Introduction

The balance and stability of ecosystems are fundamental to regional ecological security and the sustainable development of socio-economic systems1. Due to spatial heterogeneity in geographical patterns, ecosystems often perform distinct dominant functions across different regions, resulting in varying degrees of spatial differentiation in the importance of ecosystem services. A central challenge lies in identifying and prioritizing the conservation of critical natural elements and landscape configurations that underpin key ecological functions. Concurrently, rapid socio-economic development and accelerated urbanization have driven dramatic shifts in land-use patterns, intensifying anthropogenic pressures on natural environments2. These transformations have led to widespread ecological degradation and heightened environmental risks across territorial spaces. Effectively diagnosing the underlying causes and extent of ecosystem deterioration, and reconstructing damaged ecological structures and functional networks, has become a critical focus of regional conservation and governance strategies. In arid inland river basins—where ecosystems are inherently fragile, highly sensitive to disturbance, and costly to restore—precision and efficiency in coordinating the protection, development, utilization, and rehabilitation of territorial space are imperative.

Arid regions represent some of Earth’s most ecologically vulnerable and sensitive environments, characterized by limited ecosystem resilience, constrained environmental carrying capacity, and heightened susceptibility of ecological processes to external perturbations3. Under the combined pressures of climate change and anthropogenic influences, these systems exhibit pronounced predisposition toward systemic degradation. Within this context, watershed ecosystems in arid regions not only fulfill critical functions in maintaining regional ecological security and resource provisioning but also demonstrate pronounced spatial heterogeneity and functional differentiation owing to their distinctive geomorphological configurations and hydrological processes. This complexity renders them fundamentally distinct from watershed systems in other climatic zones. Governed by natural hydrological cycles, inland river basins across China’s northwestern arid region have developed an intricate ecogeographical mosaic comprising interspersed montane, oasis, and desert landscapes. The Mountain–Oasis–Desert System (MODS) in arid inland river basins constitutes a distinctive ecogeographical unit characterized by pronounced spatial heterogeneity and functional complementarity, driven by hydrological cycles and fluxes of nutrients and energy. This system exhibits a highly complex internal structure and stark differentiation in ecological functions4. Under the dual pressures of global climate change and intensified anthropogenic disturbances, the ecological security of these basins faces mounting threats, including water scarcity, land degradation, and biodiversity loss—challenges that critically undermine the prospects for regional sustainability. Some research has been devoted to MODS and its surrounding ecological dynamics, encompassing studies on system coupling mechanisms5, land-use change and its impacts6, responses to climate variability7, landscape ecological patterns8, hydrological processes9, and ecosystem services10. However, existing efforts to delineate ecological conservation and restoration zones in these regions often adopt fragmented perspectives—focusing narrowly on geographic conditions, territorial spatial functions, ecological issues, or grid-scale classifications—thereby limiting a holistic understanding of regional differentiation, ecological service provisioning, and potential environmental degradation. This piecemeal approach falls short in guiding the design of integrated and adaptive restoration strategies. In light of the emerging spatial governance paradigm emphasizing element interlinkages, process coupling, and spatial coordination, there is a pressing need to construct an ecologically informed territorial spatial restoration framework rooted in systemic thinking. This study integrates the geographic patterns of mountain-oasis-desert composite systems, ecosystem service functions, and potential ecological risks to identify structural deficiencies and process imbalances among different ecological components. Through grid-scale analysis, we delineate ecological protection and restoration zones scientifically, calculate ecological water requirements for each zone, and examine ecological water allocation strategies within the study area. This approach establishes a differentiated ecological protection and restoration framework for inland river basins, characterized by rational spatial configuration and targeted management strategies.

A growing body of scholarship has explored ecological conservation and restoration zoning across diverse regions, focusing primarily on three dimensions. First, zoning based on specific ecological elements—such as wetlands, green spaces, and farmlands—has been widely applied to identify and prioritize key ecological zones for protection and restoration11. Second, Ecological conservation and restoration zoning has been conducted across multiple spatial scales, including municipal jurisdictions11, provincial regions12, ecologically fragile zones13, national parks14, and grid-based units15. Third, researchers have adopted a range of analytical perspectives, including ecosystem service supply–demand relationships16,17 ecological environmental quality12, ecosystem service valuation18, landscape ecological risk19, and the interplay between land use and ecological resilience20. For example, Ji et al.21 delineated ecological management zones for the fragile alpine ecosystems of the Tibetan autonomous regions in Yunnan by coupling ecosystem service supply–demand dynamics with ecosystem resilience. Xu et al.22 conducted ecological zoning for coastal megacities by integrating ecosystem restoration capacity—derived from ecological remote sensing indices—with land use patterns to assess ecological risk. Ecological importance captures the irreplaceable role of ecosystem functions, spatial structures, and key areas in safeguarding biodiversity and supporting the sustainable use of natural resources. In contrast, ecological risk reflects the probability of ecosystem degradation under adverse environmental pressures. The coupling of ecological importance and ecological risk represents a systems-level modeling of ecological capital stocks and anthropogenic disturbance flows. In arid inland river basins—where spatial heterogeneity is pronounced—zoning strategies that integrate ecological importance as a value-oriented driver and ecological risk as a constraint can support precise, adaptive management of ecological resources and socio-economic factors. This approach offers a robust framework for restoring ecosystem integrity and ensuring long-term ecological sustainability in these vulnerable landscapes.

In arid inland river basins, vegetation ecological water demand refers to the volume of water required to sustain the structural stability and functional performance of the mountain–desert–oasis ecosystem. It represents the essential water consumption needed by these open systems to buffer adverse environmental disturbances and maintain a trajectory of positive ecological development23,24. A variety of methods have been developed to quantify ecological water demand in such regions, including the quota-based approach, estimations based on plant evapotranspiration, water balance models, biomass-based calculations, and remote sensing–driven methodologies. In this study, we adopt an enhanced Penman–Monteith equation to estimate vegetation ecological water demand. This method is widely recognized for its maturity and operational feasibility. By incorporating parameters such as vegetation coefficients, soil moisture limitation factors, and vegetation coverage, it enables more accurate simulations of plant transpiration and actual ecological water use, as well as precise characterization of the spatiotemporal distribution of regional water demand. To date, most research on ecological water demand in inland river basins has focused on descriptive analyses. For example, Hao et al.25 applied the FAO-recommended method to investigate the spatial and temporal patterns of natural vegetation water demand, while Wei et al.26 used an evapotranspiration-based approach in conjunction with land cover data to analyze water demand and its differentiation across vegetation types. However, integrative studies linking ecological water demand with water resource allocation and ecological restoration remain relatively scarce, underscoring a critical gap in current research.

