The Aral Sea was once the fourth largest lake in the world. Since the 1960s, due to the demands of agricultural irrigation, the regions of the Aral Sea basin have diverted a large amount of water from the Amu Darya and Syr Darya rivers, resulting in the rapid shrinkage of the Aral Sea, the reduction of water levels, and also the deterioration of water quality. By the beginning of the 21^st century, the lake’s surface had shrunk to 1/8 of its original size, and the dried lake bottom had become a salt desert with high salinity. Many biological species decreased and the ecological environment deteriorated, causing an ecological crisis. After the independence of the Central Asian countries, the conflict between the upper and lower parts of the Amu Darya River and Syr Darya River resulted from the lack of water, which seriously affected the relations between these countries. Despite repeated negotiations, the Central Asian countries failed to come up with a common solution to the Aral Sea water crisis. In the absence of regional cooperation, Kazakhstan took independent measures and saved part of the waters of the northern part of Aral Sea. Moreover, Uzbekistan also took a proactive approach to managing the Aral Sea crisis in recent years. The prevailing academic opinion is that the Aral Sea crisis is human-made and that linking it to global climate change is inappropriate. Thus, the Aral Sea crisis, which has been improved because of governance and groundwater recharge, may not disappear as previously predicted and considerable uncertainty remains as to how much it will recover. This study offers a complete discussion of the history, status, and prospects of the Aral Sea crisis to provide a reference for the governance of the arid environment in northwestern China.

Oases are unique and ecologically sensitive landscape types in arid and semiarid regions and play a crucial role in sustaining human survival and socioeconomic development. However, climatic changes and human activities are causing drastic changes to water resources and the oasis eco-environment. This study analyzes terrestrial water storage changes and assesses the ecological security of oases in the Tarim River Basin of Xinjiang, China. The assessment was performed using the fraction of vegetation cover, a remote sensing ecological index, and net primary productivity (NPP) using the Carnegie-Ames-Stanford approach. The analysis used moderate-resolution imaging spectroradiometer satellite images, GRACE data, land use data, and climatic gridded and observed data from 2002 to 2020. The results indicate the following: (1) Terrestrial water storage in the Tarim River Basin decreased at a rate of 0.27 mm per month. Spatially, terrestrial water storage in the northern and western regions of the Tarim River Basin exhibited a negative trend, whereas that in the southern regions of the Basin showed a positive trend. (2) The total oasis area in the Tarim River Basin expanded by 6.49% (0.42×10⁴ km²) from 2000 to 2020. The ecological security of the basin improved, and the eco-environment ranged from poor to general grade. Approximately 69% of the region’s eco-environment improved, whereas the area of ecological degradation was less than 5%. The normalized difference vegetation index increased from 0.13 in 2000 to 0.16 in 2020, the fraction of vegetation cover increased by 36.79%, and the NPP expanded by 31.55% in the past 20 years. (3) Rising temperatures and precipitation contributed to increased downstream river runoff and spatiotemporal variability of water resources in the Tarim River Basin. However, human activities are a key factor in the expansion of oases.

