Low Impact Areas Research Articles

Biomarkers and occurrences of heavy metals in sediment and the bioaccumulation of metals in crabs (Ucides cordatus) in impacted mangroves on the Amazon coast, Brazil

In this study, we analyzed biomarkers and heavy metals in Ucides cordatus specimens caught in mangrove areas [A1 = reference (low impact area); A2, A3 and A4 = port complex (potentially impacted area)] of the Amazonian northern coast of Brazil. Sediments and crab muscles sampled from the potentially impacted mangroves showed high levels of metals. Additionally, catalase and glutathione S-transferase enzymes in the gills and hepatopancreas of the collected crabs were elevated in crabs from A2, A3 and A4 relative to those from A1. The histological characteristics of the gills and hepatopancreas differed in crabs collected from A2, A3 and A4 compared with those collected from A1. The crabs were larger and heavier in the rainy season in A1 and A3 and heavier in the dry season in A4. Heavy metal analyses of sediments, crab muscles and biological responses indicated that the animals are subjected to stress levels differentiated in the mangroves due to a gradient (A4>A3>A2>A1) of anthropogenic pressure in São Marcos Bay. In conclusion, the analyses of metals in the sediment and in the muscles of crabs, as well as the biochemical biomarker and histological analyses, suggest that crabs from mangroves in the port complex region are subject to pollutants that compromise their health.

A Comparison of All-Terrain Vehicle (ATV) Trail Impacts on Boreal Habitats Across Scales

ABSTRACT: Recreational trails are an agent of anthropogenic disturbance in nature reserves and other low human impact areas. Effective management must balance the desire of recreationists to use these natural areas with the need to maintain their ecological integrity. Environments with low productivity may be particularly susceptible due to low resistance and resilience to recreational impacts. Our study examined 28 all-terrain vehicle (ATV) trails within the Avalon Wilderness Reserve and the adjacent surrounding area on the island of Newfoundland, Canada. We found that different habitat types (boreal forest, heaths, and bogs) differ in resistance and resilience to both direct on-trail erosion and indirect off-trail vegetation impacts of ATV trails. Dry forested sites were more resistant to direct on-trail erosion but less resistant to indirect off-trail vegetation disturbance. Heath sites were less resistant to direct on-trail erosion but highly resistant to indirect off-trail disturbance. Bog sites had ...

Rapid response to crisis: Health system lessons from the active period of COVID-19

BackgroundThis paper outlines the need for a health systems approach and rapid response strategy for gathering information necessary for policy decisions during pandemics and similar crises. It suggests a new framework for assessing the phases of the pandemic. MethodThe paper draws its information and conclusions from a rapid synthesis and translation process (RSTP) of a series of webinars and online discussions from the Pandemic-Mental Health International Network (Pan-MHIN) - policy experts from across 16 locations in Australia, Denmark, Italy, Spain, Taiwan, the UK and the USA. While the initial focus of this research was on mental health, COVID-19 has raised much broader issues and questions for health planners. ResultsWe identified gaps affecting the capacity to respond effectively and quickly, including in relation to system indicators, the inadequacy of the prior classification of the phases of the pandemic, the absences of a healthcare ecosystem approach, and the quick shift to digital technologies. The strengths and weaknesses of COVID-19 responses across different systems, services, sites and countries been identified and compared, including both low and high impacted areas. ConclusionsThere is an urgent need for managerial epidemiology based on healthcare ecosystem research encompassing multidisciplinary teams, visualization tools and decision analytics for rapid response. Policy and healthcare context played a key role in the response to COVID-19. Its severity, the containment measures and the societal response varied greatly across sites and countries. Understanding this variation is vital to assess the impact of COVID-19 in specific areas such as ageing or mental health.

Influence of latitude on raw material consumption by biomass combined heat and power plants: Energy conservation study of 50 cities and counties in the cold region of China

In the context of the mismatch between the potential in biomass energy and energy demand, proper space allocation and energy flow are necessary to improve the utilization rate of biomass energy, but the spatial distribution of heating demand has not been fully studied. This paper takes 50 cities/counties in the UTC+0800 time zone of the centralized winter heating zone in China and investigates the effects of geographical latitude on the per-capita raw material consumption by biomass combined heat and power plants (biomass CHP plants). Per-capita energy consumption is determined by electricity and heating consumption. The per-capita raw material consumption by biomass CHP plants during heating and non-heating periods is calculated by combining the average calorific value of each province with thermal efficiency. A regression model was constructed for latitude and per-capita raw material consumption by biomass CHP plants. The resulting curve exhibited an inverse S-shape during the heating period, with a positive correlation, but an insignificant correlation during the non-heating period. The study area can be divided into a high-impact area (regions to the south of 37°N and north of 45°N) and a low-impact area (regions between 37°N and 45°N). The initial investment process for the high-impact area should use scale and the heat-to-power ratio for planning biomass CHP plants according to geographical area and the design energy flow based on latitude to improve the self-sufficiency and energy efficiency of the area.

