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Human activities continuously alter the delivery of ecosystem services (ESs), which play a crucial role in human well-being. There is a pressing need for effective ecological management strategies that consider the spatial heterogeneity of ESs to support the transition from trade-offs to synergies. This study focuses on the Haba River Basin and examines characteristics of land-use change and the shift from trade-offs to synergies. The results indicate that from 1990 to 2000, the initial phase of land development, 10.65% of the land experienced change. Subsequently, during the intensive period of land development from 2000 to 2010, 30.29% of the land underwent significant transformation, with approximately 78% of grassland, sparse grassland, forested land, and desert converted into arable land. However, between 2010 and 2020, as the focus shifted towards the establishment of native vegetation. The intensity of land development decreased, and only a small percentage (3.65%) of the total area underwent changes. Based on an in-depth analysis of spatial heterogeneity from 1990 to 2020, it is believed there has been a shift from trade-offs to co-benefits between 2000–2010 and 2010–2020. The years 2010 and 2020 were pivotal time nodes for the transition from trade-offs to synergies and for reducing trade-offs, with NPP identified as a critical driving factor for comprehensive ES (CES) functions. By considering the trade-off–synergy relationship and hotspots of ecological service functions, combined with unified water resource management policies, comprehensive ecological management measures tailored to different regions are proposed. These measures have facilitated the implementation of robust ecological protection policies to shift ES development from trade-offs to synergies in arid areas, thereby enhancing overall ecosystem service functions in the Haba River Basin. The research findings offer crucial scientific support and guidance for ecosystem management in arid areas, particularly within Central Asia. [ABSTRACT FROM AUTHOR]

Examining the chemical properties of river water and the controlling factors is crucial for devising efficacious strategies in water resources management and ecological conservation. This study investigates the hydrochemical characteristics and driving factors of the Beichuan River in the arid region of Northwest China. Surface water samples were collected during wet and dry seasons, and analyzed using hydrochemical diagrams, mathematical statistics, and principal component analysis (PCA). The results show that the pH value of Beichuan River is generally weakly alkaline, the main hydrochemical types are HCO3-Ca, and the average TDS are 224 mg/L and 236 mg/L respectively, which are higher than the world average level (115 mg/L). The seasonal variation of hydrochemical components is mainly controlled by rainfall, showing that the concentrations of Na+, Cl− and NO3 − in the wet season are higher than those in the dry season, while the concentrations of other chemical components show an opposite trend, while the spatial variation is mainly controlled by human activities, and the concentrations of hydrochemical components show a gradual increasing trend from upstream to downstream, especially Na+, Mg2+, Cl− and NO3 − . Rock weathering is the key natural factor controlling the Hydrochemical Composition of Beichuan River. Na+ and Cl− are mainly from the dissolution of silicate, Ca2+ and Mg2+ are mainly from the weathering of carbonate rocks and silicate, and SO4 2- is mainly from the dissolution of evaporite. It is noted that human activities, especially domestic sewage and agricultural runoff, contribute significantly to NO3 − in the water body. PCA identified rock weathering and agricultural runoff as major wet-season factors, while domestic sewage predominantly affects the dry season. This study can provide a scientific basis for the rational development of water resources and ecological environment protection in arid areas. [ABSTRACT FROM AUTHOR]

The information of the temporal and spatial distribution of irrigation events is of great significance for protecting the cultivated land quality and coping with climate change. Irrigation information can traditionally be captured using farmland water conservancy construction and field investigation. However, there is a great variation in the time and space of irrigation information from the different regions, due to the various water sources, planting structures, irrigation technology, water transmission, and measurement facilities. At the same time, remote sensing can be expected to timely and accurately monitor the ground surface all day. The previous research focused mainly on the crop growing season without considering the influence of different vegetation coverage on the irrigation remote sensing signals. Therefore, it is very necessary to detect the year-round events of farmland irrigation using remote sensing, particularly for different vegetation coverage. In this study, the farmland irrigation events were detected in the arid areas of northwest China using remote sensing. The research area was taken as Daman Super Station in Ganzhou District, Zhangye City, Gansu Province, China. The comparison was also performed on the conventional, near-infrared band reflectivity with MOD09GA optical remote sensing data, segmented PDI differential threshold model, microwave moisture products, and the combination of PDI differential threshold and microwave moisture products. An optimal scheme was achieved in the remote sensing detection suitable for all-year farmland irrigation events with different vegetation coverage. The performance was finally tested from the space-time dimension. The results show that there was a strong negative linear correlation between the PDI difference threshold and NDVI. Thus, a segmented PDI difference threshold model was constructed in 2016; The highest accuracy of irrigation events was achieved in the microwave moisture products combined with the PDI differential threshold. There was a close relationship between the soil surface water after irrigation and the response of vegetation to the soil water supply. The content of soil water reached saturation after irrigation. But the soil surface water continued to decrease and then returned to the pre-irrigation water content in about three days, due mainly to the evaporation. Furthermore, the microwave data was more sensitive to the surface soil moisture than the vegetation, indicating the dominant soil dielectrics. The high time resolution was realized to timely and effectively capture the occurrence of irrigation events. However, the electromagnetic wave energy was attenuated by crops with the increase in crop coverage. The water status of the soil surface failed to be monitored. Therefore, it was suitable for the case of no crops or low vegetation coverage. Moreover, the time resolution was low in the optical data. The content of soil surface water was captured in time, but it was also sensitive to the vegetation. Plant growth was subjected to water stress before irrigation. Once the soil water supply was sufficient, a significant difference was found in the vegetation water content and leaf structure, indicating the vegetation spectral in the near-infrared and red bands before irrigation. Optical data was used to indirectly monitor the irrigation events using these spectral. In particular, microwave water products were compensated for the irrigation monitoring the vigorous growth of crops or high coverage. The best performance was achieved in dry years, followed by normal years. The regional inversion showed that the distribution map of irrigation times made by microwave moisture products combined with the PDI differential threshold was consistent with the actual situation. The farmland with low irrigation capacity was distributed mainly on the edge of Zhangye Basin, which was far from the river, indicating the greater risk of climate change. Therefore, it was suitable to use microwave moisture products combined with PDI differential threshold in the detection and application of irrigation events in arid areas of northwest China. The findings can provide a theoretical basis for the efficient acquisition of actual irrigation information, cultivated land quality protection, and response to climate change. [ABSTRACT FROM AUTHOR]

Background: The Minqin Oasis, which is located in Wuwei City, Gansu Province, China, faces a very serious land desertification problem, with about 94.5% of its total area desertified. Accordingly, it is crucial to implement ecological restoration policies such as cropland abandonment in this region. In abandoned croplands, abiotic factors such as soil properties may become more important than biotic factors in driving vegetation succession. However, the connections between soil properties and vegetation succession remain unclear. To fill this knowledge gap, this study investigated these connections to explore major factors that affected vegetation succession, which is meaningful to designing management measures to restore these degraded ecosystems. Methods: This study investigated seven 1–29-year-old abandoned croplands using the "space for time" method in Minqin Oasis. Vegetation succession was classified into different stages using a canonical correlation analysis (CCA) and two-way indicator species analysis (Twinspan). The link between soil properties and vegetation succession was analyzed using CCA. The primary factors shaping community patterns of vegetation succession were chosen by the "Forward selection" in CCA. The responses of dominant species to soil properties were analyzed using generalized additive models (GAMs). Results: Dominant species turnover occurred obviously after cropland abandonment. Vegetation succession can be classified into three stages (i.e., early, intermediate, and late successional stages) with markedly different community composition and diversity. The main drivers of vegetation succession among soil properties were soil salinity and saturated soil water content and they had led to different responses of the dominant species in early and late successional stages. During the development of vegetation succession, community composition became simpler, and species diversity decreased significantly, which was a type of regressive succession. Therefore, measures should be adopted to manage these degraded, abandoned croplands. [ABSTRACT FROM AUTHOR]

Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Shallow groundwater is a critical water resource for sustaining vegetation growth in arid and semi-arid environments and affects stand transpiration (T) dynamics. However, it is still difficult to quantify the impact of groundwater on T. Here, we introduced a novel groundwater response function in the Jarvis-type model (referred to as MJSG) and tested its performance using Populus popularis sapflow data over two main growing seasons (2018–2019). The results showed that the performance of the MJSG model depended on groundwater level. Specifically, when groundwater table depth was within 1.2–2.0 m, the precision of daily T simulation by the MJSG model was higher than that by the MJS model without groundwater response function over two years, with an increase in Nash-Sutcliffe Efficiency (NSE) from 0.787 to 0.825. Furthermore, in contrast to the MJS model, the MJSG model could better capture the diurnal course of T in 10:00–16:00, with a significant increase in NSE from 0.592 to 0.706. The improvement allows a more accurately estimate of tree water use under shallow groundwater fluctuations, which will help broaden the ecohydrological application of the Jarvis-type model to similar areas.

The dynamics and complexity of plant communities influence the diversity and distribution of animals in various environments. Coleoptera are the most diverse group of insects and are valued as monitoring and environmental assessment tools. However, their diversity and dynamics in these high-altitude environments are poorly known. Using pitfall traps and suction sampling, we collected beetles to study their community responses to changes in different vegetation heterogeneities (low, intermediate, and high). The heterogeneity gradient was determined by considering the dominant plant species in each habitat, the percentage of vegetation coverage, and the percentage of vertical strata. Guild's responses to vegetation heterogeneity were analysed in conjunction with the patterns of alpha and beta diversity in beetles. Representatives of 41 species/morphospecies of beetles, 16 families, and four guilds were reported. Significant variations were observed in guild composition and alpha and beta diversity, especially between high and low vegetation heterogeneity habitats. The significant species turnover between sites is the main factor responsible for the high beta diversity, supporting considerable habitat heterogeneity within these environments. Phytophagous, detritivorous, necrophagous, and predatory beetles exhibited distinct responses to the vegetation's heterogeneity. This suggests that every habitat under investigation possesses a distinct structure of beetle communities. Predators were important in habitats with more diverse vegetation, while phytophagous were important in the most homogeneous ones. Beetle communities in the Puna and Altos Andes of Salta province respond positively to vegetation heterogeneity, which plays a crucial role in determining the composition of small-scale beetle communities in arid high-altitude environments.

Background and Aims: The intercropping has great advantages in production gain, resources use and soil quality improvement. However, the effects of perennial forage legumes intercropped with annual grain crop on soil alkali-salinity was not well revealed. This study aimed to propose a spring wheat (Triticum aestivum L.)/alfalfa (Medicago sativa L.) intercropping and reveal whether this cropping system could ameliorate soil salinity. Methods: A two-year field experiment was conducted under 3 cropping systems at 3 irrigation amounts in the inland arid area of northwestern China. The cropping systems were sole spring wheat cropping (W), 12 rows spring wheat/4 rows alfalfa intercropping (W12A4) and 8 rows spring wheat/4 rows alfalfa intercropping (W8A4), and irrigation amounts included 450 (full irrigation amount, If), 360 (moderate irrigation amount, Im) and 180 mm (low irrigation amount, Il). Results: The intercropping system, especially W8A4, could more decrease soil salinity, pH and topsoil bulk density, and increase soil water content, topsoil porosity, and Ca2+ and Mg2+ contents, compared to W. Soil electrical conductivity was positively correlated with topsoil bulk density and negatively correlated with topsoil porosity, which were enhanced by intercropping and irrigation. There was weak correlation between soil electrical conductivity and soil water content. W12A4 and W8A4 led to reduction in contents of Na+, K+, Cl−, and SO42−, while Ca2+ and Mg2+ accumulated in the soil. Conclusion: Intercropped alfalfa and spring wheat could reduce soil salinity, improve soil structure and ions balance. It was recommended that W8A4 with 360 mm irrigation could be extensively used in the arid area of northwestern China, gaining grain and forage production, and helping reduce salt accumulation. [ABSTRACT FROM AUTHOR]

The primarily bat-associated argasid tick, Secretargas transgariepinus (White, 1846), is a member of the Afrotropical and southern Palaearctic fauna. Probably because of its secretive life style, little is known about this species and records of its collection are scant. Based on morphological revisions of the available specimens, we report new Middle Eastern records for this tick species that had been misidentified as other bat-associated argasid taxa. These specimens are larvae from three localities, and represent the first records of S. transgariepinus from two countries: one larva from Sabratha (Libya) was collected from an unidentified bat species (possibly Eptesicus isabellinus), seven larvae from Azraq-Shishan (Jordan), and 78 larvae from Shamwari (Jordan) were all collected from Otonycteris hemprichii. Twenty larvae from Shamwari were also tested for the presence of both, viral or bacterial microorganisms by PCR. Three ticks were found to be infected with the Murid gammaherpesvirus 68 (MHV-68), one with Borrelia burgdorferi sensu lato, and four with a Rickettsia sp. closely related to Rickettsia slovaca. The findings represent a first evidence for the occurrence of these possible pathogens in S. transgariepinus. [ABSTRACT FROM AUTHOR]

Many factors determine the quality of the growth and development of cotton. To compare their influences on the quality of the growth and development of cotton, nine different irrigation modes, including flood irrigation, drip irrigation under a film, and subsurface irrigation under a film, are considered at other lower limits as the influential factors and are regarded as the optimal indices in this paper. A synthetic assessment model is established according to relevant experimental results based on the AHP-TOPSIS theory, and the accelerated genetic projection pursuit algorithm to analyze and compare the different schemes, and the experimental results are compared with the theoretical results. The results show that subsurface irrigation under a film with a lower irrigation index limit of 70-75% of the field water capacity is the best scheme for the growth and development of cotton; with this scheme, the cotton production can be increased. The conclusions provide a specific theoretical basis for selecting future irrigation modes in arid areas. [ABSTRACT FROM AUTHOR]

Jujubes (Ziziphus jujuba) are a crucial industry in the arid region of Xinjiang, facing challenges such as water scarcity and low water use efficiency. This study focuses on jujube orchards located at the edge of the Taklimakan Desert to investigate whether applying trace elements can effectively enhance jujube growth, development, and fruit quality. By foliar spraying boron and zinc micro-fertilizers onto jujube leaves, we analyzed the effects of different doses on growth parameters, photosynthetic activity, crop yield, water use efficiency, and fruit quality. The results revealed that the length of the fruit branch, leaf area index, and fruit longitudinal/transverse diameter increased by 19.35%, 25.72%, and 32.9%/2.28%, respectively; net photosynthetic rate, transpiration rate, and stomatal conductance increased by 105.51%, 91.43%, and 75.3%, respectively, while intercellular CO2 concentration decreased by 13.09%; yield and water use efficiency improved by 16.95% and 12.68%, respectively; soluble sugar content, titratable acid content, and flavonoid content increased by 13.56%, 51.63%, and 86.12%, respectively. Based on these findings, the optimal application rate for boron micro-fertilizer was determined to be 3.51~3.59 kg/hm2, and for zinc micro-fertilizer, it was 3.16~3.32 kg/hm2. This study provides practical methods along with theoretical support for applying micro-fertilizers in arid regions. [ABSTRACT FROM AUTHOR]

