Eastern Xinjiang Research Articles

The Matching Relationship Between the Distribution Characteristics of High-Grade Tourist Attractions and Spatial Vitality in Xinjiang

The development of the tourism industry serves as a crucial pathway for guiding urban spatial vitality, making the study of the matching relationship between the spatial distribution characteristics of tourist attractions and regional spatial vitality particularly important for the advancement of the tourism sector. This study combines Amap POI data and Weibo sign-in data, employing various quantitative methods, including Kernel Density Estimation (KDE), Hotspot Analysis (Getis-Ord Gi*), and the Geographically Weighted Regression (GWR) model, to thoroughly explore the distribution characteristics of different grades of tourist attractions in Xinjiang and their matching relationship with spatial vitality. The findings indicate that AAAAA attractions are primarily concentrated in Urumqi and its surrounding areas, where spatial vitality highly matches the distribution of attractions. The distribution of AAAA attractions shows regional differences, exhibiting higher matching degrees in certain areas of southern and western Xinjiang, while some regions in northern Xinjiang demonstrate lower matching degrees. Conversely, AAA attractions are more widely distributed in remote areas, where the matching between vitality and attraction distribution is low, particularly in southern and eastern Xinjiang, revealing a notable mismatch between tourism resources and spatial vitality. By analyzing the matching relationship between tourism resources and spatial vitality, this study provides a scientific basis for optimizing the allocation of tourism resources in Xinjiang and enhancing regional tourism spatial vitality. Additionally, this study also offers valuable insights for tourism managers and planners to formulate more precise tourism development policies.

A fluorite bead from Bronze Age Tianshanbeilu cemetery, Xinjiang, Northwest China

The Tianshanbeilu cemetery is the largest Bronze Age cemetery in eastern Xinjiang, China, and plays important roles in connecting the Eurasian interior to the Hexi Corridor, and further to the Central Plains region. Utilizing micro-XRF and Raman spectroscopy techniques, we identified a fluorite bead at this cemetery. This barrel bead is the earliest record of such a fluorite bead in China, dating back to approximately 1385–1256 BCE. Comparing the unearthed records of fluorite beads in eastern China spanning from the Neolithic Age to the Western Zhou dynasty, we notice that in the early Western Zhou period, fluorite beads found in élite burials are only in barrel or biconical shapes, both of which first appeared in the eastern region of Xinjiang, such as the Tianshanbeilu cemetery in Hami and the Yanghai cemetery in the Turpan Basin. We proposed that the barrel fluorite bead drilled by metal tubular drill first appearing in the Tianshanbeilu cemetery might have spread eastward to the Central Plains region and finally constituted a component of the ritual revolutions during the Western Zhou dynasty.

Are Regions Conducive to Photovoltaic Power Generation Demonstrating Significant Potential for Harnessing Solar Energy via Photovoltaic Systems?

To achieve the goals of carbon peak and carbon neutrality, Xinjiang, as an autonomous region in China with large energy reserves, should adjust its energy development and vigorously develop new energy sources, such as photovoltaic (PV) power. This study utilized data spatiotemporal variation in solar radiation from 1984 to 2016 to verify that Xinjiang is suitable for the development of PV power generation. Then, the averages of the solar radiation, sunshine duration, and other data in the period after 2000 were used to assess the suitability of Xinjiang, based on spatial principal component analysis (SPCA). Finally, the theoretical power generation potential, fossil fuel reduction, and CO2 emissions reduction were estimated. The results are as follows: (1) In terms of temporal variation, the solar radiation in Xinjiang decreased (1984–2002), increased (2002–2009), and decreased again (2009–2016), but the fluctuations were not statistically significant. In terms of spatial distribution, the Kunlun Mountains in southern Xinjiang had the highest solar radiation during the span of the study period. Hami and Turpan, in eastern Xinjiang, had sufficiently high and stable solar radiation. (2) The area in Xinjiang classed as highly suitable for solar PV power generation is about 87,837 km2, which is mainly concentrated in eastern Xinjiang. (3) In the situation where the construction of PV power plants in Xinjiang is fully developed, the theoretical potential of annual solar PV power generation in Xinjiang is approximately 8.57 × 106 GWh. This is equivalent to 2.59 × 109 tce of coal. Furthermore, 6.58 × 109 t of CO2 emissions can be reduced. PV power generation potential is approximately 27 times the energy consumption of Xinjiang in 2020. Through the suitability assessment and calculations, we found that Xinjiang has significant potential for PV systems.

