scholarly journals Correlating drought conservation practices and drought vulnerability in a tropical agricultural system

2018 ◽  
Vol 33 (3) ◽  
pp. 279-291 ◽  
Author(s):  
Nora L. Álvarez-Berríos ◽  
Sandra Soto-Bayó ◽  
Eva Holupchinski ◽  
Stephen J. Fain ◽  
William A. Gould
Keyword(s):  
Puerto Rico ◽  
Cover Crops ◽  
Spatial Databases ◽  
Extreme Drought ◽  
Climate Projections ◽  
Severe Drought ◽  
Conservation Practices ◽  
Eastern Region ◽  
Drought Conditions ◽  
Moderate Drought

AbstractRecent droughts in Puerto Rico and throughout the Caribbean have emphasized the region's agricultural vulnerability to this hazard and the increasing need for adaptation mechanisms to support sustainable production. In this study, we assessed the geographic extent of agricultural conservation practices incentivized by US Department of Agriculture Natural Resources Conservation Service (NRCS) and evaluated their large-scale contribution to drought adaptability. We identified concentrations of drought-related practices (e.g. cover crops, ponds) applied between 2000 and 2016. Using information from spatial databases and interviews with experts, we assessed the spatial correlation between these practices and areas exposed to drought as identified by the US Drought Monitor. Between 2000 and 2016, Puerto Rico experienced seven drought episodes concentrated around the south, east and southeastern regions. The most profound drought occurred between 2014 and 2016 when the island experienced 80 consecutive weeks of moderate drought, 48 of severe drought and 33 of extreme drought conditions. A total of 44 drought-related conservation practices were applied at 6984 locations throughout 860 km2 of farmlands between 2000 and 2016 through the NRCS-Environmental Quality Incentives Program (EQIP). Practices related to water availability were statistically clustered along the coasts, whereas soil and plant health practices were clustered in the mountainous region. While these concentrations strongly correlated with areas exposed to moderate drought conditions, >80% did not coincide with areas that experienced severe or extreme drought conditions, suggesting that areas highly exposed to drought conditions generally lacked drought preparedness assisted by EQIP. Climate projections indicate an increase in the frequency and intensity of drought events, particularly in the eastern region of Puerto Rico. Our analysis highlighted the need to implement more conservation practices in these areas subject to drought intensification and exposure. Government programs intended to address vulnerabilities and enhance capacity and resilience may not be reaching areas of highest exposure. Recommendations include raising producer awareness of past and future exposure and making programs more accessible to a broader audience.

scholarly journals Spatio-Temporal Assessment of Meteorological Drought in Puerto Rico between 1950 and 2019

2021 ◽  
Vol 8 (1) ◽  
pp. 40
Author(s):  
Rogert Sorí ◽  
Rafael Méndez-Tejeda ◽  
Milica Stojanovic ◽  
José Carlos Fernández-Alvarez ◽  
Albenis Pérez-Alarcón ◽  
...  
Keyword(s):  
Puerto Rico ◽  
Meteorological Drought ◽  
Extreme Drought ◽  
Eastern Coast ◽  
Severe Drought ◽  
Daily Data ◽  
Drought Conditions ◽  
Moderate Drought ◽  
Spatio Temporal ◽  
Maximum Temperatures

The phenomenon of drought is one of the most dangerous for small islands because of its impacts on freshwater availability. Thus, in this study, the spatio-temporal evolution of meteorological drought that affected the main island of Puerto Rico in the period 1950–2019 was investigated. In doing so, the Standardized Precipitation–Evapotranspiration Index (SPEI), using monthly values of minimum and maximum temperatures and precipitation derived from Daymet Version 4 daily data at a 1 km × 1 km spatial resolution, was used. At a 1 month temporal scale, the SPEI showed great temporal variability, but there was a clear tendency towards wetting in the last years of the study period. A total of 85 meteorological drought episodes were identified. The spatial analysis also revealed that major affectation by moderate drought conditions occurred across the half west and south of the island, by severe drought also in the west half of the island but also along the eastern coast, and finally the extreme drought conditions, which were less frequent, principally affected the northeast of the country. A trend analysis of the area affected by moderate, severe, and extreme drought conditions revealed a tendency to decrease, which is reflected by the prevalence of positive spatial trends of the SPEI1 across the country.