The dynamics and complexity of plant communities influence the diversity and distribution of animals in various environments. Coleoptera are the most diverse group of insects and are valued as monitoring and environmental assessment tools. However, their diversity and dynamics in these high-altitude environments are poorly known. Using pitfall traps and suction sampling, we collected beetles to study their community responses to changes in different vegetation heterogeneities (low, intermediate, and high). The heterogeneity gradient was determined by considering the dominant plant species in each habitat, the percentage of vegetation coverage, and the percentage of vertical strata. Guild's responses to vegetation heterogeneity were analysed in conjunction with the patterns of alpha and beta diversity in beetles. Representatives of 41 species/morphospecies of beetles, 16 families, and four guilds were reported. Significant variations were observed in guild composition and alpha and beta diversity, especially between high and low vegetation heterogeneity habitats. The significant species turnover between sites is the main factor responsible for the high beta diversity, supporting considerable habitat heterogeneity within these environments. Phytophagous, detritivorous, necrophagous, and predatory beetles exhibited distinct responses to the vegetation's heterogeneity. This suggests that every habitat under investigation possesses a distinct structure of beetle communities. Predators were important in habitats with more diverse vegetation, while phytophagous were important in the most homogeneous ones. Beetle communities in the Puna and Altos Andes of Salta province respond positively to vegetation heterogeneity, which plays a crucial role in determining the composition of small-scale beetle communities in arid high-altitude environments. [ABSTRACT FROM AUTHOR]

The water delivery capacity of Karez is gradually declining, and it is possible that such a traditional water supply systems might be completely replaced by modern water conservancy projects. To determine whether these ancient water conservancy projects have a future, we conducted a study in a typical research area of Xinjiang Province, China. Using remote sensing technology, in situ surveying, and the analytic hierarchy process, we evaluated Karez in terms of water delivery capacity, water intake convenience, and capability to maintaining the ecological stability of the surrounding area. The derived results are as follows. (1) During 2005–2020, the length of 14 Karez systems in the study area decreased; however, the calculated water access convenience degree (C) indicated that Karez are more convenient for water intake compared with modern transmission channels, i.e., Ckarez = 0.68 and Cchannel = 0.51. (2) The mean annual runoff of the Karez system was 69.38 × 106 m3, similar to that of the modern water transmission channels in the area (73.49 × 106 m3). (3) Change in ecological sensitivity occurred mostly in regions where Karez systems have disappeared, with increase of 70.69 % and 14.51 % in high and medium sensitivity areas, respectively, and decline of 21.53 % and 9.74 % in low-sensitivity and non-sensitivity areas. Our research shows that Karez have considerable water delivery capacity, and that their existence is beneficial to maintaining the stability of the surrounding ecology. The Karez system can be considered a template for harmonious coexistence between humans and nature.

Background The Minqin Oasis, which is located in Wuwei City, Gansu Province, China, faces a very serious land desertification problem, with about 94.5% of its total area desertified. Accordingly, it is crucial to implement ecological restoration policies such as cropland abandonment in this region. In abandoned croplands, abiotic factors such as soil properties may become more important than biotic factors in driving vegetation succession. However, the connections between soil properties and vegetation succession remain unclear. To fill this knowledge gap, this study investigated these connections to explore major factors that affected vegetation succession, which is meaningful to designing management measures to restore these degraded ecosystems. Methods This study investigated seven 1–29-year-old abandoned croplands using the “space for time” method in Minqin Oasis. Vegetation succession was classified into different stages using a canonical correlation analysis (CCA) and two-way indicator species analysis (Twinspan). The link between soil properties and vegetation succession was analyzed using CCA. The primary factors shaping community patterns of vegetation succession were chosen by the “Forward selection” in CCA. The responses of dominant species to soil properties were analyzed using generalized additive models (GAMs). Results Dominant species turnover occurred obviously after cropland abandonment. Vegetation succession can be classified into three stages (i.e., early, intermediate, and late successional stages) with markedly different community composition and diversity. The main drivers of vegetation succession among soil properties were soil salinity and saturated soil water content and they had led to different responses of the dominant species in early and late successional stages. During the development of vegetation succession, community composition became simpler, and species diversity decreased significantly, which was a type of regressive succession. Therefore, measures should be adopted to manage these degraded, abandoned croplands.

Human activities continuously alter the delivery of ecosystem services (ESs), which play a crucial role in human well-being. There is a pressing need for effective ecological management strategies that consider the spatial heterogeneity of ESs to support the transition from trade-offs to synergies. This study focuses on the Haba River Basin and examines characteristics of land-use change and the shift from trade-offs to synergies. The results indicate that from 1990 to 2000, the initial phase of land development, 10.65% of the land experienced change. Subsequently, during the intensive period of land development from 2000 to 2010, 30.29% of the land underwent significant transformation, with approximately 78% of grassland, sparse grassland, forested land, and desert converted into arable land. However, between 2010 and 2020, as the focus shifted towards the establishment of native vegetation. The intensity of land development decreased, and only a small percentage (3.65%) of the total area underwent changes. Based on an in-depth analysis of spatial heterogeneity from 1990 to 2020, it is believed there has been a shift from trade-offs to co-benefits between 2000–2010 and 2010–2020. The years 2010 and 2020 were pivotal time nodes for the transition from trade-offs to synergies and for reducing trade-offs, with NPP identified as a critical driving factor for comprehensive ES (CES) functions. By considering the trade-off–synergy relationship and hotspots of ecological service functions, combined with unified water resource management policies, comprehensive ecological management measures tailored to different regions are proposed. These measures have facilitated the implementation of robust ecological protection policies to shift ES development from trade-offs to synergies in arid areas, thereby enhancing overall ecosystem service functions in the Haba River Basin. The research findings offer crucial scientific support and guidance for ecosystem management in arid areas, particularly within Central Asia.

Featured Application: The integrated analysis method for understanding the main driving factors shaping forested areas proposed in this paper can provide helpful insight into sustainable and long-term land use systems in Senegal. Understanding the factors influencing the vulnerability of forested areas is crucial for human well-being and effective governance of ecosystem supply and demand. Based on remote sensing data, this study also considered ten natural and human variables as indexes to explore the main influencing factors that may impact the vulnerability of the Thies region's forested areas. The 2005, 2010, 2015, and 2020 satellite image data were processed using ArcGIS 10.6 and ENVI 5.1 software. The methodology includes using the transfer matrix approach and calculating the geographic landscape index to describe the dominant morphology of forested areas. Furthermore, a mixed linear regression model was built to establish the connection between forested areas and the potential contributing components. Our study revealed that the forested areas led to relative fragmentation, with an average of 88 patches for Aggregation Index (AI), 3.25 for Largest Patch Index (LPI), 2.50 for Patch Density (PD), and 112 for Landscape Shape Index (LSI) between 2005 and 2020. In addition, the transfer matrix indicated that the loss of forestry areas was about −78.8 km2 for agricultural land, −127.8 km2 for bare land, and −65.3 km2 for artificial surfaces. The most critical factors that influenced forested areas were agricultural and manufactural added value, rainfall (p < 0.05), slope, distance to the road, and agricultural sown area (p < 0.001). Overall, this investigation has revealed that the effective management of forested areas in the Thies region requires an understandable assessment. It was observed that both human anthropogenic and natural factors significantly contribute to the decline in forested areas. [ABSTRACT FROM AUTHOR]