Microbial community shift under exposure of dredged sediments from a eutrophic bay.

Microbial communities occur in almost every habitat. To evaluate the homeostasis disruption of in situ microbiomes, dredged sediments from Guanabara Bay-Brazil (GB) were mixed with sediments from outside of the bay (D) in three different proportions (25%, 50%, and 75%) which we called GBD25, GBD50, and GBD75. Grain size, TOC, and metals-as indicators of complex contamination-dehydrogenase (DHA) and esterase enzymes (EST)-as indicators of microbial community availability-were determined. Microbial community composition was addressed by amplifying the 16S rRNA gene for DGGE analysis and sequencing using MiSeq platform (Illumina).We applied the quality ratio index (QR) to the GB, D, and every GBD mixture to integrate geochemical parameters with our microbiome data. QR indicated high environmental risk for GB and every GBD mixture, and low risk for D. The community shifted from aerobic to anaerobic profile, consistent with the characteristics of GB. Sample D was dominated by JTB255 marine benthic group, related to low impacted areas. Milano-WF1B-44 was the most representative of GB, often found in anaerobic and sulfur enriched environments. In GBD, the denitrifying sulfur-oxidizing bacteria, Sulfurovum, was the most representative, typically found in suboxic or anoxic niches. The canonical correspondence analysis was able to explain 60% of the community composition variation and exhibit the decrease of environmental quality as the contamination increases. Physiological and taxonomic shifts of the microbial assemblage in sediments were inferred by QR, which was suitable to determine sediment risk. The study produced sufficient information to improve the dredging plan and management.

Assessing the Distribution and Concentration of Heavy Metals in Soils of an Agricultural Frontier in the Brazilian Cerrado

The continuous use of agricultural inputs for grain, fiber, and energy production in the Brazilian savannah can increase heavy metal (HM) concentrations in the soils. In this context, we aimed to determine the natural concentrations and establish the quality reference values (QRVs) of HMs in reference soils of a sedimentary watershed under native vegetation in one of the latest agricultural frontiers of Brazil in order to assess the impact of cultivation on the metal concentrations in cropped soils. Additionally, we studied the spatial variability of HMs and the efficiency of the multivariate analyses to distinguish between natural and anthropogenic sources of metals in the soils. Thirty-two and 30 composite soil samples were collected in areas under agricultural exploration and natural vegetation with minimal anthropic interference (low impact areas), respectively. The QRVs established could be ranked as follows (mg kg−1): Fe (18,700) > V (47.83) > Cr (43.44) > Ba (9.11) > Pb (2.73) > Ni (0.80) > Cu (0.74) > Zn (0.46) > Mo (0.34) > Cd (0.05) > Sb ( Co (< 0.00008). Natural concentrations observed in non-anthropogenic soils are lower than those found in other regions, with the exception of Cr. Also, we found that the mean concentrations of Cd, Cu, Cr, Mo, Mn, Ni, Sb, V, and Zn in agricultural soil were far higher than their background values of the watershed topsoil. Based on our findings, the increased metal concentration in the agricultural soils increases the ecological risk. On the other hand, the mean metal concentrations remain close to the prevention value for soils established by the Brazilian Council for the Environment for agricultural land, which indicates that these areas require monitoring to guarantee foodstuff safety. Our results are useful for public policies not only in the studied area but also worldwide where soils are derived predominantly from sedimentary rocks such as sandstones, siltstones, shales, and limestones.

Global human influence maps reveal clear opportunities in conserving Earth's remaining intact terrestrial ecosystems.