Urbanization-driven land use intensification has heightened ecological stress, amplifying ecosystem vulnerability in this arid region27. Intensified anthropogenic land use has heightened ecological stress, amplifying ecosystem vulnerability in this arid region. Inland river basins in arid regions, shaped by distinctive environmental constraints, face an increasingly acute conflict between socioeconomic development and ecological integrity—one that calls for immediate resolution under the imperatives of carbon neutrality. Situated at the intersection of the Tibetan Plateau, the Loess Plateau, and the Inner Mongolia Plateau, the Shiyang River Basin represents a strategically vital ecological barrier and a key oasis-based agricultural hub within China’s arid northwest. Yet, the region suffers from fragile environmental conditions, pronounced conflict between human development and natural systems, and spatial land-use structures that are poorly aligned with principles of sustainable growth28. In response, this study establishes a dual-core ecological protection and restoration zoning framework that integrates “functional maintenance” and “risk governance” for the Shiyang River Basin. The framework comprehensively incorporates ecosystem service functional importance and potential ecological risk assessment, utilizing ecological importance as the value orientation and ecological risk as the constraint condition. Based on 1 km × 1 km grid-scale evaluations of ecosystem service functional importance and ecological risk, we implement ecological protection and restoration zoning classification to achieve precise and efficient ecological conservation at the microscale. This approach facilitates targeted restoration, reduces ecological rehabilitation costs, and enhances restoration efficacy, providing innovative perspectives and pathways for establishing holistic approaches, systematic thinking, and efficient advancement of ecological restoration work in territorial spatial governance of inland river basins in arid regions. Furthermore, we explore ecological water allocation mechanisms for each protection and restoration zone based on ecological water demand calculations and propose differentiated governance strategies tailored to specific zones. These contributions hold significant implications for improving human-environment systems in arid and semi-arid regions, promoting high-quality development of inland river basins, and advancing the modernization of territorial spatial governance systems and capabilities.

Materials and methods

Overview of the study area

Situated on the northern foothills of the Qilian Mountains, west of the Wushaoling range, the Shiyang River Basin (36°29′N–39°27′N, 101°41′E–104°16′E) occupies the eastern segment of the Hexi Corridor in Gansu Province. The basin experiences a temperate continental arid climate, characterized by scarce precipitation, intense evaporation, and large diurnal temperature fluctuations, with a mean annual temperature of 6.4 °C and an average annual rainfall of 260.0 mm. Administratively, the basin encompasses the entirety of Liangzhou District, Minqin County, Gulang County, Tianzhu Tibetan Autonomous County, Yongchang County, and Jinchuan District, as well as parts of Sunan Yugur Autonomous County—spanning seven county-level units across three prefecture-level cities (Fig. 1). Covering a total area of 42,473 km², the Shiyang River Basin represents a quintessential inland river basin in Northwest China’s arid zone. Due to its unique geographic setting and environmental conditions, the basin hosts a tripartite ecological structure of mountains, oases, and deserts arranged longitudinally from upstream to downstream. The basin sustains a permanent population of 1.9 × 10⁶ inhabitants, representing one of the most densely populated inland river basins in China with the highest intensity of water and land resource exploitation29. It fulfills multiple functions encompassing regional food security assurance, ecological stability maintenance, and socioeconomic coordinated development support. The basin confronts formidable challenges regarding ecological security and sustainable socioeconomic development. Global warming has induced glacial retreat and snowline elevation in the Qilian Mountains30, while historical indiscriminate deforestation has precipitated forest and grassland degradation, intensified soil erosion, and persistent threats to biodiversity. The oasis system exhibits excessive water resource consumption with acute supply-demand contradictions, accompanied by soil salinization and ecological space compression. Excessive water diversion by oases has resulted in downstream water scarcity and perennial flow cessation, rendering desert ecosystems extremely vulnerable with continuous desertification expansion. Ecological flow interruption has led to the periodic desiccation of terminal lakes. Under the compounding multiple ecological pressures, the Shiyang River Basin has emerged as one of the most critical regions in arid inland river basins, where ecological protection and restoration tasks are most urgent and governance demands most concentrated.

Fig. 1
figure 1

Overview map of the study area. (The map was generated by ArcGIS 10.8 http://www.esri.com/software/arcgis and does not require any permission from anywhere).

Full size image

Data sources and processing

The land use data for the Shiyang River Basin in 1990 and 2020 employed in this study were obtained from the Resource and Environmental Science and Data Center of the Chinese Academy of Sciences (http://www.resdc.cn), with a spatial resolution of 30 m. This dataset was derived from remote sensing satellite imagery, utilizing data from Landsat 8 OLI, GF-2, and other satellite platforms. Following the Chinese land use remote sensing mapping classification system established by Liu Jiyuan et al.31, the dataset was generated through an integrated high-resolution remote sensing-UAV-ground survey observation framework, incorporating human-computer interactive visual interpretation methods based on geoscientific knowledge. The overall accuracy exceeded 88.95%. Land use classification adhered to the “Classification of Land Use Status"” (GB/T21010—2007) and the national remote sensing monitoring land use/cover classification system. Considering the distinctive landscape characteristics of the Shiyang River Basin and applying the principle of differentiating heterogeneity while synthesizing commonalities, the study area was categorized into six landscape types: arable land, forestland, grassland, construction land, water, and unused land. Road and settlement data were extracted from land use datasets, and distance metrics to roads and settlements were subsequently derived through spatial proximity analysis. To ensure consistency across datasets, all raster data were resampled to a spatial resolution of 1 km × 1 km, and all layers were reprojected to the WGS_1984_Albers coordinate system. Table 1 summarizes the main data in detail.