What represents a water source for the ecological restoration of a plant in an arid region is still up to debate. To address this issue, we conducted an in situ experiment in the Ulan Buh Desert of China, to study desert plants absorbing atmospheric water vapor. We selected Tamarisk, a common drought-salt-tolerant species in the desert, for ecological restoration as our research subject, used a newly designed lysimeter to monitor precipitation infiltration, and a sap flow system to track reverse sap flow that occurred in the shoot, branch, and stem during the precipitation event, and observed the precipitation redistribution process of the Tamarisk plot. The results showed that Tamarisk indeed directly absorbs precipitation water: when precipitation occurs, the main stem, lateral branch, and shoot all show the signs of reversed sap flow, and the reversed sap flow accounted for 21.5% of the annual sap flow in the shoot and branch, and 13.6% in the stem. The precipitation event in the desert was dominated by light precipitation events, which accounted for 81% of the annual precipitation events. It was found that light precipitation can be directly absorbed by the Tamarisk leaves, especially during nighttime or cloudy days. Even when the precipitation is absent, it was found that desert plants can still absorb water from the unsaturated atmospheric vapor; even the absorbed atmospheric water vapor was transported from the leaves to the stem, forming a reversed sap flow, as a reversed sap flow was observed when the atmospheric relative humidity reached 75%. This study indicated that the effect of light precipitation on desert plants was significant and should not be overlooked in terms of managing the ecological and hydrological systems in arid regions. [ABSTRACT FROM AUTHOR]

Under the background of global warming, extreme flood disasters occur frequently, with a particularly significant impact on Xinjiang, which is located in arid and semi-arid regions. The risk of flood disasters in this region is significantly increased. In order to improve the flood disaster response capacity of Xinjiang Province, reduce losses caused by flood disasters, and provide an example for rivers in arid areas to respond to flood disasters, this paper selects Kushan River in Xinjiang to carry out flood process simulation research. Kushan River is located at the western edge of Tarim Basin in southern Xinjiang, which is a typical river in arid inland areas. This paper constructs a flood analysis and calculation model for the Kushan River, determines the key parameters and boundary conditions of the model. A typical flood is selected to validate the constructed model, and four indicators, absolute error (AE), relative error (RE), determination coefficient (R2), and Nash coefficient (NSE), are selected for model evaluation. The calculation results show that the average absolute error of water depth is 24.1 cm, the relative error is 24%, and the determination coefficient is 0.66. The Nash coefficient of flow is 0.86, and the determination coefficient reaches 0.97, indicating that the constructed model and parameter settings have high accuracy. Using high-precision river terrain, flood disaster risk survey results, remote sensing information, a basin data base is established to calculate the flood progression, inundation range, water depth distribution, and inundation duration of the Kushan River under five typical frequencies of 10 year, 20 year, 50 year, 100 year, and 200 year, achieving large-scale simulation of flood routing in arid areas of the entire basin. The research results can provide a technical basis for flood risk analysis of rivers in arid inland areas. [ABSTRACT FROM AUTHOR]

Taking the Weigan-Kuqa River Delta Oasis as an example, based on five salt spectral indices (NDSI, SI, SI1, SI2, SAVI), three red edge bands and near-infrared narrow bands in Sentinel2A multispectral images were selected for expansion. A new spectral index based on red edge and near-infrared narrow bands was proposed, and a partial least squares regression (PLSR) method was used to construct a soil conductivity remote sensing inversion model. The results showed that compared to traditional spectral index, the correlation between the spectral index introduced in the red edge 1 band (B5) and the near-infrared narrow band (B8a) and soil conductivity was significantly improved; the modeling effect of soil conductivity information using PLSR based on Sentinel2A images was good (R² = 0. 77), and the model was accurate and reliable. The results of salt inversion indicated that the soil salt content in the study area was generally high, and the impact of salinization was extensive. There was a transition from non salinization-mild-moderate-severe salinization from the interior to the exterior of the oasis. There were more mild saline soils distributed in the western and southern parts of the oasis, while there were severe saline soils and extremely severe saline soils distributed in the eastern, southeast and southwest directions of the oasis, with a higher degree of salinization. [ABSTRACT FROM AUTHOR]

Different types of mulch are often used in agricultural production to enhance soil moisture and improve crop yields. The question of which mulch provides superior water retention in arid regions, where water resources are scarce, is a major concern for agricultural production. We conducted observations and studies at a typical irrigated experimental station in an arid zone with four types of mulch, including liquid mulch (LM), biodegradable mulch (BM), ordinary black mulch (OBM), and ordinary white mulch (OWM), and plots with no mulch. Samples were collected and analyzed at 1, 3, 5, and 7 days after each rainfall or irrigation to obtain soil moisture changes and to analyze the effect of different mulches on soil moisture retention. The results showed that mulch cover was effective in retaining soil moisture compared to plots without mulch cover. Specifically, soil moisture was highest in the farmland with OWM during the observation period. OWM, OBM, and BM were all effective in reducing soil water evaporation and maintaining soil moisture. LM and BM were capable of utilizing rainfall to recharge soil water in a superior way, and polyethylene mulches (OBM and OWM) had a significant barrier impact on rainfall. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Oil Crop Sciences is the property of Oil Crops Research Institute of Chinese Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Planting trees is considered a crucial factor in mitigating the increase in carbon emissions in the atmosphere by generating plant biomass. In addition to advancing our understanding of how tree biomass is allocated in desert environments, we explore potential variations in biomass partitioning based on the irrigation regimes (4, 8, and 12 L h−1) supporting the growth of these trees. Specifically, this study compares the pattern of biomass distribution between above-ground and belowground organs of 11-year-old trees (U. pumila, E. moorcroftii, and T. ramosissima) planted in a desert site in Mongolia. An interesting result of this study is the demonstration that biomass partitioning among roots of different diameter classes differs between the tree species tested, suggesting that each tree species establishes its own type of root/soil interaction. The differences in biomass partitioning in roots could determine specificity in the strength of anchorage and efficiency of nutrition for the trees. We also demonstrate that the presence of plantations influences certain chemical properties of the desert soil, with differences depending on the tree species planted. In addition to presenting a method for planting trees in desert sites, this study underscores that a reliable evaluation of atmospheric carbon sequestration in trees must necessarily include root excavation to obtain an accurate measurement of biomass stored in belowground structures. Assessing the overall biomass produced by these trees allows us to determine the potential for carbon sequestration achievable through plantations established in desert sites. [ABSTRACT FROM AUTHOR]

Water is a stabilizer for production and life in the arid areas. According to research shared by the Pacific Institute and The Guardian, there were 228 incidents of water conflict globally in 2022. Therefore, comprehensive measures are necessary to achieve regional water security. This objective can be achieved by the application of interdisciplinary and professional approaches through establishing a dynamic equilibrium of the different water consumers, and trade-offs and synergies for water allocation between them. A multi-objective optimization model is proposed for managing the water-agriculture-energy-environment (WAEE) nexus in water-scarce areas. Real and integer-encoded multi-objective evolutionary algorithms (EMCMO) were applied to solving management models. Multiple objectives, such as the maximization of economic benefits from agriculture and hydropower generation, the minimization of ecological water shortages for local plants, and the minimization of environmental risks influenced by land use and food supply, were defined in the model. The model was applied to the Yanqi Basin, an important agriculture and energy producer in Xinjiang province, Northwest China. The results indicated that (1) the four-dimensional Pareto solution set has the advantage of presenting the WAEE nexus, highlighting the trade-offs and synergies between high-value crops, surface water, and groundwater, ecological water demand, hydropower generation and total nitrogen and phosphorus loading (TNP); (2) An excessive increase in the agricultural economy will increase TNP loading and agricultural non-point source pollution; (3) Optimization of WAFE for local ecosystem restoration. Optimization in a wet year, reduced agricultural economic benefits by 0.20%, and agricultural TNP loading by 13.19% while increasing ecological water by 58.33%, and hydropower generation by 3.98%; in a normal year, reduced agricultural economic benefits by 6.62%, agricultural TNP loading by 13.19% while increasing ecological water by 46.43%, and hydropower generation by 0.79%; in a dry year, reduced agricultural economic benefits by 17.19%, agricultural TNP loading by 9.72%, and hydropower generation by 16.18% while increasing ecological water by 42.86%. The trade-offs and synergies of the WAEE nexus also apply to other similar water-scarce areas.

