: An Analysis Using Modeled and Reanalysis Soil Moisture Products

Drought has a great impact on agriculture and food security, and climate change is increasing its frequency and exacerbating its intensity. Given the enormous interest in studying the recent drought evolution, in this work, agricultural drought trends over the past four decades on the Iberian Peninsula (IP) were analyzed. A trend analysis was performed with soil moisture based on the study of the evolution of anomalies and the Soil Water Deficit Index (SWDI). Two soil moisture databases (Lisflood and ERA5-Land) were used and the analysis was performed at daily and weekly temporal scales. Climate characteristics and soil properties were also considered to detect whether a trend spatial pattern could be identified. The results have shown a clear predominance of negative trends. A marked temporal pattern with negative trends was obtained over a 10-month period that coincided with the growing season of most of the crops on the IP, while a positive trend was observed over 2 months. No differences were found based on the climatic zone or soil characteristics. However, negative trends were observed to decrease as the clay content increased. These results can provide useful information for better water management and agriculture of the IP and other Mediterranean areas.

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Ambiguous Agricultural Drought: Characterising Soil Moisture and Vegetation Droughts in Europe from Earth Observation

Remote Sensing ◽

10.3390/rs13101990 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1990

Author(s):

Theresa C. van Hateren ◽

Marco Chini ◽

Patrick Matgen ◽

Adriaan J. Teuling

Keyword(s):

Soil Moisture ◽

Surface Soil ◽

Heat Waves ◽

Growing Season ◽

Earth Observation ◽

Agricultural Drought ◽

Positive Anomaly ◽

Surface Soil Moisture ◽

Modis Ndvi ◽

The Past

Long-lasting precipitation deficits or heat waves can induce agricultural droughts, which are generally defined as soil moisture deficits that are severe enough to negatively impact vegetation. However, during short soil moisture drought events, the vegetation is not always negatively affected and sometimes even thrives. Due to this duality in agricultural drought impacts, the term “agricultural drought” is ambiguous. Using the ESA’s remotely sensed CCI surface soil moisture estimates and MODIS NDVI vegetation greenness data, we show that, in major European droughts over the past two decades, asynchronies and discrepancies occurred between the surface soil moisture and vegetation droughts. A clear delay is visible between the onset of soil moisture drought and vegetation drought, with correlations generally peaking at the end of the growing season. At lower latitudes, correlations peaked earlier in the season, likely due to an earlier onset of water limited conditions. In certain cases, the vegetation showed a positive anomaly, even during soil moisture drought events. As a result, using the term agricultural drought instead of soil moisture or vegetation drought, could lead to the misclassification of drought events and false drought alarms. We argue that soil moisture and vegetation drought should be considered separately.

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Ambiguous agricultural drought: characterising soil moisture and vegetation droughts in Europe from earth observation

10.5194/hess-2020-583 ◽

2020 ◽

Author(s):

Theresa C. van Hateren ◽

Marco Chini ◽

Patrick Matgen ◽

Adriaan J. Teuling

Keyword(s):

Climate Change ◽

Soil Moisture ◽

Heat Waves ◽

Growing Season ◽

Earth Observation ◽

Agricultural Drought ◽

Severe Drought ◽

Positive Anomaly ◽

The Past ◽

Near Future

Abstract. Climate change will likely lead to more regular and more severe drought events in the near future, with large impacts on agriculture, especially during long-lasting precipitation deficits or heat waves. This study focuses on agricultural droughts, which are generally defined as soil moisture deficits so severe, that vegetation is negatively impacted. However, during short soil moisture drought events, vegetation is not always negatively affected, and sometimes even thrives under these conditions. Because of this duality in agricultural drought impacts, the use of the term agricultural droughts is ambiguous. Here we show that, in major European droughts over the past two decades, clear asynchronies and discrepancies occur between soil moisture and vegetation anomalies. A clear delay is visible between the onset of soil moisture drought and vegetation drought, and correlation between the two types of drought generally peaks at the end of the growing season. This behaviour seems to be different in droughts at lower latitudes, where correlations peak earlier in the season, likely due to water limited conditions occurring much earlier there. Moreover, results indicate that in some cases, vegetation can show a positive anomaly, even when soil moisture anomalies are negative. As a result, the use of the term agricultural drought could lead to misclassification of drought events and false drought alarms depending on whether vegetation or soil moisture is used to quantify the drought. We argue that it is necessary to make a distinction between soil moisture drought and anomalies in vegetation.