Table 1 List of main data.
Full size table

Research methodology

Conceptual framework

This study aims to delineate ecological restoration and conservation zones within the Shiyang River Basin, guided by ecological importance as the primary value orientation and constrained by ecological risk assessment. Through quantifying ecological water requirements, we examine water allocation mechanisms across distinct conservation zones to formulate precise and effective ecological restoration strategies. The methodological framework encompasses five sequential components: (1) We established a comprehensive technical framework for demarcating mountain, oasis, and desert ecosystems, utilizing 2020 baseline data integrated with field conditions. Mountain ecosystems serve as critical watershed sources and repositories for mineral nutrients and genetic resources. We employed spatial threshold delineation, defining areas with slopes exceeding 15° and elevations above 1500 m as mountain system criteria. Since threshold-based regions exhibited fragmented small-patch distributions incompatible with the continuous geomorphological characteristics inherent to mountain systems, spatial optimization was achieved through buffer analysis. Iterative analysis determined that a 1.5 km buffer radius optimized mountain system aggregation. Oasis ecosystems constitute vital centers for human survival and development, characterized by elevated productivity and biodiversity. We applied multidimensional feature extraction to identify areas with vegetation coverage exceeding 15%, subsequently overlaying these with water bodies and construction land patches derived from land use data. To eliminate classification redundancy, we excluded discrete small patches and spatially intersecting areas with mountain systems. Desert ecosystems represent extensive and ecologically sensitive arid regions that form the matrix and background environment of the composite system. Desert system extraction employed spatial exclusion methodology, whereby areas beyond mountain and oasis systems were classified as desert systems. (2) Based on ecosystem service importance and ecological risk assessments, we utilized natural break classification to stratify ecological importance and risk into five hierarchical levels: high, relatively high, moderate, relatively low, and low. (3) We established criteria for ecological conservation and restoration zoning based on ecological importance and risk gradients, implementing spatial overlay analysis to delineate conservation zones. (4) We calculated ecological water requirements for each conservation zone using a modified Penman-Monteith equation tailored to the Shiyang River Basin. (5) Ecological water allocation mechanisms were examined for each conservation zone based on water demand analysis, culminating in differentiated management strategies tailored to specific zonal characteristics. The detailed methodological framework is illustrated in Fig. 2.

Fig. 2
figure 2

Research framework.

Full size image

Assessment of ecosystem service importance

Drawing on previous studies32,33 and the specific conditions of the Shiyang River Basin, this study evaluates the importance of ecosystem services using four key indicators: food provision, water retention, carbon sequestration, and wind break and sand fixation. The importance of ecosystem service functions in the Shiyang River Basin was assessed using the Ecosystem Service Importance (ESI) evaluation index. The comprehensive ESI was classified into five levels: ESI ≤ 8.0 (low), 8.0 < ESI ≤ 14.0 (moderate-low), 14.0 < ESI ≤ 20.0 (medium), 20.0 < ESI ≤ 26.0 (moderate-high), and ESI > 26.0 (high). The specific calculation methods are presented in Table 2.

Table 2 Assessment methods of ecosystem services importance.
Full size table

Construction of the ecological risk assessment index system

This study adopts the composite ecosystem theory34 to establish an ecological risk assessment framework for the Shiyang River Basin, incorporating 12 indicators across natural, social, and economic dimensions (Table 3). From the natural perspective, the Qilian Mountains in the southwestern portion of the basin maintain the hydrological cycle foundation through dynamic regulation of solid water storage. Climate warming trends manifest significant altitudinal gradients in alpine ecological risk, whereby risk intensifies with elevation. Slope gradient serves as a critical indicator of surface steepness and exhibits a power-law relationship with geological hazard probability—steeper slopes typically correlate with elevated ecological risk35. Vegetation coverage functions as a biomass proxy; reduced regional vegetation coverage generally corresponds to diminished ecosystem service capacity and heightened ecological risk. Land cover types represent naturally formed or anthropogenically modified physical surface categories, with water bodies and forests providing the highest ecosystem service values and relatively minimal ecological risk36. Conversely, construction land experiences substantial human disturbance, resulting in comparatively elevated ecological risk. Soil erosion, categorized by external forces into hydraulic, aeolian, and freeze-thaw processes, demonstrates a positive correlation between erosion intensity and regional ecological risk levels37. Precipitation and water resource abundance constitute fundamental determinants of human production activities and regional ecological conditions—greater water resource availability enhances habitat quality while reducing regional ecological risk38. Given the limited precipitation in the Shiyang River Basin and its constrained influence on vegetation growth, vegetation distribution correlates more closely with surface runoff patterns. Therefore, alongside precipitation indicators, distance to water bodies was incorporated. Mean temperature reflects regional annual thermal conditions; in arid regions where evaporation typically exceeds precipitation, higher temperatures drive increased evaporation, reduced vegetation coverage, and elevated ecological risk39. From the economic dimension, per-unit area GDP typically reflects regional economic development levels40. For arid inland river basins primarily dependent on low-end industries and irrigated agriculture, higher per-unit area GDP often signifies greater regional water consumption, more severe ecological degradation, and elevated ecological risk levels. Nighttime light indices effectively capture industrial production, commercial activities, and energy consumption patterns, serving as proxies for regional economic development41. Higher nighttime light indices indicate intensified human disturbance to ecological environments and elevated ecological risk levels. From the social perspective, population density and road proximity reflect the scope and intensity of human activities within regions. Human activities typically pose threats to regional ecological environments. While ecological restoration can mitigate ecological risks, the environmental damage caused by human production and living activities in arid regions proves difficult to remedy in the short term42. Consequently, higher population densities and closer proximity to roads correlate with increased ecological risk. Based on regional characteristics and prior research, the natural breaks classification method was employed to stratify the ecological risk of each indicator into five levels—ranging from low to high. Higher classification levels correspond to greater ecological sensitivity and fragility, indicating elevated levels of ecological risk.