Leading up to the Convention on Biological Diversity Conference of the Parties 15, there is momentum around setting bold conservation targets. Yet, it remains unclear how much of Earth's land area remains without significant human influence and where this land is located. We compare four recent global maps of human influences across Earth's land, Anthromes, Global Human Modification, Human Footprint and Low Impact Areas, to answer these questions. Despite using various methodologies and data, these different spatial assessments independently estimate similar percentages of the Earth's terrestrial surface as having very low (20%–34%) and low (48%–56%) human influence. Three out of four spatial assessments agree on 46% of the non‐permanent ice‐ or snow‐covered land as having low human influence. However, much of the very low and low influence portions of the planet are comprised of cold (e.g., boreal forests, montane grasslands and tundra) or arid (e.g., deserts) landscapes. Only four biomes (boreal forests, deserts, temperate coniferous forests and tundra) have a majority of datasets agreeing that at least half of their area has very low human influence. More concerning, <1% of temperate grasslands, tropical coniferous forests and tropical dry forests have very low human influence across most datasets, and tropical grasslands, mangroves and montane grasslands also have <1% of land identified as very low influence across all datasets. These findings suggest that about half of Earth's terrestrial surface has relatively low human influence and offers opportunities for proactive conservation actions to retain the last intact ecosystems on the planet. However, though the relative abundance of ecosystem areas with low human influence varies widely by biome, conserving these last intact areas should be a high priority before they are completely lost.

Study on pervious concrete pavement mix designs

Increased precipitation in recent years due to the effect of climate change is leading to increased surface runoff and water logging in urban areas while impervious concrete or asphalt covering of urban lands hinders groundwater recharge. However, Pervious Concrete Pavements have the capacity of functioning as a Sustainable Urban Drainage System (SUDS) by allowing surface water to infiltrate downwards through the porous structure of the pavements, thereby minimizing flooding risks, recharging ground water, reducing run off and peak flows, alleviating the precipitation load on overstressed drainage systems, and improving water quality by capturing pollutants. This research provides an overview on pervious concrete mix designs and their effect on strength and permeability. Materials of pervious concrete include those used in conventional concrete, however eliminating the fine aggregate content. Different mix designs have been prepared and tested to understand the behavior of Pervious Concrete and recommend an ideal mix. The findings from the Compressive Strength Test and Standard Test Method for Infiltration Rate of in place Pervious Concrete, investigate the gradually varying properties of pervious concrete with changes in the mix which are reported and discussed. Results indicate that a fine balance between compressive strength and permeability is not possible however pervious concrete pavements can be an acceptable alternative when used in low volume and low impact areas.

A Novel Support Vector Machine Based on Hybrid Bat Algorithm and Its Application to Identification of Low Velocity Impact Areas

The standard support vector machine (SVM) performs poorly on the identification problem of low velocity impact areas due to its lower accuracy rate. Improving SVM’s performance using the bat algorithm (BA) is feasible, but BA has the premature convergence problem. In this study, a hybrid bat algorithm with double mutation operations (DMBA), in which the Cauchy mutation operator and the extremal optimization mutation operator are integrated into BA, is proposed to enhance BA’s ability to jump out of the local optima. Then, a novel SVM based on this hybrid BA, which is called SVM_DMBA, is developed to address the identification problem. Compared with the standard SVM and twelve improved SVM methods which are combined with the standard algorithms, advanced algorithms, and bat variants, the significant performance of SVM_DMBA is validated using UCI datasets. Moreover, to identify low velocity impact areas, SVM_DMBA is applied to the low velocity impact localization system based on fiber Bragg grating (FBG) sensors. The statistical results indicate that SVM_DMBA is a significantly effective method for identifying the low velocity impact areas and generates higher identification accuracy than comparative methods. For 64 low velocity impact areas of $30\,\,\text {mm}\times 30\,\,\text {mm}$ on an aluminium plate, the average identification error obtained by SVM_DMBA is 1.615%.

Global areas of low human impact (\u2018Low Impact Areas\u2019) and fragmentation of the natural world

Habitat loss and fragmentation due to human activities is the leading cause of the loss of biodiversity and ecosystem services. Protected areas are the primary response to this challenge and are the cornerstone of biodiversity conservation efforts. Roughly 15% of land is currently protected although there is momentum to dramatically raise protected area targets towards 50%. But, how much land remains in a natural state? We answer this critical question by using open-access, frequently updated data sets on terrestrial human impacts to create a new categorical map of global human influence (‘Low Impact Areas’) at a 1 km2 resolution. We found that 56% of the terrestrial surface, minus permanent ice and snow, currently has low human impact. This suggests that increased protected area targets could be met in areas minimally impacted by people, although there is substantial variation across ecoregions and biomes. While habitat loss is well documented, habitat fragmentation and differences in fragmentation rates between biomes has received little attention. Low Impact Areas uniquely enabled us to calculate global fragmentation rates across biomes, and we compared these to an idealized globe with no human-caused fragmentation. The land in Low Impact Areas is heavily fragmented, compromised by reduced patch size and core area, and exposed to edge effects. Tropical dry forests and temperate grasslands are the world’s most impacted biomes. We demonstrate that when habitat fragmentation is considered in addition to habitat loss, the world’s species, ecosystems and associated services are in worse condition than previously reported.

