Wet Climate Research Articles

Response of phytoplankton composition to environmental stressors under humidification in three alpine lakes on the Qinghai-Tibet Plateau, China.

Owning to their extreme environmental conditions, lakes on the Qinghai-Tibet Plateau have typically displayed a simplistic food web structure, rendering them more vulnerable to climate change compared to lakes in plains. Phytoplankton, undergoing a changing aquatic environment, play a crucial role in the material cycle and energy flow of the food chain, particularly important for the unique fish species of the Tibetan Plateau. To identify the changing environment indexes and determine the response of phytoplankton composition to the environment change in alpine lakes, three lakes-Lake Qinghai, Lake Keluke and Lake Tuosu-were selected as study areas. Seasonal sampling surveys were conducted in spring and summer annually from 2018 to 2020. Our findings revealed there were significant changes in physicochemical parameters and phytoplankton in the three lakes. Bacillariophyta was the predominant phytoplankton in Lake Qinghai from 2018 to 2020, with the genera Synedra sp., Navicula sp., Cymbella sp. and Achnanthidium sp. predominated alternately. Lake Keluke alternated between being dominated by Bacillariophyta and cyanobacteria during the same period. Dolichospermum sp., a cyanobacteria, was prevalent in the summer of 2018 and 2019 and in the spring of 2020. In Lake Tuosu, Bacillariophyta was the predominant phytoplankton from 2018 to 2020, except in the summer of 2019, which was dominated by cyanobacteria. Synedra sp., Oscillatoria sp., Pseudoanabaena sp., Chromulina sp. and Achnanthidium sp. appeared successively as the dominant genera. Analysis revealed that all three lakes exhibited higher phytoplankton abundance in 2018 that in 2019 and 2020. Concurrently, they experienced higher average temperatures in 2018 than in the subsequent years. The cyanobacteria, Bacillariophyta, Chlorophyta and overall phytoplankton increased with temperature and decreased with salinity and NH4-N. Besides, the ratios of cyanobacteria, and the ratios of Bacillariophyta accounted in total phytoplankton increased with temperature. These findings suggest that cyanobacteria and phytoplankton abundance, especially Bacillariophyta, may have an increase tendency in the three alpine lakes under warm and wet climate.

Fire–climate–human dynamics over the last 1800 years in the mesic Araucaria‐Nothofagus forests

AbstractAimFew palaeoenvironmental studies have been performed in Araucaria‐Nothofagus forests, which are highly vulnerable to ongoing threats from climate change and anthropogenic activities. The primary goal of this work is to reconstruct past environmental changes related to fire disturbances over the last 1800 years in Tolhuaca National Park (TNP), Chile.LocationTNP, Araucanian region (38.2°S; 71.8°W), Northwestern Patagonia, Chile.TaxaAraucaria araucana (Araucariaceae), Nothofagus spp. (Nothofagaceae).MethodsWe completed charcoal and pollen analyses to create two new palaeoecological records that span 1800 years. We compared the lake‐based reconstruction with the available local tree‐ring fire scar chronologies from the last 430 years. Using these data, we compute forest index changes, biomass burning trends and compare with estimates of archaeological radiocarbon density. We place our inferences with context of published regional palaeoclimatic proxies from the Patagonian‐Andean region.ResultsOur results showed that fire activity was higher than present between 200 and 1500 CE, with peaks around 200–400 CE and 1100–1500 CE. Periods with high fire activity are associated with reduced forest cover, as Araucaria declined when mixed‐severity fire regime occurred for extended periods. Pollen assemblages suggested a shift from dry to wet climate conditions at 1500 CE, and from 1750 CE onward, the arrival of exotic species reflected the land‐use changes related to forest clearance and transhumance practices.Main ConclusionsThe palaeoenvironmental reconstructions showed changes in vegetation, fire and climate over the past 1800 years in TNP. Wildfires have been the main disturbance process modifying the vegetation structure in the Araucaria and Nothofagus forests. Since 1750 CE intensive post‐Hispanic land‐use changes (forest clearances by fire and logging) took place in the study area, reducing the native vegetation cover. Climate variability, modulated by SAM‐like and ENSO‐like conditions, influenced the fire activity (availability and flammability of fuels), concomitantly with high archaeological density. The recent (after 2000 CE) increase of catastrophic wildfires may negatively affect the conservation strategies of Araucaria‐Nothofagus forests.