Table 3 Ecological security evaluation index system of Shiyang river Basin.
Full size table

Ecological risk index calculation

Spatial Principal Component Analysis (SPCA), an advanced multivariate statistical method that incorporates spatial autocorrelation, is particularly suited for dimensionality reduction and feature extraction in geospatial datasets43. Unlike conventional PCA, SPCA facilitates the intuitive spatial extension of results, enhancing interpretability through geovisualization. In this study, the SPCA tool within ArcGIS was employed to extract statistically significant principal components—those with a cumulative variance contribution exceeding 90%. Each component was associated with a corresponding spatial loading map and quantified contribution ratio. The Ecological Risk Index (ERI) was then defined as a weighted composite of these principal components, with the variance contribution of each component serving as its respective weight. The resulting ERI values were classified into five ordinal risk levels: ERI ≤ 1.0 (low), 1.0 < ERI ≤ 2.0 (moderate-low), 2.0 < ERI ≤ 3.0 (medium), 3.0 < ERI ≤ 4.0 (moderate-high), and ERI > 4.0 (high). The index is formalized as follows:

$$\:ERI=\sum\:_{j=1}^{m}{P}_{ij}{w}_{j}$$

In the equation, ERI denotes the Ecological Risk Index for the i-th assessment unit (grid cell); \(\:{P}_{ij}\) represents the value of the j-th principal component in the i-th unit; and \(\:{w}_{j}\) denotes the corresponding weight, determined by the variance contribution of the j-th component.

Ecological conservation and restoration zoning methodology

The core implementation pathway of ecological conservation and restoration adheres to a dual strategy of functional maintenance and problem-oriented intervention. The function-oriented approach emphasizes the preservation of essential ecosystem attributes by systematically conserving ecologically strategic elements, biological communities, and regional landscape networks, thereby constructing a resilient ecological barrier against external disturbances. In parallel, the problem-oriented mechanism targets the precise identification and remediation of ecological degradation within territorial spaces, underpinned by a multidimensional ecological risk assessment framework that enables accurate evaluation of ecological damage across spatial elements44. Therefore, the essence of ecological conservation and restoration lies in accurately evaluating the importance of ecosystem service functions alongside their associated ecological risks. This involves delineating the spatial distribution of ecosystem service capacities, systematically identifying the mechanisms and spatial heterogeneity of ecosystem degradation, and integrating priority areas for conservation and restoration. Such an approach enables the delineation of scientifically grounded conservation zones and the formulation of a spatially differentiated ecological governance framework characterized by rational layout and targeted interventions45. Given the expansive area of the Shiyang River Basin, coupled with generally low ecological quality and high restoration costs and complexity, this study adopts a strategy guided by the principles of conservation prioritization, resource efficiency, and natural recovery. When regional ecosystem service functions are weak but ecological risks are high, such as in wilderness areas and wasteland, this reflects prominent natural attributes with minimal human interference, yet fragile ecosystems with limited recovery capacity. Such areas are designated as wilderness protection zones, requiring maximum reduction of human intervention while prioritizing maintenance of ecological authenticity and system integrity. When regional ecosystem service functions are moderate to high while ecological risk levels remain low to medium, this indicates adequate ecological carrying capacity and self-regulation capability, making these areas suitable as transitional zones between ecological cores and human activity areas, thus designated as ecological buffer zones. Areas with moderate high or high ecosystem service functions but simultaneously facing elevated ecological risks indicate functionally important but severely damaged ecosystems, representing regions with the most pronounced ecological contradictions that require priority ecological governance and systematic restoration, hence designated as ecological restoration zones. In contrast, areas with critically important ecosystem service functions but low ecological risks reflect overall healthy, stable ecosystems with intact structures, serving as core spaces for safeguarding basin ecological security and warranting strict protection as ecological core zones. Additionally, areas with both low ecosystem service functions and low ecological risk levels typically represent highly developed regions with limited ecological potential, yet retain certain capacity for recovery and ecological function enhancement, thus designated as ecological set-aside zones that may serve as potential backup spaces for future ecological regulation. Based on 1 km × 1 km grid-scale assessments of ecosystem service importance and ecological risk levels (for the year 2020), spatial data were extracted and categorized into five classes—high (H), moderate-high (MH), medium(M), moderate-low (ML), and low (L). Through spatial overlay analysis, the Shiyang River Basin was partitioned into five ecological management zones: Wilderness Reserve Zone, Ecological Buffer Zone, Ecological Restoration Zone, Ecological Core Zone, and Ecological Set-aside Zone. Detailed classification criteria are presented in Table 4.

Table 4 Zoning standards of ecological protection and restoration.
Full size table

Modified penman equation

In this study, ecological water requirements refer to the minimum water volume necessary to maintain regional ecosystem structural stability and functional integrity. Given the characteristic arid ecological features of the Shiyang River Basin, the ecosystem types are predominantly various vegetation communities (including desert shrubland, grassland, and forest), whose ecological processes are intimately linked to vegetation physiological activities. Consequently, ecological water demand is primarily manifested as the fundamental water requirements of vegetation. Therefore, this study employs vegetation ecological water requirements as a proxy for overall ecological water requirements, reflecting the essential water resource security needs of the ecosystem. The classical Penman equation is typically used to estimate potential evapotranspiration under ideal conditions—characterized by ample water and nutrient supply, and the absence of pests or diseases—thus reflecting the maximum water demand of vegetation46. The modified Penman approach extends this framework by incorporating vegetation coefficients and soil constraint factors to more accurately approximate actual plant water requirements47. Due to the lack of long-term, continuous in-situ observations in the study area, this research draws on prior empirical studies of forest and grassland vegetation in Northwest China48, alongside the Forest Ecosystem Service Function Assessment Manual49, to determine vegetation coefficients for cropland, forest, and grassland in the Shiyang River Basin for the year 2020. Informed by previous studies on soil critical moisture thresholds and wilting points50, the soil critical moisture content was set at 15%, and the wilting coefficient at 8%. Detailed computational procedures are presented in Table 5.

