Assessment of algal biofuel resource potential in the United States with consideration of regional water stress

Regional and seasonal water stress analysis of United States thermoelectricity

Rising agricultural water scarcity in China is driven by expansion of irrigated cropland in water scarce regions

Decreasing yields due to water stress form a threat to rural livelihoods and can affect migration dynamics, especially in vulnerable regions that lack the capacity to adapt agriculture to water stress. But since migration is complex, non-linear and context-dependent, it is not feasible to predict the precise number of people that will migrate due to water stress. It is possible to map the different conditions that shape regional vulnerabilities and the number of people affected. This study presents a vulnerability approach to identify areas on the African continent where emigration associated with water stress is expected to be relatively high by 2050 under a middle-of-the-road scenario (SSP2) and compares the results with the 2010 situation. By utilizing among other indicators the water yield gap, the impact of water stress on rainfed agricultural crop yields is included, reflecting the impact of water stress on rural livelihoods depending on crop farming. The analysis was done on a water-province level, 393 in total. Clusters of potential emigration associated with the impacts of water stress on agriculture are projected for parts of the Sahel, the Horn of Africa and regions of Angola. The regions where migration associated with water stress is expected to be relatively high by 2050 are approximately the same as those of 2010, although more people are projected to be living in these water-stressed regions. By developing this vulnerability approach, this manuscript enlarges the current insights regarding future clusters of water stress-related migration.

Microalgae have great potential as an energy and feed resource. Here we evaluate the water use associated with freshwater algae cultivation and find it is possible to scale U.S. algae biofuel production to 20.8 billion liters of renewable diesel annually without significant water-stress impact. Among potential sites, water-stress is significantly more variable than algae productivity across location and season. Thus, it is possible to reduce water-stress impact, quantified as water scarcity footprint, through the choice of algae site location. We test three site-selection criteria based on (1) biomass productivity, (2) water-use efficiency, and (3) water-stress impact and find that adding water-stress constraints to productivity-based ranking of suitable sites reduces water-stress impact by 97% and water consumption by half, compared with biomass-productivity ranking alone, with little productivity impact (<1.7% per-site on average). With 20.8 billion liters, algae could meet 19.7% of U.S. jet fuel demand with a freshwater demand of less than 1.4% of U.S. irrigation consumption. Evaluating water-stress impact is important because the impact of unit water consumption on water stress varies significantly across regions and seasons. Considering seasonal water balances allows producers to understand the combined seasonal effects of hydrologic flows and productivity, thereby avoiding potential short-term water stress.

Preparation of almond orchards for harvest by withdrawal of irrigation may result in prolonged periods of water stress. It is during these periods (from July to mid-August) that mite populations often increase and are associated with partial defoliation. The impact of spider mites and water stress, alone and in combination, was investigated on gas exchange and water potential of almond leaves during the 1982 and 1983 growing seasons. The impact of water stress on mite densities was also studied in 1982. In both years, water stress caused highly significant reductions in leaf water potential, whereas mites alone had no measurable impact. In 1982, significantly higher mite eggs and motile stages developed on water-stressed foliage as compared with unstressed foliage. The effect of mites on gas exchange of water-stressed leaves was greater than on unstressed leaves in 1982 as indicated by significant interactions. Significant interactions representing the same trend did not occur in the 1983 trial. When water stress was severe, as in 1983, no additional impact of mites on gas exchange was detected.

Like all animals, plant growth and productivity depend on water. Water plays an important role in plant vegetation as well as economic gain from the crop plant cultivation. An in-depth analysis is performed to see the impacts of water availability on functional factors of irrigated rice (Boro) production and productivity. Primary and secondary data were used to perform the qualitative and quantitative analysis. Primary data were collected from five districts of northwestern regions of Bangladesh considering the severity of groundwater scarcity. A total 643 samples were selected from irrigated rice (Boro) producer across the regions to analyze the water stress effect on factors of production and productivity. Severity of water stress has positive relationship with irrigation and pesticide cost, and negative relationship with lease value, labor and seed cost. Remaining two factors of production such as fertilizer and tillage cost shows a volatile indicator in water stressed condition. In the water stressed areas, though irrigation cost is higher, and farmers get lower yield from their land, but the net return is not much lower compared to less water stressed areas because of getting higher price of rice in the water stressed regions. The water stressed effect on irrigated rice production is significant which leads the policy maker to think of factors preventing farmers to adopt less water consuming crop varieties in the drought prone areas of Bangladesh and rice market to reach equilibrium price during the season.

