Desert Landscape Research Articles

Ethnomedicinal and Ceremonial Plants of Kukshow-Veiled Village of the Trans-Himalayan Cold Desert of Ladakh

Cold desert landscape of Ladakh holds endemic and unique biodiversity of ethnobotanically important medicinal plants. These medicinal plants have been regarded as rich resources of traditional medicines since the advent of human civilization. As a result of rugged terrain, inaccessible landscape, harsh climate and lack of medical facilities in the region, the indigenous community is totally dependent on the local flora for healing. Study was based on seasonal reconnaissance surveys in years 2021 and 2022. 35 villagers were questioned based on semi-structured questionnaire to record ethnobotanical information. It enumerates 32 important and unique plant species. Asteraceae (6 species) is the most dominant family followed by Polygonaceae (3 species), Scrophulariaceae (3 species), Apiaceae, Fabaceae, Ranunculaceae and Rosaceae, each representing 2 plants; whereas the other families were represented by single taxa. The habit of the plants comprised a majority of 27 herbs, 3 shrubs and 2 trees. 15 plants among them were exclusively utilized for medicinal purpose only. Enumeration of the medicinal plants along with their usage will act as the baseline data for further chemical investigation of plant constituents in pharmacological industries. This current information on plants used by native communities could be promulgated to the new generation for awareness and sustainable utilization of plants. The festivity with which they celebrate the flowers in spring time is a valuable heritage and conservation ethos, which needs to be understood by the new generations.

Micromorphological features of medieval cultural layers formed in different environmental backgrounds

This research compares results of micromorphological case studies conducted on four early medieval archaeological sites with differentiated spatialization of human impacts and a varied craft production located in different background environments: humid climate, subzone of mixed forests, floodplain of the Dnieper River (Gnezdovo site); semi-humid climate, subzone of forest-steppe, Middle Volga region (Muromsky Gorodok and Malaya Ryazan’ sites); arid climate, cold desert of the Aral region, ancient delta-alluvial plain of the Syr-Darya River (Dzhankent site). Micromorphological studies of habitation deposits revealed clear geographical and geochemical regularities in the occurrence of geogenic (soil, sedimentary and post-sedimentary) features. Intrasoil migration and accumulation of clay and coarser silicate material in textural pedofeatures were described in cultural layers of sites located in forest and the forest-steppe zones. An anthropogenic input of phosphates provokes simultaneous migration and illuvial accumulation of phosphates and clay. In the habitation deposits in steppe landscapes with calcareous lithology, the key background soil process is redistribution and intrasoil accumulation of calcium carbonates. In the alluvial desert landscape, major soil processes are accumulation of gypsum and readily soluble salts. All layers are or were affected by at least some seasonal over-moisturizing that resulted in a variety of redoximorphic features depending on their palaeo- and/or contemporary water regime. The high variety of anthropogenic processes and corresponding microfeatures was grouped as follows: (1) input, output, turbation, compaction; (2) neoformation and migration; (3) pyrogenic processes (products); technological processes (products). The set of anthropogenic features records past human impact in the locality. The higher the variety of anthropogenic features and their general abundance is, the more intensive and variable the human impact which had occurred in the past. At the same time, the occurrence of certain anthropogenic features may indicate not only human-related processes of their formation (or input), but also a contemporary soil environment. This environment can be favorable, or, in the opposite, deteriorative for earlier formed anthropogenic features.

Green silk roads, partner state development, and environmental governance: Belt and road infrastructure on the Sino-East African frontier

ABSTRACT China's Belt and Road Initiative (BRI) is reorienting global development. Few scholars, however, query relationships between green silk road discourse, BRI infrastructure, partner state development goals, and environmental governance. This article details the roots of green silk road discourse in efforts to environmentally engineer China's desert landscapes. Much like large-scale nature-based infrastructure projects in China, BRI infrastructure projects abroad precipitate a range of socioeconomic and environmental outcomes. Through juxtaposing terrestrial infrastructure development in Ethiopia with maritime infrastructure development in Djibouti, the article demonstrates how different types of BRI infrastructure projects shape environmental governance and advance the development agendas of partner countries. Sugar plantations, roads, railways, and energy infrastructure in Ethiopia further Ethiopian state development plans while transforming Indigenous people's relations to their land and livelihoods. In Djibouti, port infrastructure and military bases figure centrally in strategic rentiership for the Djiboutian state with ancillary effects on fisheries and international trade. The article illustrates how relative articulations between East African central government development interests, environmental governance, and infrastructure are mediated by varieties of Chinese capital. The comparative analysis disrupts simplistic narratives of “win-win” partnerships and “China as threat” to partner state autonomy.