Table 5 Calculation method of vegetation water demand.
Full size table

Results and analysis

Delineation of the mountain–desert–oasis composite ecosystem

Based on an established classification framework for mountain–oasis–desert systems, the Shiyang River Basin was partitioned into three distinct sub-ecosystems: mountainous, oasis, and desert (Fig. 3), exhibiting pronounced spatial differentiation from southwest to northeast. The mountainous system comprises the largest proportion, accounting for 44.28% of the total basin area. Predominantly located in the Qilian Mountains in the southwest, this system is characterized by land use dominated by grasslands (45.83%), forested areas (16.63%), and croplands (17.31%). In contrast, the oasis system represents the smallest share, covering 16.79% of the basin. Concentrated in the central corridor region, it is primarily composed of croplands and urbanized land, accounting for 53.26% and 59.56% of the basin’s total cultivated and built-up areas, respectively. This region serves as the principal hub for human habitation and agricultural activity. The desert system spans 16,531.00 km² (38.93%), and is primarily distributed across the northwestern transitional zone between the Tengger and Badain Jaran Deserts. Land use within this system is dominated by unused or barren land, which constitutes 82.17% of its area. Overall, the mountainous system features high vegetation cover and functions as a critical ecological service zone within the basin. The oasis system, with flat terrain and relatively abundant water resources, is a key area for agricultural production and urban–rural development. Meanwhile, the expansive and ecologically fragile desert system—characterized by gobi landscapes, exposed soils, and desert grasslands—acts as a vital refuge for characteristic flora and fauna of arid ecosystems and plays a crucial role in sustaining regional ecological balance and biodiversity.

Fig. 3
figure 3

The results of mountain, oasis and desert ecosystems and the spatial distribution of land use in each ecosystem in 2020. (MS, Mountain System; OS, Oasis System; DS, Desert System. The map was generated by ArcGIS 10.8 http://www.esri.com/software/arcgis and does not require any permission from anywhere).

Full size image

Spatiotemporal dynamics of ecosystem service importance

In this study, the importance of ecosystem services within the Shiyang River Basin was assessed using a composite index of the ecosystem service value. The results were classified into five ordinal levels—high, moderate-high, medium, moderate-low, and low—using the natural breaks (Jenks) method (Fig. 4). From 1990 to 2020, the ecosystem service importance index exhibited a steadily increasing trend, with the mean value rising from 12.658 to 15.495. Spatially, a distinct gradient emerged, characterized by moderate-high values in the southwest and moderate-low values in the northeast. Within mountain system, areas categorized as having high or moderate-high importance expanded substantially, increasing from 12.50% to 25.37% of the total mountainous area in 1990 to 36.66% and 28.04% in 2020, respectively. This shift reflects the transition from widespread ecosystem degradation due to intensive anthropogenic disturbances to large-scale ecological restoration initiatives. Notably, the implementation of reforestation and grassland restoration programs, along with the launch of the ecological civilization strategy and the establishment of Qilian Mountains National Park since 2012, have markedly enhanced regional ecosystem service functionality. In oasis system, zones of moderate-high and high importance showed a pronounced expansion—from 15.11% to 0.86% of the total oasis area in 1990 to 42.65% and 5.21% in 2020, respectively—while areas of moderate-low and medium importance concurrently declined. This indicates a substantial elevation in the ecological value of oasis regions, which now fulfill not only essential socio-economic roles but also increasingly vital ecological functions. These changes can be attributed to cropland development, the construction of ecological shelterbelts, and the promotion of water-efficient agro-pastoral practices. In contrast, desert system exhibited a modest expansion in areas of medium and moderate-high importance, alongside a contraction of zones with low and relatively low importance. These changes are closely linked to large-scale ecological engineering projects implemented during the study period, such as the Three-North Shelterbelt Program and sand stabilization initiatives. Overall, areas classified as having high or moderate-high ecosystem service importance remain limited, accounting for only 36.82% of the basin’s total area. These zones are primarily concentrated in the Qilian Mountains and oasis regions. In contrast, areas of low or moderate-low importance are mainly located in the northwestern part of the basin, adjacent to desert margins where wind erosion and arid conditions render the ecological environment fragile and the functional capacity of ecosystems relatively low.

Fig. 4
figure 4

Evaluation results of ecosystem service function importance. (MS, Mountain System; OS, Oasis System; DS, Desert System. The map was generated by ArcGIS 10.8 http://www.esri.com/software/arcgis and does not require any permission from anywhere).

Full size image

Spatiotemporal dynamics of ecological risk

Based on the calculated Ecological Risk Index (ERI), this study evaluates the ecological risk patterns across the Shiyang River Basin, categorizing ERI values into five discrete levels—high, moderate-high, medium, moderate-low, and low—using the natural breaks (Jenks) classification method (Fig. 5). From 1990 to 2020, the spatial distribution of ecological risk exhibited pronounced differentiation, with risk intensifying progressively from the southwest to the northeast. Over the study period, the average ERI increased from 3.844 to 3.904, indicating an overall upward trend in ecological risk. Mountain system was predominantly characterized by low to medium risk levels, though their extent declined markedly—from 79.84 to 69.08% of the basin area. This contraction reflects the positive ecological impact of the Qilian Mountains conservation policies, which substantially enhanced vegetation cover, reinforced environmental regulation in mining zones, and curtailed land disturbance and pollution risks51. In contrast, oasis system—primarily encompassing Jinchuan District, Liangzhou District, Yongchang County, Gulang County, and Minqin County—was dominated by medium to high risk levels. The average ERI within these regions rose from 4.330 to 4.386. Rapid urban expansion encroached upon large swaths of arable land, grassland, and unused land, leading to habitat fragmentation and loss. As a result, the area classified as medium risk shrank by 1,090.21 km², while high-risk zones expanded by 1,835.57 km². Desert system was predominantly under high ecological risk, although the average ERI decreased from 4.996 to 4.815. Notably, in Minqin County—situated between the Badain Jaran and Tengger Deserts—a suite of integrated restoration measures, including sand stabilization afforestation, riparian reforestation, ecological migration, farmland reversion, and habitat enclosure, led to significant environmental improvements around Qingtu Lake. Consequently, the area exposed to high ecological risk declined by 1,300.68 km². Collectively, the Shiyang River Basin is subject to persistently elevated ecological risk. Mountain, oasis, and desert systems exhibit a gradient of increasing risk, forming a spatial pattern that impedes wildlife migration, seed dispersal, nutrient cycling, and gene flow across the basin’s upper, middle, and lower reaches. This fragmented ecological landscape imposes substantial constraints on regional ecosystem stability and poses significant challenges to sustainable socio-environmental development.