scholarly journals Computational Analysis for Rainfall Characterization and Drought Vulnerability in Peninsular India

2021 ◽  
Vol 2021 ◽  
pp. 1-27
Author(s):  
M. P. Akhtar ◽  
Firoz Alam Faroque ◽  
L. B. Roy ◽  
Mohd. Rizwanullah ◽  
Mukesh Didwania
Keyword(s):  
Tamil Nadu ◽  
Drought Index ◽  
Extreme Drought ◽  
Annual Rainfall ◽  
Drought Indices ◽  
Severe Drought ◽  
Drought Vulnerability ◽  
Drought Conditions ◽  
Moderate Drought ◽  
Standard Deviations

This paper analyzes the historical rainfall characterization and drought conditions in two major southern states of India, namely, Tamil Nadu and Karnataka, through estimation of meteorological drought indices, namely, drought index (DI), Palmer drought index (PDI), and standardized precipitation index (SPI). Monthly and yearly rainfall data, including temperature, have been considered for 110 years. Deficient rainfall conditions have been identified and compared using annual rainfall classification thresholds. Annual rainfall variability and trend have been estimated using Mann–Kendall test and Sen’s slope test. Comparative study on results implies that drought characterization using SPI may amply facilitate the standardization of threshold classification for severity and frequency. Based on threshold classification, it is found that Tamil Nadu witnessed on an average 11 years of moderate drought, 4.36 years of severe drought, and 1.32 years of extreme drought conditions with standard deviations of 4.28, 1.87, and 1.63 years, respectively, during the study period, whereas Karnataka witnessed on an average 9.74 years of moderate drought, 3.91 years of severe drought, and 2.30 years of extreme drought conditions with standard deviations of 4.54, 2.04, and 2.21 years, respectively, during the study period. According to the analysis, drought vulnerability in Tamil Nadu was higher than in Karnataka, based on the number of dry and wet years in terms of SPI threshold values and area covered over 110 years. Karnataka was more susceptible in terms of severity. When compared with other indices, analysis based on drought indices indicates that a single variable-based estimation using SPI is easy to assess and may be significant and definitive in terms of decision making for prioritizing drought mitigation measures in the study area in case of inadequate available data for multiple variable-based drought analysis.

scholarly journals Quantifying the spatial extent and intensity of recent extreme drought events in the Amazon rainforest and their impacts on the carbon cycle

2020 ◽  
Author(s):  
Phillip Papastefanou ◽  
Christian S. Zang ◽  
Zlatan Angelov ◽  
Aline Anderson de Castro ◽  
Juan Carlos Jimenez ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Amazon Basin ◽  
State Of The Art ◽  
Amazon Region ◽  
Extreme Drought ◽  
Spatial Extent ◽  
Amazon Rainforest ◽  
Severe Drought ◽  
Drought Conditions ◽  
Moderate Drought

Abstract. Over the last decades, the Amazon rainforest was hit by multiple severe drought events. Here we assess the severity and spatial extent of the extreme drought years 2005, 2010, and 2015/2016 in the Amazon region and their impacts on the carbon cycle. As an indicator of drought stress in the Amazon rainforest, we use the widely applied maximum cumulative water deficit (ΔMCWD). Evaluating an ensemble of ten state-of-the-art precipitation datasets for the Amazon region, we find that the spatial extent of the drought in 2005 ranges from 2.8 to 4.2 (mean = 3.2) million km2 (46–71 % of the Amazon basin, mean = 53 %) where ΔMCWD indicates at least moderate drought conditions (ΔMCWD anomaly