Projected heatwaves in Xinjiang Uygur autonomous region, China

Introduction: Heatwaves (HWs) are the serious natural disaster that exert great impacts on human health and social economy. Projecting future changes in HWs is crucial for the development of effective adaptation strategies.Method: This study investigates the variations of HWs in Xinjiang for three time periods (near-term, mid-term, and long-term) under four Shared Socioeconomic Pathways (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5) using multi-model ensemble (MME). To enhance confidence in HWs projection, we evaluate the performance of 17 climate models in simulating HWs in terms of interannual variability and spatial patterns using interannual variability skill score (IVS) and distance between indices of simulation and observation (DISO), respectively, and generate MME using the overall performance.Results: Compared to the observed data, the overall performance of MME outperforms most of individual models, although many models effectively capture the characteristics of HWs. Projections indicate that HWs in Xinjiang will become more longer lasting and severe. Specifically, heatwave frequency (HWF) and heatwave duration (HWD) are projected to reach 7.5 times and 61 days, respectively, in the long-term under the SSP5-8.5 scenario. The spatial distribution of HWs exhibits significant heterogeneity, with high value regions primarily distributed in eastern Xinjiang and the eastern part of southern Xinjiang. Although the HWs area is projected to expand under all scenarios, the spatial pattern is anticipated to remain largely unchanged.Conclusion: These findings provide a comprehensive assessment of future variations in HWs, which are necessary for improving regional adaptive capacity to extreme heat risk.

Measuring and decomposing natural capital use in Xinjiang from a regional-industry perspective

Accurately portraying the mechanism of the flow of natural resource consumption between regions and its impact on ecology is of crucial value in deepening the understanding of the coordinated relationship between population, resources, environment and development. Consequently, this promotes the sustainable development of the natural economy and society. Based on a regional-industrial perspective, this study used a localized three-dimensional ecological footprint model to measure and decompose natural resources in Xinjiang from 2005 to 2020. In doing so, the study clarified the supply, demand, and flow utilization of natural capital in Xinjiang, the balance of spatial and temporal allocation of resources, the coupling between economic growth and resource consumption, and the coordination between industrial structure and ecological environment. The results showed that (1) Xinjiang's per capita ecological deficit grew from 2.096 to 11.667 in 2005–2020. Moreover, the energy footprint was a decisive part of the ecological deficit throughout the study period. Furthermore, the trend of increased ecological pressure was higher in northern and eastern Xinjiang than in southern Xinjiang. (2) The overall Gini coefficient of Xinjiang's ecological carrying capacity was at the critical value of spatial equilibrium (0.4), with differences between the groups: Northern & Southern Xinjiang > Northern & Eastern Xinjiang > Eastern & Southern Xinjiang. The reasons for this inter-regional economic disparity are related to fiscal expenditure/GDP, level of urbanization, and regional industrial output. Overall, the decoupling relationship between environmental pressures and economic growth was optimistic. (3) From an industrial perspective, the levels of industrial structural efficiency and the industrial ecological harmony index were still relatively low, but the overall trend was on the rise. (4) Resource endowment, economic development, consumption structure, and population had significant driving effects on the ecological footprint, whereas environmental protection, science, and technology could inhibit its growth to a certain extent. This study aimed to provide an in-depth analysis of the current situation and problems of natural resource use in Xinjiang and provide theoretical and practical references for sustainable development in the region.