How Low-Paid Parents Navigate The Complex Financial Landscape Of Benefits Cliffs And Disincentive Deserts.

Policy makers are concerned that benefits cliffs-the phenomenon by which low-paid workers abruptly lose public benefits as their wages increase-may disincentivize work. The related concept of disincentive deserts refers to occasions when pay increases have little or no effect on a worker's financial well-being because of the resulting gradual reductions in public benefits. Little is known about how low-paid workers navigate this complex financial terrain. Based on in-depth interviews with twenty-five low-paid parents, this article reveals that parents' decisions about how much to work when facing benefits cliffs and disincentive deserts are based on their nuanced assessments of their currently available resources-financial, material, and emotional-of which public benefits are just one small piece. The primary driver of parents' decision making is their ability to care for their families. In no case did they base their decisions solely on a particular wage, income level, or ability to maintain public benefits. Thus, economic modeling, which draws conclusions about the impact of public benefits policies based solely on financial resources from work and benefits, is insufficient for understanding how parents make difficult choices when time, stress, and health are also relevant factors. The article concludes with recommendations for policy makers to expand and simplify public benefits.

Preserving the Gobi: Identifying potential UNESCO world heritage in Mongolia’s Gobi Desert

The Gobi Desert, Asia’s largest desert, covers roughly 1,300,000 square kilometers across southern Mongolia and northern China. One of the world’s most iconic deserts, the Gobi is a functioning, healthy ecosystem home to spectacular landscapes that support an impressive variety of biological diversity, including many rare and endangered species. Human activity in the Gobi has existed for at least 5,000 years and several culturally and historically significant archeological sites have been documented in the region; the Gobi continues to support an ancient and enduring nomadic lifestyle. Prehistoric traces of ancient life are also widespread, making the Gobi a hotspot for fossil discoveries. Despite a wealth of natural and cultural heritage the Gobi Desert in Mongolia lacks any recognition as UNESCO World Heritage. This article explores the natural and cultural heritage of the Gobi Desert in Mongolia and using UNESCO’s framework for “Outstanding Universal Value,” identifies several sites with exceptional geological, ecological, and ethnological features that we believe meet the criteria for World Heritage status. In the face of looming threats from human interference and climate change, increased recognition and appreciation of Gobi Desert landscapes is crucial to ensure the long-term protection of these irreplaceable sources of life and inspiration.

The Changing Landscape of Food Deserts and Swamps over More than a Decade in Flanders, Belgium.

Food deserts and swamps have previously been mostly studied in Anglo-Saxon countries such as the USA and Great Britain. This research is one of the first studies to map food deserts and swamps in a mainland European, densely populated but heavily fragmented region such as Flanders. The evolution of food deserts and swamps between 2008 and 2020 was assessed. Special focus was given to areas where high numbers of elderly, young people and/or families with low income live. Food deserts were calculated based on supermarket access within 1000 m and bus stop availability, while food swamps were calculated using the Modified Food Environment Retail Index. The main cause behind the formation of food deserts in Flanders is its rapidly aging population. Food deserts with a higher number of older people increased from 2.5% to 3.1% of the residential area between 2008 and 2020, housing 2.2% and 2.8% of the population, respectively. Although the area that could become a food desert in the future due to these sociospatial and demographic evolutions is large, food deserts are currently a relatively small problem in Flanders in comparison to the widespread existence of food swamps. Unhealthy retailers outnumbered healthy retailers in 74% of residential areas in 2020, housing 88.2% of the population. These food swamps create an environment where unhealthy food choices predominate. Residential areas with a higher number of elderly people, young people and families with low incomes had healthier food environments than Flanders as a whole, because these areas are mostly found in dense urban centers where the ratio of healthy food retailers to all retailers is higher. This research showed that food deserts and swamps could be a growing problem in European regions with a high population density that experience the high pressures of competing land uses.