Hot water extractable organic carbon (HWOC), the labile carbon component, is often used to indicate soil organic carbon (SOC) dynamics. Nevertheless, few studies have been carried out in arid climate areas which affects our full understanding of HWOC. Here, we investigated the change in HWOC in the topsoil of different ecosystems in the southern part of the Loess Plateau in the semiarid region of China and compared it with that in other regions. The HWOC concentrations of the study area (0-10 cm) were 0.27 ± 0.12 g C kg−1 and 0.19 ± 0.04 g C kg−1 in the natural and agricultural systems respectively, and the HWOC proportions were 1.38 ± 0.38% and 2.18 ± 0.22%. The HWOC concentration and proportion in the study area were much lower than the reported data in other areas, which may be affected by drought conditions. Irrigation could weaken the difference in HWOC between agricultural systems in different regions. Since HWOC is easily lost due to the impact of the arid climate, the soil carbon balance and carbon sequestration in arid and semiarid areas are relatively unstable, indicating that soil management should be improved in combination with water management.

【Objective】 Jujube is an important cash crop in the arid region in northwestern China. Understanding energy dynamics in it is hence crucial to improving water use efficiency. This paper is to analyze the energy balance in a jujube orchard using the eddy covariance. 【Method】 Flux from a jujube orchard was measured from 2018 to 2019 using the eddy covariance method. The data were used to analyze the patterns and distribution of the energy changes, and daily variations in the thermal storage. 【Result】 ① Daily average energy change in net radiation, latent heat flux, sensible heat flux, and soil heat flux exhibited a single-peaked pattern in each month, primarily driven by net radiation changes. ② The annual 30-minute energy balance ratio in 2018 and 2019 was 73.45% and 73.11%, respectively. Incorporating the heat storage term increased the energy balance by 3.72% and 2.75% to 77.17% and 75.86%, respectively, in 2018 and 2019. ③ The daily change in soil heat storage exhibited similar pattern during the fertility and dormancy stage. Latent and sensible heat storage showed different patterns between fertility and dormancy stage, while photosynthesis and canopy heat storage were zero during the dormancy stage and displayed typical daily variation during the fertility stage. 【Conclusion】 The thermal storage has a minimal contribution to the energy balance. Thus, the energy allocation to the jujube is influenced mainly by water, vegetation types and climate.

Arid regions hold a prominent position as global tourist destination. However, their ecological fragility and sensitivity to economic and social factors make them more susceptible to various disruptive elements, thereby exacerbating the instability of the tourism socio-ecological system. Consequently, there has been a growing focus on tourism socio-ecological system resilience (TSESR) in arid regions. This study has developed a scientific and universally applicable assessment framework to evaluate TSESR in arid regions, considering the system's process mechanisms and dimensions. The framework encompasses four key domains: resistance, recovery, adaptation, and renewal, further divided into twelve criterion layers. This study conducted a case study in 14 prefecture-level units in Xinjiang, China, from 2010 to 2020. An improved TOPSIS model, Gini coefficient, Kernel density estimation, and Obstacle degree model were employed to investigate the levels, spatiotemporal variations, and obstacle factors of TSESR. The research findings indicate that during the study period, the resilience levels of the 14 prefecture-level cities exhibited an overall upward trend with fluctuations. There are notable spatial disparities, yet these disparities are diminishing. Furthermore, factors such as resource endowment, market potential, economic foundation, industrial environment, and human capital represented common obstacles, while unique regional impediments also existed. The TSESR assessment index system can scientifically and comprehensively evaluate resilience levels, offering an adaptive indicators framework for arid regions. It promotes the development of a resilient tourism socio-ecological system, thereby achieving sustainable tourism development.

With the development of human society, the balance between the minimum ecological instream flow requirement (MEIFR), which is an essential part of the ecological water demand in arid areas, and anthropogenic water depletion has received increasing attention. However, due to the lack of hydrological station data and river information on arid basins, previous researchers usually considered only the individual ecological water demand of rivers, lakes, or oases. To address this issue, a new method that combines river hydraulic parameters and the wet circumference obtained by an unmanned aerial vehicle (UAV) and remote sensing hydrological station (RSHS) technologies was applied to obtain the MEIFR and, then, systematically and quantitatively explore the balance from the perspective of the entire basin of Aiding Lake from 1990 to 2022, which is the lowest point of Chinese terrestrial territory. The results showed the following: (1) since 1990, the discharge of the seven rivers in the study area increased by 1–6%, and the MEIFR of these rivers increased by 15–100%; both quantities decreased by 3–5% from the upper to the lower reaches of the basin; (2) the surface area and water level of Aiding Lake decreased by 5% and 14%, respectively, but the MEIFR first decreased by 25% from 1990 to 2013 and, then, increased by 66.7% from 2013 to 2022; and (3) from 2011 to 2022, the MEIFR and anthropogenic water depletion exhibited a balance. Against the background of climate change, this research revealed that the MEIFR of the rivers in the Aiding Lake Basin have shown an upward trend over the past 30 years and quantitatively determined the above balance relationship and the period of its occurrence. This study supplied a method that could provide guidance for water resource management by decision-makers at a global level, thus helping achieve the sustainable development goals (SDGs). [ABSTRACT FROM AUTHOR]

This study employs Geographic Information Systems (GIS) tools and spatial data to evaluate water resource availability for livestock watering in Algeria's southwestern Wilaya of Naama. The research adopts a two-stage approach, starting with the creation of seven thematic maps encompassing livestock water needs, proximity to water sources, water quantities from boreholes, hillside reservoirs, wells, and springs, precipitation, and land use/land cover (LULC). Subsequently, an Analytic Hierarchy Process (AHP) is utilized to identify suitable areas within the Wilaya for livestock watering. Beyond its primary objective of establishing a benchmark for water resources to facilitate optimal and sustainable livestock management, this study also aims to assess suitable sites for livestock and provide a comprehensive evaluation of water resources for grazing. The findings reveal that the majority of the area is unsuitable for grazing due to limited water resources, with approximately 2.43% being "highly suitable" (S1), 13.42% "moderately suitable" (S2), and the remaining 84.15% categorized as "marginally suitable" (S3), "temporarily unsuitable" (N1), or "permanently unsuitable" (N2). These results underscore the significance of GIS and spatial analysis in natural resource management and emphasize the need for further research to refine the methodology. The data generated in this study will be invaluable to researchers and water stakeholders for informed decision-making in this sensitive zone. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Over the past few years, incubated biocrusts (IBSC)—the inoculation of soil/sand with cyanobacteria, moss, and lichen—have become one of the most promising biotechnological strategies for preventing soil erosion and restoring soil function in degraded drylands. Soil nutrient content (C, N, and P) is one of the key factors that influences IBSC colonization and development; however, the effects of soil C:N, C:P, and N:P stoichiometric ratios on the colonization and development of IBSC in desert environments are little known. We used four soil substrates, collected from four areas on the southeastern edge of the Tengger Desert, China, to incubate biocrusts. The four substrates differed in particle size and nutrient content. We flattened the dunes so their sand surfaces were level before covering them with soil substrates. We used a fully factorial design with four soil substrates and with and without biocrust additions, generating a total of 12 different treatments. The soil substrates differed in C, N, and P content and C:N, C:P, and N:P stoichiometric ratios. We measured IBSC coverage and thickness to establish relationships between IBSC characteristics and soil C:N, C:P, and N:P stoichiometric ratios. After 12 months of development, all treatments had significantly more cyanobacteria coverage, lichen coverage, and total coverage of IBSC than did control plots, which had little or no IBSC development. C:N and C:P ratios were significantly positively related to cyanobacteria coverage and total coverage of IBSC. Soil C:N and C:P ratios were mainly controlled by soil C; C limitation was greater than N and P limitation. Our study indicates that increasing initial soil substrate C content to improve C:N and C:P ratios will help the recovery of biocrusts and IBSC colonization. We demonstrate that stoichiometric ratios of soil should be a concern when assessing IBSC restoration treatments and when using IBSC to restore degraded land, especially at large scales. [ABSTRACT FROM AUTHOR]