Late Holocene high-resolution paleoenvironmental reconstruction from Beaver Lake in the northwest lowlands of the Olympic Peninsula, Washington (USA)

Fire is an essential component of the landscapes and forests of the Pacific Northwest, including the temperate rainforests of the Olympic Peninsula. Previous fire history reconstructions from the peninsula show that fire return intervals varied throughout the postglacial period, primarily in response to climatic changes and corresponding shifts in vegetation. However, much less is known about the fire history of the low-elevation forests of the Olympic Peninsula and the role of cultural fire regimes in these environments. The purpose of this study was to reconstruct the paleoenvironmental history of a low-elevation study site, Beaver Lake, located in the northwestern part of the peninsula. Using macroscopic charcoal, pollen, and sedimentological analyses of a ca. 3440-year-long record, we reconstructed a high-resolution record that shows fire activity was remarkably high during the late Holocene for an area considered part of a temperate rainforest. However, patterns of burning varied throughout the record, with the first third (ca. 3440 to 2350 cal yr BP) and last third (ca. 800 cal yr BP to the present day) recording much higher amounts of fire activity compared to the middle portion (ca. 2350 to 800 cal yr BP), which recorded very little fire activity. Larger and/or more severe fires that likely burned during multi-year droughts correlate with peaks in magnetic susceptibility and pollen trends that indicate substantial geomorphic responses and successional changes in forest structure following these events. Cooler temperatures and a wetter climate, indicated by nearby glacial advancements, may have staved off fire activity during the period of low fire activity. Cultural burning by the Indigenous tribes of the Olympic Peninsula likely contributed to the observed fire activity at Beaver Lake as nearby prairies were managed for resource procurement, indicated in particular by an increase in herbaceous morphotype charcoal during the past 800 years.

Late Pleistocene-Holocene sea level and climate changes in the Gulf of Saros: Evidence from seismostratigraphic record and sediment core data

A detailed record of sea level changes and climate oscillations in the Gulf of Saros during the late Pleistocene to the Holocene is provided by high-resolution seismic reflection profiles and analysis of a sediment core. The seismic stratigraphy reveals the formation of four main depositional units bounded by prominent reflection surfaces, reflecting high sea level variations. The Last Glacial Maximum period in the gulf is associated with the lowstand sea level, forming the deepest marine terrace at −148 m. The increasing sea level due to post-glacial warming was accompanied by the deposition of transgressive units characterized by coastal onlaps together with local channel-fills. This transgressive phase was modulated by three brief still-stands sea levels at 17 cal ka BP, 14.6 cal ka BP and 13.6 cal ka BP, producing the younger marine terraces in the gulf at −135 m, −112 m and −90 m, respectively. A comparison of their depths with the global sea level curve reveals elevation differences with decreasing subsidence rates from the older to younger ages, implying tectonic subsidence along the gulf floor.The close correlation of multi-proxy data from core SAG-22 in the gulf with the northern Aegean and Anatolia data strongly indicates that the timings of the past climate events generally agree with the global and regional climate patterns. The warm climate around the gulf during the late phase of Bølling/Allerød (13.3–12.6 cal ka BP) is represented by high marine biological productivity and improved ventilation in the deeper water due to subsequent transgression. Permafrost formation in the catchment area during the following cold and dry Younger Dryas period (12.6–11.7 cal ka BP) resulted in reduced soil erosion and sediment input to the gulf. Noticeable warming during the Early Holocene between 11.2 cal ka BP and 9.4 cal ka BP is recorded by the multi-proxy data of the core when the enhanced marine biological productivity occurred above the poorly oxygenated deep water column. The climatic deterioration to a cooler and drier phase during the Early to Middle Holocene transition (9.4–7.8 cal ka BP) resulted in intense physical weathering and erosion, causing the highest sedimentation in the gulf. The later period of the Holocene is associated with the formation of two discrete sapropels at 7.8 cal ka BP and 5.4 cal ka BP that were accompanied by warm and wet climates around the gulf.

