Remote Desert Research Articles

Application of the Spatial Auto-Correlation Method for Shear-Wave Velocity Studies Using Ambient Noise

Ambient seismic noise or microtremor observations used in spatial auto-correlation (SPAC) array methods consist of a wide frequency range of surface waves from the frequency of about 0.1 Hz to several tens of Hz. The wavelengths (and hence depth sensitivity of such surface waves) allow determination of the site S-wave velocity model from a depth of 1 or 2 m down to a maximum of several kilometres; it is a passive seismic method using only ambient noise as the energy source. Application usually uses a 2D seismic array with a small number of seismometers (generally between 2 and 15) to estimate the phase velocity dispersion curve and hence the S-wave velocity depth profile for the site. A large number of methods have been proposed and used to estimate the dispersion curve; SPAC is the one of the oldest and the most commonly used methods due to its versatility and minimal instrumentation requirements. We show that direct fitting of observed and model SPAC spectra generally gives a superior bandwidth of useable data than does the more common approach of inversion after the intermediate step of constructing an observed dispersion curve. Current case histories demonstrate the method with a range of array types including two-station arrays, L-shaped multi-station arrays, triangular and circular arrays. Array sizes from a few metres to several-km in diameter have been successfully deployed in sites ranging from downtown urban settings to rural and remote desert sites. A fundamental requirement of the method is the ability to average wave propagation over a range of azimuths; this can be achieved with either or both of the wave sources being widely distributed in azimuth, and the use of a 2D array sampling the wave field over a range of azimuths. Several variants of the method extend its applicability to under-sampled data from sparse arrays, the complexity of multiple-mode propagation of energy, and the problem of precise estimation where array geometry departs from an ideal regular array. We find that sparse nested triangular arrays are generally sufficient, and the use of high-density circular arrays is unlikely to be cost-effective in routine applications. We recommend that passive seismic arrays should be the method of first choice when characterizing average S-wave velocity to a depth of 30 m (Vs30) and deeper, with active seismic methods such as multichannel analysis of surface waves (MASW) being a complementary method for use if and when conditions so require. The use of computer inversion methodology allows estimation of not only the S-wave velocity profile but also parameter uncertainties in terms of layer thickness and velocity. The coupling of SPAC methods with horizontal/vertical particle motion spectral ratio analysis generally allows use of lower frequency data, with consequent resolution of deeper layers than is possible with SPAC alone. Considering its non-invasive methodology, logistical flexibility, simplicity, applicability, and stability, the SPAC method and its various modified extensions will play an increasingly important role in site effect evaluation. The paper summarizes the fundamental theory of the SPAC method, reviews recent developments, and offers recommendations for future blind studies.

Groundwater sources assessment for sustainable supply through photovoltaic water pumping system, in M’zab valley, Ghardaia

The solar photovoltaic water pumping system seems to be the best suited technology to supply water for domestic usage, in the remote desert areas. The Algerian high plateaus and Sahara are the main candidate regions. However, the system performance optimality is generally affected by different dynamic variability parameters, in particular solar radiation and ambient temperature. Nevertheless, other parameters have an important impact on the system performances; as the provided/required water volumes, spatial characteristics of the area, the kind and type of crops, as well as the techniques adopted in collecting and conducting water. In this view, a survey study on spatial area of the M’Zab valley, Ghardaia, has been conducted, including the assessment of the groundwater source behavior. The goal was to select the appropriate wells suitable for standalone PVWPS installations. Accordingly, a field investigation has been carried out throughout different locations of the M’Zab valley to determine the hydraulic structure of the water table and the spatial characteristics distribution of the region. According to the statistical data, obtained, previously, it has been averred that the valley involves abundant water table within static average between 100 and 150 m, on upstream and between 50 and 80 m on downstream. The phreatic water table is reached between 20 and 50 m, as medium averages, whereas, the Ben-Isguen, Bounoura and AL-Atteuf zones are considered to be the suitable for PVWPS installations.