The changing landscape of food deserts and swamps in Flanders, Belgium

Abstract Introduction For decades, people's body weight has been increasing at alarming rates, leading to a worldwide obesity epidemic. One of the main causes of this obesity epidemic is poor diet quality. The food environment has been suspected to be one of the principal drivers of poor diet quality. Older people and families with a poor socioeconomic background can be disproportionately affected. Methods This study maps the food environment in Flanders between 2008 and 2020 by using the concepts of food deserts and food swamps. Food deserts have been defined as neighborhoods that lack access to some or all foods that are required for a balanced, nutritionally adequate diet. Food swamps refer to places where there is an abundance of unhealthy food options relative to healthy food options. A spatial analysis using population- and retail density datasets yielded the change in food deserts and swamps between 2008 and 2020. Results Food deserts in Flanders are found to be small in area and very localized. While food deserts in areas with the two highest deciles of people older than 65 years increased from 1.3% to 1.6% of total surface area in Flanders between 2008 and 2020, the food deserts in areas with the two lowest deciles of low income families decreased from 4% to 2.4%. Food swamps in Flanders on the other hand, are ubiquitous. In 2020, 42.9% of the residential area examined contained no healthy food retailers and 77.7% of the area can be considered a severe food swamp. Areas with a high number of vulnerable groups are healthier than Flanders as a whole because these areas are mostly found in dense urban centers where the ratio of healthy food retailers to all retailers is higher. Conclusions Food deserts are a relatively small problem in Flanders in comparison to the widespread occurrence of food swamps. These food swamps exacerbates the obesity epidemic in Flanders and lead to a shorter health span of the affected individuals and to increased medical costs for society. Key messages • The food environment in Flanders is generally unhealthy, making it easy for individuals to buy unhealthy foods. • Food swamps are a major problem in Flanders, where unhealthy retailers drown out healthy retailers.

Geoconservation Through Geotourism Around Geologically Significant Sites and Desert Landscapes in Potential Geopark in Jaisalmer Basin, Western India

Geoconservation Through Geotourism Around Geologically Significant Sites and Desert Landscapes in Potential Geopark in Jaisalmer Basin, Western India

Bird Beta Diversity in Sharp Contrasting Altai Landscapes: Locality Connectivity Is the Influential Factor on Community Composition.

Simple SummaryUnderstanding the ecological processes involved in establishing a metacommunity, a collection of small communities linked by species dispersal, could help with biodiversity conservation. In this work, we examine how local community connectivity affects the distributional patterns of various bird species across metacommunities in the strikingly different Altai landscapes. We discovered that connectivity was most important for determining community composition in metacommunities. High beta diversity and a high turnover component in the research region showed that regional-scale conservation efforts should consider overall biodiversity. Although they are not part of the Altai-Sayan biodiversity ecoregion, the riparian and desert landscapes are essential to the birds that reside in the mountain ranges and should be regarded as integral parts of the ecoregion, and high connectivity stepping-stone habitats in these landscapes should be protected.Located on the southwest slope and plain areas of the Altai Mountains in China, this study aims to explore bird composition variation (beta diversity) in mountain landscape (metacommunity M), riparian landscape (metacommunity R), desert landscape (metacommunity D) and across the three landscapes (metacommunity A), and to assess how patch connectivity with environmental and spatial factors influence species distributional patterns across multiple metacommunities. In 78 transect lines over the study area, 9724 detections of 139 bird species were detected. We calculated the beta diversity, its turnover and nestedness components in four metacommunities. We used the variation partitioning method to investigate the relative importance between the environment, spatial variation and locality connectivity in driving bird community composition variation. We found high beta diversities with a small contribution of nestedness components in all four metacommunities. When only a single set of predictors is contained in the model, the predictor that best explains the variation of bird community composition is connectivity in metacommunity M, R and D and spatial predictor in metacommunity A. In all three sets of predictors, 73.8~85.4% of variations of community composition can be explained in the four metacommunities, and connectivity always contributed the most. High beta diversity and a high turnover component imply that regional-scale conservation efforts should be thought of as preserving overall biodiversity. A conservation strategy is to keep stepping-stone habitats with good connectivity in the middle of the riparian landscape. Along with the Altai-Sayan biodiversity ecoregion, the desert and riparian environments are essential for birds residing in the mountainous terrain. Furthermore, they should be regarded as integral parts of the ecoregion.