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Agricultural Drought Detection with MODIS Based Vegetation Health Indices in Southeast Germany

Remote Sensing ◽

10.3390/rs13193907 ◽

2021 ◽

Vol 13 (19) ◽

pp. 3907

Author(s):

Simon Kloos ◽

Ye Yuan ◽

Mariapina Castelli ◽

Annette Menzel

Keyword(s):

Soil Moisture ◽

Agricultural Land ◽

Growing Season ◽

Condition Index ◽

Agricultural Drought ◽

Drought Indices ◽

Limiting Factor ◽

Vegetation Growth ◽

Vegetation Health ◽

Agricultural Yield

Droughts during the growing season are projected to increase in frequency and severity in Central Europe in the future. Thus, area-wide monitoring of agricultural drought in this region is becoming more and more important. In this context, it is essential to know where and when vegetation growth is primarily water-limited and whether remote sensing-based drought indices can detect agricultural drought in these areas. To answer these questions, we conducted a correlation analysis between the Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST) within the growing season from 2001 to 2020 in Bavaria (Germany) and investigated the relationship with land cover and altitude. In the second step, we applied the drought indices Temperature Condition Index (TCI), Vegetation Condition Index (VCI), and Vegetation Health Index (VHI) to primarily water-limited areas and evaluated them with soil moisture and agricultural yield anomalies. We found that, especially in the summer months (July and August), on agricultural land and grassland and below 800 m, NDVI and LST are negatively correlated and thus, water is the primary limiting factor for vegetation growth here. Within these areas and periods, the TCI and VHI correlate strongly with soil moisture and agricultural yield anomalies, suggesting that both indices have the potential to detect agricultural drought in Bavaria.

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Spatiotemporal Analysis of Soil Moisture Variation in the Jiangsu Water Supply Area of the South-to-North Water Diversion Using ESA CCI Data

10.20944/preprints202112.0078.v1 ◽

2021 ◽

Author(s):

Yue Wang ◽

Jianjun Cao ◽

Yongjuan Liu ◽

Ying Zhu ◽

xuan Fang ◽

...

Keyword(s):

Soil Moisture ◽

Water Supply ◽

Water Transfer ◽

Agricultural Drought ◽

The South ◽

The Past ◽

Pumping Stations ◽

Moisture Variation ◽

Local Soil ◽

North Water

The South-to-North Water Transfer Jiangsu Water Supply Area (JWSA) is a mega inter-basin water transfer area (water source) that provides water resources from JiangHuai, combines drainage and flooding management, and regulates nearby rivers and lakes. Analyzing the spatiotemporal soil moisture dynamics in the area will inform agricultural drought and flood disaster assessment and early warning studies. Therefore, we evaluated the quality of European Space Agency Climate Change Initiative Soil moisture (ESA CCI_SM) data in the South-North Water Transfer JWSA. Then, we used ensemble empirical modal decomposition, Mann-Kendall tests, and regression analysis to study the spatiotemporal variation in soil moisture for the past 29 years. The CCI _SM data showed a high correlation with local soil measurements at nine sites. We then analyzed the CCI_SM data from three pumping stations (the Gaogang, Hongze, and Liushan stations) in the South-North Water Transfer JWSA. These stations had similar periodic characteristics of soil moisture, with significant periodic fluctuations around 3.1 d. The overall soil moisture at the three typical pumping stations showed an increasing trend. We then investigated whether there were abrupt soil moisture changes at each station. The spatial distribution of soil moisture in the South-North Water Transfer JWSA was characterized by “dry north and wet south”, with higher soil moisture in winter, followed by autumn, and low soil moisture in spring and summer. Although the linear trend of soil moisture in the South-North Water Transfer JWSA varied in significance, the overall soil moisture in the JWSA has increased over the past 29 years. The areas with significantly enhanced soil moisture are mainly distributed in the Yangzhou and Huai'an areas in the southeastern part of the study area. The areas with significantly decreased soil moisture are small in size and mainly located in northern Xuzhou.

