Drought Scenarios Research Articles

Leaf rolling precedes stomatal closure in rice (Oryza sativa) under drought conditions.

Leaf rolling is a physiological response to drought that may help to reduce water loss, but its significance as a contribution to drought tolerance is uncertain. We scored the leaf rolling of four rice genotypes along an experimental drought gradient using an improved cryo-microscopy method. Leaf water potential (Ψleaf), gas exchange, chlorophyll fluorescence, leaf hydraulic conductance, rehydration capacity, and the bulk turgor loss point were also analysed. During the drought process, stomatal conductance declined sharply to reduce water loss, and leaves rolled up before the stomata completely closed. The leaf water loss rate of rolled leaves was significantly reduced compared with artificially flattened leaves. The Ψleaf threshold of initial leaf rolling ranged from -1.95 to -1.04 MPa across genotypes. When a leaf rolled so that the leaf edges were touching, photosynthetic rate and stomatal conductance declined more than 80%. Across genotypes, leaf hydraulic conductance declined first, followed by gas exchange and chlorophyll fluorescence parameters. However, the Ψleaf threshold for a given functional trait decline differed significantly among genotypes, with the exception of leaf hydraulic conductance. Our results suggested that leaf rolling was mechanistically linked to drought avoidance and tolerance traits and might serve as a useful phenotypic trait for rice breeding in future drought scenarios.

Relationships between xylem embolism and tree functioning during drought, recovery, and recurring drought in Aleppo pine.

Recent findings suggest that trees can survive high levels of drought-induced xylem embolism. In many cases, the embolism is irreversible and, therefore, can potentially affect post-drought recovery and tree function under recurring droughts. We examined the development of embolism in potted Aleppo pines, a common species in hot, dry Mediterranean habitats. We asked (1) how post-drought recovery is affected by different levels of embolism and (2) what consequences this drought-induced damage has under a recurring drought scenario. Young trees were dehydrated to target water potential (Ψx ) values of -3.5, -5.2 and -9.5 MPa (which corresponded to ~6%, ~41% and ~76% embolism), and recovery of the surviving trees was measured over an 8-months period (i.e., embolism, leaf gas-exchange, Ψx ). An additional group of trees was exposed to Ψx of -6.0 MPa, either with or without preceding drought (Ψx of -5.2 MPa) to test the effect of hydraulic damage during repeated drought. Trees that reached -9.5 MPa died, but none from the other groups. Embolism levels in dying trees were on average 76% of conductive xylem and no tree was dying below 62% embolism. Stomatal recovery was negatively proportional to the level of hydraulic damage sustained during drought, for at least a month after drought relief. Trees that experienced drought for the second time took longer to reach fatal Ψx levels than first-time dehydrating trees. Decreased stomatal conductance following drought can be seen as "drought legacy," impeding recovery of tree functioning, but also as a safety mechanism during a consecutive drought.

Effect of droughts and climate change on future soil weathering rates in Sweden

Abstract. In a future warmer climate, extremely dry, warm summers might become more common. Soil weathering is affected by temperature and precipitation, and climate change and droughts can therefore affect soil chemistry and plant nutrition. In this study, climate change and drought effects on soil weathering rates and release of Ca, Mg, K and Na were studied on seven forest sites across different climates in Sweden, using the dynamical model ForSAFE. Two climate scenarios were run, one medium severity climate change scenario from IPCC (A1B) and one scenario where a future drought period of 5 years was added, while everything else was equal to the first scenario. The model results show a large geographical variation of weathering rates for the sites, without any geographical gradient, despite the strong dependence of temperature on weathering and the strong gradient in temperature in Sweden. This is because soil texture and mineralogy have strong effects on weathering. The weathering rates have a pronounced seasonal dynamic. Weathering rates are low during winters and generally high, but variable, during summers, depending on soil moisture and temperature. According to the model runs, the future yearly average weathering rates will increase by 5 %–17 % per degree of warming. The relative increase is largest in the two southeastern sites, with low total weathering rates. At sites in southern Sweden, future weathering increase occurs throughout the year according to the modelling. In the north, the increase in weathering during winters is almost negligible, despite larger temperature increases than in other regions or seasons (5.9 ∘C increase in winter in Högbränna; the yearly average temperature increase for all sites is 3.7 ∘C), as the winter temperatures still will mostly be below zero. The drought scenario has the strongest effect in southern Sweden, where weathering during the later parts of the drought summers decreases to typical winter weathering rates. Soil texture and amount of gravel also influence how fast the weathering decreases during drought and how fast the soil rewets and reaches normal weathering rates after the drought. The coarsest of the modelled soils dries out and rewets quicker than the less coarse of the modelled soils. In the north, the soils do not dry out as much as in the south, despite the low precipitation, due to lower evapotranspiration, and in the northernmost site, weathering is not much affected. Yearly weathering during the drought years relative to the same years in the A1B scenario are between 78 % and 96 % for the sites. The study shows that it is crucial to take seasonal climate variations and soil texture into account when assessing the effects of a changed climate on weathering rates and plant nutrient availability.

