Search Results (34)

This study aimed to determine the characteristics and driving factors of spatial evolution in urban historical areas during urbanization and urban renewal and recommend how to protect these areas. The urban historical district of Zhangye, a famous historical and cultural city in China, was chosen as the study area. The research used a land transfer matrix, spatial design network analysis (sDNA), GIS analysis, and relevant statistical methods. It analyzed the spatial evolution characteristics of the district by considering the transformation of land use, the evolution of road networks, and the renewal of building profiles. GeoDetector was used to explore the effects of the factors. The study found that in the district, commercial and business land increased while industrial, manufacturing, logistics, and warehouse land decreased. The evolution speed at each stage had a wave-like development. The street pattern maintained the basic “cross” shape, with continuous improvements in the road system and overall accessibility. The building volume also increased gradually. The main types of architectural renewal included setback, integration, demolition, and addition. Meanwhile, economic and industrial factors had the most significant influence on the renewal of the district, whereas cultural factors had increasing influence. Finally, the dual-factor effects were more significant than the single-factor impacts. Full article

Plant species diversity and spatial distribution patterns are critical for understanding ecosystem dynamics in arid and fragile environments. This study investigates the diversity, spatial distribution, and interspecific associations of shrubs and herbaceous plants in the transition zone of the desert oasis located in the Hexi Corridor and southern edge of the Badanjilin Desert, China. Vegetation data were collected across sample plots spanning three counties in Zhangye City. Important values, diversity indices, and spatial distribution metrics were calculated to evaluate plant species dominance and community structure. Interspecific relationships were analyzed using variance ratio (VR), clumping indicators, and corrected χ² tests. The shrub community exhibited low species diversity (H′ = 1.754) and was dominated by Reaumuria songarica (Pall.) Maxim (IV = 111.175), reflecting its superior adaptability to arid conditions. In contrast, the herbaceous community displayed higher diversity (H′ = 2.498), with Aristida adscensionis L. (IV = 48.6174) as the dominant species. Both communities showed predominantly aggregative spatial distribution patterns, influenced by localized resource availability and adaptive strategies. Weak interspecific associations characterized the shrub community, with limited competition among dominant species, while the herbaceous community demonstrated significant negative correlations, indicating stronger resource competition. The study highlights the contrasting diversity and ecological roles of shrubs and herbaceous plants in arid ecosystems, shaped by resource limitations and environmental stressors. Effective conservation strategies are needed to protect dominant species and sustain ecosystem resilience in desert regions. Future research should focus on below-ground interactions and long-term monitoring to enhance understanding of species coexistence and community stability. Full article

Exploring the ecological footprint and ecological carrying capacity is an effective method to evaluate the sustainable development and utilization of natural resources. Gansu Province, one of the typical arid regions in northwest China that is primarily focused on agriculture, was selected to analyze the evolution of the water ecological footprint and carrying capacity in this paper. In addition, the breadth and depth of the water footprint were combined to further evaluate the current situation of water resource utilization and management across different regions. This study can complement the research on the ecological footprint in arid areas dominated by agriculture. The results showed that (1) the agricultural water footprint was the main footprint and the key to water conservation. The overall water ecological footprint indicated a slow decline trend from 2009 to 2022 in Gansu Province. There was a gradual reduction in the agricultural water footprint and a notable increase in the ecological environment water footprint, indicating water use structures were generally becoming reasonable. (2) During the period, the eco-capacity and per capita eco-capacity exhibited similar trends in fluctuation and change, and spatial distribution was relatively dispersed due to the precipitation, total water resources, and industrial structure in the regions. (3) For prefecture-level cities, the depth of the water ecological footprint showed obvious spatial agglomeration. According to the results, the water footprint breadth of Zhangye and Longnan was larger, and the water resource flow can meet the local water demand. The water footprint depth of Lanzhou, Jinchang, Baiyin, and Jiayuguan was high, indicating the stock of water resources needs to be consumed to satisfy social production and living. The results can provide a scientific basis for the effective management and rational conservation of water resources. Full article