A new species of frog-eyed gecko, genus Teratoscincus Strauch, 1863 (Squamata: Sphaerodactylidae), from southeastern Iran

Herein we describe a new species of Teratoscincus Strauch, 1863 from remote desert areas of the Sistan and Baluchistan Province in southeastern Iran. Based on morphological characters, this species, Teratoscincus sistanense sp. n., has a close relationship with T. microlepis and is distinct from all other members of its genus by the number of small scales around the midbody. We provide information about the ecology, biology and conservation of this new species. A comparison with the other three Iranian species of Teratoscincus and an updated key to this genus in Iran are presented.http://www.zoobank.org/urn:lsid:zoobank.org:pub:77F54322-6CCA-46F1-A74B-B8A75E1F1F8D

Observational Evidence for Desert Amplification Using Multiple Satellite Datasets

Desert amplification identified in recent studies has large uncertainties due to data paucity over remote deserts. Here we present observational evidence using multiple satellite-derived datasets that desert amplification is a real large-scale pattern of warming mode in near surface and low-tropospheric temperatures. Trend analyses of three long-term temperature products consistently confirm that near-surface warming is generally strongest over the driest climate regions and this spatial pattern of warming maximizes near the surface, gradually decays with height, and disappears in the upper troposphere. Short-term anomaly analyses show a strong spatial and temporal coupling of changes in temperatures, water vapor and downward longwave radiation (DLR), indicating that the large increase in DLR drives primarily near surface warming and is tightly associated with increasing water vapor over deserts. Atmospheric soundings of temperature and water vapor anomalies support the results of the long-term temperature trend analysis and suggest that desert amplification is due to comparable warming and moistening effects of the troposphere. Likely, desert amplification results from the strongest water vapor feedbacks near the surface over the driest deserts, where the air is very sensitive to changes in water vapor and thus efficient in enhancing the longwave greenhouse effect in a warming climate.

Building the World's Longest Heated Pipeline—A Technology Application Review

The world depends on oil for much of its energy needs and global demand for oil is forecast to increase significantly in the future as countries such as China and India continue to develop Much of the world's conventional or “easy” oil sources have already been located and developed, so oil companies are increasingly turning to more difficult nonconventional oil sources that require innovative technology to be developed successfully. Often it is the physical properties of the oil that define it as nonconventional, such as being unusually heavy or viscous or containing a high percentage of wax, presenting difficult flow assurance and transportation problems that must be overcome. This paper describes the development of an Indian oil field containing a kind of oil so waxy that it is solid at ambient temperatures, requiring the construction of the world's longest heated pipeline to transport the waxy crude more than 600 km from a remote desert location to a coastal refining hub. The topics covered include the evaluation of various transportation solutions, selection of a skin effect heating system, thermal insulation, power sources and distribution, challenges associated with the design and construction, and lessons learnt that could enhance the safety and reliability of future projects.

A brief history of exploration in Lechuguilla Cave in New Mexico, USA

Lechuguilla Cave, a complex three-dimensional cave with a single known entrance, is located in remote desert terrain in Carlsbad Caverns National Park, in southeastern New Mexico, USA. The Guadalupe Mountains there contain uplifted limestone and dolomite rock in the Permian-age Capitan Reef complex. Hundreds of caves have been found in this region, but Lechuguilla Cave greatly exceeds the size of all others known. It was only a small pit mined for bat guano in the early twentieth century. In the 1970s the Cave Research Foundation performed digs at the bottom, where profuse air movement had been noted in the debris. This work ceased but another team of cavers visited in 1984, hearing and feeling the significant air, and began a digging project approved by the Park. The cavers dug into continuing passage in 1986. It was explored in three major branches, generally trending west/southwest to east/northeast, parallel to the reef face, with north-south connections along deep rift features. Depositional and corrosional events during sulfuric-acid speleogenesis created remarkable speleothems and speleogenesis, and the cave has often been called “the Jewel of the Underground”. The rapidly growing cave passed 80 km of surveyed length by 1990. Within the first ten years of exploration, 28 large-scale expeditions led to the cave reaching 113 km in length. From 1997 to 2013, 109 additional kilometers were mapped with smaller teams of up to 12 cavers per expedition. Exploration and mapping is now done in three to five expeditions per year, and recent work has focused on climbs and smaller leads such as tight crawls and fissures that were previously passed. Significant discoveries continue to be found using these techniques. The cave reaches a depth of 475 m and has been mapped to over 222 km in length. Exploration to the extreme ends is efficiently done with multi-day expeditions, using established camps in each branch. Cavers from the United States and dozens of other countries have been involved in this mapping project. The cave now has more than 35,000 survey stations, and the complexity of the maze of passages creates significant challenges for cartographers. Based on ever-present airflow and porosity of the bedrock, it is expected that this cave will continue to surprise and delight explorers and speleo-scientists in the future.