Colorado River (Argentina) Water Crisis Scenarios and Influence on Irrigation Water Quality Conditions

The characterization and evaluation of water quality in the Valle Bonaerense del Río Colorado (VBRC), Buenos Aires, Argentina, is necessary, given the immense importance of this region for sustaining the population livelihoods and maintaining the ecological balance, especially in the face of drought and climate change scenarios, and loss of crop production yields. This study evaluated the possible reuse of drainage canals from the perspective of their use for irrigation. Surface water samples were collected at four sampling sites during 2015–2021, one over the Colorado river entering the VBRC, and the remaining three drainage canals flow into the Atlantic Ocean. These physicochemical parameters were performed following the protocols proposed using standard methods: total dissolved solids, pH, electrical conductivity (EC), calcium, magnesium, sodium, potassium, carbonates, bicarbonates, chlorides, sulfates and sodium adsorption ratio were analyzed and classified. The irrigation water quality index (IWQI), principal component analysis, hierarchy of classes analysis and statistical analysis were applied to the dataset. The general hydrochemistry of the VBRC river water indicates a slightly alkaline nature, with a mean pH value of 8.03, and the predominance order of the major ions follows the pattern of Na+ > Ca2+ > Mg2+ > K+, and SO42− > Cl− > HCO3− + CO32− for the anions. For the IWQI, 88.06% of the samples analyzed were classified as safe water for irrigation, and a theoretical yield loss was estimated for crops considering the salinity variable, with vegetables showing the highest losses. The surface water from rivers increases the EC due to the decrease in its discharge because of the water crisis affecting Latin America. Water reuse could be useful for one of the three drainage canals. This study concludes that the reuse of drainage water (S2) has great potential as an adaptation strategy to address the water scarcity and climate change challenges in the Colorado river basin. The research highlights the importance of considering this alternative to achieve sustainable water management in the region. Moreover, the data obtained from the study can be used for making policy and resource management decisions. In view of the possible scenarios of low water flow and increases in the EC values, it is recommended to reorient agricultural production toward crops with higher tolerance to salinity as an alternative, to ensure the sustainability and viability of production in the basin.

Multi-scale planning model for robust urban drought response

Increasingly severe droughts are straining municipal water resources and jeopardizing urban water security, but uncertainty in their duration, frequency, and intensity challenges drought planning and response. We develop the Drought Resilient Interscale Portfolio Planning model (DRIPP) to generate optimal planning responses to urban drought. DRIPP is a generalizable multi-scale framework for optimizing dynamic planning strategies of long-term infrastructure deployment and short-term drought response. It integrates climate and hydrological variability with high-fidelity representations of urban water distribution, available technology options, and demand reduction measures to yield robust and cost-effective water supply portfolios that are location-specific. We apply DRIPP in Santa Barbara, California to assess how least cost water supply portfolios vary under different drought scenarios and identify portfolios that are robust across drought scenarios. In Santa Barbara, we find that drought intensity, not duration or frequency, drives cost increases, reliability risk, and regret of overbuilding infrastructure. Under uncertain drought conditions, a diversified technology portfolio that includes both rapidly deployable, decentralized technologies alongside larger centralized technologies minimizes water supply cost while maintaining high robustness to climate uncertainty.