Bioenergy from rice biomass feedstock is considered one of the potential clean energy resources and several small biomass-based powerplants have been established in rice–growing areas of Thailand. Rice production is significantly affected by drought occurrence which results in declined biomass production and quality. The impact of water stress (WS) was evaluated on six rice cultivars for biomass quality, production and bioenergy potential. Rice cultivars were experimented on in the field under well–watered (WW) and WS conditions. Data for biomass contributing parameters were collected at harvest whereas rice biomass samples were analyzed for proximate and lignocellulosic contents. Results indicated that WS negatively influenced crop performance resulting in 11–41% declined biomass yield (BY). Stability assessment indicated that cultivars Hom Pathum and Dum Ja were stress–tolerant as they exhibited smaller reductions by 11% in their BY under WS. Statistics for proximate components indicated a significant negative impact influencing biomass quality as ash contents of Hom Chan, Dum Ja and RD-15 were increased by 4–29%. Lignocellulosic analysis indicated, an increase in lignin contents of Hom Nang Kaew, Hom Pathum, Dum Ja and RD–15 ranging 7–39%. Reduced biomass production resulted in a 10–42% reduction in bioenergy potential (E). Results proved that cultivation of stress-susceptible cultivars or farmer’s choice and occurrence of WS during crop growth will reduce biomass production, biomass feedstock availability to biomass-based powerplants and affect powerplant’s conversion efficiency resulting in declined bioenergy production.

Influence of potassium fertilization, water and salt stress, and their interference on rheological soil parameters in planted containers

Functional-structural plant models simulate the development of plant structure, taking into account plant physiology and environmental factors. The L-PEACH model is based on the development of peach trees. It demonstrates the usefulness of L-systems in constructing functional-structural models. L-PEACH uses L-systems both to simulate the development of tree structure and to solve differential equations for carbohydrate flow and allocation. New L-system-based algorithms are devised for simulating the behavior of dynamically changing structures made of hundreds of interacting, time-varying, nonlinear components. L-PEACH incorporates a carbon-allocation model driven by source-sink interactions between tree components. Storage and mobilization of carbohydrates during the annual life cycle of a tree are taken into account. Carbohydrate production in the leaves is simulated based on the availability of water and light. Apices, internodes, leaves and fruit grow according to the resulting local carbohydrate supply. L-PEACH outputs an animated three-dimensional visual representation of the growing tree and user-specified statistics that characterize selected stages of plant development. The model is applied to simulate a tree's response to fruit thinning and changes in water stress. L-PEACH may be used to assist in horticultural decision-making processes after being calibrated to specific trees.

Climate change, socioeconomic development, and irrigation management are exacerbating water scarcity in many regions worldwide. However, current global-scale modeling approaches used to evaluate the impact of these factors on water resources are limited by coarse resolution and simplified representation of local socioeconomic and agricultural systems, which hinders their use for regional decision making. Here, we upgraded the irrigation water use simulation in the system dynamics and water environmental model (SyDWEM) and integrated it with the water supply stress index (WaSSI) ecosystem services model. This integrated model (SyDWEM-WaSSI) simulated local socioeconomic and agricultural systems to accurately assess future water stress associated with climate change, socioeconomic development, and agricultural management at subbasin levels. We calibrated the integrated model and applied it to assess future water stress levels in Texas from 2015 to 2050. The water stress index (WSI), defined as the ratio of water withdrawal to availability, was used to indicate different water stress levels. Our results showed that the integrated model captured changes in water demand across various sectors and the impact of climate change on water supply. Projected high water stress areas (WSI &gt; 0.4) are expected to increase significantly by 2050, particularly in the Texas High Plains and Rolling Plains regions, where irrigation water use was projected to rise due to the impact of climate change. Metropolitan areas, including Dallas, Houston, Austin, and San Antonio, were also expected to experience increased domestic water demand, further exacerbating water stress in these areas. Our study highlights the need to incorporate socioeconomic planning into water resources management. The integrated model is a valuable tool for decisionmakers and stakeholders to evaluate the impacts of climate change, socioeconomic development, and irrigation management on water resources at the local scale.

Yield features of two soybean varieties under different water supplies and field conditions

The impact of new urbanization and industrial structural changes on regional water stress based on water footprints

Characterization of water stress and prediction of yield of wheat using spectral indices under varied water and nitrogen management practices

This research aims to evaluate the impact of nitrogen deprivation and water stress on gas exchange and chlorophyll fluorescence in young plants of five cultivars of Arabic coffee. A factorial experiment 5 (cultivars) × 3 (treatments: control without stress, water stress of −1.5 MPa and stress of N – 0.0 mmol L−1 N) was carried out in a complete randomized block design with three replicates. Before being submitted to the treatments, the plants were grown in a greenhouse for 240 days, and then transferred to a growth chamber under controlled conditions. Subsequently, after the experimental period of 96 h we measured photosynthetic rate (A), stomatal conductance to water vapor (gs), transpiratory rate (E), internal and external carbon ratio (Ci/Ca), water use efficiency (A/E), electron transport rate (ETR), actual quantum yield of PS II electron transport (φFSII), and maximum photochemical efficiency of PS II (Fv/Fm). Water stress reduced A, gs, E, A/E, ETR, φFSII, and Fv/Fm. The nitrogen deficiency reduced ETR, φFSII, and Fv/Fm. Under short-term water stress Catuaí Vermelho maintain the A values due to better stomatal control, reduced water lost by transpiration (E) and better water use efficiency A/E, while Mundo Novo and Acauã show lower damage to Fv/Fm. Short-term nitrogen stress has low impact on A of young plants of Coffea arabica cultivars with adequate N-nutrition.

Exploring the potential impact of implementing carbon capture technologies in fossil fuel power plants on regional European water stress index levels