Km Of Water Research Articles

Land Bridges and Rafting Theories to Explain Terrestrial-Vertebrate Biodiversity on Madagascar.

Madagascar's celebrated land-vertebrate assemblage has long been studied and discussed. How the ancestors of the 30 different lineages arrived on the island, which has existed since 85 Mya and is separated from neighboring Africa by 430 km of water, is a deeply important question. Did the colonizations take place when the landmass formed part of Gondwana, or did they occur later and involve either now-drowned causeways or overwater dispersal (on vegetation rafts or by floating/swimming)? Following a historical review, we appraise the geological-geophysical evidence and the faunal-suite colonization record. Twenty-six of the clades are explained by temporally stochastic overwater dispersals, spanning 69-0 Mya, while two others are considered Gondwanan vicariant relicts. Due to a lack of information, the remaining two groups cannot be evaluated. The findings thus appear to resolve a debate that has rumbled along, with sporadic eruptions, since the mid-1800s.

Multidimensional Evaluation of Traditional Villages in Jiangnan Region, China: Spatial Pattern, Accessibility and Driving Factors

Assessment of the spatial distribution and accessibility of traditional villages is closely related to their development. However, the impacts of spatial heterogeneity on the accessibility of traditional villages remain largely unknown. A total of 644 national-level traditional villages in the Jiangnan region were used to explore the spatial heterogeneity impact with a geographically weighted regression (GWR) model. We found: (1) spatially, the villages exhibit a predominant aggregation distribution pattern with significant local spatial disparities (R < 1, p < 0.01), predominantly originating from the Song and Ming dynasties (59.21%). Their clustering shifts from northeast to southwest, with over 70% of the villages located on slopes ranging from 0° to 20° and within 1 km of water. (2) The accessibility of these villages is generally low, with 85.66% being accessible within 200 ~ 300 min; it decreases concentrically outwards from Changzhou and exhibits clustering autocorrelation characteristics (Moran’s I > 0, Z > 2.58). (3) Road network density, elevation, and slope are significantly correlated with accessibility (p < 0.05), demonstrating pronounced spatial heterogeneity in their effects, with these factors collectively explaining approximately 85% of the accessibility levels. These findings provide a basis for comprehensive planning and categorized strategies for traditional villages.

Evaluation of Physiochemical Qualities and Microbiological Profile of Selected Hand Dug Well in Ado – Ekiti

Water is vital and one of the most important resources to the survival of all livings (both plants and animals). About 97% of the world’s 1.4 billion Cubic km of water is ocean water. Quality water is essential for economic development and ecological balance. However, the scarcity of water is on the increase, hence the need for proper and adequate planning, standard monitoring and proper management of water as one of natural resources. This research evaluates the effect of anthropogenic activities and domestic wastes on surface water quality in Ekiti State University Students’ Residential Area. The study determines water contaminants and the effects of water contamination to the health of students and all other residents in the study area. Primary and secondary sources of data collection were employed in the study. A total of 18 water samples (nine for microbial and physiochemical testing respectively) were obtained from the study area for laboratory analysis where physiochemical and microbiological tests were conducted. For the physiochemical tests, the organoleptic parameters include colours, turbidity, and odours, while the inorganic parameters include nitrate, Conductivity, pH, total dissolved solid, total hardness, total alkalinity, total acidity, chloride, Sulphate (SO4 ), Calcium, Magnesium (Mg +2 ), Arsenic (As), Cadmium (Cd), Chromium (Cr 6+), Copper (Cu+2 ), Iron (Fe+2 ), Lead(Pb), Manganese(Mn+2), Zinc (Zn), Dissolved Oxygen, Total Suspended Solid. Color and Odour of all samples were unobjectionable, pH values ranged from 6.03 – 6.17 with mean of 6.50, Conductivity values ranged from 135.4 – 607µs/cm with a mean value of 282µs/cm, turbidity values ranged from 1.0 – 8.0 NTU with the mean value of 3.8, Total Dissolved Solid (TDS) concentrations ranged from 30.5 – 376 mg/L having a mean of 180 mg/L, Total Hardness , Alkalinity and Total Hardness had respective values which ranged from 26.9 – 102.4 mg/L and 29.4 – 122 mg/L with the mean of 63mg/L and 75g/L respectively, chloride, Sulphate (SO4), Calcium, Magnesium(Mg+2), Arsenic(As), Cadmium (Cd), Chromium (Cr6+), Copper (Cu+2), Iron (Fe+2), Lead(Pb), Manganese(Mn+2), Zinc (Zn), Dissolved Oxygen values ranged from 3.24mg/L to 5.86mg/L, Total Suspended Solid values ranged from 0.058mg/L to 0.628mg/L. All the parameters were lower than limit as recommended by the World Health Organization (WHO) and Nigerian Standard for Drinking Water Quality (NSDWQ).