Silvopastoralism and the shaping of forest patches in the Atacama Desert during the Formative Period (ca. 3000–1500 years BP)

During the Formative period by the Late-Holocene (ca. 3000–1500 BP), semi-sedentary and sedentary human occupations had emerged in the oases, salares, and riverine systems in the central depression (2400–1000 masl) of the Atacama Desert, northern Chile (19–25°S). This hyperarid core was marginally occupied during the post-Pleistocene and middle Holocene droughts. Settlement on these lower belts was accompanied by a rise in humidity, the introduction of Andean crops, flourishment of Prosopis spp. (algarrobo) forests, and increasing integration of domestic camelid caravans. Here, we explore lowland husbandry within risk-spreading strategies, focusing on silvopastoralism and endozoochory between camelids and algarrobos. Analysis of camelid coprolites from seven archeological sites located in the Pampa del Tamarugal, Loa River, and Salar de Atacama found intense grinding from camelid chewing and indicated a ruminal digestive system. Abundant macro and microremains in the form of tissues, phytoliths, crystals, cell structures, and others, were identified as Prosopis, Atriplex, Schoenoplectus, Distichlis, and Phragmites. We conclude that camelids were foraging for Prosopis, although the rather low number of entire seeds preserved in the coprolites leads us to think that these herbivores might not have been the main vectors for the spread and germination of algarrobos. More samples and interdisciplinary studies are needed to comprehend the complex socioecological web in the shaping of these forests and the management of the Atacama Desert landscapes.

Rare preservation of Triassic pedorelicts with biogenic traces from a hot semi-arid upland palaeoenvironment at Portishead, SW England

Pedorelicts occur sporadically in coastal exposures of Middle to Late Triassic continental sediments, at Portishead, SW England. The clasts include aeolian and bedrock constituents, calcrete textures, vesicles and other pedogenic features reflecting a hot semi-arid palaeoenvironment. Interpreted as being derived from an upland soil, they are classified in palaeosol terms as Calcic Protosol. In the most significant exposure, cryptic tubular trace fossils in branching networks occur within these pedorelict clasts in a localised fluvial deposit. This extremely rare palaeoecological archive offers a glimpse into continental upland life in a Pangaean desert landscape. It is documented for its own merit, to support continuing studies of its palaeobiology and to prompt investigation for comparable deposits.The pedorelicts occur within the Mercia Mudstone Marginal Facies (MMMF), close to its basal unconformity with underlying Paleozoic strata, at the margin of the Somerset Basin. The soil from which they are derived is interpreted to have developed in an upland regolith over Tournaisian bedrock of interbedded limestone and siltstone. These weathered and, with aeolian dust containing calcite and iron minerals and siliciclastic sand, formed a structured soil. This was aided by intermittent light and moderate rainfall that promoted mainly vadose pedogenic calcretization with displacive calcite crystallisation and siliciclastic grain breakage. In places, the soil was vesicular, as an ‘Av’ horizon, and in others, it was bioturbated with the development of calcite-lined tubules and unlined tunnels. At intervals of perhaps 104 to 105 years, catastrophic deluges eroded the regolith and transported clasts downslope towards the basin to form onlapping coarse clastic beds typical of the MMMF. The soil structure disintegrated but fragments that became pedorelicts were segregated in a fault-controlled palaeo-valley, possibly partly as a debris-flow, to be deposited as localised conglomeratic lenses with fluvial sand. After burial by further sedimentation, this deposit underwent diagenetic calcite cementation and baryte mineralisation before its present exposure by coastal erosion.

