Levels Of Shortage Research Articles

Economic impacts on irrigated agriculture of water conservation programs in drought

The need to adapt irrigation patterns to water shortages in the world’s dry regions continues to inspire economically attractive measures to sustain food security and improve farm incomes. Ongoing evidence of climate variability and growing populations amplify the importance of this search. Motivated by recent severe drought in the southwestern United States, this study analyzes vulnerability, impacts, and adaptability by irrigation technology in a sub-basin of North America’s Rio Grande. The study accounts for economic incentives affecting choices on irrigation technology, crop mix, and water source in the face of water conservation subsidies under various levels of surface water shortage. Findings show that when surface water supplies are reduced, farmers shift to aquifer pumping even when pumping raises the cost of production or reduces yield. An important on-farm drought adaptation mechanism comes by converting from surface irrigation to water conserving irrigation technologies when faced with lower financial costs for conversion. Public subsidies to convert from flood to drip irrigation offset many of the negative impacts of drought on farm income. These subsidies also raise the value of food production, reduce the amount of water applied to crops, but can increase crop water depletions. Our approach for analyzing drought adaptation impacts and adjustment mechanisms can be applied where water shortages loom, food security is important, and water conservation policies are under debate. Results provide insights for the design of adaptation mechanisms for the world’s dry regions for which policymakers need to reduce economic damages from future climate variability and change.

Seabirds maintain offspring provisioning rate despite fluctuations in prey abundance: a multi‐species functional response for guillemots in the North Sea

Summary Seabirds that consume more than one prey type may adjust their foraging to maintain provisioning rates for their chicks. How energetically effective are these strategies, and what are the implications for the management of seabirds and their marine habitat? A multi‐species functional response links consumption rates to the availability of multiple prey types, but fitting multi‐species functional responses to field data can be difficult, requiring consumption measurements over a range of different prey abundances. Such detailed data may be especially difficult to obtain in marine ecosystems. We used annual time‐series data on chick provisioning for the common guillemot Uria aalge together with abundance indices for its two main prey (lesser sandeel Ammodytes marinus and sprat Sprattus sprattus) to parameterize a multi‐species functional response for parents provisioning chicks at a major North Sea colony from 1992 to 2005. The fitted model reproduced changes in diet and consumption rate which were consistent with changes in local prey abundance including a long‐term decline in sandeels. The model predicted that energy intake by chicks would be more sensitive to changes in sprat abundance than sandeel abundance. Guillemots appeared able to adjust their foraging tactics over a wide range of prey abundances to maintain a consistent energetic intake rate for chicks. Synthesis and applications. Our results suggest guillemot chicks obtain adequate calorific intake from their parents despite fluctuating prey abundances, conferring some resilience in the face of environmental variation. The parameterized multi‐species functional response model can be used to estimate levels of severe prey shortage that compromise provisioning. It also enables us to interpret predator consumption rates so that these can be used as a metric of prey availability. Further, quantifying trophic links between marine prey and apex predators is needed to support the development of multi‐species models in which the predators can be included. Such models are needed as tools to effectively manage the marine ecosystem, taking into account the objectives of fishing, conservation and the need to maintain Good Environmental Status.

VALUATION OF WATER AND SCARCE WATER RESOURCES OPTIMAL ALLOCATION AT THE RIVER BASIN LEVEL A CASE STUDY IN DOWNSTREAM AREA OF THE DONG NAI RIVER SYSTEM BASIN

Water scarcity is an ongoing reality in many river basins due to the need for increasingly water use associated with water pollution and climate change. Faced with this situation, it is necessary to know the true value of scarce water resources to contribute to effective water allocation. In this paper, a model to optimize the allocation of water resources with the constraints in terms of hydrology has developed based on the principle of balance in marginal net benefits of water use across sectors, and test applied to solve the optimal water sources allocation in the downstream area of the Dong Nai river system basin with many different water scarcity scenarios. The results show that the model allows simulating relatively good optimized water allocation for the competitive water use demands in the cases of shortage of water, and also allows determining the balanced margin net values/ benefits of raw water corresponding to the different levels of water shortage.