E&P Notes (October 2022)

E&P Notes (October 2022)

ОЦЕНКА ВОДНОГО ПОТЕНЦИАЛА ТЕРРИТОРИЙ СЕВЕРО-КАВКАЗСКОГО ФЕДЕРАЛЬНОГО ОКРУГА И ЕГО ИСПОЛЬЗОВАНИЯ В ЦЕЛЯХ МЕЛИОРАЦИИ ЗЕМЕЛЬ

Purpose: to assess the territory water potential and the efficiency of its actual use for determining the additional water withdrawal volume required for irrigation of under-irrigated serviced irrigation areas. Materials and methods. The assessment of water resources use and distribution was carried out on the basis of actual data obtained from the land reclamation departments for the period 2016–2020. Changes in the area of actually irrigated lands and data on the planned and actual water withdrawal in general and for irrigation were analyzed. Results. An analysis of the summary indicators of water withdrawal quotas and water resources distribution volumes between water management complex institutions was made. A comparison of water resources supply for all needs and for irrigation with the actual irrigation area was made. In 2020, the total water intake amounted to 6.5 cubic km of water. The total water supply from this volume to reclamation systems for all needs amounted to 4.56 cubic km (70 %), and losses – 1.96 cubic km (30 %). 493.7 thousand hectares, which is 51 % of the actually serviced irrigation areas were irrigated. It was determined that for providing the actually serviced irrigation area, it is necessary to supply additional 1.8 cubic km of water for irrigation. Taking into account transportation losses of 30 %, the water volume taken from natural water sources will be 2.3 cubic km, and the total water intake volume is 8.8 cubic km. That is, it is necessary to increase the total water withdrawal by 26 %. Conclusions. According to the results of the studies, the additional water withdrawal required for irrigation of under-irrigated serviced irrigation areas is 2330 million cubic meters, which is 35.7 % of the actual water intake for 2020. When the irrigated land area is brought up to the design values, the shortage of water resources (198.2 million cubic meters) will be observed only in the Chechen Republic.

Vector acoustic properties of explosive underwater sound

The relation between acoustic pressure and velocity associated with propagating sound from explosive sources is studied. Data originate from the 2017 Sediment Characterization Experiment where the sound source is 38 g SUS, measurement ranges are order 10 km in waters 75 m; and recent experimental studies on the effects of explosive underwater sound on fish off San Diego where the source is 4.7 kg net explosive weight, ranges are order 100 m in waters 20 m. Horizontal components of velocity are resolved into a single radial component and with the vertical component the intensity vector is derived and associated energy streamlines from simulations are presented. It is also shown how radial component of acoustic velocity is phase- locked with pressure, and nearly corresponds to it upon multiplication by the characteristic impedance; including vertical velocity for total velocity magnitude the correspondence with pressure magnitude is within calibration uncertainty. This self-evident finding concerning high-bandwidth signals is worth noting to inform the discussion on the importance of acoustic velocity to fishes. An exception for short ranges is a low-amplitude, narrow band, Scholte wave arrival that decays precipitously away from the water/sediment interface. [Research support by ONR and by the Navy LMR program.]