9. Seashells in the Jordanian Desert: a Cross-Cultural Analysis

The remains of ancient communities have been found at Wadi Ramm and Humayma, Jordan in the midst of what is now the Jordanian desert. In past times these sites were located along caravan routes and were populated by Nabataean, Roman, Byzantine, and early Islamic peoples. Despite the fact that these sites are located tens of kilometers from the seashore, seashells are frequently found in the layers associated with the different population groups. As of yet, shells from the 1996-1997 excavations at Wadi Ramm and from the 2008-2010 excavations at Humayma have not received in depth analyses allowing them to be correctly identified, quantified, and associated with significant archaeological contexts. Archaeomalacology (the study of molluscs in archaeological contexts) is a vital part of deciphering ancient human diet and activity. It is also critical in determining past environments and transportation systems. Clearly these shells came from the sea, but how did they get to these remote desert locales? Based on the preliminary descriptions provided by the field excavators, the photographs of the Wadi Ramm shells, and the actual Humayma shells which are at Queen’s, I am creating a catalogue to identify, describe, and quantify the variety of mollusc species present. This catalogue incorporates all of the significant data in one place, thus allowing me to look for patterns in the frequency, condition, and probable function of the shells. This analysis will lead to a better understanding of the diet and cultural practices of the different ancient inhabitants at Wadi Ramm and Humayma.

Review: California’s Channel Islands: A History by Frederic Caire Chiles

Book Review| February 01 2016 Review: California’s Channel Islands: A History by Frederic Caire Chiles California’s Channel Islands: A History. By Frederic Caire Chiles. (Norman: University of Oklahoma Press, 2015. 296 pp. $19.95 paper.). Karen K. Swope Karen K. Swope Karen K. Swope is a historical archaeologist with over 30 years experience throughout the U.S. West, focusing in southern California. She holds a Ph.D. in anthropology from the University of California, Riverside. Her research interests include adaptations particular to remote desert sites including homesteads and industrial sites. Search for other works by this author on: This Site PubMed Google Scholar Southern California Quarterly (2016) 98 (1): 125–127. https://doi.org/10.1525/ucpsocal.2016.98.1.125 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Cite Icon Cite Search Site Citation Karen K. Swope; Review: California’s Channel Islands: A History by Frederic Caire Chiles. Southern California Quarterly 1 February 2016; 98 (1): 125–127. doi: https://doi.org/10.1525/ucpsocal.2016.98.1.125 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentSouthern California Quarterly Search This content is only available via PDF. © 2016 by The Historical Society of Southern California2016 Article PDF first page preview Close Modal You do not currently have access to this content.

An Overview of Research on Optimization of Integrated Solar/Wind Power Generation Systems

Although transmission systems are able to cover most of the areas in many countries, there are still some isolated areas such as rural counties and remote desert lands where grid power cannot be accessed. Therefore, a reliable and economical power supply scheme is required to solve the problem. One of them combines wind/solar power generation with the support of storage system. This paper is to give an overview of the optimization methodologies about the wind/solar stand-alone system supported by storage systems or integrating with other renewable or conventional power generation sources. It is shown that continued research and optimization methodology in this area are still in great need for performance improvement.