The Loess Plateau, a region in China that is highly sensitive to climate change, serves as a focal point for investigating the spatiotemporal evolution of relative humidity (RH). Understanding the interplay between RH and geographical and meteorological factors is essential for comprehending the climate change dynamics within the plateau. This study leverages daily RH observations from 90 meteorological stations in the Loess Plateau and its environs to analyze the temporal and spatial variations in RH from 1960 to 2021, both before and after the implementation of ecological initiatives such as the conversion project of farmland to forest and grass. Using trend analysis, sensitivity analysis, and spatial interpolation, we unveil the following findings: (1) The average annual RH in the Loess Plateau exhibited a notable decrease of -0.376%·(10a)^-1 (P<0.05) from 1955 to 2021, undergoing a decadal variation characterized by a “weakening-strengthening-weakening” process. While autumn experienced a slight increase, all other seasons displayed a declining trend, with the most pronounced decrease observed in spring [-0.945%·(10a)^-1] and the least in winter [-0.194%·(10a)^-1]. (2) Spatially, the winter average RH in the Loess Plateau peaked in the south, gradually diminishing from east to west in the central and northern regions. Conversely, other time series demonstrated a gradual decline from south to north. The spatial patterns of the annual and seasonal average RH variation trends in the Loess Plateau were different. (3) Postimplementation of the ecological project, the average RH throughout the year, as well as in spring, summer, and winter, exhibited varying degrees of decrease. The trends in annual, summer, and winter RH shifted from an increasing to a decreasing trajectory. Noteworthy differences emerged in the spatial distribution characteristics of annual and seasonal average RH, coupled with their respective trend changes. The prevailing trend change combination type for all temporal RH patterns was consistently low. (4) The primary seasonal factor influencing long-term changes in annual RH in the Loess Plateau is spring, with spatial dominance primarily by a single dominant type in spring and a combination of dominant types in spring and summer. (5) The annual and seasonal average RH in the Loess Plateau demonstrated a significant negative correlation with latitude (P<0.01) and a positive correlation with precipitation (P<0.01). The geographical factors exerted the most significant influence on summer average RH. Annual, spring, and summer average RH were most sensitive to average temperature, whereas autumn and winter were most responsive to wind speed.

Water is essential for the formation of oases in arid areas. Water source districts maintain the existence of oases, facilitate sustainable development of the local economy, and ensure the stability of the ecological environment in the mountains of the northwest arid area. Forest ecosystems are important for water conservation and are called a “green reservoirs” in mountainous areas. Climate change is anticipated to alter the structure and composition of terrestrial ecosystems, affecting elements of the terrestrial water cycle and exacerbating water shortages, thereby posing a threat to arid oases. This study briefly reviews and summarizes the research progress and existing problems related to climate change and their impact on the stability and hydrological processes of mountain forest ecosystems in arid regions. In the future, it also suggests that the trend of climate change needs to be evaluated in arid mountains with an enhanced spatial resolution of 1 km. A comprehensive study of the impact of climate change on the stability of mountain forest ecosystems and hydrological processes in arid areas is recommended, considering multiple scales, interfaces, disciplines, and methods. This approach aims to promote the development of mountain ecology in arid areas and to lay the theoretical foundation for arid area management departments to adapt to and mitigate the impact of climate change. It further emphasizes the need to scientifically formulate management plans for climate change conditions and realize effective water resource management, thereby promoting sustainable environmental and socioeconomic development under climate change conditions in arid regions.

The Ili River Basin, spanning China and Kazakhstan, features a delicate ecological environment. Understanding the vegetation changes throughout the basin is essential for the region’s sustainable development. This study analyzed spatiotemporal vegetation variations in the Ili River Basin from 2000 to 2022, utilizing enhanced vegetation index data from MODIS. We examined vegetation change disparities within and outside China’s portion of the basin, among various vegetation types, and across different elevations. Our findings reveal: (1) Since 2000, vegetation conditions have generally improved across the Ili River Basin, notably in Kazakhstan, whereas a decline was observed within China. Degraded regions are predominantly at elevations between 1000 m and 3000 m. Grasslands and croplands exhibited positive trends, in contrast to forests. (2) Over the past 20 years, the Ili River Basin experienced minor vegetation fluctuations, with more pronounced variations within China. Grasslands encountered higher fluctuations compared to croplands and forests, and the 2500 m to 3000 m elevation range showed relatively stable vegetation. (3) Future projections indicate a prevailing positive trend in vegetation across the Ili River Basin, with approximately 52% of the areas expected to see ongoing improvement. Grasslands are anticipated to have higher improvement ratios than croplands and forests. Regions below 1000 m and above 3000 m in elevation are likely to experience sustained positive changes. This study’s insights into vegetation dynamics will inform ecological protection strategies in the Ili River Basin.