Landscape-scale effects of homesteads, water, and dingoes on invading chital deer in Australia’s dry tropics

AbstractIdentifying landscape features and processes that facilitate the persistence of populations is particularly important for invasive mammal species, because it can focus management interventions on relatively small areas. We used camera traps to test predictions concerning the relative abundance of invading chital deer (Axis axis) on seven cattle ranches in northern Australia: that abundance of chital deer would be highest near permanent water and near homesteads, and that dingoes (Canis dingo) reduce abundance of chital deer. Distance from the nearest homestead determined deer abundance (as indexed by images per camera-day), with negligible abundance > 4 km from homesteads. In contrast, distance from homestead did not predict abundance of feral pigs (Sus scrofa), macropods, or dingoes. Abundance of chital deer also declined with increasing distance from water, as did feral pig abundance. There was no relationship between either macropod or dingo abundance and distance to water. The abundance of chital deer was unaffected by dingo abundance, but 75–100% of dingo scats collected within 1 km of homesteads contained chital deer. The high abundances of chital deer near homesteads are likely due to increased food quality or quantity, or protection from dingoes, but these hypotheses require further testing. We conclude that homesteads and permanent water are important determinants of the distribution and abundance of invasive chital deer in northern Australia (i.e., they are “invasion hubs” for this species). Our results suggest that, during the dry season, managers should survey for and attempt to control chital deer within 4 km of homesteads and within 3 km of water.

Microsatellite analysis of genetic diversity and genetic structure of the Chinese freshwater mussel Solenaia carinata (Bivalvia: Unionidae)

Abstract The freshwater mussels (Unionidae) in the Yangtze River basin of China are among the most diverse assemblages on Earth. Freshwater mussels provide valuable ecosystem services (e.g. natural water filtration) and economic value (shell, pearls, and food), but are experiencing global declines as a result of pollution, habitat alteration, and overharvest. Despite the diversity and value of freshwater mussels in the Yangtze River basin, relatively little is known about the biology of the many species endemic to the region. Solenaia carinata is an endemic and potentially imperilled freshwater mussel (Bivalvia: Unionidae) in China that is distributed in a single major tributary of the middle Yangtze; the Poyang Lake basin in Jiangxi Province. This study represents the first analyses of the genetic diversity and population genetic structure of S. carinata. Solenaia carinata specimens (n=64) were collected from three sites in large tributary rivers of Poyang Lake. Using 19 polymorphic microsatellite markers, the results showed that S. carinata had a moderate level of genetic diversity (PIC ranged from 0.464 to 0.484), limited evidence of a recent genetic bottleneck, little genetic differentiation (FST ranged from 0.021 to 0.045), high levels of gene flow (Nm ranged from 3.675 to 33.227) and limited genetic structure among the three sampling locations. Given that S. carinata inhabits a highly interconnected system of large rivers and lakes, the results of low differentiation and high gene flow among geographically proximate sampling locations (sites separated by between 8 and 20 km of water) are not surprising. The results indicate that specimens can be used and moved from anywhere across the distribution of S. carinata for the purposes of captive propogation and translocation.

Strike-slip tectonics during the Neoproterozoic–Cambrian assembly of East Gondwana: Evidence from a newly discovered microcontinent in the Indian Ocean (Batavia Knoll)

The first dredge samples recovered from the Batavia Knoll in the eastern Indian Ocean demonstrate it is a rifted continental fragment that now lies submerged in 2km of water between the Perth Abyssal Plain and Wharton Basin, ~1600km offshore Western Australia. This knoll is the second microcontinent to have been discovered in this region, lying ~180km to the NE of Gulden Draak Knoll; both knolls rifted from the Indian margin at c. 104–101Ma during the breakup of East Gondwana. Dredged rocks include granite, granodiorite, charnockite and quartz-rich pegmatite, preserving igneous microstructure and biotite-schlieren. The composite nature of many samples suggests derivation from a felsic igneous complex. This basement is at least partly covered by Late Cretaceous sedimentary strata. Zircon grains from five representative granitoid samples primarily display modified oscillatory zoning and U-Pb data that spread along concordia over ~50–70m.y., suggesting protracted magmatism and Pb-loss during the latest Neoproterozoic–early Cambrian (c. 580–530Ma). Despite the span in U-Pb zircon ages, the primary igneous populations exhibit a relatively narrow range of initial Hf isotopic ratios (Hfi=0.281290–0.281814; εHfi=−41.40 to −23.32). This evolved nature of the Hf signature suggests derivation of melts from ancient crust (TDM2=4.05–2.92Ga) with very limited juvenile input. Plate models based on sparse paleomagnetic data imply significant relative motion between India and Australia during the late Neoproterozoic–Cambrian. We suggest the new isotopic data from the Batavia Knoll granitic rocks, coupled with other regional geological constraints, are consistent with magmatic intrusion and subsequent disturbance of U-Pb systems along a late Neoproterozoic–Cambrian sinistral strike-slip margin related to Gondwana assembly.