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Crop and Location Specific Agricultural Drought Quantification: Part II. Case Study

Transactions of the ASABE ◽

10.13031/trans.11650 ◽

2017 ◽

Vol 60 (3) ◽

pp. 729-739 ◽

Cited By ~ 2

Author(s):

Rachel L. McDaniel ◽

Clyde Munster ◽

J. Tom Cothren

Keyword(s):

Soil Moisture ◽

Biomass Production ◽

Drought Index ◽

Swat Model ◽

Growing Season ◽

Moisture Stress ◽

Agricultural Drought ◽

Row Crops ◽

Moisture Conditions

Abstract. An estimated 70% to 80% of water resources are used for agricultural production. Irrigation helps maintain adequate soil moisture for crops; however, drought can impact both the amount of water required for production and crop yields. Different crops are affected by moisture conditions in different ways, as some can handle lower moisture conditions better than others. There are many drought indices that quantify low-moisture conditions, but they are not crop-specific and therefore do not quantify moisture stress for a given crop. The goal of this study was to evaluate a crop-specific drought index by determining the index’s ability to reflect yield trends due to moisture conditions. The drought index is a weekly index that uses five variables: precipitation, temperature, biomass production, soil moisture, and transpiration. This article presents a case study that examines the effectiveness of the crop-specific drought index in determining moisture stress to crops by comparing the drought index with annual yield values. The site chosen for this study was the upper Colorado River basin (UCRB) in west Texas because it is prone to drought. Cotton is one of the most widely grown row crops in this region and was therefore used in this study. A hydrologic and crop model, the Soil Water Assessment Tool (SWAT), was used to determine the biomass production, soil moisture, and transpiration. Observed precipitation and temperature data were also used both in the SWAT model and in the drought index. A multiple linear regression model was created for each week of the growing season because each variable is important during different weeks of the growing season. For example, in the UCRB, soil moisture was found to be more important during the beginning of the growing season, while biomass production was found to be more important during the end of the growing season. Ultimately, the drought index was found to be a good indicator of moisture-related yield conditions, with an R2 of 0.67. This index can be used to assess moisture stress to agricultural crops and aid in management decisions related to irrigation timing. Keywords: Crop modeling, Drought, Drought index, Hydrologic modeling, SWAT, Water conservation, Water management, Water stress.

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Agricultural Drought Monitoring Using Satellite Soil Moisture and Other Remote Sensing Data over the Iberian Peninsula

Remote Sensing of Hydrometeorological Hazards ◽

10.1201/9781315154947-2 ◽

2017 ◽

pp. 33-52

Author(s):

José Martínez-Fernández ◽

Nilda Sánchez ◽

Ángel González-Zamora

Keyword(s):

Remote Sensing ◽

Soil Moisture ◽

Iberian Peninsula ◽

Remote Sensing Data ◽

Agricultural Drought ◽

Drought Monitoring ◽

Sensing Data

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Carbon Dynamics in Vertisols as Revealed by High-Resolution Sampling

Radiocarbon ◽

10.1017/s0033822200064687 ◽

2002 ◽

Vol 44 (1) ◽

pp. 63-73 ◽

Cited By ~ 5

Author(s):

Peter Becker-Heidmann ◽

Olaf Andresen ◽

Dov Kalmar ◽

Hans-Wilhelm Scharpenseel ◽

Dan H Yaalon

Keyword(s):

Soil Moisture ◽

Inorganic Carbon ◽

Depth Distribution ◽

Clay Content ◽

Carbon Dynamics ◽

Thin Layers ◽

Moisture Regime ◽

The Past ◽

Soil Moisture Regime ◽

Moisture Regimes

Two Vertisol soil profiles under xeric soil moisture regimes, located at Qedma and Akko, Israel, were investigated and compared to a profile under ustic moisture regime, located in Hyderabad, India. Samples were taken in complete successive 2 cm thin layers down to about 180 cm depth or more. Organic and inorganic carbon were analyzed with regard to 13C and 14C concentrations. While all soils have radiocarbon ages of several thousand years BP, the depth distributions reveal substantial differences between the soil carbon dynamics. 14C and, less pronounced, δ13C clearly reflect the pedoturbation process. Further, its strength is found to be related to mainly soil moisture regime, then clay content and land use. In one soil, a change of growing from C4 to C3 crops in the past can be concluded from the δ13C depth distribution.