Drought is one of the most disastrous extreme climate events. Studying the changes in drought risk against the background of future global warming is beneficial for scientifically advancing disaster prevention and reduction work deployment. The standardized precipitation evapotranspiration index was calculated using data from 20 climate models from the sixth phase of the Coupled Model Intercomparison Project. Drought characteristic variables were extracted for the baseline period and global temperature rise scenarios of 2 ℃, 3 ℃, and 4 ℃ in China, and the drought hazard index (DHI) was calculated. Based on the disaster-bearing body projection data, the drought exposure index (DEI), drought vulnerability index (DVI), and drought risk index (DRI) were comprehensively calculated. The distribution pattern of drought risk in China was further analyzed, and a spatial attribution analysis of future drought risk changes was performed using a geodetector. The results showed that the spatial distribution of DHI, DEI, and DVI exhibited higher values in the northwest and southeast, a pattern of being high in the east and low in the west, and a trend of being high in the west and low in the east, respectively. Based on this, the DRI specially showed a spatial positive correlation dominated by high- and low-value clustering. With an increase in the temperature rise level, the future drought risk will mainly increase across China, and the increase in the eastern coastal areas would be the most obvious. Changes in population, gross domestic product, and the proportion of cultivated land were found to be the main factors affecting changes in drought risk.

Based on daily precipitation data from 28 national meteorological stations in northern Shanxi Province, China, from 1972 to 2020, temporal and spatial changes in extreme precipitation in northern Shanxi and their correlation with atmospheric circulation factors and periodic characteristics were studied using linear regression, Pearson correlation analysis, continuous wavelet analysis, and cross wavelet transform analysis. The results show the following: (1) In terms of time, the eight extreme precipitation indices in northern Shanxi increased significantly in the late 1970s and from the late 2010s to the early 2000s: annual total wet-day precipitation (PRCPTOT), number of heavy precipitation days (R10mm), soaked days (R95P), extremely wet days (R99P), maximum 1-day precipitation amount (Rx1day), and maximum 5-day precipitation amount (Rx5day). The simple daily intensity index (SDII) increased significantly, and consecutive wet days (CWD) also increased slightly. Precipitation was unusually low throughout the 1980s. (2) Spatially, the extreme precipitation indices gradually increased from northeast to southwest. From the analysis of the stations’ trend change, the extreme precipitation indices of most stations showed an upward trend, with the most significant upward trend of the stations located southwest of Xinzhou City. PRCPTOT and SDII in Shuozhou City and southeast of Xinzhou City showed an increasing trend. However, days of CWD showed a decreasing trend, indicating that the probability of extreme precipitation events in Shuozhou City and the southeast of Xinzhou City was high. (3) Through wavelet transform analysis, it was discovered that the extreme precipitation indices in northern Shanxi had a periodic feature of recurring in approximately 4 years in the past 30 years. Among the selected atmospheric circulation indices, the North Atlantic Oscillation Index (NAO) had the most obvious influence on extreme precipitation in northern Shanxi. The larger the NAO, the smaller the PRCPTOT, R10mm, R95p, R99p, Rx1day, Rx5day, and SDII, and the lower the CWD, the greater the probability of low rainfall and drought in northern Shanxi, which is prone to flash flooding. The research results can provide a scientific theoretical basis for the prevention of meteorological disasters in northern Shanxi.

This study examines various flood disaster types in Xinjiang, China, encompassing extreme temperature fluctuations, snowstorms, and warm, humid conditions attributed to global climate change. This study focuses on the underexplored issue of snowmelt floods, addressing their escalating frequency, severity, and associated disaster risk in Xinjiang. Using VOSviewer software, this study analyzes the research keywords and collaboration networks among different authors investigating snowmelt floods in Xinjiang. In addition, it scrutinizes the research priorities of scholars at various stages. A comparative analysis of the characteristics and research status of diverse snowmelt runoff models is presented. The study advocates for future research in Xinjiang to delve into the physical mechanisms and snowmelt processes integral to snowmelt runoff models, aiming to enhance prediction and warning accuracy. An assessment of the technologies employed for predicting and warning snowmelt floods in Xinjiang is conducted, highlighting pertinent issues such as wind-blown snow, frozen ground surface snow, and rain-on-snow. Furthermore, the study recommends key technologies to augment the overall capability of flood simulation, prediction, warning, and response to abrupt floods. It also explores strategies for optimizing the use of flood resources. In conclusion, this study furnishes recommendations for refining the prediction and warning technology pertinent to snowmelt floods in Xinjiang.