Fig. 5
figure 5

Evaluation results of ecological risk assessment. (MS, Mountain System; OS, Oasis System; DS, Desert System; WB, Whole Basin. The map was generated by ArcGIS 10.8 http://www.esri.com/software/arcgis and does not require any permission from anywhere)).

Full size image

Ecological conservation and restoration zoning results

Based on the ecological conservation and restoration zoning framework proposed in this study, the Shiyang River Basin was delineated into five functional zones: Wilderness Reserve Zone, Ecological Buffer Zone, Ecological Restoration Zone, Ecological Core Zone, and Ecological Set-aside Zone (Fig. 6). The zoning results align closely with the region’s actual ecological protection and restoration needs. The Wilderness Reserve Zone encompasses the largest area, covering 18,795.17 km² (43.75%). Predominantly distributed across desert ecosystems, this zone is characterized by ecological sensitivity and fragility, with relatively high potential ecological risks. It constitutes a critical region for the conservation of characteristic arid-zone flora and fauna, the prevention of desertification, and the mitigation of ecosystem degradation. The Ecological Restoration Zone covers 4,387.28 km² (19.87%) and is primarily concentrated in oasis areas with high population density and intense economic activity. Restoration efforts in this zone aim to reconcile the demands of production with the imperatives of ecological protection. The Ecological Buffer Zone, also totaling 8,536.60 km² (10.21%), forms an important ecological shield, particularly within mountainous regions. It plays a crucial role in minimizing anthropogenic disturbances and desertification encroachment, acting as a natural barrier against windblown sand, pollutant dispersion, and biotic disruptions caused by human activity. The Ecological Core Zone spans 5,644.38 km² (13.14%) and is mainly located in mountainous areas with high vegetation cover and strong water conservation capacity. These zones are distant from densely inhabited regions and minimally disturbed by human activity, enabling them to maintain ecosystem stability and deliver essential ecological services critical to long-term regional sustainability and security. Finally, the Ecological Set-aside Zone accounts for 5,594.77 km² (13.02%), distributed primarily across mountainous and oasis landscapes. Characterized by relatively low ecological risk and limited ecosystem service capacity, these areas are designated for future spatial planning, including the advancement of ecological civilization, development of modern agriculture, and integrated urban–rural development initiatives.

Fig. 6
figure 6

Regional distribution of ecological protection and restoration in the Shiyang River Basin. (The map was generated by ArcGIS 10.8 http://www.esri.com/software/arcgis and does not require any permission from anywhere).

Full size image

Ecological water demand characteristics

Using the modified Penman equation, the total ecological water demand in the Shiyang River Basin in 2020 was estimated at 34.043 billion cubic meters. The spatial distribution of ecological water demand exhibited a pronounced south–north gradient, with higher demand in the southern regions (Fig. 7). The mountain system accounted for the largest share, totaling approximately 24.60 billion m³(72.25%)—driven by complex interactions among elevation, hydrological and climatic conditions, as well as ecological functions such as biodiversity conservation and soil stabilization. Within the mountain system, Ecological Core Zones, Ecological Buffer Zones, and Ecological Restoration Zones accounted for 51.40%, 30.62%, and 12.08% of the demand, respectively. Their per-unit-area ecological water demands were 1.71 million m³/km², 1.39 million m³/km², and 1.10 million m³/km², respectively, reflecting the higher vegetation cover and species richness in Ecological Core and Buffer Zones, where stable water supply is critical to ecosystem function. In contrast, the lower per-unit-area water demand in Ecological Restoration Zones is attributed to the relatively sparse distribution of water-intensive species or communities. The oasis system required 5.78 billion m³(16.97%) of ecological water. The Ecological Restoration zones within the oasis system accounted for 75.30% of this demand, primarily due to higher evapotranspiration rates driven by vegetation type, surface temperature, and soil properties. The Ecological Set-aside and Buffer Zones in the oasis system exhibited higher per-unit-area water demands, closely associated with denser vegetation cover. Despite its extensive spatial extent, the desert system contributed only 3.67 billion m³(10.78%). Within this system, the Wilderness Reserve Zones consumed the most water, largely because desert vegetation—such as Haloxylon ammodendron, Tamarix spp., and Nitraria tangutorum—still necessitates minimal but consistent water input. Notably, the per-unit-area water demand in desert buffer areas was extremely high, reaching 14.40 million m³/km², largely due to large-scale artificial sand-fixation afforestation projects along the fringes of the Badain Jaran and Tengger deserts, especially in Jinchuan District and Yongchang County. Overall, ecological water demand across the Shiyang River Basin is primarily concentrated in the Ecological Core Zones, Ecological Restoration Zones, and Wilderness Reserve Zones. However, the highest per-unit-area demand is observed in the Ecological Set-aside Zones and Ecological Buffer Zones, underscoring the importance of vegetation structure and functional zoning in shaping regional water allocation.

Fig. 7
figure 7

Calculation results of vegetation ecological water demand in Shiyang River Basin. (MS, Mountain System; OS, Oasis System; DS, Desert System. The map was generated by ArcGIS 10.8 http://www.esri.com/software/arcgis and the 3D graph plots were generated by Origin 2025b https://www.originlab.com/products/Origin/2025b. They do not require any permission from anywhere).