Quantifying the effects of vegetation productivity and drought scenarios on livestock production decisions and income

Quantifying the effects of vegetation productivity and drought scenarios on livestock production decisions and income

A modelling testbed to demonstrate the circular economy of water

Climate change poses significant challenges in terms of water scarcity, environmental crisis, and economic uncertainty. This situation drives an increasing need to pursue more sustainable futures and to conserve and maximise the use of resources whenever possible. The EU-funded H2020 NextGen project aimed to boost sustainability using new and novel technologies and approaches implemented within the water cycle, and to maximise the efficient use of water and water-embedded resources. To facilitate and communicate the potential benefits of such technologies, NextGen developed Serious Games (SGs), enabled by underlying System Dynamic Models (SDMs), for demonstrating how interactions between water, energy, and materials/embedded resources within the urban water cycle can be utilised in the context of the Circular Economy of water. As part of a fast-track development process, a testbed dubbed “Toy Town” was developed that encompasses a range of technologies and options that provides a demonstrable framework that can later be refined and modified accordingly for other case studies. The underlying SDM driving the SG is built using the Julia programming language. The testbed incorporates a range of components, including water-saving and water-reuse technologies, stormwater management, and wastewater treatment systems. The SDM acts fundamentally as a mass-balance model tracking over time volumetric flows of water/wastewater and the concentrations/dilution of pollutants/material within the urban water cycle. A variety of water use, water reuse and wastewater treatment components can be tested within this model to maximise the resource potential of the water and material moving through the cycle. The paper focuses on an extreme drought scenario and highlights the benefits of a modelling testbed for exploring potential technological solutions for managing the urban water cycle and how such solutions can be employed in the context of the circular economy of water. The NextGen SG thus has the potential to improve stakeholders’ understanding of the implementation of novel technologies in the water cycle and the benefits that could be accrued by such stakeholder groups.

Resource-use efficiency and environmental sustainability in the village tank cascade systems in the dry zone of Sri Lanka: An assessment using a bio-economic model

IntroductionVillage tank cascade systems (VTCSs) were built in ancient Sri Lanka as autonomous and climate-resilient agro-ecological systems. This study examines crop choices, farming profitability, and environmental sustainability under alternative rainfall regimes and market interventions in the Mahakanumulla VTCS of the Anuradhapura district.MethodA bio-economic model was developed to represent farming activities in the VTCS for the 2018-19 Maha and 2019 Yala cultivation seasons with data gathered from secondary sources and a key informant survey. The objective function of the model was the maximization of profits from farming. Resource limits were set for four types of land (highlands and lowlands in the Maha and Yala seasons), two types of labor (hired and family), and twelve-monthly water constraints. Six different models were developed for the six sub-divisions of the VTCS, considering the water-management hierarchy of the system. The models were simulated under alternative rainfall regimes and market interventions. The optimal crop mixes, farm profits, and shadow prices of resources associated with the baseline scenarios were compared with those of the counterfactual scenarios.Results and discussionThis analysis clearly illustrated that water and labor are the key determinants of the system. Also, when 922 ha of lowlands and 205 ha of uplands were allocated per annum for crop cultivation under normal environmental conditions, the annual profitability of the VTCS was LKR 111 million. During drought periods, a sharp reduction in profits was observed in the Maha season. Year-round drought caused a 77% profit reduction compared to the baseline. The Maha drought alone caused a reduction of 47%. The introduction of a buy-back arrangement for chili and maize helped farmers to increase profits by 185 and 28%, respectively, under normal climate scenarios, turning to 954 and 5% during extreme drought scenarios, compared to the baseline. The least nitrate leaching and soil losses occurred in green chili cultivation. The introduction of market-based solutions is recommended to address extreme climate events experienced by the rural communities dependent on the VTCSs in Sri Lanka.

Precision Phenotyping of Agro-Physiological Responses and Water Use of Sorghum under Different Drought Scenarios