Optimizing maize irrigation strategies is essential for improving water use efficiency and crop yields in arid regions. However, limited quantitative research exists on these optimizations. This study focuses on the Heihe River Basin in China, aiming to (1) optimize maize irrigation strategies using a differential evolution (DE) algorithm integrated with the AquaCrop model and remote sensing data; (2) compare the DE algorithm’s performance with the traditional Nelder–Mead (fmin) algorithm regarding yield improvement and irrigation water use; and (3) assess the benefits of different irrigation strategies under limited water availability. Covering 22 irrigation management zones in Zhangye City, Gansu Province, the study utilized soil, weather, and crop data from Google Earth Engine to drive the AquaCrop model. Results indicate that the DE algorithm achieved higher simulated maize yields, increasing by 0.5 to 1 t/ha on average compared to the fmin algorithm, albeit with a 30% rise in irrigation water usage. The integration of both the DE and fmin algorithms with the AquaCrop model facilitates the development of tailored irrigation strategies, providing a scientific foundation for sustainable agricultural water management. These findings can guide efficient irrigation management plans in the region and similar arid systems. Full article

Water consumption forecasting is a critical aspect of the increasingly strained water resources and sustainable water management processes. It is essential to explore the current status of water use patterns and future development directions in Zhangye City. In this study, 17 factors affecting water consumption in Zhangye City were selected to analyze changes in water consumption and to predict values from 2003 to 2022, utilizing the entropy weight–VIKOR model and the grey neural network model. The results indicate that agricultural water consumption and annual rainfall are the factors with the largest weights among the social and natural attribute indicators, respectively, significantly influencing water consumption in Zhangye City. As the proportions of water consumption for forestry, animal husbandry, fishery, livestock, urban public use, and ecological environment increase, while agricultural water consumption continues to decline, the overall water consumption trend in Zhangye City from 2003 to 2022 shows a positive trajectory. Each water consumption factor is tending toward greater balance, and the relationship between water supply and distribution is improving. The multi-year average relative error of the water consumption predictions for Zhangye City from 2003 to 2022 using the grey neural network model was 4.28%. Furthermore, the relative error values for annual predictions ranged from 0.60% to 5.00%, achieving an accuracy rate of 80.00%. This indicates a strong predictive performance. Ultimately, the model was used to predict a water consumption of 20.18 × 10⁸ m³ in Zhangye City in 2027. The model can serve as a theoretical reference for short-term water consumption forecasting and for establishing a basin water resource allocation system in Zhangye City. Full article

Microbiota density plays an important role in maintaining host metabolism, immune function, and health, and age has a specific effect on the composition of intestinal microbiota. Therefore, the age-specific effects of age differences on the structure and function of the ileum microbiota in Tibetan sheep were investigated by determining the density of the ileum microbiota, the content of VFAs, and the expression levels of their transporter-related genes at different ages. The results showed that the contents of acetic acid and propionic acid in the ileum of Tibetan sheep in the 1.5-year-old group were significantly higher (p < 0.05) than those in other age groups, and that the contents of total VFAs were also significantly higher (p < 0.05) than those in other age groups. The relative densities of ileum Rf, Ra, and Fs were significantly higher in the 1.5-year-old group than in the other age groups (p < 0.05). The ileum epithelial VFAs transport-related genes AE2, MCT-4, and NHE1 had the highest expression in the 1.5-year-old group, and the expression of DRA was significantly lower in the 1.5-year-old group than in the 6-year-old group (p < 0.05). Correlation analysis showed that Cb, Sr, and Tb were significantly positively correlated with butyric acid concentration (p < 0.05) and negatively correlated with acetic acid, but the difference was not significant (p > 0.05); MCT-1, MCT-4, and AE2 were significantly positively correlated (p < 0.05) with acetic, propionic, and isobutyric acid concentrations; NHE1, NHE2, and MCT-4 were highly significantly positively correlated (p < 0.01) with Romboutsia and unclassified_Peptostreptococcaceae, while acetic acid was significantly positively correlated (p < 0.05) with NK4A214_group; Romboutsia, and unclassified_Peptostreptococcaceae were significantly positively correlated (p < 0.05). Therefore, compared with other ages, the 1.5-year-old Tibetan sheep had a stronger fermentation and metabolic capacity in the ileum under traditional grazing conditions on the plateau, which could provide more energy for Tibetan sheep during plateau acclimatization. Full article