Ice swimming and changes in body core temperature: a case study.

Introduction‘Ice Mile’ swimming is a new discipline in open-water swimming introduced in 2009. This case study investigated changes in body core temperature during preparation for and completion of two official ‘Ice Miles’, defined as swimming 1.609 km in water of 5°C or colder, in one swimmer.Case descriptionOne experienced ice swimmer (56 years old, 110.2 kg body mass, 1.76 m body height, BMI of 35.6 kg/m2, 44.8% body fat) recorded data including time, distance and body core temperature from 65 training units and two ‘Ice Miles’.Discussion and evaluationDuring training and the ‘Ice Miles’, body core temperature was measured using a thermoelectric probe before, during and after swimming. During trainings and the ‘Ice Miles’, body core temperature increased after start, dropped during swimming but was lowest during recovery. During training, body core temperature at start was the only predictor (ß = −0.233, p = 0.025) for the increase in body core temperature. Water temperature (ß = 0.07, p = 0.006) and body core temperature at start (ß = −0.90, p = 0.006) explained 61% of the variance for the non-significant decrease in body core temperature. Water temperature (ß = 0.077, p = 0.0059) and body core temperature at finish (ß = 0.444, p = 0.02) were the most important predictors for the lowest body core temperature. In ‘Ice Miles’, body core temperature was highest ~6–18 min after the start (38.3–38.4°C), dropped during swimming by 1.7°C to ~36.5°C and was lowest ~40–56 min after finish. The lowest body core temperature (34.5–35.0°C) was achieved ~100 min after start.ConclusionsIn an experienced ice swimmer with a high BMI (>35 kg/m2) and a high percent body fat (~45%), body core temperature decreased by 1.7°C while swimming and by 3.2–3.7°C after the swim to reach the lowest temperature in an official ‘Ice Mile’. The swimmer suffered no hypothermia during ice swimming, but body core temperature dropped to <36°C after ice swimming. Future athletes intending to swim an ‘Ice Mile’ should be aware that a large body fat prevents from suffering hypothermia during ice swimming, but not after ice swimming.

The fundamental hominin niche in late Pleistocene Central Asia: a preliminary refugium model

AbstractAimWe examine hominin presence in Central Asia during the late Pleistocene in order to identify the abiotic characteristics that best predict site distribution during interglacial and glacial periods. Our goal is to build a preliminary framework for climate‐mediated hominin dispersals in this understudied part of the Old World.LocationTajikistan, Uzbekistan.MethodsWe developed an ecological niche model using presence‐only data to explain the spatial relationship of abiotic variables and hominin locations (n = 15) during glacial–interglacial transitions. The model was evaluated using the Cramér–von Mises goodness‐of‐fit statistic and empiricalK‐function.ResultsHominin locations were spatially aggregated during both glacial and interglacial periods. Of the abiotic variables analysed on a small scale (30‐m resolution), only distance to water differed significantly between glacial and interglacial periods, although most locations were within 5 km of water. At a coarse scale (5‐km resolution), hominin locations appear to have been constrained by low temperatures during glacial periods, but not during interglacials.Main conclusionsHominin groups did not abandon Central Asia during colder periods. This suggests one of three possibly complementary scenarios: (1) late Pleistocene hominin groups had a more flexible behavioural repertoire than previously anticipated and were able to buffer climatic instability culturally; (2) our study area was not as hostile an environment as traditionally considered; and (3) the area examined here represents a refugium during late Pleistocene glaciations.

Tracking fin whales in the northeast Pacific Ocean with a seafloor seismic network

Ocean bottom seismometer (OBS) networks represent a tool of opportunity to study fin and blue whales. A small OBS network on the Juan de Fuca Ridge in the northeast Pacific Ocean in ~2.3 km of water recorded an extensive data set of 20-Hz fin whale calls. An automated method has been developed to identify arrival times based on instantaneous frequency and amplitude and to locate calls using a grid search even in the presence of a few bad arrival times. When only one whale is calling near the network, tracks can generally be obtained up to distances of ~15 km from the network. When the calls from multiple whales overlap, user supervision is required to identify tracks. The absolute and relative amplitudes of arrivals and their three-component particle motions provide additional constraints on call location but are not useful for extending the distance to which calls can be located. The double-difference method inverts for changes in relative call locations using differences in residuals for pairs of nearby calls recorded on a common station. The method significantly reduces the unsystematic component of the location error, especially when inconsistencies in arrival time observations are minimized by cross-correlation.