Performance of Cocoa Fruit (Theobroma cacao L.) at Different Slope Positions in a Wet Tropical Climate

Performance of Cocoa Fruit (Theobroma cacao L.) at Different Slope Positions in a Wet Tropical Climate

Patterns, drivers, and implications of postfire delayed tree mortality in temperate conifer forests of the western United States

AbstractConifer forest resilience may be threatened by increasing wildfire activity and compound disturbances in western North America. Fire refugia enhance forest resilience, yet may decline over time due to delayed mortality—a process that remains poorly understood at landscape and regional scales. To address this uncertainty, we used high‐resolution satellite imagery (5‐m pixel) to map and quantify delayed mortality of conifer tree cover between 1 and 5 years postfire, across 30 large wildfires that burned within three montane ecoregions in the western United States. We used statistical models to explore the influence of burn severity, topography, soils, and climate moisture deficit on delayed mortality. We estimate that delayed mortality reduced live conifer tree cover by 5%–25% at the fire perimeter scale and 12%–15% at the ecoregion scale. Remotely sensed burn severity (1‐year postfire) was the strongest predictor of delayed mortality, indicating patch‐level fire effects are a strong proxy for fire injury severity among surviving trees that eventually perish. Delayed mortality rates were further influenced by long‐term average and short‐term postfire climate moisture deficits, illustrating the impact of drought on fire‐injured tree survival. Our work demonstrates that delayed mortality in conifer forests of the western United States can be remotely quantified at a fine grain and landscape scale, is a spatially extensive phenomenon, is driven by fire–climate–environment interactions, and has important ecological implications.

Top-down control of climate on long-term interactions between fires, tree-cover and soil erosion in a Mediterranean mountain, Corsica

Fire is a potential significant driver of soil erosion in the Mediterranean area, as it results in the partial removal of vegetation and the alteration of organic matter, affecting soil structure and stability. The erosion of particle sizes is influenced by the intensity and duration of rainfall, regulated by disturbance regimes and vegetation cover. We hypothesize that, during the Holocene, high fire frequency and intensity under precipitation control may have contributed to soil erosion, while plant cover and composition could have mitigated it. This plant cover, in turn, might have been influenced by biomass burning. To test this hypothesis, we conducted a detailed analysis of sediments spanning the last 11,500 years from a small mountain lake, Corsica, situated in the black pine forest belt. The high temporal resolution analysis (∼10 years per sample), used granulometry and loss-on-ignition as proxies for erosion and ecosystem productivity in both the lake and watershed, and fire and plant macroremains as fire and tree cover proxies, respectively. The correlation between particle size and the contents of organic or mineral matter with mean fire return intervals (FRI) revealed significant patterns. Long fire intervals were associated with more fine and coarse sands, whereas short mean FRI positively correlated with clay and, fine and coarse silt, along with higher total mineral and organic matter contents. These findings suggest that fires were more frequent when rain duration was sustained but runoff intensity was lower. Conversely, wildfires were less frequent during intense runoff periods (wetter climate). Unlike fire frequency, fire severity did not correlate with erosion, and tree cover and plant richness had minimal to no effect. The 8.2 kyr event was characterized by runoff transporting primarily coarse sands, i.e. a dry period with very intense rains. This suggests that the system is primarily top-down controlled by climate. Multimillennial erosion trends are influenced by fire frequency and precipitation regimes, whereas vegetation does not seem to have a mitigating effect on this process.

The impact of climate change on the agriculture and the economy of Southern Gaul: New perspectives of agent-based modelling.

What impact did the Roman Climate Optimum (RCO) and the Late Antique Little Ice Age (LALIA) have on the rise and fall of the Roman Empire? Our article presents an agent-based modelling (ABM) approach developed to evaluate the impact of climate change on the profitability of vineyards, olive groves, and grain farms in Southern Gaul, which were the main source of wealth in the roman period. This ABM simulates an agroecosystem model which processes potential agricultural yield values from paleoclimatic data. The model calculates the revenues made by agricultural exploitations from the sale of crops whose annual volumes vary according to climate and market prices. The potential profits made by the different agricultural exploitations are calculated by deducting from the income the operating and transportation costs. We conclude that the warm and wet climate of the Roman period may have had an extremely beneficial effect on the profitability of wine and olive farms between the 2nd century BCE and the 3rd century CE, but a more modest effect on grain production. Subsequently, there is a significant decrease in the potential profitability of farms during the Late Antique Little Ice Age (4th-7th century CE). Comparing the results of our model with archaeological data enables us to discuss the impact of these climatic fluctuations on the agricultural and economic growth, and then their subsequent recession in Southern Gaul from the beginning to the end of antiquity.