Organic Matter Source Traced by n-Alkane Records Derived from Sediments of Barkol Lake in Eastern Xinjiang (NW China) and Its Response to Moisture Variability in the Past 8800 Years

Organic Matter Source Traced by n-Alkane Records Derived from Sediments of Barkol Lake in Eastern Xinjiang (NW China) and Its Response to Moisture Variability in the Past 8800 Years

Improved Agricultural Drought Monitoring with an Integrated Drought Condition Index in Xinjiang, China

Drought is a natural disaster with severe global agricultural and economic impacts. Accurate drought indices are needed for improved assessment and monitoring; however, most existing drought indices poorly represent agricultural drought due to complex interactions among meteorological factors, crop and soil conditions. Here, we compute an integrated drought condition index (IDCI) based on the 3-month standardized precipitation evapotranspiration index (SPEI3), vegetation cover index (VCI) and soil moisture condition index (SMCI). We apply the IDCI to monitoring agricultural drought in Xinjiang, China. After regional evaluations with soil moisture, precipitation and air temperature observations, as well as with the scaled crop yields index, the IDCI was used to describe spatiotemporal changes in regional drought in Xinjiang during 2000–2018, revealing adverse impacts on crop yield (beet, wheat and vegetables). The IDCI is strongly correlated with observed soil moisture and performs better than SMCI, VCI or SPEI3, demonstrating that the IDCI is suitable for agricultural drought monitoring. The most severe drought occurred in the spring to autumn of 2008. Droughts before 2008 were more serious than those after 2008, in terms of both severity and frequency. Droughts in northern, southern and eastern Xinjiang, as well as in the Tianshan Mountains, were generally increasing before 2008 and then weakened after 2008.

Investigation of Antigen and Gene Frequency of Kell(K) and Rh(D) Blood Groups in Xinjiang

To investigate the phenotypes and gene frequencies of Kell blood group system K antigen and Rh blood group system D antigen in Xinjiang, and summarize and understand the distribution of Kell(K) blood type and Rh(D) blood type in this area. A total of 12 840 patients who met the inclusion criteria during physical examination and treatment in our hospital and 18 medical institutions in our district from January 1, 2019 to December 31, 2019 were collected for identification of Kell blood group system K antigen and Rh blood group System D antigen, and the distribution of K and D blood groups in different regions, genders and nationalities were investigated and statistically analyzed. The proportion of K positive in the samples was 1.39%, the highest was 1.91% in southern Xinjiang, and the lowest was 1.03% in northern Xinjiang(P<0.01). The proportion of Rh(D) negative samples was 2.75% and the gene frequency was 16.64%. The proportion of Rh(D) negative samples was 4.03% and the gene frequency was 20.10% in southern Xinjiang, followed by eastern Xinjiang and the lowest in northern Xinjiang (P<0.01). The frequency of K antigen in Uygur nationality was the highest, reaching 2.16%, Kirgiz 1.54%, and the distribution trend of D/d antigen was similar to that of K antigen. Among women, the K positive frequency of Kazak nationality was slightly higher than that of Mongolian nationality. The highest proportion of K positive in Uygur women was 2.38%, which was higher than that in Uygur men (1.86%). The frequency of d phenotype in Kazak women was 3.15%, which was higher than that in Kirgiz （2.89%） (P<0.01). The distributions of Kell(K) and Rh(D) blood groups in northern and southern Xinjiang and eastern Xinjiang had its own unique characteristics and differences. There are significant differences in blood group distribution among different ethnic groups and gender groups. In the future, k antigen detection can be included to further improve the investigation on the distribution of Kell blood group system in this region.

Interregional and intraregional interaction of the Tianshanbeilu population in eastern Xinjiang from the perspective of pottery analysis

The beginning of human settlement in the Hami Basin, located in the eastern part of Xinjiang, has been a focal question for the academic community in China. In particular, the thesis that the immigrating population from the Hexi Corridor since the late Neolithic founded the Tianshanbeilu culture has riveted the attention of scholars. Pottery wares, abundantly discovered at the synonymous cemetery of this culture, have played a key role in extrapolating population migration and cultural interaction. This paper aims to test the thesis by characterizing the chemical composition, painting pigment, and carburizing technique of 70 pottery samples from the cemetery with various scientific methods. It shows that the chemical compositions of the coarse pottery in the three colors of red, yellow, and gray, painted and unpainted alike, are remarkably different from those of fine pottery in black and red, indicating that the raw materials for the coarse and fine pottery samples are possibly procured from different sources; the pigments of the red slip and black paint are derived from hematite, black manganese ore, and carbon black; carburizing and polishing techniques are further applied to the gray coarse pottery; In combination with the compositional data of pottery samples from the Yaer cemetery also in the Hami Basin and the Xichengyi settlement in the Hexi Corridor, this paper finds that some pottery wares of the Tianshanbeilu culture were exchanged within the Hami Basin, but each site had its own production facility. No direct exchange of pottery wares with Xichengyi is attested; the similar style of pottery wares between the two sites may have resulted from population migration and technological exchange.