Full size image

Discussion

Analysis of ecological risk drivers in the Shiyang river basin

Natural factors emerges as a dominant force shaping cities in arid regions, with human activities acting as moderating influences52. To effectively manage potential ecological threats in the Shiyang River Basin, this study aims to identify the dominant stressors shaping regional ecological risk, thereby enabling targeted interventions. Spatial principal component analysis (PCA) reveals that the first six components collectively account for over 90% of the total variance, indicating their strong explanatory power in representing the basin’s ecological risk patterns (Fig. 8). These components show high loadings on six variables: mean annual precipitation, mean annual temperature, distance to roads, vegetation cover, land cover type, and soil erosion. Notably, precipitation and temperature dominate the first and second principal components, underscoring the central role of hydrothermal conditions as primary ecological risk determinants. As the principal form of moisture input, precipitation exerts a fundamental influence on ecosystem structure, function, and resilience—particularly pronounced in arid inland basins53. Spatial and temporal variations in its intensity and form critically affect ecological stability. Concurrently, rising mean annual temperatures intensify glacier melt and elevate potential evapotranspiration, thereby impacting vegetation growth, agricultural productivity, and water availability. Land cover type and vegetation cover reflect the ecosystem’s response to climatic variability and anthropogenic disturbances. Areas characterized by high vegetation density—such as grasslands and forests—tend to exhibit enhanced soil and water conservation capabilities and greater ecological resilience, thereby facing comparatively lower risk. In contrast, croplands, built-up areas, and unused lands, with their inherently fragile soil structures, are more vulnerable to erosion processes. These risks are particularly acute in zones experiencing rapid land-use transformation, such as regions undergoing agricultural expansion, urbanization, or desertification. Soil erosion, a key indicator of ecological degradation, is tightly linked to topography, precipitation, vegetation dynamics, and land use. Steep terrains at higher elevations tend to experience more intense freeze-thaw and hydrodynamic erosion. Moreover, vegetation loss or land development exposes soil surfaces to heightened water and wind erosion. Road networks, as corridors of concentrated human activity, are associated with intensified land disturbance and vegetation destruction, ultimately undermining ecosystem stability. In sum, the ecological protection and restoration of the Shiyang River Basin must adopt an integrated approach that considers the interplay between natural geographical endowment, climatic stressors, vegetation dynamics, and the spatial extent of anthropogenic pressure.

Fig. 8
figure 8

Principal component load thermogram.

Full size image

Strategic allocation of ecological water for vegetation restoration

Revegetation serves as a vital linkage for sustaining the ecological balance of inland river basins in arid regions54. Based on the ecological protection and restoration zonation delineated in this study, a differentiated ecological water allocation strategy is proposed to promote vegetation recovery and improve the ecological integrity of the basin. The upstream mountainous Ecological Core Zones receive abundant precipitation sufficient to meet the water demands of its native vegetation, while simultaneously sustaining critical water retention functions for inland hydrological systems, thereby eliminating the need for additional ecological water supplementation. However, recent global warming has accelerated glacier melt, raising concerns about the increasing frequency of abnormal precipitation events and associated geohazards such as flash floods and debris flows, which pose significant risks to ecological stability. Adjacent to the Core Zone lies the Ecological Buffer Zones, which faces relatively poor hydrological conditions. Targeted interception and redirection of water can enhance ecological water supply, improving habitat quality and reducing resistance to species migration from the Ecological Core Zones. In the central oasis system, which suffers from severe water scarcity, large-scale ecological water supplementation is essential to support vegetation regrowth. Measures such as artificial rainfall enhancement and rainwater harvesting can be employed to augment usable runoff reaching the plains, thereby strengthening the oasis’s ecological buffer and barrier function between mountain and desert systems. As the socio-economic heart of the region, the oasis system should simultaneously prioritize water conservation. This includes advancing high-efficiency irrigation technologies and promoting the reuse of treated wastewater to significantly improve water-use efficiency. On this basis, an integrated water transfer strategy should be pursued, including the potential for inter-basin water diversion from sources such as the Yellow River or Datong River, to ensure adequate water supply for both the oasis Ecological Restoration Zones and downstream Ecological Wilderness Reserve Zones. In the Ecological Set-aside zones, water allocation should be guided by the principle of prioritizing supply to other critical zones. When surplus water is available, moderate urban and industrial development may be permitted; during periods of scarcity, the ecological character of these zones must be preserved. Rational allocation of ecological water resources is foundational to ensuring regional ecological security. Restoration planning in the Shiyang River Basin should adhere to the principles of “water-defined forest, grass, wetland, and farmland”—that is, the scale and intensity of restoration must be aligned with water availability. A coordinated strategy across the basin’s protection and restoration zonation is essential to advance integrated protection and systematic management of the mountain–oasis–desert continuum, ultimately optimizing the structure and functionality of the regional ecosystem.

Zonal strategies for ecological conservation and restoration

In the face of accelerating urbanization and escalating climate change, regional development planning has become a critical instrument for aligning economic growth with ecological resilience and climate adaptation55. Emerging research underscores that effective zonal ecological management can significantly optimize ecosystem service delivery56. Building upon the unique geographical context and ecological water demands of the Shiyang River Basin, this study proposes a set of differentiated, zone-specific ecological management strategies (Table 6), aiming to inform decision-making for ecological stewardship in arid inland river basins. In the mountain system, which primarily comprises Ecological Core Zones and Ecological Buffer Zones, strict protection measures are imperative. The Ecological Core Zones should prioritize ecological preservation, afforestation via natural regeneration, and the protection of wildlife habitats, with a complete prohibition on construction and human development activities. The Ecological Buffer Zones should promote eco-friendly tourism under a regulated, semi-open access model to ensure minimal disturbance to core ecological functions. In areas with steep slopes, soil and water conservation measures such as contour terraces and level trenches should be implemented to mitigate erosion. Although the Wilderness Reserve Zones constitute a relatively small proportion of the mountain system, they play a vital role in ecological connectivity. The Wilderness Reserve Zones should enforce restricted access policies and establish ecological corridors linking to the Ecological Core Zones to facilitate biological and material flows. The Ecological Restoration Zones should receive increased investment in ecological infrastructure and technologies to support artificial restoration and ecological water supplementation, thereby enhancing ecological carrying capacity. Given the sensitivity of mountain system, the Ecological Set-aside Zones within this system should function as flexible ecological buffers to address compounded environmental stressors such as climate change and biodiversity loss.