Evaluation of per- and polyfluoroalkyl substances (PFAS) in landfill liquids from Pennsylvania, Colorado, and Wisconsin

Perand polyfluoroalkyl substances (PFAS) have been measured in aqueous components within landfills. To date, the majority of these studies have been conducted in Florida. This current study aimed to evaluate PFAS concentrations in aqueous components (leachate, gas condensate, stormwater, and groundwater) from four landfills located outside of Florida, in Pennsylvania, Colorado, and Wisconsin (2 landfills). The Pennsylvania landfill also provided the opportunity to assess a leachate treatment system. Sample analyses were consistent across studies including the measurements of 26 PFAS and physical-chemical parameters. For the four target landfills, average PFAS concentrations were 6,900, 22,000, 280, and 260 ng L−1 in the leachate, gas condensate, stormwater, and groundwater, respectively. These results were not significantly different than those observed for landfills in Florida except for the significantly higher PFAS concentrations in gas condensate compared to leachate. For on-site treatment at the Pennsylvania landfill, results suggest that the membrane biological bioreactor (MBBR) system performed similarly as aeration-based leachate treatment systems at Florida landfills resulting in no significant decreases in ∑26PFAS. Overall, results suggest a general consistency across US regions in PFAS concentrations within different landfill liquid types, with the few differences observed likely influenced by landfill design and local climate. Results confirm that leachate exposed to open air (e.g., in trenches or in treatment systems) have lower proportions of perfluoroalkyl acid precursors relative to leachate collected in enclosed pipe systems. Results also confirm that landfills without bottom liner systems may have relatively higher PFAS levels in adjacent groundwater and that landfills in wetter climates tend to have higher PFAS concentrations in leachate.

Oak leaf morphology may be more strongly shaped by climate than by phylogeny

Key messageDespite been grown under the same climate, oak species are able to correlate with looser, but still identifiable, leaf morphological syndromes, composed by morphological traits with an ecological role in their respective macroclimates.ContextEnvironmental restrictions imposed by climate have been shown to modulate leaf morphology. A reduction of leaf area in hot and dry climates reduces overheating because of a thinner boundary layer. Lobed shapes enhance hydraulic conductivity and faster cooling. Elongated leaves drain more quickly under high precipitation. Trichomes may help to reduce the effects of excessive sun exposure in hot and dry environments. Leaf mass per area (LMA) increases in stressful environments.AimTo assess the influence of global climate and clade on oak leaf syndromes comprising morphological traits with ecological roles.MethodsWe analyzed seven morphological traits in 141 oak species grown in a botanical garden, characterized into five macroclimates, and explored the partial effects of clade and climate.ResultsWe found significant associations between macroclimate and every morphological trait measured. Temperate species tend to have large, obovate, lobed, malacophyllous leaves. Species occurring in dry habitats usually present small, rounded, pubescent, sclerophyllous leaves. Warm and wet climates induce the development of slender, lanceolate, glabrous leaves with an acuminate apex.ConclusionThe functional roles of the different morphological traits are partially confirmed in genus Quercus as a response to the different macroclimates, where different leaf syndromes can be distinguished.

Evolution of winter precipitation in the Nile river watershed since the last glacial