Prokaryotic taxonomy and functional diversity assessment of different sequencing platform in a hyper-arid Gobi soil in Xinjiang Turpan Basin, China.

Turpan Basin located in the eastern Xinjiang is a typical arid inland basin with extremely scarce water resources and a fragile ecosystem. Prokaryotic communities with unique genetic and physiological modifications can survive and function in such harsh environments, offering diverse microbial resources. However, numerous microbes can enter the viable but non-culturable state because of drought stress in the desert soil. In this work, next generation sequencing (NGS) technology based on DNA nanoball sequencing platform (DNBSEQ-G400) and sequencing-by-synthesis platform (NovaSeq 6000) were applied to analyze the prokaryotic diversity in three hyper-arid Gobi soils from Flaming Mountain, Toksun, and Kumtag. The comparison between two platforms indicated that DNBSEQ-G400 had better repeatability and could better reflect the prokaryotic community of this hyper-arid region. The diversity analysis based on DNBSEQ-G400 identified a total of 36 bacterial phyla, including Pseudomonadota, Bacteroidota, Bacillota, Actinomycetota, Methanobacteriota, Acidobacteriota, Nitrososphaerota, and Planctomycetota. The environmental factors, including soluble salt, available potassium, total nitrogen, and organic matter, were positively correlated with the abundance of most prokaryote. In addition, the prokaryotic community assembly in hyper-arid soil was well described by neutral-based models, indicating that the community assembly was mainly controlled by stochastic processes. Finally, the phylogenetic analysis of Actinomycetota proved that such extremophiles played an important role in the ecosystems they colonize. Overall, our result provides a reference for choosing the appropriate sequencing platform and a perspective for the utilization of soil microbial resources from hyper-arid regions.

Analysis of Air Pollutants and Their Potential Sources in Eastern Xinjiang, Northwestern Inland China, from 2018 to 2022

Air pollution in the developed regions of eastern China has been intensively investigated in the past decade. However, there is a relative dearth of air pollution studies on the northwest of inland China (e.g., Xinjiang). In this work, hourly measurement data of six criteria air pollutants (PM2.5, PM10, CO, NO2, O3, and SO2) for the past five years (2018–2022) from Hami and Turpan cities of eastern Xinjiang were analyzed to reveal air pollution characteristics and the distribution of potential sources. Hami and Turpan had the highest AQI values in winter due to increased coal combustion for domestic heating and unfavorable meteorological conditions. The slight elevations of AQI values in spring were caused by frequent dust storms. PM10 was the most frequent main pollutant in both Hami (63.1%) and Turpan (74.1%), followed by PM2.5 and O3. Except for O3, PM2.5, PM10, SO2, NO2, and CO exhibited a generally decreasing pattern in annual average values. But the annual average concentrations of PM10 in Hami (83.5 μg·m−3) and Turpan (139 μg·m−3) in 2022 were still higher than those in eastern China. Diurnal and monthly variations of the six criteria pollutants were influenced by a combination of emission sources and meteorological conditions. The air masses in eastern Xinjiang mainly originated from the west and north and were affected by both inter-regional and intra-regional transport. Analysis of the distribution of potential sources showed that local emissions strongly impacted particulate matter pollution in winter, while regional transport played a dominant role in other seasons. O3 showed a broad distribution of potential sources across all four seasons. Considering that the trend that O3 pollution increased year by year, eastern Xinjiang might face a similar pollution situation as eastern China, i.e., the combined pollution of particulate matter and O3.