Dispatches

Dispatches

Current and projected abundance of potential nest sites for cavity‐nesting ducks in hardwoods of the north central United States

AbstractClearing of hardwood forests was widespread in the north central region of the United States at the turn of the 20th century, but largely subsided by the 1920s. Hardwood trees in the region have since regenerated and matured into sizes capable of producing nest cavities suitable for cavity‐nesting ducks. We estimated regional nest‐site abundance for cavity‐nesting ducks during 2008, 2018, and 2028 from cavity density and tree‐abundance estimates obtained at 4 hardwood forest sites in conjunction with Forest Inventory and Analysis data and tree‐growth modeling software from the United States Forest Service (Forest Vegetation Simulator). Land cover data were used to determine area of hardwood forests ≤0.5 km, 0.5–1 km, 1–1.5 km, 1.5–2 km, and &gt;2 km from wetlands and open water available to cavity‐nesting ducks. We estimated 13.2 million, 17.0 million, 19.0 million, and 20.1 million potential duck nest cavities available ≤0.5 km, ≤1 km, ≤1.5 km, and ≤2 km of water, respectively, in the region and predicted nest cavity abundance will increase 41% from 2008 to 2028. Hardwood forests in Indiana, Michigan, Ohio, and Wisconsin currently have the highest abundances of potential nest sites, but cavity‐bearing forests in Minnesota, Michigan, and Wisconsin were more commonly proximate to wetlands and open water. Because current and future estimates indicate sufficient nest sites to support growing cavity‐nesting duck populations in the north central United States, we recommend regional management efforts focus on protecting, restoring, and maintaining quality wetlands in proximity to hardwood forests. © 2011 The Wildlife Society.

Of boats and string: The maritime colonisation of Australia

Abstract For all of hominin history the Australian continent has been separated by at least 70 km of water from other coastlines. Its colonisation about 50,000 years ago can therefore be considered the first true hominin ‘migration’ as opposed to the ‘dispersals’ that happened before it. To the hominins that occupied Sunda before Sahul was colonised by anatomically modern people, the water crossing must have been a barrier. It has been argued that it was the capacity for complex communication associated with modern cognition that allowed this barrier to be transgressed but, why did people use this capacity to build boats and what was the legacy of the associated technology in the subsequent colonisation? The particular maritime physical environment of Wallacea must have been an important factor in this process. Fibre technology, which must have accompanied the mariners who arrived in Sahul, must have played an important role in the continent’s colonisation. This aspect of technology is often ignored in discussions about Sahul Pleistocene technology that suggest its simplicity compared to other regions.

Socio-spatial behaviour of an African lion population following perturbation by sport hunting

Hunting of individuals from a population can affect its demography and socio-spatial parameters. This study provided opportunities to assess such effects, and may help to improve the conservation of populations threatened by conflict and over-use. We treated the periods before and after a moratorium on the trophy hunting of lions around Hwange National Park, Zimbabwe, as a quasi-experimental opportunity to examine changes in lion socio-spatial behaviour during and after perturbation. Changes in ranging behaviour coincided with the release from heavy mortality from hunting outside the Park and were likely to be due to changes in the perturbation regime, rather than factors such as prey abundance, which did not change over the study period. Lion home range sizes decreased in both sexes after the moratorium. Overlap between groups decreased in males but increased in females. Variation in home range size reduced both annually and seasonally for both sexes. Home range centres became more closely distributed. Lions increased the use of denser vegetation cover classes (>30%) and decreased the use of open cover classes (10–30%). Lions increased the use of areas within 2–5 km of water, and decreased their use of the >20 km class. Perturbation therefore appeared to influence the socio-spatial behavior of the lion population. Managers considering the use of moratoria as a conservation tool must anticipate changes in the behavior and distribution of the target species.

Single-path acoustic scintillation results from the Shallow Water 2006 Experiment.