Human impact erodes chimpanzee behavioral diversity.

Chimpanzees possess a large number of behavioral and cultural traits among nonhuman species. The "disturbance hypothesis" predicts that human impact depletes resources and disrupts social learning processes necessary for behavioral and cultural transmission. We used a dataset of 144 chimpanzee communities, with information on 31 behaviors, to show that chimpanzees inhabiting areas with high human impact have a mean probability of occurrence reduced by 88%, across all behaviors, compared to low-impact areas. This behavioral diversity loss was evident irrespective of the grouping or categorization of behaviors. Therefore, human impact may not only be associated with the loss of populations and genetic diversity, but also affects how animals behave. Our results support the view that "culturally significant units" should be integrated into wildlife conservation.

The farmland refuge of the last Andalusian Buttonquail population

The last populations of threatened taxa usually survive in low-impacted areas, whose protection and management is critical for its conservation. However, they can also be located in humanized and highly dynamic areas, whose management can be extremely challenging. The Andalusian buttonquail (Turnix sylvaticus sylvaticus) is the critically endangered nominal subspecies of the common buttonquail, a largely unknown species due to its secretive habits. Here, we show how the last Andalusian buttonquail population is restricted to a small, intensively used agricultural area (4,675 ha) in the Atlantic coast of Morocco, where the birds adapt their life cycle to a fast crop rotation. Buttonquails occupy crops in the flowering and fruiting stages, thus changing the preferred crop types along the year, although Alfalfa fields were occupied in all seasons. We used estimated occupancy rates in different crops to obtain seasonal (2017) and year-to-year population estimates (2011, 2014 and 2017). Numbers showed wide seasonal fluctuations between the lowest in winter and the maximum in summer (112–719 individuals). Year-to-year summer estimates also showed wide variations and large uncertainties, ranging between a maximum 1,890 estimated in 2011 and a minimum in 2014 with 492 individuals. The last population estimate available was 596 in 2017. The area is suffering a rapid shift from traditional irrigation farming towards practices more akin to commercial industrial agriculture. The conservation of this critically endangered taxon is highly dependent on the maintenance of traditional farming practices and a rational on-site agricultural modernization.

Uncertainty analysis and robust areas of high and low modeled human impact on the global oceans.

Increasing anthropogenic pressure on marine ecosystems from fishing, pollution, climate change, and other sources is a big concern in marine conservation. Scientists have thus developed spatial models to map cumulative human impacts on marine ecosystems. However, these models are based on many assumptions and incorporate data that suffer from substantial incompleteness and inaccuracies. Rather than using a single model, we used Monte Carlo simulations to identify which parts of the oceans are subject to the most and least impact from anthropogenic stressors under 7 simulated sources of uncertainty (factors: e.g., missing stressor data and assuming linear ecosystem responses to stress). Most maps agreed that high-impact areas were located in the Northeast Atlantic, the eastern Mediterranean, the Caribbean, the continental shelf off northern West Africa, offshore parts of the tropical Atlantic, the Indian Ocean east of Madagascar, parts of East and Southeast Asia, parts of the northwestern Pacific, and many coastal waters. Large low-impact areas were located off Antarctica, in the central Pacific, and in the southern Atlantic. Uncertainty in the broad-scale spatial distribution of modeled human impact was caused by the aggregate effects of several factors, rather than being attributable to a single dominant source. In spite of the identified uncertainty in human-impact maps, they can-at broad spatial scales and in combination with other environmental and socioeconomic information-point to priority areas for research and management.

Morphological variation in the genus Chlorocebus: Ecogeographic and anthropogenically mediated variation in body mass, postcranial morphology, and growth.