Climate Change in the Eastern Xinjiang of China and Its Connection to Northwestern Warm Humidification

Eastern Xinjiang, as a typical extremely arid area, exhibits a high sensitivity to climate change. Gaining a comprehensive understanding of the climatic changes in this region, along with their driving mechanisms, and comparing these with the broader trend of “warming and humidifying” in the Northwest can provide a scientific foundation for adapting to and addressing climate change. Based on a study of precipitation and temperature data from seven meteorological stations in Eastern Xinjiang from 1960 to 2022, the following findings were observed: (1) The climate of eastern Xinjiang is generally characterized by a warming and humidifying trend, with the rates of mean annual temperature and total annual precipitation being 0.39 °C/10 a and 3.32 mm/10 a. The eastern part of Xinjiang has less precipitation, with a lower growth rate than that of the neighboring regions, and higher temperatures, with a higher growth rate than that of the neighboring regions. (2) The first principal component of precipitation explains 47.85% of the variation in total precipitation, with a significant upward trend (p &lt; 0.05) and an abrupt change in the late 1970s. It contains strong signals of regional precipitation, temperature, and dry and wet changes. (3) The increase in the first principal component of annual precipitation in eastern Xinjiang is mainly related to the warming of SSTs in the Indian Ocean and the central-eastern part of the tropical southern Pacific Ocean as well as the weakening of the Asian monsoon.

Ethnic and geographic variations in multiple chronic conditions among community-dwelling older people in Xinjiang: a cross-sectional study

BackgroundMultiple chronic conditions (MCC) refer to the presence of two or more chronic diseases. The incidence of MCC is higher in older people, and increases with age. Studies have shown an association between MCC and increased adverse outcome, as well as the higher mortality, decline of physical function, and poor quality of life in older populations. Herein, for the first time we provide the data of ethnic and geographic variations in the prevalence of MCC among community-dwelling older people in Xinjiang, China.MethodsA multilevel random sampling method was employed to perform an epidemiological survey in community-dwelling older adults in southern, northern, and eastern Xinjiang between January 2019 to December 2019. In total, 87,000 participants volunteered, with a response rate of 96.67%; 490 participants with incomplete data were excluded and data from 86,510 participants were analyzed.ResultsOur analysis demonstrated that hypertension (51.5%), obesity (27.0%), diabetes (16.9%), heart disease (8.2%), and anxiety/depression (4.5%) were the five main chronic diseases in Xinjiang. The prevalence of MCC in the population surveyed was 33.4% (95%CI, 33.1–33.7). The prevalence in females was 36.6% (95%CI, 36.1–37), which was higher than that in male (30%,95%CI, 29.5–30.4). The prevalence of MCC in older people aged 60–69, 70–79, 80–89, and ≥ 90 years was 32.7% (95%CI, 32.2–33.3), 34.3% (95%CI, 33.9–34.7), 32.5% (95% CI, 31.7–33.3), and 25.9% (95% CI, 23.5–28.3) respectively. As far as the ethnic group was concerned, the prevalence of MCC in Uygur, Han, Kazak, Hui, and Mongolian was 31.3% (95%CI, 30.9–31.7), 34.4% (95%CI, 33.9–35), 40.4% (95%CI, 39.1–41.8), 40.8% (95%CI, 38.9–42.7), 44.4% (95%CI, 38.1–50.6), respectively. The prevalence of MCC was 32.8% (95%CI, 32.1–33.5), 31.7% (95%CI, 31.2–32.1), 36.0% (95%CI, 35.3–36.7) and 39.2% (95%CI, 38.1–40.3) among uneducated, educated for 1–6, 7–9, and more than 10 years. After adjusting for age, sex, smoking, alcohol consumption, and education by level, the binary logistic analysis showed that, compared with eastern Xinjiang, the risk of MCC in the southern area was increased (odds ratio [OR], 1.418; 95% confidence interval [CI], 1.367–1.471), and it was relatively higher in northern Xinjiang (OR, 2.021; 95% CI, 1.944–2.102). Compared with Uygur, Han, Kazakh, Hui and Mongolian had an increased risk of MCC, which was (OR, 1.075; 95% CI, 1.040–1.111), (OR, 1.414; 95% CI, 1.332–1.501), (OR, 1.515; 95% CI, 1.396–1.644), (OR, 1.566; 95% CI, 1.216–2.017), respectively.ConclusionsThere are ethnic and geographic variations in multiple chronic conditions among community-dwelling older people in Xinjiang. The older adults living in northern and southern Xinjiang and Han, Kazakh, Mongolian and Hui older adults have a higher risk of MCC.