Abstract. Between 14.5 and 5 ka, the Sahara was vegetated owing to a wet climate during the African humid period. However, the climatic factors sustaining the “green Sahara” are still a matter of debate. Particularly the role of winter precipitation is poorly understood. Using the stable hydrogen isotopic composition (δD, where D stands for deuterium) of high molecular weight (HMW) n-alkanoic acids in a marine sediment core from the eastern Mediterranean, we provide a continuous record for winter precipitation in the Nile river delta spanning the past 18 kyr. Pairing the data with δD records from HMW n-alkanes from the same core, we show that HMW n-alkanoic acids constantly derived from the delta, while the HMW n-alkanes also received significant contributions from the headwaters between ∼ 15–1 ka when fluvial runoff enhanced. This enables us to reconstruct the evolution of Mediterranean (winter) and monsoonal (summer) rainfall in the Nile river watershed in parallel. In the delta, the Heinrich stadial 1 (HS1) evolved in two phases, with a dry episode between ∼ 17.5–16.0 ka, followed by wet conditions between ∼ 16–14.5 ka. Winter rainfall enhanced substantially between 11–6 ka, lagging behind the intensification of the summer monsoon by ca. 3 kyr. Heavy winter rainfall resulted from a southern position of the Atlantic storm track combined with elevated sea surface temperatures in the eastern Mediterranean, reinforcing local cyclogenesis. We show that during the green Sahara, monsoon precipitation and Mediterranean winter rainfall were both enhanced and infer that the winter rainfall zone extended southwards, delivering moisture to the Sahara. Our findings corroborate recent hypotheses suggesting that winter rains that extended southward were a crucial addition to the northward displacement of the summer monsoon in helping to sustain a green Sahara.

Responses of air-conditioning loads to climate change and its impact on carbon emissions in the hot summer and warm winter climate

Energy consumption of air-conditioning in wet and hot climates is not only for cooling but, to a large extent, for dehumidification. Taking urban agglomeration in the Pearl River Delta region as a case study, this study analysed the cooling and dehumidification loads during the past 20 years. In addition, the impacts of cooling and dehumidification loads on carbon emissions were determined. The results showed that there was large spatial heterogeneity in the variations of the cooling and dehumidification loads. The cooling design loads in 1991–2020 was increased 1.83% to 5.56% compared to those in 1971–2000, while the loads for dehumidification was decreased 0.92% to 5.5%. Carbon emissions from cooling were increased, exceeding the carbon reduction from dehumidification, which leads to a weak increase in total carbon emissions. This study revealed that air-conditioning design should fully consider climate change impact by separating cooling and dehumidification loads, increasing the cooling load to avoid insufficient air-conditioning output but reducing the dehumidification load to promote energy efficiency of the air-conditioning system and to reduce carbon emissions. More importantly, an assessment of design loads with climate change in city or small scales should be made before determining summer air-conditioning system design capacity.

Exploring the food-energy-water nexus in coupled natural-human systems under climate change with a fully integrated agent-based modeling framework

Managing water resources to meet increasing energy and food demands while maintaining environmental sustainability under climate change is a major challenge, especially when this nexus occurred in a coupled natural–human system (CNHS), where heterogeneous human activities affect the natural hydrologic cycle and vice versa. The relevant research has been limited by the lack of models that can effectively integrate human dynamics and hydrologic conditions with spatial details to examine co-evolutionary systems. To address this challenge, this paper develops a modeling framework that integrates an agent-based model (ABM; human behavior model) into a large-scale, process-based distributed hydrologic model to simulate human decisions endogenously in the hydrologic cycle. We then apply the Decision Scaling approach, an ex-post scenario analysis method, with our integrated model to study the bidirectional feedback of the CNHS under future changing climate conditions. With the Columbia River Basin (CRB) selected as the case study area, the calibration results show that the integrated model can simultaneously capture the historical irrigated water consumption and streamflow dynamics. Modeling results show that the trade-off between irrigated water consumption, hydropower generation, and streamflow will become more pronounced under hotter and wetter climate conditions at both the entire basin and regional (states and provinces) levels. Special attention should be given to “temperature thresholds” of different regions when the trade-off pattern started. The trade-off results can potentially inform the Columbia River Treaty renegotiation and provide insights for long-term water management policies.

Subalpine tall-herb vegetation in Bulgaria: diversity and ecology

Class Mulgedio-Aconitetea comprises plant communities that develop primarily in the upper montane to subalpine vegetation belts. It is vegetation where tall herb species (forbs, ferns, grasses) occur dominantly; in the Balkans, it was studied only marginally. In this article, based on floristic composition we assess two questions: (1) what is the diversity of the class Mulgedio-Aconitetea in Bulgaria and (2) what environmental factors are responsible for the vegetation assemblages in the area? We analyzed 387 plots. We created an expert system that classifies this vegetation and tested environmental variables for their influence on these vegetation types. In total, 15 associations and one uncategorized community were classified using the Braun-Blanquet approach. The length of the growing season (number of growing degree days > 0 °C) and climate moisture have a significant effect on the vegetation. Disturbance severity, disturbance frequency and reaction have influence over the species scores. Moreover, all variables significantly differed between the vegetation types.