Oasis cities are central to the economic and social development as well as ecological sustainability in the arid region in Northwest China. This study aims to explore the balance between river health and human well-being of local residents in the Hexi River oasis, while also enhancing the effectiveness of water resource management within the basin. Utilizing the SMI-P method, we construct a ‘Happy River’ evaluation system that integrates goals, criteria, and indicators. We analyze the evaluation index system for ‘Happy River’ construction in the study area, specifically the Zhangye City section of the Heihe River Basin, and derive a comprehensive evaluation value for the ‘Happy River’ initiative. Additionally, we assess the fit attribute of the evaluation system using the coupled coordination degree model and harmony degree theory, thereby enhancing the rationality of the evaluation method and ensuring a more thorough examination process. The results indicate that from 2017 to 2021, the urban wastewater treatment rate and the degree of water quality excellence in the Zhangye City section of the Black River Basin represent the highest and lowest weights, respectively, within the evaluation system. This suggests that improving the quality of the urban water environment has emerged as the primary factor influencing the assessment of the Happy River during the construction of the Happy River and Happy Lake. Moreover, ecological health is identified as the most significant criterion in the evaluation system, serving as the main factor affecting residents’ perceptions of happiness related to rivers and lakes. Over the five-year period, the happiness level in the study area improved from “relatively happy” to “very happy”, while the coupling coordination degree increased from 0.605 to 0.687, indicating a gradual progression toward coordinated development. Simultaneously, the harmony degree rose from 0.527 to 0.601, suggesting a tendency towards a condition of basic harmony. Additionally, the happiness index increased from 76.71 to 81.97, transitioning from a state of happiness to one of very high happiness. The composite index also improved, rising from 0.459 to 0.526, which demonstrates the preliminary success of the ‘Happy River’ construction efforts in the study area. The evaluation system and model of the ‘Happy River’, along with the final results of this study, can serve as theoretical references for the development of similar initiatives in typical characteristic rivers within the arid region of Northwest China. Full article

Water and nitrogen are the primary constraints on improving agricultural productivity. The aims of this study are to investigate the synergistic effects of water and nitrogen, optimize their combination schemes under mulched drip irrigation systems in the northwest region of China, and offer scientific insight into enhancing water and nitrogen use efficiency in potato cultivation. The traditional cultivar “Qing Shu 10” was chosen for the test material. A two-year field study on potato water–nitrogen interaction was conducted in the central Hexi Corridor, within Ganzhou District of Zhangye City, with three irrigation levels (W1 (336 mm), W2 (408 mm), and W3 (480 mm)) and three nitrogen application rates (N1 (44 kg ha⁻¹), N2 (192 kg ha⁻¹), and N3 (240 kg ha⁻¹)) using a fully randomized combination design, resulting in nine treatments. This study examined the varying responses in potato yield and water–nitrogen use efficiency to different water–nitrogen combinations in the Hexi Corridor region, developed a mathematical regression model to predict the economic benefit of potatoes based on water–nitrogen interactions, and refined the application strategy. The results indicated that both the volume of irrigation water and the rate of nitrogen application significantly influenced potato yield and water–nitrogen utilization efficiency. A distinct interactive effect was observed between irrigation volume and nitrogen application rate. The reduced irrigation volume restricted nitrogen uptake, with an average increase of 31.87% in nitrogen fertilizer partial productivity and 31.54% in potato yield when moving from W1 to W2 over two years and only a 6.02% and 5.48% increase from W2 to W3, respectively. Similarly, reduced nitrogen application rates also hindered water uptake by potatoes, with increases of 9.05% in water use efficiency, 12.14% in irrigation water use efficiency, 12.12% in yield from N1 to N2, and only 1.98% and 1.69% increases in irrigation water use efficiency and yield from N2 to N3, while water use efficiency decreased by 1.17%. The highest yield values over the two-year period were observed in the N2W3 treatment, with 43,493.54 and 43,082.19 kg ha⁻¹. The irrigation volume, nitrogen application rate, and potato economic benefit were well modeled by a quadratic regression, with an R² of 0.996 for both predicted and actual economic benefit over two years, indicating a trend of initial increase followed by a decrease as water and nitrogen levels increased. Through simulation optimization and a thorough analysis of multiple indicators, the N2W3 treatment yielded an economic benefit exceeding 25,391.13 CNY ha⁻¹ and demonstrated a high water–nitrogen utilization efficiency. This treatment not only enhances potato economic benefit but also minimizes agricultural resource inputs, establishing it as the optimal water and fertilizer management strategy for this study. Full article