In recent decades, the frequency, intensity, and extent of extreme drought events have posed serious threats to ecosystems in vulnerable regions. With low annual precipitation, the arid area in northwest China is a typical ecologically fragile area, and extreme drought events will aggravate desertification in this area. In order to control desertification, various experimental plantations have been established in Northwest China. However, there is no consensus on which plantations are more suitable to become widespread. To explore this, we conducted a comparative study on different plantations from the perspective of long-term deep (100 cm depth) soil moisture balance. In our study, six typical ecosystems were selected for comparison of the variation of soil moisture and control factors. The results showed three main findings. First, the soil moisture of all six ecosystems showed a similar hierarchy of increasing moisture with the increasing depth of the soil layer. However, the deep layer soil moisture (mean = 0.33 ± 0.22 cm3·cm−3) of the artificial poplar (Populus alba) forest exhibited a downward trend over time after the fifth year, but did not at the shallow layer for this ecosystem. Second, the trends of the maximum canopy coverage between the different ecosystems from 2010 to 2019 showed significant differences from one another, with the maximum value of the leaf area index for the poplar forest being the highest (Maximum = 7.13). Third, a negative correlation (R2 = 0.52) was found between deep soil moisture and transpiration for the poplar forest, and a positive correlation (R2 ≥ 0.23) between these two metrics was found for the other five ecosystems. The results revealed that transpiration processes had a different consumption of deep soil moisture due to the differences in the root and canopy density of several plantations. Among these ecosystems, the transpiration of the artificial poplar forest is noticeably large, resulting in a unilateral decline in soil moisture. [ABSTRACT FROM AUTHOR]

Currently, the ecological problems caused by the greenhouse effect are growing more serious, and implementing carbon sequestration methods is an effective way to address them. Arid and semi-arid desert areas have tremendous potential as carbon sinks, and artificial forests in these areas play an important role in absorbing and sequestering carbon dioxide. This study selected three main species of artificial protective trees along the Tarim Desert Highway—Haloxylon ammodendron (C.A.Mey.) Bunge, Calligonum mongolicum Turcz. and Tamarix chinensis Lour.—and evaluated them for their carbon sequestration, oxygen release capacity, and economic benefits using Pn (net photosynthetic rate) and biomass methods. The results showed that the average daily Pn value and carbon sequestration and oxygen release per unit leaf area of T. chinensis were significantly higher than those of H. ammodendron and C. mongolicum (p < 0.05). The total carbon storage of the three shelterbelts was 15.41 × 104 t, and the carbon storage of H. ammodendron was significantly higher than that of C. mongolicum and T. chinensis (p < 0.05). According to the net photosynthetic rate method, the annual carbon sequestration and oxygen release of the shelter forest is 6.13 × 104 t a−1, and the transaction price is CNY 13.73 million a−1. The total amount of carbon sequestration and oxygen release of the shelter forest obtained via the biomass method is 97.61 × 104 t, and the transaction price is CNY 218.77 million. This study conducted research on the carbon sequestration capacity of protective forests along the Tarim Desert Highway located in an extremely arid region. It highlights the significant contribution of these protective forests in terms of carbon storage, playing a crucial role in promoting ecological restoration and sustainable development in arid areas. Additionally, this study provides a scientific basis for estimating carbon storage and promoting the sustainable management of artificial forests in arid desert regions. [ABSTRACT FROM AUTHOR]

In the case study of the pollution control over the heap leaching cyanide residue left by historical gold mines in arid areas of western China. Based on a thorough analysis of climate, hydrogeology, and the characteristics of heap leaching cyanide residue pollutants, in-situ closure operation is employed to verify the pollution control effect over the pollutant such as heavy metals in heap leaching cyanide residue. The paper in detail describes the in-situ sealing and isolation scheme, control and monitoring scheme, and auxiliary schemes. After implementation, the environmental pollution risks are effectively controlled, and the peripheral environment is evidently improved, achieving anticipated engineering goals. The control technology can provide references for the pollution control of heap leaching cyanide residue generated from similar gold mines. [ABSTRACT FROM AUTHOR]

[Objective] The soil salinization characteristics under different land use types in extremely arid regions were analyzed in order to provide support for the sustainable efficient utilization of regional land resources. [Methods] We used GPS positioning technology to investigate and sample the irrigation water, irrigation drainage, and soil under four typical land use types in the area of Lower Tarm River in different seasons. We combined those data with indoor measurement results to determine the variation characteristics of salinity and salt ions in the irrigation area. [Results] The soil in the study area was alkaline, and the salt type was mainly sulfate-chloride. The salt content was between 2.44 and 118.05 g/kg, and the pH value was between 8.05 and 8.34. The overall changes of soil salt content and pH value under different land use types in each season followed the order of salt wasteland > saline-alkali grassland > cultivated land and forest land. Analysis of samples from different soil depths indicated surface accumulation of salinity in June and October, and no obvious pattern in March and December. There was an obvious surface accumulation of salt in salt wasteland and saline-alkali grassland in different seasons at different soil depths. Forest land had no obvious salt accumulation pattern in each season. Because of the geographical location of the reservoir, the groundwater level in the study area was shallow (1.4—3.51 m), the groundwater salinity was high (1.56—21.30 g/L), and the salt ions in irrigation water and groundwater were mainly Na+ and Cl-. [Conclusion] The soil salinization characteristics under different land use types in the study area were mainly affected by factors such as surface coverage, crop types, and irrigation events. The quality of groundwater and irrigation water was an important factor affecting the soil salt content and salt ion type in the study area. Certain measures should be taken to control the groundwater level and salt content so as to protect existing cultivated land and forest land. The irrigation and drainage water of high salt content from farmland should be discharged to the salt wasteland. In the future, relevant research should be conducted on the spatial configuration of agricultural land and salt wasteland, and the rational allocation of salt discharge land would be conducive to the desalination of farmland.

To improve our understanding of farmland surface process and agricultural water management in arid oasis area, we analyzed the characteristics of water and heat fluxes at different time scales, and the influence of arid advection and canopy conductance (Gc) on water and heat fluxes at different growth stages. In addition, we used path analysis to study the influence path of environmental factors on latent heat flux (LE). In this paper, the water and heat fluxes were measured by eddy-covariance in 2017. The results were as follows: (1) LE showed multiple peaks, while the other fluxes were basically unimodal shapes at the daily scale. On the whole, the values of daily net radiation (Rn) were maximum, followed by LE, sensible heat flux (H) and soil heat flux (G) at each growth stage. The variation of diurnal G showed obvious lagged effect compared to that of Rn. (2) LE and H accounted for 86% and 14% (respectively) of daytime energy during the whole growing stages, indicating that LE was the main energy consumption item. The contribution of arid advection to daytime LE ranged from 5% to 59% with an average value of 28% at whole growing season. The influence of Gc on LE was stronger at the new shoot and leaf-fall stages than that in the middle growing season. (3) LE was mainly affected by Rn, followed by vapor pressure deficit (VPD) and air temperature (Ta), and the influence degrees of VPD and Ta on LE were similar. Furthermore, the path analysis showed that Rn directly affected LE; VPD and Ta mainly affected LE indirectly through Rn. As a whole, the water and heat fluxes in vineyards of arid desert oasis in Northwest China display significant diurnal and seasonal variations, and the influences of environmental factors on these exists great discrepancies in magnitude and path.