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Capability of existing drought indices in reflecting agricultural drought in China

10.5194/egusphere-egu2020-8845 ◽

2020 ◽

Author(s):

Zhe Zhao ◽

Kaicun Wang

Keyword(s):

Soil Moisture ◽

Crop Yield ◽

Vegetation Index ◽

Meteorological Data ◽

Growing Season ◽

The Other ◽

Agricultural Drought ◽

Drought Indices ◽

Yield Data ◽

Prediction Ability

A variety of drought indices have been constructed to monitor agricultural drought using ground and satellite data. Our study aimed to evaluate the performance of drought indices to indicate agricultural drought in China. Seven drought indices of four types were selected over the main agricultural regions of China: indices based on regular meteorological data (DImet), indices based on vegetation index (DIvi), indices based on soil moisture (DIsm), and synthesized indices (DIsyn). The independent reference data used here included three aspects: soil moisture, vegetation photosynthesis and crop yield data. The latter two reference datasets were selected to check drought impact on agriculture. Drought indices with short timescales are more sensitive to topsoil moisture. Drought indices have different abilities to capture vegetation photosynthesis condition during the growing season. Expect for the Yangtze region and North China region during the wheat growing season, the DImet and DIsyn show significant positive correlations with the sun-induced chlorophyll fluorescence (SIF), while the other drought indices have weaker or no correlations. For crop yield, the prediction ability of the drought indices show a similar pattern with the results for vegetation photosynthesis but with relatively large uncertainty. Generally, our study show that DImet have better or equivalent performance than that of the other types of drought indices, and DIsyn show the widest applicability. Our study may shed light on agricultural drought research in the future.

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A New Soil Moisture Agricultural Drought Index (SMADI) Integrating MODIS and SMOS Products: A Case of Study over the Iberian Peninsula

Remote Sensing ◽

10.3390/rs8040287 ◽

2016 ◽

Vol 8 (4) ◽

pp. 287 ◽

Cited By ~ 43

Author(s):

Nilda Sánchez ◽

Ángel González-Zamora ◽

María Piles ◽

José Martínez-Fernández

Keyword(s):

Soil Moisture ◽

Iberian Peninsula ◽

Drought Index ◽

Agricultural Drought

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Spatiotemporal Analysis of Soil Moisture Variation in the Jiangsu Water Supply Area of the South-to-North Water Diversion Using ESA CCI Data

Remote Sensing ◽

10.3390/rs14020256 ◽

2022 ◽

Vol 14 (2) ◽

pp. 256

Author(s):

Yue Wang ◽

Jianjun Cao ◽

Yongjuan Liu ◽

Ying Zhu ◽

Xuan Fang ◽

...

Keyword(s):

Soil Moisture ◽

Water Supply ◽

Water Transfer ◽

Agricultural Drought ◽

The South ◽

The Past ◽

Pumping Stations ◽

Moisture Variation ◽

Local Soil ◽

North Water

The South-to-North Water Transfer Jiangsu Water Supply Area (JWSA) is a mega inter-basin water transfer area (water source) that provides water resources from JiangHuai, combines drainage and flooding management, and regulates nearby rivers and lakes. Analyzing the spatiotemporal soil moisture dynamics in the area will be informative regarding agricultural drought along with flood disaster assessment and will provide early warning studies. Therefore, we evaluated the quality of European Space Agency Climate Change Initiative Soil Moisture (ESA CCI_SM) data in the South-North Water Transfer JWSA. Furthermore, we utilized ensemble empirical modal decomposition, Mann-Kendall tests, and regression analysis to study the spatiotemporal variation in soil moisture for the past 29 years. The CCI _SM data displayed a high correlation with local soil measurements at nine sites. We next analyzed the CCI_SM data from three pumping stations (the Gaogang, Hongze, and Liushan stations) in the South-North Water Transfer JWSA. These stations had similar periodic characteristics of soil moisture, with significant periodic fluctuations around 3.1 d. The overall soil moisture at the three typical pumping stations demonstrated an increasing trend. We further investigated whether abrupt soil moisture changes existed at each station or not. The spatial distribution of soil moisture in the South-North Water Transfer JWSA was characterized as “dry north and wet south”, with higher soil moisture in winter, followed by autumn, and low soil moisture in spring and summer. Although the linear trend of soil moisture in the South-North Water Transfer JWSA varied in significance, the overall soil moisture in the JWSA has increased over the past 29 years. The areas with significantly enhanced soil moisture are mostly distributed in the Yangzhou and Huai’an areas in the southeastern part of the study area. The areas with significantly decreased soil moisture are small in size and mostly located in northern Xuzhou.

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