Assessing the levels of food shortage using the traffic light metaphor by analyzing the gathering and consumption of wild food plants, crop parts and crop residues in Konso, Ethiopia

BackgroundHumanitarian relief agencies use scales to assess levels of critical food shortage to efficiently target and allocate food to the neediest. These scales are often labor-intensive. A lesser used approach is assessing gathering and consumption of wild food plants. This gathering per se is not a reliable signal of emerging food stress. However, the gathering and consumption of some specific plant species could be considered markers of food shortage, as it indicates that people are compelled to eat very poor or even health-threatening food.MethodsWe used the traffic light metaphor to indicate normal (green), alarmingly low (amber) and fully depleted (red) food supplies and identified these conditions for Konso (Ethiopia) on the basis of wild food plants (WFPs), crop parts (crop parts not used for human consumption under normal conditions; CPs) and crop residues (CRs) being gathered and consumed. Plant specimens were collected for expert identification and deposition in the National Herbarium. Two hundred twenty individual households free-listed WFPs, CPs, and CRs gathered and consumed during times of food stress. Through focus group discussions, the species list from the free-listing that was further enriched through key informants interviews and own field observations was categorized into species used for green, amber and red conditions.ResultsThe study identified 113 WFPs (120 products/food items) whose gathering and consumption reflect the three traffic light metaphors: red, amber and green. We identified 25 food items for the red, 30 food items for the amber and 65 food items for the green metaphor. We also obtained reliable information on 21 different products/food items (from 17 crops) normally not consumed as food, reflecting the red or amber metaphor and 10 crop residues (from various crops), plus one recycled stuff which are used as emergency foods in the study area clearly indicating the severity of food stress (red metaphor) households are dealing with. Our traffic light metaphor proved useful to identify and closely monitor the types of WFPs, CPs, and CRs collected and consumed and their time of collection by subsistence households in rural settings. Examples of plant material only consumed under severe food stress included WFPs with health-threatening features like Dobera glabra (Forssk.) Juss. ex Poir. and inkutayata, parts of 17 crops with 21 food items conventionally not used as food (for example, maize tassels, husks, empty pods), ten crop residues (for example bran from various crops) and one recycled food item (tata).ConclusionsWe have complemented the conventional seasonal food security assessment tool used by humanitarian partners by providing an easy, cheap tool to scale food stress encountered by subsistence farmers. In cognizance of environmental, socio-cultural differences in Ethiopia and other parts of the globe, we recommend analogous studies in other parts of Ethiopia and elsewhere in the world where recurrent food stress also occurs and where communities intensively use WFPs, CPs, and CRs to cope with food stress.

Development of streamflow projections under changing climate conditions over Colorado River basin headwaters

Abstract. The current drought over the Colorado River Basin has raised concerns that the US Department of the Interior, Bureau of Reclamation (Reclamation) may impose water shortages over the lower portion of the basin for the first time in history. The guidelines that determine levels of shortage are affected by relatively short-term (3 to 7 month) forecasts determined by the Colorado Basin River Forecast Center (CBRFC) using the National Weather Service (NWS) River Forecasting System (RFS) hydrologic model. While these forecasts by the CBRFC are useful, water managers within the basin are interested in long-term projections of streamflow, particularly under changing climate conditions. In this study, a bias-corrected, statistically downscaled dataset of projected climate is used to force the NWS RFS utilized by the CBRFC to derive projections of streamflow over the Green, Gunnison, and San Juan River headwater basins located within the Colorado River Basin. This study evaluates the impact of changing climate to evapotranspiration rates and contributes to a better understanding of how hydrologic processes change under varying climate conditions. The impact to evapotranspiration rates is taken into consideration and incorporated into the development of streamflow projections over Colorado River headwater basins in this study. Additionally, the NWS RFS is modified to account for impacts to evapotranspiration due to changing temperature over the basin. Adjusting evapotranspiration demands resulted in a 6 % to 13 % average decrease in runoff over the Gunnison River Basin when compared to static evapotranspiration rates. Streamflow projections derived using projections of future climate and the NWS RFS provided by the CBRFC resulted in decreased runoff in 2 of the 3 basins considered. Over the Gunnison and San Juan River basins, a 10 % to 15 % average decrease in basin runoff is projected through the year 2099. However, over the Green River basin, a 5 % to 8 % increase in basin runoff is projected through 2099. Evidence of nonstationary behavior is apparent over the Gunnison and San Juan River basins.