Understanding sorghum response to water stress at different developmental stages is important for developing sorghum varieties with improved tolerance to drought. This study set out to finely characterize key agro-physiological responses and water use of sorghum subjected to different drought scenarios. A greenhouse experiment was conducted using a DroughtSpotter facility that enables real-time quantification of water use by gravimetric tracking. Four different water treatments were assessed: (i) early vegetative drought stress (DS1), (ii) DS1 plus recovery (DS1R), (iii) late vegetative drought stress (DS2), and (iv) well-watered (WW). Plant pheno-morphology and yield data were recorded. Leaf fluorescence and photosynthesis were continuously recorded throughout the experiment. Our results showed that green leaf number and plant leaf area were more affected by DS2 than DS1 and delayed plant flowering. Nevertheless, plants in DS2 were taller and produced higher stem and leaf biomass compared to DS1. No significant difference was recorded in grain yield between DS1 and DS2 but were outperformed by DS1R and WW. The transpiration and photosynthetic rates were shown to decrease at the same time as the stomatal conductance. This can therefore be assimilated to a stomatal down-regulation limiting CO2 uptake. However, the increase in intercellular CO2 concentration is likely to indicate the presence of CO2 in the substomatal cavity that was not conveyed to the carboxylation sites. This suggests a non-stomatal limitation of the photosynthesis. Moreover, the plants recovered quite well from DS1, and this was more prominent for physiological parameters than morphological ones. Globally, water use efficiency (WUE) for DS2 was higher compared to WW and DS1 treatments, confirming the growing point differentiation as a critical stage where drought stress should be avoided to ensure yield and better WUE. Adaptation responses were related to the reduction of transpiration through plant leaf area reduction, the reduction of stomatal conductance, and the increase of intercellular CO2 limiting photosynthesis. Further studies focusing on the biomarkers of stress and transcriptomic analyses are needed to provide further insight into the drought adaptation mechanisms of this line.

Assessing and optimizing the hydrological performance of Grey-Green infrastructure systems in response to climate change and non-stationary time series

Climate change has led to the increased intensity and frequency of extreme meteorological events, threatening the drainage capacity in urban catchments and densely built-up cities. To alleviate urban flooding disasters, strategies coupled with green and grey infrastructure have been proposed to support urban stormwater management. However, most strategies rely largely on diachronic rainfall data and ignore long-term climate change impacts. This study described a novel framework to assess and to identify the optimal solution in response to uncertainties following climate change. The assessment framework consists of three components: (1) assess and process climate data to generate long-term time series of meteorological parameters under different climate conditions; (2) optimise the design of Grey-Green infrastructure systems to establish the optimal design solutions; and (3) perform a multi-criteria assessment of economic and hydrological performance to support decision-making. A case study in Guangzhou, China was carried out to demonstrate the usability and application processes of the framework. The results of the case study illustrated that the optimised Grey-Green infrastructure could save life cycle costs and reduce total outflow (56–66%), peak flow (22–85%), and TSS (more than 60%) compared to the fully centralised grey infrastructure system, indicating its high superior in economic competitiveness and hydrological performance under climate uncertainties. In terms of spatial configuration, the contribution of green infrastructure appeared not as critical as the adoption of decentralisation of the drainage networks. Furthermore, under extreme drought scenarios, the decentralised infrastructure system exhibited an exceptionally high degree of removal performance for non-point source pollutants.

Modelling the population dynamics of an exploited, tropical fish species playing a fundamental role in aquatic ecosystems

AbstractThe coporo, Prochilodus mariae, plays a fundamental role in aquatic ecosystems as a detritivorous species facilitating the flow of carbon to the rest of the ecosystem's food web. It is also one of the most exploited freshwater fish species. Fishing, pollution and environmental changes in the Orinoquia region of Colombia have considerably reduced its population size. We analysed the population dynamics of P. mariae during an annual river cycle, including extreme drought and flood scenarios, by means of a mathematical model and simulations. The model we propose is novel because it relates biological, ecological and environmental factors to the population dynamics, including reproduction, growth in size and biomass of fish, recruitment, predation, fishing mortality and river flow. The proposed mathematical model apparently gives an approximate description of the population dynamics of P. mariae for 2010 because a good fit of the model to the catch data of the species of that year was obtained. The simulations showed that the first 3 months of the year are crucial for the species because this is when it is most affected by a combination of fishing, biological factors which increase natural mortality (e.g. upstream migration and predation) and environmental factors (e.g. low river flow). Hypothetical scenarios show that local extinction could occur if fishing were to increase and river flow were to decrease.