Based on daily precipitation data from 337 meteorological monitoring stations in Qinling Mountains and surrounding areas during 1980—2021, the spatiotemporal characteristics of extreme precipitation were analyzed. The generalized extreme value distribution and climate statistics methods were used to compare the differences in extreme precipitation years and seasons (spring, summer, and autumn) between two phases: the first phase (1980—2000) and the second phase (2001—2021). The results are as follows: (1) Extreme precipitation in Qinling and surrounding areas mainly concentrated from April to November, with July registering the highest number of extreme precipitation days. Over the past 40 years, extreme precipitation has shown an overall increasing trend. Spatially, the southeast exhibits higher values for the extreme daily precipitation threshold and daily maximum precipitation than the northwest. Additionally, a clear boundary along the north-south direction, aligning with the Qinling, highlights more occurrences in the southern region than in the northern region. (2) On an annual scale, there is a discernible rise in both the number and intensity of extreme precipitation events during 2001—2021 compared with 1980—2000. The spatial changes in the extreme daily precipitation threshold, the number of extreme precipitation days, and daily maximum precipitation also show an overall increasing trend, with more meteorological stations exhibiting an increasing trend. (3) Considerable seasonal differences in extreme precipitation exist, particularly between spring and summer/autumn. The probability and frequency of extreme precipitation were generally higher in spring during 1980—2000, whereas in 2001—2021, extreme precipitation peaks in summer and autumn. Spatial distribution differences are also evident. In spring, the extreme daily precipitation threshold and the number of extreme precipitation days generally show an increasing trend in the western region, contrasting with a decreasing trend in the eastern region, transitioning from positive to negative values. A greater number of stations display a decreasing trend than an increasing trend. In contrast, in summer and autumn, the number of stations demonstrating an increase in the extreme daily precipitation threshold and the number of extreme precipitation days exceeds those witnessing decreasing trends, particularly in autumn, where the proportion of stations with increasing trends is higher.

Water, energy, and carbon exert significant influence on the intricate interconnected systems of economy, society, and ecology. Alterations in any one of these factors can instigate a cascading effect, transferring ecological pressures and impacting the sustainable development of both regions and industries. Focusing on Xinjiang, China, and utilizing input and output data from 2007, 2012, and 2017, this paper employed the environmental input-output model to calculate implicit water consumption, implicit energy consumption, and implicit carbon emissions across 18 industrial sectors in Xinjiang. Additionally, an ecological network analysis model was employed to elucidate system circulation rates, robustness, and control dependencies. The findings revealed the following insights: (1) Mixed water was predominantly allocated to domestic outflow and household consumption, whereas mixed energy and mixed carbon were primarily utilized for domestic outflow and total capital formation. (2) The circulatory rates of water networks remained below 42%, while those of energy networks and carbon networks were below 25%, indicating an overall declining trend in the network system. (3) The system robustness of water networks, energy networks, and carbon networks signified a development stagnation, portraying an unsustainable overall developmental state. (4) A weak correlation was observed among the water system, energy system, and carbon system in various departments within the “water-energy-carbon” coupling system in Xinjiang. Control and dependence relationships are currently in an incidental state, lacking the formation of a synergistic “water-energy-carbon” relationship between industries. This study elucidated the governing principles of the “water-energy-carbon” coupling system in Xinjiang, providing valuable data to support the realization of a low-carbon and efficiently integrated resource management model.