scholarly journals Enhancement of drought tolerance in diverse Vicia faba cultivars by inoculation with plant growth-promoting rhizobacteria under newly reclaimed soil conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Elsayed Mansour ◽  
Hany A. M. Mahgoub ◽  
Samir A. Mahgoub ◽  
El-Sayed E. A. El-Sobky ◽  
Mohamed I. Abdul-Hamid ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Plant Growth ◽  
Plant Growth Promoting Rhizobacteria ◽  
Severe Drought ◽  
Drought Conditions ◽  
Moderate Drought ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Effects Of Drought

AbstractWater deficit has devastating impacts on legume production, particularly with the current abrupt climate changes in arid environments. The application of plant growth-promoting rhizobacteria (PGPR) is an effective approach for producing natural nitrogen and attenuating the detrimental effects of drought stress. This study investigated the influence of inoculation with the PGPR Rhizobium leguminosarum biovar viciae (USDA 2435) and Pseudomonas putida (RA MTCC5279) solely or in combination on the physio-biochemical and agronomic traits of five diverse Vicia faba cultivars under well-watered (100% crop evapotranspiration [ETc]), moderate drought (75% ETc), and severe drought (50% ETc) conditions in newly reclaimed poor-fertility sandy soil. Drought stress substantially reduced the expression of photosynthetic pigments and water relation parameters. In contrast, antioxidant enzyme activities and osmoprotectants were considerably increased in plants under drought stress compared with those in well-watered plants. These adverse effects of drought stress reduced crop water productivity (CWP) and seed yield‐related traits. However, the application of PGPR, particularly a consortium of both strains, improved these parameters and increased seed yield and CWP. The evaluated cultivars displayed varied tolerance to drought stress: Giza-843 and Giza-716 had the highest tolerance under well-watered and moderate drought conditions, whereas Giza-843 and Sakha-4 were more tolerant under severe drought conditions. Thus, co-inoculation of drought-tolerant cultivars with R. leguminosarum and P. putida enhanced their tolerance and increased their yield and CWP under water-deficit stress conditions. This study showed for the first time that the combined use of R. leguminosarum and P. putida is a promising and ecofriendly strategy for increasing drought tolerance in legume crops.

New roller crimper concepts for mechanical termination of cover crops in conservation agriculture

2009 ◽  
Vol 24 (3) ◽  
pp. 165-173 ◽  
Author(s):  
T.S. Kornecki ◽  
A.J. Price ◽  
R.L. Raper ◽  
F.J. Arriaga
Keyword(s):  
Cover Crops ◽  
Field Experiments ◽  
Soil Surface ◽  
Conservation Agriculture ◽  
The United States ◽  
International Standards ◽  
Severe Drought ◽  
Original Design ◽  
Growing Seasons ◽  
Drought Conditions