Direct comparative work in morphology and growth on widely dispersed wild primate taxa is rarely accomplished, yet critical to understanding ecogeographic variation, plastic local variation in response to human impacts, and variation in patterns of growth and sexual dimorphism. We investigated population variation in morphology and growth in response to geographic variables (i.e., latitude, altitude), climatic variables (i.e., temperature and rainfall), and human impacts in the vervet monkey (Chlorocebus spp.). We trapped over 1,600 wild vervets from across Sub-Saharan Africa and the Caribbean, and compared measurements of body mass, body length, and relative thigh, leg, and foot length in four well-represented geographic samples: Ethiopia, Kenya, South Africa, and St. Kitts & Nevis. We found significant variation in body mass and length consistent with Bergmann's Rule in adult females, and in adult males when excluding the St. Kitts & Nevis population, which was more sexually dimorphic. Contrary to Rensch's Rule, although the South African population had the largest average body size, it was the least dimorphic. There was significant, although very small, variation in all limb segments in support for Allen's Rule. Females in high human impact areas were heavier than those with moderate exposures, while those in low human impact areas were lighter; human impacts had no effect on males. Vervet monkeys appear to have adapted to local climate as predicted by Bergmann's and, less consistently, Allen's Rule, while also responding in predicted ways to human impacts. To better understand deviations from predicted patterns will require further comparative work in vervets.

The Impact of Hurricane Sandy on HIV Testing Rates: An Interrupted Time Series Analysis, January 1, 2011‒December 31, 2013.

Background: Hurricane Sandy made landfall on the eastern coast of the United States on October 29, 2012 resulting in 117 deaths and 71.4 billion dollars in damage. Persons with undiagnosed HIV infection might experience delays in diagnosis testing, status confirmation, or access to care due to service disruption in storm-affected areas. The objective of this study is to describe the impact of Hurricane Sandy on HIV testing rates in affected areas and estimate the magnitude and duration of disruption in HIV testing associated with storm damage intensity.Methods: Using MarketScan data from January 2011‒December 2013, this study examined weekly time series of HIV testing rates among privately insured enrollees not previously diagnosed with HIV; 95 weeks pre- and 58 weeks post-storm. Interrupted time series (ITS) analyses were estimated by storm impact rank (using FEMA’s Final Impact Rank mapped to Core Based Statistical Areas) to determine the extent that Hurricane Sandy affected weekly rates of HIV testing immediately and the duration of that effect after the storm.Results: HIV testing rates declined significantly across storm impact rank areas. The mean decline in rates detected ranged between -5% (95% CI: -9.3, -1.5) in low impact areas and -24% (95% CI: -28.5, -18.9) in very high impact areas. We estimated at least 9,736 (95% CI: 7,540, 11,925) testing opportunities were missed among privately insured persons following Hurricane Sandy. Testing rates returned to baseline in low impact areas by 6 weeks post event (December 9, 2012); by 15 weeks post event (February 10, 2013) in moderate impact areas; and by 17 weeks after the event (February 24, 2013) in high and very high impact areas.Conclusions: Hurricane Sandy resulted in a detectable and immediate decline in HIV testing rates across storm-affected areas. Greater storm damage was associated with greater magnitude and duration of testing disruption. Disruption of basic health services, like HIV testing and treatment, following large natural and man-made disasters is a public health concern. Disruption in testing services availability for any length of time is detrimental to the efforts of the current HIV prevention model, where status confirmation is essential to control disease spread.

IMPROVING THE EFFICIENCY OF AFRICAN RESEARCH ETHICS COMMITTEES AND STANDARDISING ETHICS REVIEW PROCESSES THROUGH AN AUTOMATED REVIEW PLATFORM

BackgroundThe sheer amount of research being conducted in Africa, the under-resourced research ethics committees (RECs), and the lack of modern review technologies has resulted in unprecedented review timelines – with...

Sustained Increase in the Incidence of Acute Decompensated Heart Failure After the 2011 Japan Earthquake and Tsunami

This study investigated the long-term impact of the 2011 Japan earthquake and tsunami on the incidence of acute decompensated heart failure (HF) in the disaster area. This was a population-based study using comprehensive registration for all hospitals within the study area. The standardized incidence ratio (SIR) and 95% confidence interval (CI) for new onset of HF during the disaster year (2011) and postdisaster years (2012 to 2014) were determined. When SIR were compared between the low- and high-impact areas, as defined by the extent of tsunami inundation in residential areas, SIR showed a significant increase in high-impact areas in 2011 (1.67, 95% CI 1.45 to 1.88) and tended to return to baseline in 2012, the first postdisaster year (1.25, 95% CI 1.06 to 1.43). The rate again increased in 2013 (1.38, 95% CI 1.18 to 1.57) and 2014 (1.55, 95% CI 1.35 to 1.75). In low-impact areas, no such increase was apparent during either the disaster year or the postdisaster years. Mean postdisaster period SIR for municipalities significantly correlated with the percentage of tsunami flooding in residential areas (r= 0.52, p <0.05) and with the percentage of refugees within the population (r= 0.74, p <0.01). There was no significant relation between maximum seismic intensity and mean SIR in these municipalities. In conclusion, these results suggest that the catastrophic tsunami but not the earthquake per se resulted in a prolonged increase in the incidence of HF among the general population living in tsunami-stricken areas.