The Shule River Basin is located in the northwest inland region of China and is a key node of the Belt and Road Initiative. In recent years, with the increasing intensity of global changes and economic and social activities, problems, such as the rapid expansion of construction land and desertification have affected the sustainable development of regional ecology and economic society. The Shule River Basin is located at the center of the northern sand prevention belt of China, and an evaluation of its wind prevention and sand fixation value is of great ecological significance for building a regional ecological security pattern and ensuring sustainable development of the basin. On the basis of the revised wind erosion equation model, the value of wind prevention and sand fixation in the Shule River Basin from 2008 to 2018 was evaluated. The results are as follows: (1) The total amount of wind prevention and sand fixation in the Shule River Basin from 2008 to 2018 was 43.927×10⁴ to 129.530×10⁴ t·km⁻², with an increasing trend in wind prevention and sand fixation capacity. (2) The value of wind prevention and sand fixation in the Shule River Basin rapidly increased from 2008 to 2018, with an annual average value ranging from high to low to reduce the value of land loss (99.46%), maintain the value of soil fertility (0.47%), maintain the value of soil organic matter (0.04%), and reduce the value of economic loss of transportation (0.03%). (3) The function of wind prevention and sand fixation in river basins is closely related to land use. Among them, the areas with stronger windproof and sand-fixing capability are primarily distributed in grassland, cropland, and other areas with higher vegetation cover; the low-value areas are primarily distributed in unused land of the land use type of the river basin. (4) Natural indicator factors have a greater impact on the value of wind and sand fixation functions in river basins than social factors. These findings can provide a basis for determining the subject and object of ecological compensation and compensation standards in the Shule River Basin.

Using RA5 monthly reanalysis data from the European Centre for Medium-Range Weather Forecasts and monthly precipitation records from the Global Precipitation Climatology Centre spanning 1980 to 2019, this study examines the influence of May soil moisture anomalies on subsequent June precipitation variability in Central Asia. The findings unveil the following key insights: (1) The spatial distribution of springtime soil moisture exhibited elevated levels in Central Asia’s northern and central regions and lower levels in the southwest and southeast. Maximum standard deviations occurred in southwest Central Asia during March and April. In the north of Central Asia, soil moisture experiences a noteworthy increasing trend in March but displays a declining trend from April to May. Conversely, southwest Central Asia witnessed substantial decreases in March. (2) June precipitation in Central Asia positively correlates with local soil moisture in May. Persistent wet soil moisture anomalies from May to June contribute to increased atmospheric precipitable water, modifying regional evaporation patterns in June. Heightened evaporation leads to increased latent heat flux and reduced sensible heat flux. A small Bowen ratio indicates a relatively shallow boundary layer that promotes low-layer moist entropy and a heightened potential for convective activity. Consequently, June rainfall over the central regions of Central Asia increased. (3) A notable positive correlation exists between soil moisture in May and precipitation in June over middle Central Asia and the preceding winter Niño3.4 index. The influence of the preceding El Nino-Southern Oscillation (ENSO) on June precipitation in middle Central Asia is mediated by May soil moisture. Nonetheless, soil moisture anomalies can independently impact the variability of June precipitation, separate from the influence of ENSO.

The assessment of ecological security in tourism destinations is intricately linked to the sustainable development of tourism, and the careful selection of evaluation methods plays a critical role in mitigating uncertainties surrounding the results of such assessments. On the basis of analysis, this study focuses on the tourism ecological safety situations in five prefecture-level cities in the Hexi Corridor region of Gansu Province, China from 2011 to 2020. It constructs a comprehensive index system for evaluating tourism ecological safety and uses the entropy weight TOPSIS method and the fuzzy matter-element model to quantitatively assess the results. (1) The results of both methods suggest that there is a general upward trend in tourism ecological security in the Hexi Corridor region. (2) The trend of change in the driving force and pressure composite indices in the Hexi Corridor region is coordinated, the trend of change in the impact and state composite indices is similar, and the response composite index better reflects the results of regional government initiatives. (3) The evaluation results obtained using the fuzzy matter-element model method have higher credibility. These findings can offer valuable insights for the selection of models to evaluate the ecological safety of tourism systems.