Dust aerosol emission over the Sahara during summertime from Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) observations

Dust aerosols are an important component of the climate system and a challenge to incorporate into weather and climate models. Information on the location and magnitude of dust emission remains a key information gap to inform model development. Inadequate surface observations ensure that satellite data remain the primary source of this information over extensive and remote desert regions. Here, we develop estimates of the relative magnitude of active dust emission over the Sahara desert based on data from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). Utilising the unique vertical profile of aerosol characteristics provided by CALIOP our algorithm identifies emission from aerosol extinction and lidar backscatter in the near surface layers. From the long-term CALIOP archive of day and night-time orbits over 2006–13 we construct coarse resolution maps of a new dust emission index (DEI) for the Sahara desert during the peak summer dust season (June to September). The spatial structure of DEI indicates highest emission over a broad zone focused on the border regions of Southern Algeria, Northern Mali and northwest Niger, displaced substantially (∼7°) to the east of the mean maximum in satellite-derived aerosol optical depth. In this region night-time emission exceeds that during the day. The DEI maps substantially corroborate recently derived dust source frequency count maps based on back-tracking plumes in high temporal resolution SEVIRI imagery. As such, a convergence of evidence from multiple satellite data sources using independent methods provides an increasingly robust picture of Saharan dust emission sources. Various caveats are considered. As such, quantitative estimates of dust emission may require a synergistic combined multi-sensor analysis.

A pastoral frontier: From chaos to capitalism and the re-colonisation of the Kazakh rangelands

There is little research on pastoralists' responses to new expansion opportunities. We explore how pastoralists in Kazakhstan have responded to rapid, fundamental institutional and macroeconomic changes. We compare use patterns of grazing and water sites in two periods; 1999–2003, after the collapse of the Soviet Union, when the rural economy was in crisis and 2012–14, following a recovery in livestock numbers and a boost in the national economy. The study uses historical studies, formal surveys and anthropological interviews to document changes in livestock ownership, management and selection of pasture and water sites. In 2012–14, owners of the largest flocks had extended their grazing sites further away from the settled villages, moving away from more densely used sites more easily accessed in the 1990s. These new pastoral elites are colonising abandoned state-owned pastures and wells developed by Soviet state farms. Smaller-scale livestock owners based in villages are now less able to entrust their animals to larger-scale owners at remote desert sites, a change since the early post-Soviet period. The economic recovery of Kazakhstan has encouraged pioneering moves by entrepreneurial individuals, moves permitted by post-Soviet laws for privatised pasture land tenure. This expansionist movement parallels ecological patterns of site sequencing in wildlife.

Using Aerial Imagery to Characterize Redband Trout Habitat in a Remote Desert Landscape

AbstractRemote sensing products, including aerial imagery, can be used to quantify characteristics of watersheds and stream corridors that often predict the distribution and abundance of aquatic species. We conducted a supervised, object‐oriented classification of imagery from the National Agricultural Imagery Program to develop a high‐resolution (1‐m) land cover data set with four cover classes, emphasizing accurate characterization of woody riparian vegetation along stream corridors in northern Nevada and southwestern Idaho. The overall classification accuracy was 76%, and producer's accuracy (reflecting false positives) and user's accuracy (reflecting false negatives) for the woody vegetation class were 84% and 70%, respectively. Using logistic and quantile regression models in a model‐selection framework, we found woody vegetation to be positively associated with the occurrence and density of Redband Trout Oncorhynchus mykiss gairdneri. In addition, occurrence probabilities and densities were highest at mean August stream temperatures (predicted from a stream temperature model) ranging from 13°C to 17°C. When considered together with stream temperature, percent woody vegetation typically predicted Redband Trout occurrence and density better than most field‐measured instream and riparian habitat variables in northern Nevada. Our study highlights how free high‐resolution imagery can be used to characterize woody riparian vegetation and Redband Trout habitat across a large and remote desert landscape that can be difficult to access for field surveys. It also suggests that imagery from the National Agricultural Imagery Program may have wider application in identifying stream habitat restoration opportunities, where land and water uses have negatively impacted woody riparian vegetation in desert regions of the interior western United States.