Angaracris rhodopa (Fischer et Walheim), Calliptamus abbreviatus (Ikonnikov), Myrmeleotettix palpalis (Zubowsky), and Oedaleus decorus asiaticus (Bey-Bienko) are the main grasshoppers that harm the natural grassland in the Hexi Corridor in Gansu, northwest China. In this study, the MaxEnt model was employed to identify the key environmental factors affecting the distribution of the four grasshoppers’ habitats and to assess their distribution under current and future climate conditions. The aim was to provide a basis for grasshopper monitoring, prediction, and precise control. In this study, distribution of suitable habitats for A. rhodopa, C. abbreviates, M. palpalis, O. decorus asiaticus were predicted under current and future climatic scenarios using the Maxent model. The average AUC (area under the ROC curve) and TSS (true skill statistic) values of the four grasshoppers were greater than 0.9, and the simulation results were excellent and highly reliable. The mean annual precipitation was the main factor limiting the current range of suitable areas for these four species. Under the current climate, A. rhodopa, C. abbreviatus, and O. decorus asiaticus were mainly distributed in the central and eastern parts of the Hexi Corridor, and M. palpalis was distributed throughout the Hexi Corridor, with a suitable area of 1.29 × 10⁴, 1.43 × 10⁴, 1.44 × 10⁴, and 2.12 × 10⁴ km², accounting for 13.7%, 15.2%, 15.3%, and 22.5% of the total area of the grasslands in the Hexi Corridor, respectively. The highly suitable areas of A. rhodopa, C. abbreviatus, and O. decorus asiaticus were mainly distributed in the eastern-central part of Zhangye City, the western part of Wuwei City, and the western and southern parts of Jinchang City, with areas of 0.20 × 10⁴, 0.29 × 10⁴, and 0.35 × 10⁴ km², accounting for 2.2%, 3%, and 3.7% of the grassland area, respectively. The high habitat of M. palpalis was mainly distributed in the southeast of Jiuquan City, the west, middle, and east of Zhangye City, the west of Wuwei City, and the west and south of Jinchang City, with an area of 0.32 × 10⁴ km², accounting for 3.4% of the grassland area. In the 2030s, the range of A. rhodopa, C. abbreviatus, and O. decorus asiaticus was predicted to increase; the range of M. palpalis will decrease. The results of this study could provide a theoretical basis for the precise monitoring and control of key areas of grasshoppers in the Hexi Corridor. Full article

Under the background of climate change, the problems of water resource allocation and desertification in arid areas are becoming increasingly prominent, which seriously threatens the sustainable development of society. Constructing an ecological network is an important measure to improve the ecological environment and maintain ecological service function. This study takes the Hexi Corridor as an example and relies on land use data from 2000 to 2020, and comprehensively applies methods, such as morphological spatial pattern analysis (MSPA), the minimum cumulative resistance model (MCR), and the network evaluation index to construct and optimize the ecological network of the Hexi Corridor. Our results show: (1) the spatial distribution of the landscape elements in the Hexi Corridor was not uniform and that the ecological foundation in the north was poor; (2) the resistance surface was “low in the south and high in the north”, with low-value areas mainly located to the south of Jiuquan City, Zhangye City, and Wuwei City, and the high-value areas were mainly located in the middle and to the north of Jiuquan City and Wuwei City; (3) the ecological source areas, corridors, and nodes showed a fluctuating upward trend, and they were mainly located to the southwest of Zhangye City, Jiuquan City, and Wuwei City; (4) the network closure (α), line point rate (β), and network connectivity (γ) showed a W-shaped change trend; (5) after the ecological network optimization, 22 new ecological source areas, 78 new corridors, and 61 new nodes were added, as a result, the α, β, and γ indices all increased. Our results provide a reference for ecological environment restoration research and serve as a regionally balanced means of sustainably developing the Hexi Corridor. Full article

According to the natural condition of water resources and the economic, social, and ecological environment status of Zhangye City, the water resources carrying capacity of Zhangye City is evaluated by using the water resources carrying capacity Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) model with combination assignment. The results show that: (1) From 2010 to 2020, the water resources carrying capacity of Zhangye City was generally stable at the macro level, ranking at grades III and IV. However, from the micro level, the water resources carrying capacity fluctuates to a certain extent and shows an increasing trend year by year. (2) The steady improvement of economic and social conditions is the main driving force for the improvement of the comprehensive water resources carrying capacity of Zhangye City, and the changes in the ecological environment are also important factors affecting the carrying capacity of water resources. The results provided a decision basis for future comprehensive development and utilization of water resources in Zhangye City and a reference for water resource carrying capacity and water resource security assessment in other arid and semi-arid areas in our country. Full article