Gypsum in the desert landscape: Floristic variations within the Cuatro Ciénegas basin in Coahuila, Mexico

Plant species growing on gypsum substrates, usually found in arid and semi-arid zones, create characteristic landscapes that can harbor highly specialized species, several of which are endemic. In the Cuatro Ciénegas basin (CCB) gypsum is abundant and creates patches of plant assemblages, but little is known about the floristic differences between them and the ecological factors driving them. In this study, we describe and compare the floristic composition of twelve fixed plots placed in six different positions on the landscape (five gypsum-rich sites and one with a minimal gypsum concentration, as a control site) within the CCB and the nearby La Virgen valley. Species presence was recorded twice a year for two years, the floristic composition of each plot was determined and compared through Beta diversity. A principal component analysis was performed to identify species contribution to the assemblage differentiation and the effect of gypsum and topographic variables were tested. A total of 98 species from 62 genera and 31 families were registered. The results show that gypsum plays an important role in community assembly and differentiation, and within gypsum-rich sites, species assemblages are related to the effect of topographic factors, slope and altitude. However, we suggest that within gypsic soils, more punctual environmental conditions like microclimate, water dynamics, and most likely soil characteristics such as salinity or texture (rockiness), other than gypsum concentration, influence community floristic differentiation.

Poetry as Spiritual Exercise

Poetry as Spiritual Exercise

Pleistocene drivers of Northwest African hydroclimate and vegetation

Savanna ecosystems were the landscapes for human evolution and are vital to modern Sub-Saharan African food security, yet the fundamental drivers of climate and ecology in these ecosystems remain unclear. Here we generate plant-wax isotope and dust flux records to explore the mechanistic drivers of the Northwest African monsoon, and to assess ecosystem responses to changes in monsoon rainfall and atmospheric pCO2. We show that monsoon rainfall is controlled by low-latitude insolation gradients and that while increases in precipitation are associated with expansion of grasslands into desert landscapes, changes in pCO2 predominantly drive the C3/C4 composition of savanna ecosystems.

Relating Ø/to/in the desert: Scottish World War II Poets in North Africa and the Middle-East

“Relating” meaning both recounting and connecting, it is a suitable term to describe war literature which is, at the same time, aesthetic and testimonial. Scottish poets were sent to the African front during the Second World War and their poems, letters or diaries reflect their experience in Egypt, Libya and Tunisia, offering sharp contrasts with what is commonly believed or imagined of desert landscapes and the Desert War. The aim of this article is to examine how Scottish war poems may be inscribed in an artistic as well as a historical counter-discourse. The first part is a historical and cultural survey which contextualizes life and literary relationship in Cairo at the time, while evoking the main literary landmarks poets might have called up as they faced desert landscapes. The second part analyzes how they related to or broke away from these landmarks to relate their desert experience, with particular focus being set on the poem as a silent camera obscura. The last part turns to human landscapes and examines relationship within the 8th Army and the strong affinities Scottish poets felt towards German simple soldiers or North African civilians.

Reconstruction of early Paleogene landscapes and climate in the Jianghan Basin, central China: Evidence from evaporites and palynology

The early Paleogene environment and climate of East Asia are poorly understood. To improve knowledge, we investigated the palynological record of well ZK0303 in the southwest Jianghan Basin, Hubei Province (central China). The well lithology comprises three intervals whose lithofacies represent the deposits of a saline lake: anhydrite/silty mudstone, halite/mudstone, and dolomite/siltstone. Based on a study of 37 palynological samples, three assemblages were recognized. Assemblage A, which correlates with Paleocene, is dominated by Ephedripites and contains a high proportion of thermophilic and xerophytic taxa. Assemblage B, which correlates with the early Eocene, is dominated by Taxodiaceaepollenites and hygrophilous taxa while the proportion of xerophytes is generally low. Assemblage C, probably early Eocene too, is dominated by Ephedripites and contains higher numbers of xerophytic species while hygrophilous species decrease to nearly half of their earlier abundances. These palynological data show that the early Paleogene climate of the Jianghan Basin experienced a transition from hot and arid to warm and humid conditions, with the latter period interrupted by short arid intervals. Afterwards, hot-arid conditions prevailed again. The reconstructed desert shrub and mountain forest vegetation suggests that the regional Paleocene landscape resulted from basin and range tectonics. Under the influence of a hot and arid climate controlled by global circulation patterns and rain-shadow effects, desert landscape and evaporites were formed in central China during the early Paleogene, whilst humid climate and forest vegetation prevailed in central China under the influence of the Paleocene-Eocene Thermal Maximum (PETM).