Monitoring stomatal conductance of Jatropha curcas seedlings under different levels of water shortage with infrared thermography

Model simulations and experimental measurements were used to investigate the applicability of infrared thermography for the estimation of stomatal conductance and drought stress under sub-optimal meteorological conditions. The study focused on the stomatal conductance index I g, calculated from the leaf temperature and the temperature of a dry and wet reference leaf. The simulations revealed that I g is influenced by leaf dimension, wind speed and air temperature and not or hardly by leaf angle, albedo, relative humidity or insolation. In addition, I g was found to be very sensitive to differences in wind speed, air temperature, insolation, leaf dimension and leaf angle between the measured and the reference leaves. In the experimental part, we evaluated if infrared thermography can be used to improve the knowledge on the water use of Jatropha curcas L., a tropical biofuel crop. Thermal images from Jatropha seedlings grown under three different drought treatments were made on a day with very variable insolation and a day with very low insolation. Smaller newly formed leaves and the active control of the leaf angle proved efficient ways of Jatropha to protect leaves under drought stress from overheating. I g, assessed in four different ways, and four simplified drought stress indices were derived and related to the measured stomatal conductance ( g s) of the seedlings. The strongest correlation with g s and the highest discriminative power between the different water treatments were achieved when I g was calculated by taking the average leaf temperature per plant and the temperature of the dry and wet reference leaves of this plant, rather than the average temperature of several reference leaves. Using the difference between the dry reference and the measured leaf ( T dry − T l) as a simplified index gave similar results, although correlations were weaker. Other simplified thermal indices were not well correlated with leaf stomatal conductance or with water treatment. Recommendations were formulated for the measurement of I g and ( T dry − T l).

Transfusion Practices of Critical Care Physicians During Shortages

AbstractAbstract 4401 Background16 million units of pRBCs were transfused in the United States in 2006. The number of units transfused increases by 5–7% yearly, although the number of donated units has not increased proportionally leading to increasing shortages. The regional blood banks are responsible for the majority of collections. They typically communicate with hospital blood banks and distribute blood to match predicted needs. The hospital blood banks communicate with hospital administration and ordering physicians about shortages and may recommend strategies to decrease usage. Although the overall blood transfused decreases during a shortage, the effect of a shortage on physician prescribing behavior has not been studied. We randomized critical care physicians in an experimental survey design to understand the effect of varying levels of pRBC shortage on their prescription of blood products. Study Design and MethodsWe used an experimental survey design to assess changes in critical care physicians' pRBC transfusion threshold during times of varying scarcity. 1,940 Critical care physicians received two clinical scenarios, varying only whether there was a hospital wide shortage of blood products, a regional shortage, or no shortage. The vignette stated: “You are the primary physician for this patient. The patient is a 54 year old woman with dark, heme positive stools who is otherwise asymptomatic and is hemodynamically stable.” The physicians were asked whether they would initiate transfusion at 5 different hgb/hct levels from 5g/dl/15% to 10g/dl/30% and the number of units they would transfuse.VersionShortage Scenario #1Shortage Scenario #21NoneHospital2HospitalNone3HospitalRegional4RegionalHospital5NoneRegional6RegionalNoneParticipants also responded to specific questions about personal and practice characteristics, attitude scales and transfusion practices. ResultsSurvey respondents (n= 575, response rate 30%) significantly changed their transfusion threshold based on changing shortage scenarios. Order effects were demonstrated in all surveys where the respondent was presented with a less severe shortage scenario followed by a more severe shortage scenario. [Display omitted] Single unit transfusions were utilized by 54.1% of respondents at their transfusion threshold. The percentage of physicians transfusing single units increased substantially in each of the versions that went from less serious to more serious shortage vignettes. In response to statements about allocation of resources, a majority of physicians endorsed the need for rationing (73.4%). A majority also expressed the view that individual physicians are not capable of allocating scarce resources fairly (55.1%). ConclusionsThis study has three main findings. First, the respondents revealed progressively more restricted use of pRBC transfusions in the setting of progressively more proximate shortages of blood products. This finding suggests that physicians attend to information about shortages and in these scenarios, are willing to change their transfusion practices with individual patients in ways that reflect the needs of other patients. Second, these observed effects were substantially altered by the order of presentation of scenarios. Physicians often became stricter about their use of blood products when told about a shortage or a more proximate shortage, but they did not become more relaxed when later told about no shortage, or a more distant shortage. These findings suggest that continued reminders about scarcity might make physicians thriftier in their use of blood products. Third, physician's revealed use of blood products in response to hypothetical scenarios corresponds to more general feelings about rationing determined from their responses to attitude scales. Disclosures:No relevant conflicts of interest to declare.