Spatiotemporal variability of photosynthetic and non-photosynthetic vegetation under climate change in arid and semiarid regions in China

ABSTRACT Understanding the spatiotemporal characteristics of photosynthetic vegetation (PV) and non-photosynthetic vegetation (NPV) is critical for the study of vegetation in arid and semiarid regions. However, the evaluation of the fractional cover of PV (f PV) and NPV (f NPV) in Xinjiang has received very little attention. Thus, this study aims to evaluate the spatiotemporal variation characteristics of PV and NPV and their responses to precipitation and temperature in Xinjiang from 2001 to 2020. The results showed that the overall stability of f PV and f NPV were of the low fluctuation and high fluctuation types, respectively. A significant increase trend of f PV was found in most regions (P < 0.01), while f NPV showed an insignificant increase trend in general, except for eastern Xinjiang (P > 0.05). The comparison of f PV and f NPV shows that the vegetation of Xinjiang has improved over time, except for the Yili region, showing the need to strengthen the environmental protection of this region. Through the spatial analysis, some agricultural oasis areas experienced an expansion in the distribution of vegetation, while some sparse vegetation distribution area has not improved. From the climate perspective, the response degree of f PV and f NPV with precipitation is higher than that of temperature. The responses of f PV and f NPV to precipitation are greater in the summer and spring phases, respectively. Whereas, the responses of both f PV and f NPV to temperature are greater in the autumn phase. In the time phase, precipitation mainly promotes the distribution of PV and NPV, while temperature mainly inhibits their distribution. This study provides a theoretical basis for ecological restoration and conservation in Xinjiang and other arid and semiarid regions worldwide.

Population genetics analysis of Tolai hares (Lepus tolai) in Xinjiang, China using genome-wide SNPs from SLAF-seq and mitochondrial markers.

The main topic of population genetics and evolutionary biology is the influence of the ecological environment, geographical isolation, and climatic factors on population structure and history. Here, we estimated the genetic diversity, genetic structure, and population history of two subspecies of Tolai hares (Lepus tolai Pallas, 1778), L. t. lehmanni inhabiting Northern and Northwest Xinjiang and L. t. centrasiaticus inhabiting Central and Eastern Xinjiang using SNP of specific-length amplified fragment sequencing (SLAF-seq) and four mitochondrial DNA (mtDNA). Our results showed a relatively high degree of genetic diversity for Tolai hares, and the diversity of L. t. lehmanni was slightly higher than that of L. t. centrasiaticus, likely due to the more favorable ecological environment, such as woodlands and plains. Phylogenetic analysis from SNP and mtDNA indicated a rough phylogeographical distribution pattern among Tolai hares. Strong differentiation was found between the two subspecies and the two geographical groups in L. t. centrasiaticus, possibly due to the geographical isolation of mountains, basins, and deserts. However, gene flow was also detected between the two subspecies, which might be attributed to the Tianshan Corridor and the strong migration ability of hares. Tolai hare population differentiation occurred at approximately 1.2377 MYA. Population history analysis based on SNP and mtDNA showed that the Tolai hare population has a complex history and L. t. lehmanni was less affected by the glacial event, possibly because its geographic location and terrain conditions weaken the drastic climate fluctuations. In conclusion, our results indicated that the joint effect of ecological environment, geographic events, and climatic factors might play important roles in the evolutionary process of L. t. lehmanni and L. t. centrasiaticus, thus resulting in differentiation, gene exchange, and different population history.