Impact of the Tengiz Oil Field on the State of Land Cover

Abstract The study of the transformation of natural complexes in areas with a developed infrastructure for oil subsurface use is a prerequisite condition for solving the environmental problems of oil-producing regions. Located in the territory of the Atyrau Region in Western Kazakhstan, the Tengiz oil field is one of the largest oil fields in the world. The field has been under intensive development for more than 40 years and is characterised by a large volume of anthropogenic load, which contributes to a significant transformation of the landscape complex. The purpose of this study is to investigate the dynamics of landscape changes in the territory of the Tengiz field and to assess its ecological condition. Based on the materials from many years of research, the features of the Tengiz field and the main technogenic sources affecting the landscape complex were identified. Several quantitative indicators characterising the anthropogenic load were calculated based on satellite images. On the basis of Landsat – 5 TM, 7 ETM+ and 8 OLI and Sentinel-2A (S2A) data, the vegetation index of land cover was calculated using normalised difference vegetation index (NDVI), demonstrating the dynamics of landscape changes in the period from 1990 to 2020. The obtained results show that the areas of some landscape components continue to deteriorate. For example, the area of open soil in 2020 decreased due to the withdrawal of these areas for industrial facilities, which increased by 2.2 times by 2020 due to intensive field development. This study demonstrates the importance of monitoring and studying desert landscape complexes under active anthropogenic impact to ensure the sustainable development of territories.

Call It Horses by Jessie van Eerden

Reviewed by: Call It Horses by Jessie van Eerden Jayne Moore Waldrop (bio) Jessie van Eerden. Call It Horses. Ann Arbor, Mich.: Dzanc Books, 2021. 246 pages. Hardcover. $26.95. In Call It Horses, three women—a niece, her aunt, an unwanted stowaway—hit the road in a long, rusted Oldsmobile Royale in the late 1980s, leaving Caudell, West Virginia, for Abiquiu, New Mexico, and the desert landscape of Georgia O'Keeffe. From the start, nothing about the trip hints at pleasure or relaxation. Instead, the journey is more of an escape from everything they know as they attempt to outrun the grief and troubles chasing each of them. There's been no planning for the trip, which heightens the atmosphere of escape. Frankie, the driver and narrator, is in her mid-thirties. She was orphaned as a teenager and raised, sort of, by her aunt Mave. After dropping out of high school, Frankie was homeschooled, sort of, by Mave, who unevenly tried to show Frankie a bigger view of the world through books. As [End Page 108] the journey begins, Mave is close to the end of her life from cancer, her condition so fragile she requires portable oxygen tanks and an assortment of pills for the pain. Mave wants to reach Abiquiu, but she can't make it there alone. Nan is a young artist with a black eye courtesy of her husband Dillon, who was Frankie's first love. Nan is unwanted and relegated to the back seat, invited because she has the only car that's still running at the time of departure. She's described as loose in her actions and her words, a revealing indictment in a story built upon the value of language and finding the proper words to name things. As in the archetypal American road trip, the women head west, traveling through West Virginia, Kentucky, Tennessee, and along I-40 into the desert, in search of the landscape of Georgia O'Keeffe. In sections set at home, the reader can almost feel the heaviness of the lush, humid landscape, a place of forests, caves, and bogs filled with decaying vegetation. There's stark contrast between the thick air that constricts Frankie's airways and the clear, bright paintings of O'Keeffe's desert world filled with flowers and bleached skulls, which are seen as "souvenirs of death." The novel is structured as a series of letters written by Frankie to Ruth, a deceased linguist who was Mave's longtime lover. Ruth, who had studied the languages and hieroglyphs of the Sinai Desert on sabbaticals, had been Frankie's pen pal for three years when Frankie was a teenager. At the time, Mave and Ruth lived together on the east coast in a relationship considered immoral by Mave's sisters. Ruth, who had grown up with privilege and opportunity, had observed promise in young Frankie's writing, and from that point, both Ruth and Mave encouraged her writing. [End Page 109] Although Frankie and Ruth never meet, their correspondence becomes a private, sustaining lifeline for Frankie during adolescence. After Ruth's death, the letters stop. Mave had returned to West Virginia with an unexpected inheritance of money and books, along with a grief that alcohol couldn't assuage. But even after death, Ruth provides a measure of stability for Frankie amid the cluttered chaos of Mave's life. The letters provide structure for the novel, but the narrative is remarkably nonsequential, written with layers that need to be peeled like an onion from Frankie's garden. It's a short novel, but not a fast read. Significant details from the past weave throughout the letters. Some readers may wish for more straightforward linear movement in the storytelling. Frankie's writing finally, carefully, takes shape in the form of a journal documenting the road trip, written on a Dollar Store notepad. I write you about the dead. I write you to stayalive and, after all this time, I write you, stillto become myself…. On a rough-lumber tablewith a vinyl tablecloth, I write this to you.Dear, Ruth, can you feel the unfolding of ourdisaster? I should write each...