Paddy Drying Technologies: A Review of Existing Literature on Energy Consumption

This study explores the existing literature on specific energy consumption (SEC) use for paddy drying and consolidates all relevant data for comparisons across technologies. Energy consumption data for a range of drying technologies are consolidated from published literature and normalized to enable comparison. A large proportion of the source data are generated from operational performance in industrial or laboratory settings, while the remainder is derived from computer simulations. The SEC of paddy drying is driven primarily by technology type; however, operational factors (such as the system size, temperature, and airflow) and external factors (such as the local climate and paddy moisture content) also heavily influence system energy use. The results of our analysis show that the industrial drying technologies explored in this study have an average SEC of 5.57 ± 2.21 MJ/kg, significantly lower than the 20.87 ± 14.97 MJ/kg observed in a laboratory setting, which can potentially be attributed to differences in processing capacity. Multi-stage drying typically has higher energy efficiency when tempering stages are incorporated. The self-circulating design of some drying systems may provide additional opportunities for heat exchange, leading to efficient drying performance without the need for a separate tempering stage. Beyond traditional methods, we have observed a notable shift towards solar-assisted and infrared drying technologies in laboratory settings, reflecting an increasing interest in sustainable and efficient drying solutions. In summary, this review consolidates SEC data for rice drying technologies, analyzes the energy intensity and performance of each drying technology, and identifies data gaps that might be addressed in future research.

Influence of microclimate and forest management on bat species faced with global change.

Climate refugia, areas where climate is expected to remain relatively stable, can offer a near-term safe haven for species sensitive to warming temperatures and drought. Understanding the influence of temperature, moisture, and disturbance on sensitive species is critical during this time of rapid climate change. Coastal habitats can serve as important refugia. Many of these areas consist of working forestlands, and there is a growing recognition that conservation efforts worldwide must consider the habitat value of working lands, in addition to protected areas, to effectively manage large landscapes that support biodiversity. The sensitivity of forest bats to climate and habitat disturbance makes them a useful indicator taxon. We tested how microclimate and forest management influence habitat use for 13 species of insectivorous bats in a large climate refugium in a global biodiversity hotspot. We examined whether bat activity during the summer dry season is greater in forests where coastal fog provides moisture and more stable temperatures across both protected mature stands and those regularly logged. Acoustic monitoring was conducted at a landscape scale with 20 study sites, and generalized linear mixed models were used to examine the influence of habitat variables. Six species were positively associated with warmer nighttime temperature, and 5 species had a negative relationship with humidity or a positive relationship with climatic moisture deficit. Our results suggest that these mammals may have greater climate adaptive capacity than expected, and, for now, that habitat use may be more related to optimal foraging conditions than to avoidance of warming temperatures and drought. We also determined that 12 of the 13 regionally present bat species were regularly detected in commercial timberland stands. Because forest bats are highly mobile, forage over long distances, and frequently change roosts, the stewardship of working forests must be addressed to protect these species.

Amplified Extreme Floods and Shifting Flood Mechanisms in the Delaware River Basin in Future Climates

AbstractHistorical records in the Delaware River Basin reveal complex and spatially diverse flood generating mechanisms influenced by the region's mountains‐to‐plains gradients. This study focuses on predicting future flood hazards and understanding the underlying drivers of changes across the region. Using a process‐based hydrological model, we analyzed the hydrometeorological condition of each historical and future flood event. For each event, at the subbasin scale, we identified the dominant flood generating mechanism, including snowmelt, rain‐on‐snow, short‐duration rain, and long‐duration rain. The rain‐induced floods are further categorized based on the soil's Antecedent Moisture Condition (AMC) before the event, whether dry, normal, or wet. Our historical analysis suggests that rain‐on‐snow is the primary flood mechanism of the Upper Basin. Although most frequent, the magnitude of rain‐on‐snow floods is often less severe than short rain floods. In contrast, historical floods in the Lower Basin are primarily caused by short rain under normal AMC. Given the uncertainties in climate projections, we used an ensemble of future climate scenarios for flood projections. Despite variations in regional climate projections, coherent perspectives emerge: the region will shift toward a warmer, wetter climate, with a projected intensification of extreme floods. The Upper Basin is projected to experience a marked decrease in rain‐on‐snow floods, but a substantial increase in short rain floods with wet AMC. The largest increase in flood magnitude will be driven by short rains with wet AMC in the Upper Basin and by short rains with normal AMC in the Lower Basin.