AbstractRollers crimpers have been used in conservation agriculture to terminate cover crops; however, excessive vibration generated by the original straight-bar roller design has delayed adoption of this technology in the United States. To avoid excessive vibration, producers generally reduce operating speeds that increase the time needed to perform the field operation. The objectives of this research were to identify roller crimper designs that terminated rye cover crops consistently, resulted in soil moisture conservation after use, and minimized vibrations when operated in the field. Six different roller types were developed and tested at 3.2 and 6.4 km h−1 in Alabama field experiments during the 2006, 2007 and 2008 growing seasons. All roller types were used alone and one also in combination with glyphosate. Rye mortalities were evaluated 1, 2 and 3 weeks after rolling and compared with the check (non-rolled standing rye). Soil volumetric moisture content (VMC) was measured at the day of rolling, and then at 1, 2 and 3 weeks after rolling. Vibration was measured on the rollers' and tractor's frames during operation. Mortality for rolled rye 2 weeks after rolling was at least 98% compared with 96% for the check in 2006, 93% for rolling compared with 75% for the check in 2007, and 94% for rolling compared with 60% for the check in 2008 (P<0.10). There were no consistent differences in rye mortality across roller types (without glyphosate) and speeds. VMC for soil in non-rolled rye plots was consistently lower than in rolled rye plots, averaging 3% compared with 7% 2 weeks after rolling in 2006, and 4% compared with 8% in 2008. During 2007, VMC was affected by severe drought conditions, and differences between roller treatments were detected but minor. The straight-bar roller generated the highest vibration on the tractor's frame at 6.4 km h−1 (0.71 m s−2, RMS), which exceeded International Standards (International Standard Office (ISO)). At 6.4 km h−1, new roller designs generated significantly lower acceleration levels from 0.12 to 0.32 m s−2 on the tractor's frame and were below detrimental effects on health ‘health limits’ classified by ISO. Overall, 2 weeks after rolling, all roller designs effectively terminated rye above 90%, which is the recommended termination level of rye to plant a cash crop into residue mat, while protecting soil surface from water loss. New roller designs generate less vibration than the original design and can be used safely at higher operating speeds.

scholarly journals Evaluation of temporal drought variation and projection in a tropical river basin of Kerala

2020 ◽  
Vol 11 (S1) ◽  
pp. 115-132 ◽  
Author(s):  
M. A. Jincy Rose ◽  
N. R. Chithra
Keyword(s):  
River Basin ◽  
Standardized Precipitation Index ◽  
Drought Severity ◽  
Climate Projections ◽  
Severe Drought ◽  
Tropical River ◽  
The Past ◽  
Drought Conditions ◽  
The Future ◽  
The Standardized Precipitation Index

Abstract Temperature is an indispensable parameter of climate that triggers evapotranspiration and has vital importance in aggravating drought severity. This paper analyses the existence and persistence of drought conditions which are said to prevail in a tropical river basin which was once perennial. Past observed data and future climate projections of precipitation and temperature were used for this purpose. The assessment and projection of this study employ the Standardized Precipitation Evapotranspiration Index (SPEI) compared with that of the Standardized Precipitation Index (SPI). The results indicate the existence of drought in the past and the drought conditions that may persist in the future according to RCP 4.5 and 8.5 scenarios. The past drought years identified in the study were compared with the drought declared years in the state and were found to be matching. The evaluation of the future scenarios unveils the occurrence of drought in the basin ranging from mild to extreme conditions. It has been noted that the number of moderate and severe drought months has increased based on SPEI compared to SPI, indicating the importance of temperature in drought studies. The study can be considered as a plausible scientific remark helpful in risk management and application decisions.

Spatio-temporal changes of drought in Romania (1961-2015), according to atmospheric circulation types and teleconnection indices

2020 ◽  
Author(s):  
Radu-Vlad Dobri ◽  
Liviu Apostol ◽  
Lucian Sfîcă ◽  
Simona Țîmpu ◽  
Ion-Andrei Niță
Keyword(s):  
Atmospheric Circulation ◽  
Standardized Precipitation Index ◽  
Atmospheric Precipitation ◽  
Climatic Conditions ◽  
Extreme Drought ◽  
Drought Severity ◽  
Severe Drought ◽  
Circulation Types ◽  
Teleconnection Indices ◽  
Moderate Drought