The issue of imbalanced and insufficient development in China’s tourism industry remains prominent. Clarifying the spatiotemporal evolution characteristics and driving forces of tourism efficiency is crucial for enhancing efficiency and promoting the high-quality development of regional tourism. Using the data envelopment analysis model, this study assesses the tourism development efficiency of 31 provinces (excluding Hong Kong, Macao, and Taiwan regions) from 2009 to 2019. It employs spatial autocorrelation, cold and hot spot analysis, and regression models to analyze the spatiotemporal evolution characteristics and factors influencing China’s provincial unit tourism efficiency. The research reveals the following: (1) Between 2009 and 2019, China’s tourism industry efficiency exhibited a steady upward trend. Significant differences in the spatial distribution of various efficiency levels were observed, with strengthening spatial agglomeration characteristics. The tourism growth mode is transitioning from extensive to intensive development. (2) There is a notable spatial positive correlation in the development efficiency of China’s provincial tourism industry. The average comprehensive efficiency, average pure technical efficiency, and average scale efficiency of tourism industry development exhibit a spatial pattern of “hot in the south and cold in the north” at the local level. (3) The comprehensive efficiency of the tourism industry is strongly influenced by the quality of tourism resources. Pure technical efficiency is primarily affected by the positive impact of transportation reachability, while the quality of tourism development is the main positive impact factor of scale efficiency. (4) Enriching tourism product formats, improving regional tourism cooperation mechanisms, and optimizing the tourism industry structure emerge as crucial strategies for enhancing the development efficiency of China’s provincial tourism industry. The research findings provide a theoretical basis and practical paradigm for formulating regional tourism collaborative development strategies and achieving the high-quality development of the tourism industry.

The Datong River Basin is located on the northeastern edge of the Qinghai-Tibet Plateau and is a sensitive and fragile ecological environment. It is of great significance to conduct research on the evolution and attribution of water resources in changing environments for the protection of the water ecological environment in the area and the construction of water ecocivilization. Statistical methods such as linear regression, concentration degree, concentration period, ordered clustering test, and wavelet analysis were used to analyze the characteristics of annual variation, seasonal distribution, periodicity, and abrupt changes in basin runoff. On the basis of the cumulative slope change rate method and double cumulative curve, the effects of climate factors and human activities on runoff changes were quantitatively evaluated. The results showed the following: (1) The climate in the Datong River Basin had warmed and humidified significantly in the past 60 years, with increases in average annual temperature, precipitation, and potential evapotranspiration of 0.42 ℃·(10a)^-1, 8.9 mm·(10a)^-1, and 5.6 mm·(10a)^-1, respectively. The annual runoff showed a decreasing trend, with a tendency rate of 0.67×10⁸ m³·(10a)^-1. (2) The concentration degree and uneven coefficient of runoff showed a weak downward trend, and the increasing dry season runoff trend was evident. The seasonal distribution was more uniform, and the concentration period showed a delayed trend, with a delay rate of 3.0 d·(10a)^-1. (3) The annual runoff oscillated significantly at a scale of approximately 44 years, and the mutation occurred in 1990. After the mutation, runoff decreased by 3.52×10⁸ m³. The distribution of glaciers in the basin showed a decreasing trend, whereas the vegetation cover did not show a significant change. (4) The contributions of climate and human activities to the runoff decrease in the Datong River were -17.7% and 117.7%, respectively. Precipitation was the main source of water supply in the Datong River Basin, and interbasin water transfer was the main driving factor for runoff reduction.