Optical Microwave Scintillometer Evaporation Measurements over a Saline Lake in a Heterogeneous Setting in the Atacama Desert

Abstract Estimating lake evaporation is a challenge due to both practical considerations and theoretical assumptions embedded in indirect methods. For the first time, we evaluated measurements from an optical microwave scintillometer (OMS) system over an open-water body under arid conditions. The OMS is a line-of-sight remote sensing technique that can be used to measure the sensible and latent heat fluxes over horizontal areas with pathlengths ranging from 0.5 to 10 km. We installed an OMS at a saline lake surrounded by a wet-salt crust in the Salar del Huasco, a heterogeneous desert landscape in the Atacama Desert. As a reference, we used eddy covariance systems installed over the two main surfaces in the OMS footprint. We performed a footprint analysis to reconstruct the surface contribution to the OMS measured fluxes (80% water and 20% wet salt). Furthermore, we investigated the applicability of the Monin–Obukhov similarity theory (MOST), which was needed to infer fluxes from the OMS-derived structure parameters to the fluxes. The OMS structure parameters and MOST were compromised, which we mitigated by fitting MOST coefficients to the site conditions. We argue that the MOST deviation from values found in the literature is due to the effects of the surface heterogeneity and the nonlocal processes induced by regional circulation. With the available dataset we were not able to rule out instrument issues, such as additional fluctuations to the scintillation signal due to absorption or the effect of vibration in high-wind conditions. The adjusted MOST coefficients lowered by a factor of 1.64 compared to using standard MOST coefficients. For H and LυE, we obtained zero-intercept linear regressions with correlations, R2, of 0.92 and 0.96, respectively. We conclude that advances in MOST are needed to successfully apply the OMS method in landscapes characterized by complex heterogeneity such as the Salar del Huasco.

Mid-Pleistocene formation of modern-like desert landscape in North China

The formation and evolution of the deserts in North China have been extensively studied over the past three decades. However, due to the complexity of proxy interpretation and chronological uncertainty, our understanding of the formation of modern-like desert landscapes in North China remains controversial, as inferred from the borehole records within these deserts and eolian deposits in the downwind region. In this study, we synthesised five borehole records within five deserts and seven aeolian sequences in the adjacent loess areas to address the timing and evolution of modern-like desert landscape in North China. A combination of lithological characteristics and proxy records of these boreholes and loess sequences reveals that the formation of the modern-like desert landscape across North China had generally occurred around the Middle Pleistocene. However, the exact timing of each desert change varies slightly from 1.5–0.6 Ma in Northwest China to 1.2–0.7 Ma in Northeast China. Because the uplift of the Tibetan Plateau to its present height occurred much earlier, and considering the general synchronicity of large-scale drying in North China, we propose that global cooling, the expansion of the Northern Hemisphere ice sheets, and increased amplitude of glacial–interglacial (dry–wet) fluctuations may have played a key role in the formation of the modern-like desert landscapes in North China during the Middle Pleistocene.