Consistent response of Indian summer monsoon to Middle East dust in observations and simulations

Abstract. The response of the Indian summer monsoon (ISM) circulation and precipitation to Middle East dust aerosols on sub-seasonal timescales is studied using observations and the Weather Research and Forecasting model coupled with online chemistry (WRF-Chem). Satellite data show that the ISM rainfall in coastal southwest India, central and northern India, and Pakistan is closely associated with the Middle East dust aerosols. The physical mechanism behind this dust–ISM rainfall connection is examined through ensemble simulations with and without dust emissions. Each ensemble includes 16 members with various physical and chemical schemes to consider the model uncertainties in parameterizing short-wave radiation, the planetary boundary layer, and aerosol chemical mixing rules. Experiments show that dust aerosols increase rainfall by about 0.44 mm day−1 (~10 % of the climatology) in coastal southwest India, central and northern India, and north Pakistan, a pattern consistent with the observed relationship. The ensemble mean rainfall response over India shows a much stronger spatial correlation with the observed rainfall response than any other ensemble members. The largest modeling uncertainties are from the boundary layer schemes, followed by short-wave radiation schemes. In WRF-Chem, the dust aerosol optical depth (AOD) over the Middle East shows the strongest correlation with the ISM rainfall response when dust AOD leads rainfall response by about 11 days. Further analyses show that increased ISM rainfall is related to enhanced southwesterly monsoon flow and moisture transport from the Arabian Sea to the Indian subcontinent, which are associated with the development of an anomalous low-pressure system over the Arabian Sea, the southern Arabian Peninsula, and the Iranian Plateau due to dust-induced heating in the troposphere. The dust-induced heating in the mid-upper troposphere is mainly located in the Iranian Plateau rather than the Tibetan Plateau. This study demonstrates a thermodynamic mechanism that links remote desert dust emissions in the Middle East to ISM circulation and precipitation variability on sub-seasonal timescales, which may have implications for ISM rainfall forecasts.

Conches of the Caribbean: the Blessing of the Pink Pearl

Conches of the Caribbean: the Blessing of the Pink Pearl

Dust Effect on Optical Transmittance of Photovoltaic Module Glazing in a Desert Region

The energy strategy of Algeria is based on the acceleration of the development of solar energy. The strategic choice is motivated by the availability of a huge potential in solar energy. This energy is the major focus of the energetic program where the photovoltaic (PV) solar systems constitute an essential part. The photovoltaic energy fully meets the needs of facilities in remote desert areas where connection to the grid is too expensive. However, the southern Algerian regions are generally characterized by frequent sandstorms. This natural phenomenon causes the dust accumulation on PV modules. Consequently, this may reduce the efficiency of PV array. The objective of this research is to study the effects of the dirt accumulation on the optical transmittance of a PV array glazing in desert regions of Algeria. Firstly, we have validated our model of irradiance on tilted plane, which was the result of Hottel model improvement for Algerian sites. Secondly, the experiments have been conducted on the effect of the dust particle accumulation on the PV modules glazing. The tests were performed with the PVPM2540C in natural conditions to determine the current/voltage characteristics and see the resulting efficiency. It was found in this study, that the dust accumulation on the PV generator glazing surface tilted at 32° can significantly decrease the irradiance transmittance during the day by an average between 0% and 8% after an exposure period of several months.

Probing cosmic mysteries in a remote desert

The POLARBEAR telescope in Chile’s Atacama Desert aims to reveal the nature of neutrinos and the origins of the universe. Image courtesy of Adrian Lee.