Several factors affect the evapotranspiration process. Potential evapotranspiration (ET₀) interacts with meteorological variables in a complex manner. Therefore, there is an urgent need to determine the response mechanism of ET₀ changes to meteorological variables. Based on meteorological data from 21 meteorological stations in the Hexi Corridor, Gansu Province, China and its surrounding areas, qualitative and quantitative methods were adopted to reveal the spatiotemporal variation of ET₀ and to clarify the sensitivity of ET₀ to changes in various meteorological factors and contributions by taking two spatial scales of the Hexi Corridor as a whole and three subdistricts. The results showed the following: (1) ET₀ in both the Hexi Corridor and the subdistrict showed a significant fluctuating upward trend (Z>1.98), with a linear change rate of 2.94 mm·a^-1, and the most obvious change was observed in the Heihe subdistrict. (2) ET₀ increased from the southeast to northwest. It was smaller in the Shiyang River subdistrict (1003.78 mm) and Heihe subdistrict (1031.30 mm) in the central and eastern parts of the Hexi Corridor, and larger in the Shule River subdistrict (1171.89 mm) in the western part of the Hexi Corridor. (3) The sensitivity of ET₀ to changes in meteorological factors in the Hexi Corridor was ranked as relative humidity (RH), daily maximum temperature (T_max), sunshine duration (n), average wind speed (u), and daily rainfall (P), with ET₀ being the most sensitive to decreases in RH and least sensitive to changes in P. (4) The increase in u was the main cause of the increase in ET₀ in the Hexi Corridor, followed by a decrease in RH, increase in T_max, and increase in n. (5) The ET₀ in the subdistricts of the Shule River, Heihe River, and Shiyang River showed an increasing change, with the factors that contributed the most being T_max (5.13%), u (8.22%), and T_max (5.97%), respectively, and the factor that contributed the least being n. Variations in wind speed and air temperature were important factors that influenced the ET₀ change in the Hexi Corridor. The research results are significant for the rational planning of irrigation water use and improvement of the utilization efficiency of agricultural water resources.

Based on temperature, precipitation, and snow depth data from five hydrological stations in four sources of the Tarim River Basin of Xinjiang, China, from 1981 to 2020, flood magnitude, frequency, and peak time were analyzed using maximum and peak-over-threshold (POT) sampling methods. Moreover, correlation analysis was performed to reveal the relationship between different flood indicators and influencing factors and identify key influencing factors. The results show the following: (1) From 1981 to 2020, the peak discharge of each hydrological station in “four sources” of the Tarim River Basin is as follows: Kaqung>Xehera>Tongguzlok>Sharikilank>Daschankou. The annual and seasonal flood peak discharge generally exhibited an increasing trend, and the occurrence time of the flood peak in winter exhibited an earlier state, among which the average annual advance of Sharikilank was 2.61 days, whereas that of the Kaqung station was only 0.67 days. (2) There were two periods of high flooding in the Tarim River Basin, namely, 1994—2002 and 2006—2011, with several flood occurrences in the Tarim River Basin after 1990. (3) The minimum temperature, precipitation, and snow depth at different times before the floods mainly exhibited an increasing trend, while the maximum temperature mainly exhibited a decrease. The highest correlation was found between spring flood indicators and maximum 3-day precipitation, whereas the highest correlation was found between autumn flood indicators and maximum 7-day precipitation. The correlation between multi-day precipitation and flood indicators was higher than that between single-day precipitation and flood indicators. Among the snow depth-related factors, the maximum 15-day snow depth had the highest correlation with spring flood indicators at each station. These findings provide a theoretical basis for regional water resource management and flood disaster prediction.

The bedrock of the Danxia landscape is predominantly cemented by calcareous and ferruginous cements; thus, it has special landscape elements and formation mechanisms. It has become an important tourism resource with much attention because of its high scientific and ornamental values. However, compared with southeast humid areas, little attention has been paid to the characteristics and causes of the Danxia landscape in the arid climate of Northwest China. The Wensu Grand Canyon in the Aksu Prefecture of Xinjiang was selected and investigated to explore the characteristics and causes of the Danxia landscape by field investigation, sample microscope observations, salt chemistry and element geochemistry experiments, and ArcGIS hypsometry. The results are as follows: (1) The study area is characterized by canyon, peak and peak forest landscapes, well-developed mud flow films along slopes, and cap rock columns. The bedrock comprises red fluvial conglomerates and sandstones of Neogene age. The hard conglomerate beds are favorable for the formation of cap rock columns. (2) The study area is located near the Wensu salt dome with a high salt content, and the main salt minerals are probably chlorides, nitrates and sulfates, as inferred from the salt experiment. Most of the major elements of sandy debris samples within caverns migrated compared with the surface rock, indicating active chemical weathering in the arid climate. (3) The hypsometric integral (HI) shows that the HI value of the southern part of the study area is 0.61, which suggests an early stage. The HI value of the northern part is 0.38, which indicates a late stage. Therefore, the geomorphic evolution and development stages differ in the study area. Although the precipitation in the study area is very low, river erosion is obvious. Tectonism is also considered the main controlling factor of Danxia landscape evolution.