Work-Related Unintentional Injuries Associated With Hurricane Sandy in New Jersey.

We aimed to evaluate the occurrence of work-related injuries after Hurricane Sandy potentially related to response and recovery. Emergency and hospital discharges (patients aged 18-65 years) with a diagnosis of unintentional injury were obtained from the New Jersey Department of Health. Work-related injuries were identified as those with a workers' compensation payer or other work-related codes. Counties were categorized as high-, medium-, or low-impact areas. Poisson regression analysis was used to compare the rate of work-related injury the year following Sandy landfall with the 3 previous years. Total work-related injuries declined the week immediately after Sandy (rate ratio [RR]: 0.85; 95% confidence interval [CI]: 0.69-1.05) and no overall increase was found in the year after Hurricane Sandy. However, high-impact counties showed an elevated risk of work-related injuries in the first and third quarters after Hurricane Sandy among men, especially for blacks and Hispanics. The greatest excesses occurred in the third quarter after the storm, May to July, for falls (RR: 1.30; 95% CI: 1.08-1.57), cut/pierce injuries (RR: 1.24; 95% CI: 1.09-1.40), struck-by injuries (RR: 1.17; 95% CI: 1.02-1.34), and overexertion (RR: 1.26; 95% CI: 1.10-1.44). Hospital data suggested an increase in injuries associated with rebuilding and recovery rather than with initial response. Future efforts aimed at prevention should evaluate the mechanisms and circumstances of injury in more detail. (Disaster Med Public Health Preparedness. 2016;10:394-404).

Distribution and abundance of exotic earthworms within a boreal forest system in southcentral Alaska

Little is known about exotic earthworms (Oligochaeta: Lumbricidae) in Alaska outside its southeastern panhandle. This study documents the distribution of exotic earthworms in the relatively undisturbed Kenai National Wildlife Refuge (KNWR), a large, primarily wilderness refuge in southcentral Alaska. We sampled 69 sites near boat launches, along road corridors, and in low human impact areas > 5 km from the road, finding three species of earthworms ( Dendrobaena octaedra, Dendrodrilus rubidus, and Lumbricus terrestris). Most road sites (90%) and boat launches (80%) contained earthworms; half (50%) of low human impact sites contained earthworms. Distance to roads was the only significant factor in predicting earth worm occurrence; soil pH, soil moisture, leaf litter depth, and vegetation cover were not. The disparate distributions of these three species suggest that within the KNWR road construction and vehicle traffic played a role in dispersal of the widespread, abundant Dendrobaena octaedra and uncommon Dendrodrilus rubidus; bait abandonment appeared to be the primary method of introduction of Lumbricus terrestris. While the distribution of harmful anecic earthworms in KNWR is currently limited, the prohibition of Lumbricus spp. as bait within conservation units in Alaska may be warranted.

Drought stress impacts of climate change on rainfed rice in South Asia

Rice production is threatened by climate change and the productivity of rainfed rice is increasingly challenged. A better understanding of the future trends of rice production associated with climate change is important for improving food security. Rice production under irrigated and rainfed conditions was simulated using the rice crop model ORYZA2000. Simulated rice yield representing crop and environment interaction was used to evaluate the drought impact of climate change on rainfed rice in South Asia. If rainfed rice system was applied in all current rice cultivating areas in South Asia, drought stress could result to yield losses of more than 80 in 22 %, but crop failure was lower than 40 in 73 % of the areas under mild and severe SRES A1B and A2. The spatial patterns of drought stress on rainfed rice were similar under both A1B and A2, and the yield loss and crop failure decreased slightly in the far future (2045 to 2074) in areas where drought risk was high in the near future (2015 to 2044), but the impacts would gradually increase over initially low-impact areas. Both A1B and A2 would shift the best sowing season of rainfed rice to be earlier or later by up to 90 days in 30 years. Appropriate adjustment of sowing season is a major adaptation strategy for rainfed rice production in South Asia to benefit from climate change. In this case, rainfed rice yield could potentially increase by about 10 % in most areas of South Asia associated with 10 to 50 % lower inter-annual variation and slightly higher risk for crop failure.