The land surface albedo (LSA) represents the ability of the land surface to reflect solar radiation. It is one of the driving factors in the energy balance of land surface radiation and in land–air interactions. In this paper, we estimated the land surface albedo based on GF-1 WFV satellite data that have a high spatial and temporal resolution and cross-validated the albedo estimation results. The albedo estimations and validations were performed in the Ganzhou District, Zhangye City, China, and the Sindh Province, Pakistan. We used the direct estimation method which used a radiative transfer simulation to establish the relationship between the narrow band top of the atmosphere bidirectional reflectance and the land broadband albedo to estimate the albedo data. The results were validated with ground data, Landsat data, MODIS products, and GLASS products. The results show that the method can produce highly accurate albedo estimation results on different land cover types (RMSE: 0.026, R²: 0.835) and has a good consistency with the existing albedo products. This study makes a significant contribution to improving the utilization of GF data and contributes to the understanding of land–air interactions. Full article

This study was conducted at the Yimin Irrigation Experiment Station, Minle County, Zhangye City, Gansu Province, from April to October in 2019 and 2020. The relationship between water consumption and yield of potato at different stages of fertility under deficit-regulated irrigation was analyzed in a field trial study over two growing seasons. The results showed that the average annual water consumption in the tuber bulking stage was the largest, reaching 185.35~239.52 mm, followed by the average annual water consumption in the tuber initiation stage and starch accumulation stage, which were 100.02~132.30 mm and 82.48~112.36 mm, respectively, and the average annual water consumption in the seedling stage was the least, at 49.32~69.81 mm. Simultaneously, the average annual yield of potatoes in the treatment of WD1 was the highest, reaching 47,766.96 kg·hm⁻², followed by CK, which was 43,707.6 kg·hm⁻², and the yield of WD6 was the smallest in the treatment of moderate water deficit during tuber initiation, which was only 35,721.25 kg·hm⁻². Combining the four moisture production function models of Jensen, Minhas, Blank and Stewart, the Jensen and Stewart models were identified as suitable for the potato moisture production function in a cold and arid environment. The water production function model was used to investigate the relationship between water consumption and yield in each growth period of potato, and to provide a theoretical basis for the optimization of the irrigation system under deficit-regulating irrigation conditions for potato in this irrigation area. Full article

The city of Zhangye (Gansu Region, China) has been subjected to several changes related to the development of new profitable human activities. Unfortunately, this growth has led to a general decrease in water quality due to the release of several toxic wastes and pollutants (e.g., heavy metals) into the Heihe River. In order to assess the environmental exposure and the potential threat to human health, microbiological diversity for the monitoring of water pollution by biotic and abiotic impact factors was investigated. In particular, we analysed samples collected on different sites using 454 pyrotag sequencing of the 16S ribosomal genes. Then, we focused on alpha-diversity indices to test the hypothesis that communities featuring lower diversity show higher resistance to the disturbance events. The findings report that a wide range of environmental factors such as pH, nutrients and chemicals (heavy metals (HMs)), affected microbial diversity by stimulating mutualistic relationships among bacteria. Furthermore, a selection in bacterial taxa related to the different concentrations of polluting compounds was highlighted. Supporting the hypothesis, our investigation highlights the importance of microbial communities as sentinels for ecological status diagnosis. Full article

Dust weather is common and disastrous at the Tibetan Plateau. This study selected a typical case of dust weather and analyzed its main development mechanism in the northeast of the Tibetan Plateau, then applied six machine learning methods and a time series regression model to predict PM₁₀ concentration in this area. The results showed that: (1) The 24-h pressure change was positive when the front intruded on the surface; convergence of vector winds with a sudden drop in temperature and humidity led by a trough on 700 hPa; a “two troughs and one ridge” weather situation appeared on 500 hPa while the cold advection behind the trough was strong and a cyclone vorticity was formed in the east of Inner Mongolia. (2) The trajectory of air mass from the Hexi Corridor was the main air mass path influencing Xining City, in this case, since a significant lag in the peak of PM₁₀ concentration appeared in Xining City when compared with Zhangye City. (3) The Multiple Linear Regression was not only timely and effective in predicting the PM₁₀ concentration but had great abilities for anticipating the transition period of particle concentration and the appearance date of maximum values in such dust weather. (4) The M_A and M_P in the clean period were much lower than that in the dust period; the PM₁₀ of Zhangye City as an eigenvalue played an important role in predicting the PM₁₀ of Xining City even in clean periods. Different from dust periods, the prediction effect of Random Forest Optimized by Bayesian hyperparameter was superior to Multiple Linear Regression in clean periods. Full article