Continuous measurements of greenhouse gases and atmospheric oxygen at the Namib Desert Atmospheric Observatory

Abstract. A new coastal background site has been established for observations of greenhouse gases (GHGs) in the central Namib Desert at Gobabeb, Namibia. The location of the site was chosen to provide observations for a data-poor region in the global sampling network for GHGs. Semi-automated continuous measurements of carbon dioxide, methane, nitrous oxide, carbon monoxide, atmospheric oxygen, and basic meteorology are made at a height of 21 m a.g.l., 50 km from the coast at the northern border of the Namib Sand Sea. Atmospheric oxygen is measured with a differential fuel cell analyzer (DFCA). Carbon dioxide and methane are measured with an early-model cavity ring-down spectrometer (CRDS); nitrous oxide and carbon monoxide are measured with an off-axis integrated cavity output spectrometer (OA-ICOS). Instrument-specific water corrections are employed for both the CRDS and OA-ICOS instruments in lieu of drying. The performance and measurement uncertainties are discussed in detail. As the station is located in a remote desert environment, there are some particular challenges, namely fine dust, high diurnal temperature variability, and minimal infrastructure. The gas handling system and calibration scheme were tailored to best fit the conditions of the site. The CRDS and DFCA provide data of acceptable quality when base requirements for operation are met, specifically adequate temperature control in the laboratory and regular supply of electricity. In the case of the OA-ICOS instrument, performance is significantly improved through the implementation of a drift correction through frequent measurements of a reference cylinder.

Cooperate Social Responsibility in Recent Thar Crisis: A Case Study of FFC Fertilizer MirPur Mathelo

The current research investigates the Cooperate Social Responsibility and Sustainable Development: A Case Study of FFC Fertilizer MirPur MatheloData were collected from300 stake holders and 400 local people from Mirpur Mathelo and their vicinity. Structural questionnaire were developed for the reliability and validity of the data. It was revealed that The unfolding drought in Tharparkar has created a humanitarian crisis for the approximate 1.5 million inhabitants of the district. An all-out relief effort is underway to assist the remote desert communities. The recent draught in Thar where thousands of child were died with out feed. FFC not only provide them feed but also help them by providing health facilities to them.

The National Heritage Potential of Landscapes Within the Australian Drylands

This paper presents a summary of an internal report on the potential National Heritage values of Australian geomorphology within a defined area. The desktop study sought information on landforms which best demonstrate the evolution of the characteristic landscapes now found in Australia's drylands. Australian dryland landscapes owe much to continental stability, which allows inheritance of landscape features and preserves the effects of previous climates. Aridity is only the latest and not always the most powerful of a long series of influences. Twenty-eight places with high potential to pass heritage criteria were identified across eight geomorphic themes (astroblemes, sand deserts, karst, arid coasts, tectonic landforms, uplands, regolith, watercourses). Some were significant within a single theme (the Acraman Impact Structure, the Nullarbor Plain); others had value across many themes/sub-themes (two Cooper Creek sites, the Neales Catchment, Rodinga Range). Many had sufficient information to identify particular locations (e.g. Gosses Bluff, the Zuytdorp Cliffs), but those without were assigned broad indicative areas, from which suitable locations can be found (e.g. the Eastern Goldfields Palaeodrainages, the Simpson Desert, the Black Soil Plains). Knowledge gaps are identified, especially the remote Great Sandy Desert and Great Victoria Desert dunefields and the Davenport–Murchison Ranges. Clusters of potential heritage occur along the Amadeus Basin ranges, and within the Lake Eyre Basin.

Cooperate Social Responsibility in Recent Thar Crisis: A Case Study of FFC Fertilizer Mir Pur Mathelo

The current research investigates the Cooperate Social Responsibility and Sustainable Development: A Case Study of FFC Fertilizer MirPur Mathelo Data were collected from300 stake holders and 400 local people from Mirpur Mathelo and their vicinity. Structural questionnaire were developed for the reliability and validity of the data. It was revealed that the unfolding drought in Tharparkar has created a humanitarian crisis for the approximate 1.5 million inhabitants of the district. An all-out relief effort is underway to assist the remote desert communities. The recent draught in Thar where thousands of child were died without feed. FFC not only provide them feed but also help them by providing health facilities to them.