Allocating bank regulatory powers: Lender of last resort, deposit insurance and supervision

We examine the optimal institutional allocation of bank regulation. We find that centralizing the lending of last resort and deposit insurance functions in a regulator leads to excessive forbearance. It also leads the bank to invest suboptimally in loans. Giving this regulator supervision improves on both problems, but it still does not lead to the efficient outcome. In the multi-regulator arrangement, we find that it is beneficial to give supervision to the deposit insurer. The choice between the unified-regulator arrangement and the multi-regulator arrangement involves a trade-off: The multi-regulator arrangement reduces the forbearance problem at high levels of liquidity shortage but may exacerbate it at low levels. These results assume the absence of information frictions. When banks are better informed than regulators, we show that regulators may have an incentive not to share private information, suggesting it is important to consider regulators’ informational advantages when deciding on the allocation of regulation.

Combined effects of ultraviolet-B radiation and food shortage on the sensitivity of the Antarctic amphipod Paramoera walkeri to copper.

Investigations on the combined effects of ultraviolet (UV)-B radiation and anthropogenic toxicants have focused primarily on the chemical interactions between UV-B and organic compounds. Only a few studies have examined whether exposure to UV-B changes sensitivity to toxicants. This question is addressed in a laboratory study using the common shoreline Antarctic amphipod Paramoera walkeri and exposure to environmentally realistic levels of copper, UV-B radiation, and food shortage. Exposure to copper for 21 d in the absence of any additional stressors (food present, no UV-B) showed a lowest observable effective concentration (LOEC) of greater than 100 microg Cu/L. Exposure to copper and UV-B in combination, with no shortage of food, resulted in a LOEC of 45 microg Cu/L. When exposed to copper and UV-B, with shortage of food, a LOEC of 3 microg Cu/L was recorded. Hence, the combination of environmental stress from exposure to UV-B radiation and shortage of food increases the sensitivity of P. walkeri to copper more than 30-fold. Increased metabolic energy requirements for defense mechanisms in response to toxicants and UV-B are discussed as possible explanations. It is concluded that consideration of environmental stressors in combination with toxicants increases the accuracy of ecological risk assessments of toxicants and should be part of the process for developing guidelines for ecologically acceptable concentrations of contaminants in the environment.

Effects of alternative water distribution rules on irrigation system performance: a simulation analysis

Based on a simulation model reflecting physical and economic conditions typically found in rice irrigation systems in Asia, the irrigation performance implications of alternative water distribution rules for dry season irrigation are evaluated under varying degrees of water shortage. The rules examined reflect differing water distribution strategies designed either to maximize conveyance efficiency, economic efficiency, or equity; or to achieve a balance between efficiency and equity objectives. Irrigation performance is evaluated using several efficiency measures reflecting the physical, agronomic and economic productivity of water, and one measure of equity. Economic efficiency and equity among farmers within the portion of the irrigation system that is “on” in any given season are shown to be complementary, and not competing objectives. Economic efficiency and equity among all farmers within the command area of the irrigation system are largely complementary strategies at the lower levels of water shortage, but with increasing shortage, significant tradeoffs develop between these objectives. An operational rule for water distribution under a goal of maximizing economic efficiency is developed, and the data requirements for its implementation are shown to be modest. Under the model's assumed conditions of dry season rice production dependent solely on surface irrigation for water, the distribution strategy designed to maximize conveyance efficiency results in only modestly lower levels of economic efficiency and equity than could be achieved by the strategy designed to maximize economic efficiency.

The nurse shortage. Myth or reality?

The proportion of vacant positions for registered nurses in hospitals doubled between September 1985 and December 1986,1 reaching the levels of the last national nursing shortage of 1979. Current r...

Perspectives on urban transportation energy contingency planning in the United States

The typical urban transportation energy contingency plan for the USA is based on one or more scenarios of sudden fuel shortages ranging from five percent to 30 percent. For comparison, the 1973-74 oil embargo and the 1979 shortage both were reported to have caused shortages in the range 8-13 percent, varying among different parts of the country. The most systematic of the contingency plans produce two or three different action plans for two or three levels of shortage, say, 5 percent, 15 percent and 25 percent. The package of measures to be implemented increases in severity accordingly. To simplify the presentation, the approximately 60 contingency measures to be discussed are collected in five groups, depending upon purpose. It seems that all measures encountered in the literature can be categorized as attempting to accomplish one of the following: (1) managing fuel supplies; (2) improving road system operating efficiency; (3) encouraging ridesharing; (4) altering travel demand and other behavior; (5) increasing public transportation capacity and efficiency. The measures in the five groups are summarized in tables and are discussed briefly. (TRRL)