Architectural Model of a Dryland Gravel Braided River, based on 3D UAV Oblique Photogrammetric Data: A Case Study of West Dalongkou River in Eastern Xinjiang, China

AbstractThree‐dimensional unmanned aerial vehicle (UAV) oblique photogrammetric data were used to infer mountainous gravel braided river lithofacies, lithofacies associations and architectural elements. Hierarchical architecture and lithofacies associations with detailed lithofacies characterizations were comprehensively described to document the architectural model, architectural element scale and gravel particle scale. (1) Nine lithofacies (i.e., Gmm, Gcm, Gcc, Gci, Gcl, Ss, Sm, Fsm and Fl) were identified and classified as gravel, sand and fine matrix deposits. These are typical depositional features of a mountainous dryland gravel‐braided river. (2) Three architectural elements were identified, including channel (CH), gravel bar (GB) and overbank (OB). CH can be further divided into flow channel and abandoned channel, while GB consists of Central Gravel bar (CGB) and Margin Gravel bar (MGB). (3) The gravel bar is the key architectural element of the gravel braided river, with its geological attributes. The dimensions of GBs and their particles are various, but exhibit good relationships with each other. The grain size of GB decreases downstream, but the dimensions of GB do not. The bank erosion affects the GB dimensions, whereas channel incision and water flow velocity influence the grain size of GB. The conclusions can be applied to the dryland gravel braided river studies in tectonically active areas.

Spatiotemporal variation of irrigation water requirements for grain crops under climate change in Northwest China.

Clarifying the spatiotemporal variation of crop irrigation water requirement (IWR) under the background of climate change is an essential basis for water resource management, determining the irrigation quota and adjusting the planting structure. Using 61years of climate data from 205 stations in Northwest China, this study investigated the spatiotemporal variations of climatic factors and IWR during the growth period of five main grain crops (spring wheat, winter wheat, spring maize, summer maize, and rice) and explored the dominant climatic driving factors of IWR variation. Results showed that (1) the IWR of grain crops showed distinct differences. Rice was the highest water consumption crop (mean of 753.78mm), and summer maize was the lowest (mean of 452.90mm). (2) The variation trends and average values of IWR of different grain crops have spatial heterogeneity across Northwest China. For most crops, high values and increasing trends of IWR were mainly located in eastern Xinjiang, western Gansu, and western Inner Mongolia. (3) Tmax (maximum temperature), Tmin (minimum temperature), and Peff (effective precipitation) showed an increasing trend during the growth period of each grain crop, while U10 (wind speed at 10m height), SD (solar radiation), and RH (relative humidity) presented decreasing trends. (4) SD, Tmax, and U10 promoted the increase of grain crops' IWR, while Peff and RH inhibited it. The impacts of climatic factors on the grain crop IWR differed among different regions. Peff was the most influential factor to the IWR of all grain crops in most areas. Therefore, under the premise of a significant increase in T and uncertain precipitation mode in the future, it is urgent to take effective water-saving measures according to the irrigation needs of the region. To cope with the adverse impact of climate change on the sustainable development of agriculture in the northwest dry area, to ensure regional and national food security.

Analysis of Urban Expansion and Human–Land Coordination of Oasis Town Groups in the Core Area of Silk Road Economic Belt, China

Under economic globalization, synergy among cities has been actively promoted. Establishing inter–city networks and joint regional development could catalyze economic growth. The mode and pace of urban growth could be gauged by construction land expansion and human–land coordination. This study adopted the dynamic change, the center of gravity, and coordination analyses to comprehensively portray spatial patterns and changes amongst 13 oasis town groups in Xinjiang, China, from 2000 to 2018. The results identified that 2010 was the turning point of acceleration in construction land expansion, demonstrating notable spatial differentiations among town groups. Northern Xinjiang experienced faster urban growth than southern Xinjiang. The Urumqi–Changji–Shihezi (UCS) town group on the northern slope of the Tianshan Mountains constituted the crucial urban core with the fastest construction land expansion. Although the towns in southern Xinjiang were small and beset by inherent limitations in the early period, some town groups acquired new impetus and vitality and became the fastest–developing areas in Xinjiang in recent years. The growth was driven by China’s western development program, economic assistance, and Silk Road Economic Belt. Eastern Xinjiang had convenient transportation, but its small urban entities needed population supplementation to invigorate urban expansion. In the far north, the Altay and Tacheng–Emin (TE) town groups were situated too far from development cores. They lacked the collateral benefits of nearby strong–growth loci, resulting in sluggish growth. A north–south dual–hub strategy was proposed to spearhead the dissemination of urban growth by fostering core–periphery linkages pump–primed by improved road connections.