Densidade e classificação da rede pluviométrica e análise espaço-temporal das chuvas na região do alto Rio Paraná, Brasil

ABSTRACT Water management aims to ensure the water availability necessary to meet the current and future demand for water resources. For which it is essential to implement monitoring networks that support the investigation of events that interfere with the rainfall regime of watersheds, such the phases of the ocean-atmospheric phenomenon El Niño – Southern Oscillation (ENSO). The classification of the rainfall network was proposed according to the World Meteorological Organization (WMO) for 14 management watersheds in the Upper Parana River (UPR) region, Brazil. On the other hand, the spatial and temporal variability of annual rainfall was analyzed using geostatistical techniques and confronted with ENSO data. To this purpose, data from 408 stations were collected via the Hidroweb portal, for the period from 1990 to 2020. The low representativeness of data in the region was verified from the observational network. The areas with the lowest and highest rainfall reduction were the north and northwest regions of the UPR, and the areas surrounding the Paraná River, respectively. The years 2019 and 2020 were identified as the most critical period of the last 3 decades with below-average rainfall (-13.21%) in 49.55% of the studied area, indicating a persistence in the drought scenario.

The Impact of Climatic Conditions on Oil Content and Quality, in Sunflower

Sunflower (Helianthus annuus L.) crop is grown worldwide, under a range of agro-environments. This crop is primarily grown for its edible oil but also for its achenes (confectionery types), both commonly used in human food. With ongoing climate change, sunflower, as a spring crop, could be more exposed to the direct effect of heat stress and to different drought scenarios, resulting in severe yield losses, oil content decrease and alteration of fatty acids composition. The oil concentration in sunflower (whether linoleic or oleic varieties) is valued above the contribution of genotype, of environment but also of the crop management. In our study, with different sunflower hybrids, experimented in different conditions of the environment, we obtained results on oil content and fatty acids composition. The oil content in kernels is influenced by climate. This depends by air temperature in period of anthesis or during grain filing, also by rainfall. The unsaturated fatty acids of sunflower oil are much more affected by genotype and environment than the saturated ones. Cooler regions offer a more favorable climate for the oil and linoleic acid synthesis. There is an indirect relationship for oleic and linoleic content, in sunflower oil.

Spatiotemporal Assessment of Meteorological Drought of Paschim Medinipur District, West Bengal, India

The drought phenomenon is linked to the water scarcity and these are the pressing issues that require careful and thoughtful consideration. Drought in India mostly affects regions that are part of numerous plateaus, including the Chottanagpur plateau and the Deccan plateau. The Paschim Medinipur District of West Bengal, which is located in the southern portion of the Chottanagpur plateau, has recently experienced extreme and severe drought on multiple occasions. The assessment of the drought scenario in this region is, nevertheless, still very far from being finalized. Using the Standardized Precipitation Evapotranspiration Index (SPEI) at various time intervals (e.g., 3 months, 6 months, 12 months and 48 months) between 1979 and 2014, we have evaluated drought both geographically and temporally in this study. Here, the drought evaluation metrics include peak intensity, average intensity, magnitude, occurrence rate (%) and trend. Peak intensity, magnitude, average drought intensity, and the frequency of Extreme to Severe (ES) droughts are all seen to decline noticeably as time steps move forward. The frequency of moderate droughts starts to rise as time moves forward. Peak intensity, magnitude, average drought intensity, drought duration, ES and moderate drought occurrence rate is high in southern and southwestern portions of Paschim Medinipur. Additionally, the Principal Component Analysis (PCA) composite scores used to identify the drought-prone zones are estimated using the aforementioned parameters at various time steps. As the time step increases the area under the high and high moderate drought prone zone decreases, but very low and low drought prone area increases. Overall 16% area is found under high to high moderate drought prone category, whereas, approximately, 65% area is found under the low to low moderate drought category. The outcome of this research may be helpful to combat with drought and to make a fruitful move to manage water resources in the Paschim Medinipur region, West Bengal. Additionally, the study makes use of a superb methodology to comprehend the spatiotemporal variation of meteorological drought, which is applicable to all parts of the globe.

Simulating the Impacts of Drought and Warming in Summer and Autumn on the Productivity of Subtropical Coniferous Forests