Evapotranspiration is an important component of the terrestrial water cycle, and is complex in cold and arid environments. The northern slope of the Kunlun Mountains in Xinjiang of China, situated on the northern edge of the Qinghai-Xizang Plateau, lacks a comprehensive understanding of potential evapotranspiration due to the absence of long-term meteorological observations. This study examined the spatiotemporal variations of potential evapotranspiration from 1979 to 2021, especially from a sub-basin perspective, and analyzed the relationship between potential evapotranspiration and other meteorological parameters using the Mann-Kendall test and empirical orthogonal function. The results indicate that: (1) The long-term mean of potential evapotranspiration is 733.5 mm per year, exhibiting a spatial variation trend that decreases gradually from the southern edge of the Tarim Basin towards the south. (2) From 1979 to 2021, the mean potential evapotranspiration has increased by 8.7 mm·(10a)^-1. Before 2007, there was an increasing trend, although a decreasing trend can be seen after 2007. (3) Among the six sub-basins, i.e., the Kaxgar River Basin, the Yarkant River Basin, the Hotan River Basin, the Keriya River Basin, the Qarqan River Basin and the Kumkol Basin, the Qarqan River Basin has the highest annual mean potential evapotranspiration of 810.8 mm and the highest linear trend of 11.4 mm·(10a)^-1. In contrast, the linear trends in the Hotan River Basin (4.9 mm·(10a)^-1) and the Keriya River Basin (5.0 mm·(10a)^-1) are lower. In the future, efforts should be made to enhance hydro-meteorological observations in high-altitude regions of the northern slope of the Kunlun Mountains in Xinjiang to understand hydrological uncertainties under the background of global change.

With the warming of the Qinghai-Tibet Plateau, the trend of increase in the number and size of plateau lakes is on the rise, with a noticeable expansion of lakes over the Kumkuli Basin in the eastern Kunlun Mountains. Ayakkum Lake is the largest saltwater lake in the Kumkuli Basin, and the Third Xinjiang Scientific Expedition data indicates that the lake has expanded to become the largest lake in Xinjiang. Based on the expedition data and remote sensing imagery, this study analyzes and subsequently discusses the change in the water volume of Ayakkum Lake and replenishment of its water sources, including glacier, permafrost, temperature, and precipitation. The results show that: (1) The area of Ayakkum Lake expanded from 623.03 km² in 1990 to 1141.67 km² in 2023, and the lake level rose by 7.28 m from 2002 to 2023, corresponding to an increase in water storage of 66.64×10⁸ m³. (2) The glacier area in the Ayakkum Lake Basin decreased by 16.4 km² from 1990 to 2023, with a volume reduction of 1.96 km³. Until 2023, there were 451 glaciers with a total area of 324.26 km² in the region. (3) A distribution map of permafrost over the Qinghai-Tibet Plateau in 2010 shows that the continuous permafrost area was 12395 km² and seasonal permafrost area was 10652 km². (4) A water balance analysis of the area indicates that glacier and permafrost meltwater account for 9% and 5% of the total inflow into Ayakkum Lake, respectively, whereas runoff from land surface precipitation in seasonal frost and permafrost regions accounts for 67% of the total inflow into Ayakkum Lake. Additionally, replenishment to the lake water surface via direct precipitation accounts for 19% of the total inflow into Ayakkum Lake. In other words, the expansion of the lake mainly resulted from an increase in precipitation over the Ayakkum Lake Basin. This study reveals the land surface hydrological processes in the Kumkuli Basin and provides reference for local governments to optimize water resource allocation and management.