In “sound transmission through a fluctuating ocean,” Flattxe et al. described saturation of a single acoustic path as that path becoming a number of interfering uncorrelated micropaths due to refraction by internal waves. The probability density function of intensity becomes exponential with a scintillation index of 1.0. In deep water, however, full saturation is not achieved due to weak scattering and absorption. Mid‐frequency (1–10 kHz) data from the Shallow Water 2006 Experiment are used to determine single‐path intensity statistics. At a range of 1 km in water 80 m deep, an acoustic path is isolated that went through two upper turning points separated by a single bottom reflection. The data were collected during a period when large nonlinear internal waves were absent. The scintillation index calculated from the data increases with frequency until reaching a maximum of 1.2 around 6 kHz. It then decreases to 1.0, suggesting that single‐path saturation can be achieved at mid‐frequencies in shallow water. The probability density functions of intensity at various frequencies show a trend toward exponential. Because shallow water internal waves are dominated by the first mode, uncorrelated micropaths are an unlikely mechanism for producing the observed saturation. [Work supported by ONR.]

Body temperatures during three long-distance polar swims in water of 0–3 °C

1. We report body temperature responses in a single individual to 3 swims of 1000 m or longer in ice-cold water (0–3 °C) during which he swam the normal crawl stroke with his face in the water whilst wearing only a swimming costume, swimming cap and goggles. 2. He began each swim with a rectal temperature between 37.8 and 38.4 °C, which he maintained above 37.5 °C for more than 20 min. Following a swim of 1.6 km in water of 2–3 °C his lower limb muscle temperature fell to below 32 °C. 3. There was a marked post-swim after-drop in his rectal temperature reaching 33.6 °C 13 min after the 1.6 km swim in water of 2–3 °C. 4. Re-warming in a hot shower usually returned his core temperature to 37 °C within 70–90 min after the swims. Re-warming for 70 min after the 1.6 km swim failed to increase his lower limb muscle temperature. 5. This study may have identified the limiting durations for swimming at 0–3 °C without protective clothing in this specific individual following an intensive programme of acclimatized to such cold water.

Climate‐driven fluctuations in surface‐water availability and the buffering role of artificial pumping in an African savanna: Potential implication for herbivore dynamics

Abstract In arid and semiarid environments surface‐water strongly constrains the distribution and abundance of large herbivores during the dry season. Surprisingly, we know very little about its variability in natural ecosystems. Here we used long‐term data on the dry‐season occurrence of water at individual waterholes to model the surface‐water availability across Hwange National Park, Zimbabwe, under contrasted climatic and management scenarios. Without artificial pumping only 19.6% of the park occurred within 5 km of water under average climatic conditions. However surface‐water availability was strongly influenced by annual rainfall, and over 20 years the variability of the surface area of the park occurring within 5 km of water was slightly larger than the variability of rainfall. This contrasts with the usual buffered response of vegetation production to rainfall fluctuations, and suggests that the variability in dry‐season foraging range determined by surface‐water availability could be the main mechanism regulating the population dynamics of large herbivores in this environment. Artificial pumping increased surface‐water availability and reduced its variability over time. Because changes in surface‐water availability could cause the greatest changes in forage availability for large herbivores, we urge ecologists to investigate and report on the variability of surface‐water in natural ecosystems, particularly where rapid climate changes are expected.

Drilling and operational sounds from an oil production island in the ice-covered Beaufort Sea

Recordings of sounds underwater and in air, and of iceborne vibrations, were obtained at Northstar Island, an artificial gravel island in the Beaufort Sea near Prudhoe Bay (Alaska). The aim was to document the levels, characteristics, and range dependence of sounds and vibrations produced by drilling and oil production during the winter, when the island was surrounded by shore-fast ice. Drilling produced the highest underwater broadband (10-10,000 Hz) levels (maximum= 124 dB re: 1 microPa at 1 km), and mainly affected 700-1400 Hz frequencies. In contrast, drilling did not increase broadband levels in air or ice relative to levels during other island activities. Production did not increase broadband levels for any of the sensors. In all media, broadband levels decreased by approximately 20 dB/tenfold change in distance. Background levels underwater were reached by 9.4 km during drilling and 3-4 km without. In the air and ice, background levels were reached 5-10 km and 2-10 km from Northstar, respectively, depending on the wind but irrespective of drilling. A comparison of the recorded sounds with harbor and ringed seal audiograms showed that Northstar sounds were probably audible to seals, at least intermittently, out to approximately 1.5 km in water and approximately 5 km in air.