The impacts of drought and/or warming on forests have received great attention in recent decades. Although the extreme drought and/or warming events significantly changed the forest demography and regional carbon cycle, the seasonality quantifying the impacts of these climate extremes with different severities on the productivity of subtropical coniferous forests remains poorly understood. This study evaluated the effects of seasonal drought and/or warming on the net primary productivity (NPP) of subtropical coniferous forests (i.e., Cunninghamia lanceolata and Pinus massoniana forests) from Hengyang–Shaoyang Basin in southern China using the Ecosystem Demography model, Version 2.2 (ED-2.2) and based on the datasets from forest inventory, meteorological reanalysis, and remotely sensed products. The results showed that the goodness of fit of the DBH-height allometric equations was better than that of the default in ED-2.2 after model calibration; the ED-2.2 model qualitatively captured the seasonality of NPP in the subtropical coniferous forests; and the mismatch between simulated annual NPP and MODIS-NPP (MOD17A3HGF) became smaller over time. The effect of seasonal drought on NPP was greater than that of warming; the decline rate of NPP gradually increased and decreased with time (from July to October) under the seasonal drought and warming scenarios, respectively; NPP decreased more seriously under the combined drought-warming scenario in October, with an average decrease of 31.72%, than the drought-only and warming-only scenarios; seasonal drought had an obvious legacy impact on productivity recovery of subtropical coniferous forests, but it was not the case for warming. With the increase in drought severity, the average values of soil available water and NPP together showed a downward trend. With the increase in warming severity, the average values of canopy air space temperature increased, but NPP decreased. Seasonal drought and/or warming limit forest production through decreasing soil moisture and/or increasing canopy air space temperature, which impact on plant photosynthesis and productivity, respectively. Our results highlight the significance of taking into account the impacts of seasonal warming and drought when evaluating the productivity of subtropical coniferous forests, as well as the significance of enhancing the resistance and resilience of forests to future, more severe global climate change.

Subsurface Lateral Flows Buffer Riparian Water Stress Against Snow Drought

AbstractIn the Sierra Nevada, CA, the Mediterranean climate exposes montane forests to water stress during the summer drought. Normally, spring snowmelt alleviates summer water stress, especially in riparian ecosystems that receive subsurface lateral inputs from groundwater. However, snow drought could potentially eliminate these beneficial effects. This research investigates how subsurface lateral redistribution mediates hillslope‐scale vegetation responses to snow drought. We apply a spatially‐distributed ecohydrologic model (Regional Hydro‐Ecologic Simulation System (RHESSys)) to a snow‐dominated watershed in the Sierra Nevada. We incorporate observed sap flow data along a hillslope to estimate relative differences in water stress for upslope and riparian sites, and constrain RHESSys drainage parameter uncertainty. Our model results show that subsurface lateral inputs buffer riparian water stress against snow drought. For all drought types, both upslope and riparian sites experience substantial losses of net primary productivity (NPP), and on average upslope sites are more adversely affected (upslope loss of NPP = 45% vs. riparian = 28%). Dry droughts from a lack of rain or snow induce substantial loss of biomass for upslope and riparian trees because of low annual precipitation, but a small snowpack retained during cold, dry years slightly alleviates these effects and delays water stress by 2 weeks in riparian areas and 3 weeks upslope. While riparian forests are often buffered against drought stress, our study also shows that riparian forests can suffer from water stress. We found 21% of drought scenarios where riparian trees experience greater water stress than upslope trees that were mostly associated with wet and warm snow droughts.

A study on changes in drought in Haiduong provinces of Vietnam in the context of climate change

Hai Duong is a province in the Red River Delta of northern Vietnam, with a GDP of 3020 USD/year. Its economy depends mainly on natural conditions, especially agriculture. In the context of climate change, drought will be a natural disaster that greatly affects the economy and agriculture is no exception. Using the Pearson correlation coefficient evaluation method and building multi-linear regression equations, a good correlation was found between total evaporation and total monthly rainfall, monthly mean temperature, monthly maximum temperature and monthly minimum temperature. This is the basis for calculating potential future evaporation based on climate change scenarios. Calculating the drought index K with the input data of climate change scenarios for Vietnam, this analysis has calculated the drought evolution for the three driest months of the year (12, first, 2) for the period 2021- 2050 in Hai Duong province. Results show that with both scenarios (RCP 4.5 and RCP 8.5), the drought index K is at drought and very high drought levels. The drought level in RCP 8.5 is higher than in RCP 4.5 while the drought level at Chi Linh meteorological station is 1.4-1.5 times higher than that at Hai Duong meteorological station. It emerges that drought is clearly cyclical with the drought scenario RCP 8.5 which reaches its maximum every 9-10 years.