Weathering Incongruence in Mountainous Mediterranean Climates Recorded by Stream Lithium Isotope Ratios

AbstractLithium isotope ratios (δ7Li) of rivers are increasingly serving as a diagnostic of the balance between chemical and physical weathering contributions to overall landscape denudation rates. Here, we show that intermediate weathering intensities and highly enriched stream δ7Li values typically associated with lowland floodplains can also describe small upland watersheds subject to cool, wet climates. This behavior is revealed by stream δ7Li between +22.4 and +23.5‰ within a Critical Zone observatory located in the Cévennes region of southern France, where dilute stream solute concentrations and significant atmospheric deposition otherwise mask evidence of incongruence. The water‐rock reaction pathways underlying this behavior are quantified through a multicomponent, isotope‐enabled reactive transport model. Using geochemical characterization of soil profiles, bedrock, and long‐term stream samples as constraints, we evolve the simulation from an initially unweathered granite to a steady state weathering profile which reflects the balance between (a) fluid infiltration and drainage and (b) bedrock uplift and soil erosion. Enriched stream δ7Li occurs because Li is strongly incorporated into actively precipitating secondary clay phases beyond what prior laboratory experiments have suggested. Chemical weathering incongruence is maintained despite relatively slow reaction rates and moderate clay accumulation due to a combination of two factors. First, reactive primary mineral phases persist across the weathering profile and effectively “shield” the secondary clays from resolubilization due to their greater solubility. Second, the clays accumulating in the near‐surface profile are relatively mature weathering byproducts. These factors promote characteristically low total dissolved solute export from the catchment despite significant input of exogenous dust.

Penyuluhan dan Pemberian Obat Cacing Sebagai Upaya Pencegahan Kecacingan Bagi Siswa Kelas IV/A di UPT SPF SD Negeri Pannara

Intestinal diseases caused by transmission from worms as a source of helminthiasis generally occur in areas with subtropical and tropical climate conditions which have a wet climate and lack of awareness among the public regarding maintaining health and sanitation of the surrounding environment. Around 60 percent of Indonesians experience worm infections. The largest age group is 5-14 years old. The prevalence figure is 60 percent, 21 percent of which attack elementary school age children. This disease can be spread by eggs in human waste found in soil and water, therefore awareness of clean and sanitary living is very influential, the process or pattern of feces disposal is also very influential in the spread of this worm. The high rate of soil contamination by Ascaris, which reaches >70%, can also be caused by feces that are thrown anywhere, such as in bushes or around houses close to where you live. Preventing recurrent infections is very important by practicing clean and healthy living habits such as avoiding contact with soil that may be contaminated with human feces, washing hands with soap and water before handling food, protecting food from soil and washing or heating food that falls on the floor. Several researchers have shown that school age is a group that is often affected by worm infections because they are often in contact with soil. Apart from the government, the role of teachers and parents is very important in providing understanding or knowledge about worms so that they are more disciplined. The aim of community service is to provide knowledge and understanding to class IV/A students at SD N Pannara regarding the dangers of worms and how to prevent them and administer worm medicine.

STUDY OF MODERN TROPICAL ARCHITECTURAL DESIGN CONCEPT IN VERTICAL RESIDENCE

Indonesia is a country with a wet tropical climate with high rainfall intensity and short dry season. Indonesia is also one of the archipelagic countries which is quite densely populated, this density makes the demand for residential housing increasing every year. The solution to overcome these problems is to create vertical residences, or commonly referred to as flats, apartments, and condominiums. However, with the tropical climate conditions in Indonesia, vertical housing has more challenges in overcoming the problem of residential temperature due to areas that are more exposed to the sun. Therefore, this study aims to examine the quality of the vertical occupancy of Kampung Akuarium Flats against tropical climatic conditions. This research method is carried out by describing the condition of the building against the parameters of a tropical climate-based dwelling. The results of the study show that the design applied has climatic factors and can meet the needs of residential density in Indonesia.