The heat source of the Qinghai-Xizang Plateau not only strengthens the formation and maintenance of the climate background in drylands of China， but also has a significant impact on the climate anomalies there.A deep understanding of the relationship between Qinghai-Xizang Plateau heat source variety and climate anomalies in drylands of China is of great significance for maintaining ecological security， preventing major meteorological disasters and promoting regional sustainable development.This paper reviews and combs the current relevant research on the impact of Qinghai-Xizang Plateau heat sources on climate anomalies in drylands of China， including the climate characteristics of Qinghai-Xizang Plateau heat sources， the impact of Qinghai-Xizang Plateau heat sources on climate anomalies in drylands of China， and the prediction function of Qinghai-Xizang Plateau heat sources’ early signals on climate anomalies in drylands of China.Previous studies have shown that the temporal and spatial distribution characteristics of Qinghai-Xizang Plateau heat sources have significant discrepancy of seasonality， regionality and time stages.By regulating the circulation systems such as the meridional circulation on the northern side of Qinghai-Xizang Plateau， South Asian high， westerly jet and zonal planetary wave， it has an impact on the climate anomalies in drylands of China； At the same time， the Qinghai-Xizang Plateau snow and frozen soil change the surface energy balance and soil water and heat transfer through the land surface process， and affect the Qinghai-Xizang Plateau heat source， which can be used as the early signal for the prediction of summer precipitation in drylands of China.Finally， based on the summarizing of previous research progress and achievements， the future research direction of the impact of Qinghai-Xizang Plateau heat sources on climate anomalies in drylands of China is prospected.Under the background of global warming， there is still great uncertainty in the temporal and spatial variation law of Qinghai-Xizang Plateau heat sources.At present， the way of Qinghai-Xizang Plateau heat source affecting climate anomalies in drylands of China is not comprehensive， and the internal influence mechanism between them still needs to be further studied.

Jujubes (Ziziphus jujuba) are a crucial industry in the arid region of Xinjiang, facing challenges such as water scarcity and low water use efficiency. This study focuses on jujube orchards located at the edge of the Taklimakan Desert to investigate whether applying trace elements can effectively enhance jujube growth, development, and fruit quality. By foliar spraying boron and zinc micro-fertilizers onto jujube leaves, we analyzed the effects of different doses on growth parameters, photosynthetic activity, crop yield, water use efficiency, and fruit quality. The results revealed that the length of the fruit branch, leaf area index, and fruit longitudinal/transverse diameter increased by 19.35%, 25.72%, and 32.9%/2.28%, respectively; net photosynthetic rate, transpiration rate, and stomatal conductance increased by 105.51%, 91.43%, and 75.3%, respectively, while intercellular CO2 concentration decreased by 13.09%; yield and water use efficiency improved by 16.95% and 12.68%, respectively; soluble sugar content, titratable acid content, and flavonoid content increased by 13.56%, 51.63%, and 86.12%, respectively. Based on these findings, the optimal application rate for boron micro-fertilizer was determined to be 3.51~3.59 kg/hm2, and for zinc micro-fertilizer, it was 3.16~3.32 kg/hm2. This study provides practical methods along with theoretical support for applying micro-fertilizers in arid regions.

IntroductionScientific evaluation of the suitability of human settlement in arid areas and a grasp of their spatial differentiation characteristics are of great significance for the implementation of regional human settlement environment (HSE) improvement according to local conditions.MethodsIn this study, we took Gansu Province (GS), a typical arid area in China, as the research object. First, based on field research, we used the analytic hierarchy process to determine the weights of 12 evaluation indicators and build an HSE evaluation model from the two dimensions of nature and humanities. Then, we conduct a comprehensive evaluation of each factor based on the GIS spatial analysis module. Finally, we used the GIS natural breakpoint method and zoning statistics to understand the suitability of the HSE and its spatial distribution characteristics in GS Province.ResultsThe study findings can be summarized as follows: (1) The spatial distribution of the suitability of the natural environment in GS Province shows that the east-central part of the province is significantly higher than the northwestern, and there is a big difference between localities. (2) The comprehensive suitability of human settlement in GS Province appears as a spatial distribution characteristic, gradually decreasing from the central urban area to the surrounding areas. The suitability index of the living environment is between 0.26 and 0.71. (3) The area sizes of the five types of suitability are ranked as the following: low suitable (138,502 km2) > moderately suitable (133,761 km2) > critical suitable (97,244 km2) > high suitable (47,459 km2) > unsuitable (38,980km2); in 14 cities, the average value of habitat suitability index is more than 0.5 accounting for 42.9%.DiscussionOur research not only fills a gap in the research of human settlement in arid zones but also provides policy support for government departments to improve human settlement.

Xinjiang is located in the northwest of China, with a vast territory and abundant resources, which holds an important strategic position for China. However, the climate in the region is arid and the ecological environment is fragile. In recent years, with the growth of population and the improvement of economic development level, construction and agricultural land in Xinjiang have gradually expanded, and ecological land has been extensively occupied. The competition between land resources is becoming increasingly fierce, leading to some ecological and environmental problems in the region. In this context, understanding the spatiotemporal changes and driving factors of Xinjiang's production space, living space and ecological space (PLES) is of great practical significance for promoting sustainable development in the region, and can also provide reference for the research of PLES in other arid areas at home and abroad. At present, most of the research on PLES is focused on small-scale areas such as urban agglomerations, rural areas, and watersheds, or non arid areas with relatively superior natural conditions, with less research on large-scale arid areas. In this study, the transfer matrix, the center of gravity movement trajectory, Moran's I and the spatial conflict measurement model were used to illustrate the spatial–temporal evolution of PLES in Xinjiang, and the correlation coefficient was used to determine the main factors affecting the change of PLES. Results show that (1) Xinjiang is dominated by ecological space, which accounts for more than 90% of the total area of Xinjiang and has significant continuity. They are mainly distributed in Tarim, Turpan, and the northern Junggar Basin. The production space area accounts for about 5% of the total area of Xinjiang and is distributed in the vicinity of the Tianshan and Kunlun Mountains. Living space accounts for about 1% of Xinjiang's total area and is scattered around cities. (2) From 2000 to 2020, the change degree of PLES in Xinjiang in the last decade is higher than that in the first decade, most of which is the transformation from ecological space to production space. The three types of spaces influence and restrict each other in the development process. (3) Population, crop sown area, natural conditions, policy and the development level of agricultural science and technology are the main factors affecting the spatial distribution of production. Environmental factors such as altitude, soil erosion and temperature have a great influence on ecological space. Population, the output value of various industries and total retail sales of consumer goods are the main factors affecting residential space. The evolution of Xinjiang PLES is the result of multiple factors. (4) The medium spatial conflict dominates, mainly distributed in Tarim Basin and Junggar Basin. The weak and strong space conflicts are concentrated in the oases in the north of the Tianshan and Kunlun Mountains, and the number is small. From 2000 to 2020, the increasing degree of spatial conflicts in Xinjiang is due to land desertification.