Response of the natural grassland vegetation change to meteorological drought in Xinjiang from 1982 to 2015

In recent years, drought frequency has gradually increased, which has reduced vegetation growth and development. The response of grassland to meteorological drought is more sensitive than other vegetation types and can differ substantially among grassland types. In this study, the response of vegetation change to meteorological drought at different time scales was evaluated using data from the normalized difference vegetation index (NDVI) and the standardized precipitation evapotranspiration index (SPEI) to analyze the spatial and temporal variation trends and correlations of the NDVI and SPEI of three grassland types in Xinjiang from 1982 to 2015. Over this 34-year period, the NDVI of meadow, steppe, and desert grassland in Xinjiang increased, with growth rates of 0.002, 0.002, and 0.0003 per decade, respectively, although the increase was insignificant (p &amp;gt; 0.05). The most obvious vegetation improvement areas of the three grassland types were mainly distributed in the Tianshan Mountains. The SPEI-12 of meadow, steppe, and desert grassland in Xinjiang indicated an extremely significant drying trend (p &amp;lt; 0.01), with change rates of −0.31, −0.38, and −0.34 per decade, respectively. The overall pattern was the gradual drying from the northwest to southeast, and the degree of aridification was the largest in eastern Xinjiang. On the annual scale, the correlation between the NDVI and SPEI-12 of the three grassland types was significantly different between northern and southern Xinjiang. The degree to which the vegetation of the three grassland types responded to drought was higher in northern Xinjiang than in southern Xinjiang, and most responses were significant. On the monthly scale, the response of meadow to the SPEI-12 was the highest in autumn (September) (r = 0.53; p &amp;lt; 0.05), the response of steppe to the SPEI-3 was the highest in summer (August) (r = 0.49; p &amp;lt; 0.05), and the response of desert grassland to the SPEI-12 was the highest in summer (June) (r = 0.44; p &amp;lt; 0.05). The results can provide a scientific basis for natural grassland drought response, ecological environmental improvement, and disaster prevention and mitigation.

Probability distribution characteristics of summer extreme precipitation in Xinjiang, China during 1970–2021

Based on the daily precipitation data of 96 stations in Xinjiang, China, from 1970 to 2021, the trend of summer extreme precipitation indices and their regional characteristics are analyzed. The generalized extreme value (GEV) model is used to investigate the probability distribution characteristics of summer extreme precipitation indices in northern, southern, and eastern Xinjiang. The results show that (1) The summer maximum 1-day precipitation (RX1day) and maximum 5-day precipitation (RX5day) of most stations in Xinjiang showed an increasing trend, while the summer consecutive dry days (CDD) showed a decreasing trend. (2) The climatology (mean intensity) of RX1day, RX5day, and CDD at most stations in northern Xinjiang were more than 10 mm, more than 15 mm, and less than 25 days, respectively, while those at most stations in southern and eastern Xinjiang were less than 10 mm, less than 15 mm, and more than 25 days. The regional averaged climatology and inter-annual variability of RX1day/RX5day (CDD) in southern and eastern Xinjiang were smaller (larger) than that in northern Xinjiang. (3) The 20-year return level (RL20) of RX1day, RX5day, and CDD at stations in northern Xinjiang were 19.38–56.57 mm, 28.05–70.91 mm, and 22.51–51.05 days, respectively. The RL20 of RX1day, RX5day, and CDD at stations in southern Xinjiang were 21.31–46.07 mm, 23.99–72.89 mm, and 14.94–89.80 days, respectively. The RL20 of RX1day, RX5day, and CDD at stations in eastern Xinjiang were 8.89–36.36 mm, 10.13–50.66 mm, and 26.75–92.00 days, respectively. Compared with northern Xinjiang, there were lesser RX1day and RX5day events, with weaker intensity and smaller variability in southern and eastern Xinjiang. And the CDD events were opposite.