Drought Impacts on the Crop Sector and Adaptation Options in Burkina Faso: A Gender-Focused Computable General Equilibrium Analysis

The crop sector in Burkina Faso has been facing recurrent droughts since 1970. This study analyzes the impacts of droughts and adaptation options such as the use of irrigation capacity development methods, integrated soil management and drought-tolerant crop varieties on the crop sector. Indeed, we focus on the consequences of agricultural droughts on economic growth and employment and on the gender dimension of household poverty. Using a gendered dynamic computable general equilibrium model linked to a microsimulation model, we conduct simulations of various drought scenarios (mild, moderate and severe). We show that the mild, moderate and intense droughts experienced by Burkina Faso over the past ten years have negatively affected the country’s economic performance and considerably degraded the welfare of its households. The gross domestic product has fallen by 3.0% in the short term and 3.3% in the long term due to intense droughts. Moreover, the number of poor people is growing faster in male-headed households than in female-headed households. Given the large female population in both groups of households, women bear the brunt of droughts. These results also demonstrate how these negative impacts could worsen in the future with the recurrence of intense droughts due to the threat of global climate change. We find that Burkina Faso has room to reduce the negative impacts by adopting drought-tolerant crop varieties, integrated soil management approaches or expanding their irrigation capacity.

System Dynamics Modeling in Local Water Management: Assessing Strategies for the City of Boerne, Texas

As more pressure is exerted onto water sources, hydrologic systems may be altered in ways that are difficult to predict. In Texas, water deficits can become widespread as sources are strained beyond capacity. For smaller communities, such as Boerne, Texas, water management and planning is a way to prepare. The supply-demand water balance in Boerne is conceptualized through causal loop diagrams and system dynamics modeling. Through stakeholder engagement, xeriscaping, rainwater harvesting, and smart meters were chosen as interventions, each varied in adoption levels. The resulting 125 combinations were analyzed under three scenarios: a base case assuming maximum supply of water is firm, and two responses to a meteorological drought. Results show that the city can effectively forestall a deficit. Different combinations of adoptions can achieve the same goal, giving the city optionality in choosing strategies that are best suited for its needs and constraints. Rainwater harvesting was found to be the dominant intervention influencing demand, but its influence is reduced in the two drought scenarios. Xeriscaping was the second most influential intervention and smart meters for irrigation had no effect on demand. The approach used in this study highlights the interdependency between community adoption of conservation strategies and the importance of considering these relationships using systems modeling.

Spatio-temporal drought assessment of the Subarnarekha River basin, India, using CHIRPS-derived hydrometeorological indices.

Precipitation studies have a crucial role in deciphering climate change and monitoring natural disasters such as droughts. Such studies lead to better assessment of rainfall amounts and spatial variabilities; and have a vital role in impact assessment, mitigation, and prediction of occurrence. Thus, this study has been undertaken in the Subarnarekha River basin using Climate Hazards group Infrared Precipitation with Stations (CHIRPS) dataset. Precipitation datasets helped in deriving hydrometeorological indices such as the Rainfall Anomaly Index (RAI) and Standardized Precipitation Index (SPI) for the identification of drought occurrences. The core objective was to infer spatio-temporal drought scenarios and their trend characterization covering four decades over the years 1981 to 2020. Quantitative drought assessment was done using run theory for identifying the Drought Duration (DD), Drought Severity (DS), Drought Intensity (DI), and Drought Frequency (DF). Mann-Kendall (MK) test was performed to understand the precipitation and drought trends at annual and seasonal scales. Eight severe drought events were identified in the Subarnarekha River basin for the past 40years and the average DI value of 0.8 was recorded. MK test results for the precipitation showed a significant positive trend (95% confidence level) for pre-monsoon periods. However, for SPI, a significant positive trend was observed over the intervals of 3 (SPI3), 6 (SPI6), and 12 (SPI12) months respectively at an annual timescale, suggesting wetter conditions within the study area. Moreover, there had been insignificant negative trends for SPI1 and SPI3 during winter. It indicates that during the short-term SPI scale, i.e., 1month (SPI1) and 3months (SPI3), the instances of negative SPI values inferred were high, which point to the increasing incidences of meteorological drought possibly due to deficient soil moisture. Thus, the results indicated that the CHIRPS precipitation product-derived hydrometeorological indices could act as a valuable tool for assessing the past spatio-temporal drought conditions of the Subarnarekha River basin. This may further be helpful in planning for sustainable water resource management of such river basins.