In the context of the rural revitalization strategy, an accurate grasp of the spatial differentiation characteristics and influencing factors of rural settlements in underdeveloped arid inland river basins is urgently required. Taking the Shiyang River Basin as an example, rural settlements from 2000 to 2019 were examined via visual interpretation using satellite remote sensing data and official statistical data. Following the logic of "state characteristics—evolutionary patterns—influence factors—layout optimization", the average nearest index, the gravity-center migration model, spatial statistical analysis, and other methods were used in combination with GIS. The spatiotemporal pattern evolution characteristics of rural settlements in the past 20 years were analyzed. The results revealed the following: (1) The distribution pattern of rural settlements in the study area is sheet-like and strip-shaped. The projects in the southeast are mostly distributed in a patchy pattern with high density, while the characteristics in the west and north are exactly opposite. The objects in the south are distributed in an alluvial area of rivers, while settlements in the north are located in an oasis area. (2) From 2000 to 2019, the scale of rural settlements in the Shiyang River Basin, where there is a simultaneous occurrence of newly-built and disappearing phenomena, shows an expansion trend that first increased quickly and then slowed down. Spatially, rural settlements in the basin show a clustering trend toward the southwest. (3) The distribution characteristics of rural settlements are close to water and roads, and they are greatly influenced by urban–rural integration and ecological migration. The results will provide a scientific basis for accelerating the modernization of rural areas and the construction of new rural areas according to local conditions. [ABSTRACT FROM AUTHOR]

Unsaturated zones are critical for water and material exchange between groundwater and surface ecosystems. Understanding the migration patterns of soil water and salts in these zones can offer theoretical support for maintaining the equilibrium between groundwater and surface ecosystems in Northwestern China's salinized regions. This study explores the correlation between soil particle composition and soil water and salt distribution at a test site in the lower reaches of the Shiyang River basin. It analyzes the way in which water and salt patterns vary with different soil structures over various timescales. The results indicate that lithological profiles with similar structures but varying fine particle contents exhibit distinct water–salt variation patterns. Higher fine particle content leads to increased water and total dissolved solid content, but a decreased infiltration rate. When the middle layer has the highest fine content, soil evaporation is partially inhibited. The more complex the lithologic structure, the less effective irrigation is in leaching salt. However, when the lithologic structure remains constant, fine particle content has minimal impact on salt leaching. [ABSTRACT FROM AUTHOR]

Soil organic carbon is very important to increase crop yield. Understanding the composition changes and migration characteristics of SOC under different irrigation conditions in arid oasis areas is of great significance for the sustainable development of agro-ecosystem and the estimation of carbon balance of farmland ecosystem in arid areas. In this paper, classical statistics and geostatistics were used to study the leaching characteristics and migration laws of soil organic carbon under different irrigation conditions in Minqin Oasis, and the leaching amount and loss process and mechanism of SOC under different irrigation conditions were quantified. The research results showed that: (1) Irrigation increased the average 0–100 cm SOC content. After irrigation, SOC content decreased first and then increased with the increase in soil depth, with the maximum value of 8.56 g/kg and the minimum value of 1.82 g/kg. Compared with that before irrigation, SOC content in 0–30 cm surface layer was in leaching state, SOC content in 30–70 cm surface layer was accumulated, and SOC content in 70–100 cm surface layer had no obvious change. (2) Water was an important factor affecting soil carbon. The greater the irrigation amount, the higher the carbon leaching rate and the greater the migration amount. The SOC content in 0–30 cm soil layer was most significantly affected by irrigation, and the migration amount of SOC gradually decreased with the increase in soil depth. The maximum leaching rate of SOC was 36.8%, the minimum leaching rate was 13.5%, and its average leaching rate was 23.4%. (3) Due to the influence of soil infiltration rate under water, SOC content in different irrigation periods showed that the greatest SOC occurred in the 0–70 cm layer, and SOC content in soil was basically the same as that in non-irrigated areas on the fifth day after irrigation. (4) Precipitation, plastic film mulching, soil physical and chemical properties and other environmental factors were important factors affecting the migration and change in SOC content. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With high resolution and wide coverage, satellite precipitation products like the Multi-Source Weighted Ensemble Precipitation (MSWEP) could support hydrological research in arid regions, where the spatial heterogeneity of precipitation is high, but rain gauges are sparse, but these products are inevitably subject to errors. In this study, we integrated measured precipitation and topographic data, and improved MSWEP by interpolation and an optimal regression model. The Tianshan Mountain area was taken as a typical arid area, and spatial stratified heterogeneity of precipitation was analyzed. The results show that: (1) The optimal regression model combined the advantages of site interpolation and MSWEP and improved the underestimation of precipitation in mountainous areas; (2) The precipitation decreased from West to East, and from North to South, and the precipitation in West and East subregions increased linearly with the elevation. The maximum precipitation height zone in the North is located at 4300 m. There are two maximum precipitation height zones in the South; (3) The accuracy of spatial interpolation of station data was limited by the uneven distribution of the stations in the East subregion, and the inaccuracy of MSWEP was due to the land cover and topography of the North and South subregions. The improved MSWEP (IMMSWEP) not only resolved the problem of lack of rainfall stations in arid area, but also resulted in an inversion of regional spatial precipitation differentiation with high resolution and high precision, providing a reference for meteorological researchers. [ABSTRACT FROM AUTHOR]

In order to formulate a reasonable water input model for cotton fields in southern Xinjiang for scientific and rational fertilization, to reduce soil carbon leaching, and to improve soil carbon sequestration capacity, an undisturbed soil column leaching test was used to simulate the current field management method in the study area. Two methods, drip irrigation and flood irrigation, were set up, and three irrigation and three nitrogen fertilizer levels were used to carry out the undisturbed soil column leaching test. The results showed that the amount and mode of water and nitrogen input affected the distribution and leaching loss of organic carbon and inorganic carbon in the soil. When the nitrogen application rate increased from 270 kg·hm−2 to 450 kg·hm−2, the leaching loss of soluble organic carbon and soluble inorganic carbon increased significantly. When the water input increased from 6000 m3·hm−2 to 9000 m3·hm−2, the leaching loss of DOC and DIC increased significantly. The carbon leaching loss under drip irrigation was higher than that under flood irrigation. The leaching rates of DOC and DIC were fastest under the conditions of high water (9000 m3·hm−2) and high fertilizer (450 kg·hm−2). This shows that water and nitrogen input and irrigation methods are important factors affecting soil carbon leaching. In the case of excessive water input, long-term high-frequency irrigation is the main factor affecting carbon leaching. [ABSTRACT FROM AUTHOR]

Understanding the impact of continuous cropping with straw return on soil organic matter functional groups is of great importance for maintaining chemical stabilization of SOC in arid regions. Infrared spectral characteristics of cotton field soil with different continuous cropping durations (0, 5, 10, 15 and 20 years) were determined with Fourier‐transform infrared spectroscopy for fields in Manasi River Basin, Xinjiang province, China. The effects of continuous cropping duration on the stability and chemical composition of soil organic carbon (SOC) were analysed. The results indicate an initial increase in the SOC, soil particulate organic carbon (POC), and mineral‐associated organic carbon (MOC) content of soil under continuous cropping with straw return. However, as continuous cropping duration increased, the levels of SOC, POC, and MOC in soil began to decrease. The soil POC content and POC/MOC were highest after 5 years of straw return, and started to decrease as the continuous cropping duration increased. The SOC and MOC contents were highest after 10 years of continuous cropping, and were 3.30 and 1.84 times higher than the control, respectively. As continuous cropping duration increased, the relative peak intensities for polysaccharides and aromatic groups in soil organic matter decreased, while the relative peak intensities for aliphatic compounds and hydroxyketone increased. In conclusion, continuous cropping with straw return in cotton fields promotes SOC but only for about 10 years. An increase in straw return duration boosts the degree of esterification in soil organic matter. Moreover, enhanced protection by mineral binding was observed for soil organic matter, increasing organic matter stabilization. This study aimed to provide an empirical foundation for the management of the SOC pool and the establishment of rational straw return practices for cotton fields in arid areas. [ABSTRACT FROM AUTHOR]