&lt;p&gt;Drought can be determined by climatic conditions (atmospheric precipitation, water supply from soil accessible to the plant, moisture and air temperature and wind speed) but is also induced by environmental aspects some of them related to anthropogenic influences.&lt;/p&gt;&lt;p&gt;In order to monitor the drought and its impact for Romania, four indices were analyzed in the present study (SPI (Standardized Precipitation Index), PNI (Percent of Normal Index), DI (Deciles index), and ZSI (Z-score Index)), through Meteorological Drought Monitoring software, using the total daily amount of precipitation for 27 weather stations in Romania, of which 22 stations for the period 1961-2015, 4 stations for the period 1961-2000 and one station for the period 1964-2015.&lt;/p&gt;&lt;p&gt;Preliminary analyzes resulting from the use of these indices were correlated with 18 GWT (Gro&amp;#223;wettertypen) atmospheric circulation types of daily mean sea level pressure (SLP). This was done using COST733 class software to evaluate the influence of large-scale mechanisms of atmospheric circulation. Also, four teleconnection indices were used, more exactly AO (Arctic Oscillation), NAO (North Atlantic Oscillation), PNA (Pacific-North American Pattern) and AAO (Antarctic Oscillation) that are recognized for their effect on climatic conditions at European scale, &amp;#160;&lt;br&gt;provided by National Oceanic and Atmospheric Administration (NOAA) &amp;#8211; Climate Prediction Center.&lt;/p&gt;&lt;p&gt;Therefore, according to the types of circulation, the amount of precipitation produced in certain areas and implicitly the degree of drought severity is influenced. The types of anticyclonal circulation 13, 16 or 18, for example, which occur on average in 46 (12.7%), 14 (3.9%) , respectively 20 (5.4%) days a year, cause less precipitation as known, compared to the types of cyclonal circulation 1, 2 or 17 for example with an average of 12 (3.2%), 12 (3.2%), respectively 19 (4.3%) days a year.&lt;/p&gt;&lt;p&gt;In terms of drought analysis indices, according to SPI, the entire analysis interval for Iasi, located in the northeast region of Romania, was 6 years of &quot;moderately dry&quot;, 5 years of &quot;severely dry&quot;, and one year of &quot;extremely dry&quot;, unlike Cluj, located in the central western region, with two years of &quot;moderately dry&quot;, 3 years of &quot;severely dry&quot; and two years of &quot;extremely dry&quot;. In Bucharest, located in the southern region of Romania there were 4 &quot;moderately dry&quot; years and 5 &quot;severely dry&quot; years. In Iasi, according to the ZSI index with the same classifications as the SPI index, there were 3 &quot;moderately drought&quot; years, 7 &quot;severely drought&quot; years and 7 &quot;extreme drought&quot; years, while in Cluj there were 9, 3 and respectively 6 years and in Bucharest 7, 5 and respectively 6 years with the above classification.&lt;/p&gt;&lt;p&gt;According to the PNI index, there were 5 &quot;moderate drought&quot; years in Iasi and Cluj and 6 &quot;moderate drought&quot; years in Bucharest. Also, there were 9 &quot;weak drought&quot; years in Iasi, 3 in Cluj and 5 in Bucharest.&lt;/p&gt;&lt;p&gt;And last but not least, according to the DI index, at all 3 stations there were 5 &quot;extreme drought&quot; years, 6 &quot;severe drought&quot; years and 5 &quot;moderate drought&quot; years.&lt;/p&gt;

scholarly journals 'The drought is my teacher’: Adult learning and education in times of climate crisis

2018 ◽  
Vol 1 (1) ◽  
pp. 146
Author(s):  
Shirley Walters
Keyword(s):  
United States ◽  
Adult Learning ◽  
Cape Town ◽  
The United States ◽  
Extreme Drought ◽  
Severe Drought ◽  
Drought Conditions ◽  
Climate Crisis ◽  
Key Questions

In Cape Town we have been experiencing the most severe drought in our history. We are not alone.Other cities – for example, in the United States, Brazil, Spain, Belgium, Australia, Morocco andPakistan – are also learning to live under new, more extreme, drought conditions. In this article Iuse the local drought as an aperture through which to identify key insights into how adult learningand education (ALE) can and should respond in times of climate crisis. The article is exploratory, asthe ambitious topic opens up a raft of complex economic, socio-ecological and political issueswhich can only be touched upon. It aims to prompt deeper conversations about ALE and climatecrises and to identify key questions for future ALE research.

scholarly journals Effects of root phenotypic changes on the deep rooting of Populus euphratica seedlings under drought stresses

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6513 ◽  
Author(s):  
Zi-qi Ye ◽  
Jian-ming Wang ◽  
Wen-juan Wang ◽  
Tian-han Zhang ◽  
Jing-wen Li
Keyword(s):  
Drought Stress ◽  
Root Architecture ◽  
Mass Fraction ◽  
Populus Euphratica ◽  
Severe Drought ◽  
Root Depth ◽  
Phenotypic Changes ◽  
Positive Effects ◽  
Drought Conditions ◽  
Moderate Drought

Background Deep roots are critical for the survival of Populus euphratica seedlings on the floodplains of arid regions where they easily suffer drought stress. Drought typically suppresses root growth, but P. euphratica seedlings can adjust phenotypically in terms of root-shoot allocation and root architecture and morphology, thus promoting deep rooting. However, the root phenotypic changes undertaken by P. euphratica seedlings as a deep rooting strategy under drought conditions remain unknown. Methods We quantified deep rooting capacity by the relative root depth (RRD), which represents the ratio of taproot length to plant biomass and is controlled by root mass fraction (RMF), taproot mass fraction (TRMF), and specific taproot length (STRL). We recorded phenotypic changes in one-year-old P. euphratica seedlings under control, moderate and severe drought stress treatments and assessed the effects of RMF, TRMF, and STRL on RRD. Results Drought significantly decreased absolute root depth but substantially increased RRD via exerting positive effects on TRMF, RMF, and STRL. Under moderate drought, TRMF contributed 55%, RMF 27%, and STRL 18% to RRD variation. Under severe drought, the contribution of RMF to RRD variation increased to 37%, which was similar to the 41% for TRMF. The contribution of STRL slightly increased to 22%. Conclusion These results suggest that the adjustments in root architecture and root-shoot allocation were predominantly responsible for deep rooting in P. euphratica seedlings under drought conditions, while morphological changes played a minor role. Moreover, P. euphratica seedlings rely mostly on adjusting their root architecture to maintain root depth under moderate drought conditions, whereas root-shoot allocation responds more strongly under severe drought conditions, to the point where it plays a role as important as root architecture does on deep rooting.

scholarly journals Spatiotemporal Variation of Drought Characteristics Based on Standardized Precipitation Index in Central Java over 1990-2010

2021 ◽  
Vol 893 (1) ◽  
pp. 012022
Author(s):  
Misnawati ◽  
R Boer ◽  
F Ramdhani
Keyword(s):  
Standardized Precipitation Index ◽  
Rain Gauge ◽  
Precipitation Index ◽  
Extreme Drought ◽  
Drought Severity ◽  
Severe Drought ◽  
Drought Event ◽  
Drought Characteristics ◽  
Central Java ◽  
Moderate Drought

Abstract Drought is a natural hazard that results from a deficiency of precipitation, leading to low soil moisture and river flows, reduced storage in reservoirs, and less groundwater recharge. This study investigates the spatial variations of drought characteristics (drought event frequency, duration, severity, and intensity). This study using the Standardized Precipitation Index (SPI) to analyse the drought characteristics in Central Java during 1990-2010. The rain gauge station data and CHIRPS rainfall data over Central Java is used to calculate the SPI index. The SPI was calculated at multiple timescales (1-, 3-, 6-, 12-, 24- and 48-month), the run theory was used for identification and characterization of drought events. Analysis of drought characteristics by SPI from 1990 to 2010 shows the longest drought event is four months, the maximum drought severity is 6.06, and the maximum drought intensity is 2.02. El Nino year probability drought occurrence reached 100% in August for moderate drought, severe drought, and extreme drought category, whereas the probability drought occurrences in the Normal and La Nina year range 0-70% for moderate drought, 0-50% for severe drought category and 0-40% for extreme drought category. The results of this study may help inform researchers and local policymakers to develop strategies for managing drought.

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