The oasis system is predominantly characterized by agricultural and urban land cover, with the Ecological Restoration Zones, Wildness Reserve Zones, and Ecological Buffer Zones as the primary management units. These areas should be structured around a defensive greenbelt composed of shelterbelts at the oasis margins, integrated farmland windbreak networks, and targeted sand control measures at key desert–oasis transition points. Strategies include the establishment of new protective forests, vegetative green corridors, and windbreak barriers to form a comprehensive green ecological shield against encroaching desertification. Major ecological engineering efforts—such as combating land degradation, advancing the “Three North” Shelter Forest Program, implementing anti-desertification measures, expanding ecological public forests, wetland conservation and restoration, and reforestation of marginal farmland—should be intensified. Initiatives should focus on afforestation, fencing and enclosure for grassland recovery, and wetland conservation with an emphasis on exclusionary protection. Improvement of urban and rural human settlements must also be prioritized. Rational planning of green space—through rooftop greening, vertical landscaping, and green infrastructure—will increase vegetation cover and enhance the quality of urban and rural green areas. Building ecological buffer green spaces, peripheral greenbelts, and wilderness parks at the oasis fringe will further strengthen ecological resilience. Additionally, modernization of water-saving irrigation systems and promotion of green agriculture are essential for improving water-use efficiency. Technologies for water-conserving irrigation should be broadly adopted to reduce waste and improve agricultural productivity. The region’s solar and thermal resource advantages can be leveraged to develop high-value, locally adapted agroforestry industries, thereby supporting the establishment of a sustainable ecological economy. Although the Ecological Set-aside Zones in the oasis system occupy only 5.75 km², they hold strategic significance. During periods of agricultural instability induced by extreme climate events, these areas may be temporarily converted into production areas. In contexts where increasing demand for development land results in land-use conflicts, the Ecological Set-aside Zones could serve as green industrial or urban expansion areas under strict ecological constraints.

The desert ecosystem exhibits inherent sensitivity and fragility, comprising diverse land types including gobi terrain, bare soil, and sparse grasslands. It primarily serves critical ecological functions such as wind erosion control, sand stabilization, and biodiversity conservation for typical arid-zone flora and fauna, constituting priority wilderness conservation areas within the Shiyang River Basin. The transitional zones between desert, oasis, and montain systems present complex ecological architectures subject to intensive anthropogenic disturbances, representing convergence zones where ecological degradation intersects with compounded human activities. These interfaces constitute both focal points and persistent challenges for ecological conservation and restoration efforts. Given the substantial area of 15,873.90 km² encompassed by wilderness conservation zones and the considerable restoration complexities involved, management strategies should adhere to the principle of “natural recovery primacy with supplementary anthropogenic intervention.” This approach emphasizes minimizing human perturbations while maintaining ecosystem succession processes to enhance system stability. Concurrently, severely degraded critical patches within transitional zones require targeted, differentiated ecological restoration measures to arrest degradation propagation. Ecological conservation and restoration initiatives should prioritize natural recovery mechanisms while employing artificial restoration as complementary measures. Natural recovery minimizes anthropogenic disruption to ecosystem integrity, facilitating intrinsic self-repair and regeneration processes, with targeted restoration applied to severely impacted areas. Addressing multiple ecological stressors and systemic vulnerabilities of desert margin ecosystems necessitates integrated ecological restoration and boundary management approaches. Priority should be accorded to biological treatment methods including drought-tolerant sand-fixing vegetation establishment, soil amelioration, and microtopographic regulation. These measures should be complemented by engineering interventions such as ecological water supplementation and oasis-margin ecological buffer zone construction to enhance moisture conditions requisite for vegetation establishment and system water retention capacity. Scientific delineation of ecological buffer zones and development boundaries is essential to restrict human encroachment toward desert margins. Simultaneously, promoting eco-friendly specialized industries will enhance marginal area ecological carrying capacity and economic self-circulation levels. Water resources constitute critical limiting factors for desert ecosystem stability. Under the premise of ensuring basin-wide ecological security, measures including trans-basin ecological water supplementation, channel restoration, and waterway construction should be implemented for rational water resource development and utilization, preventing overexploitation and waste while achieving effective water allocation and storage. These interventions aim to augment desert system water availability, satisfying minimum ecological water requirements and providing essential moisture conditions for desert ecosystem recovery, thereby improving desert vegetation growth environments. Concurrently, scientific delineation of development zone boundaries should facilitate development of locally adapted specialized industries, actively accommodate industrial transfers from eastern regions, and promote rational exploitation of regional mineral resources while preventing disorderly extraction. Emphasis should be placed on ecological restoration of mining facilities and surrounding decertified grasslands, encouraging innovative models such as photovoltaic-assisted desertification control and photovoltaic-enabled prosperity enhancement. These integrated approaches will achieve synergistic outcomes for ecological restoration and regional economic development.

Table 6 Integrated results of ecosystem importance-risk-ecological water demand in the Shiyang river basin and restoration guidelines.
Full size table

Strengths, limitations and future direction

This study offers three key contributions to the existing literature. First, it refines the ecological understanding of the Shiyang River Basin by delineating the mountain–oasis–desert system into three distinct ecological subsystems. This spatially explicit stratification enables a more nuanced diagnosis of structural deficiencies and functional imbalances within each subsystem, reflecting the heterogeneous ecological processes across the arid landscape. Second, we propose a dual-core zoning framework for ecological conservation and restoration that integrates both “ecosystem function maintenance” and “ecological risk governance.” By taking ecosystem service importance as the value driver and ecological risk as the constraint, we conduct zoning based on 1 km × 1 km grid-level assessments, offering a fine-scale, spatially detailed approach to prioritizing ecological interventions. Third, and most innovatively, we extend the zoning results by quantifying ecological water demand across different zones, thereby linking spatial planning with water resource allocation. This provides practical insights for optimizing ecological water replenishment schemes and improving water management strategies in arid inland river basins.

A key limitation of this study stems from the dual-core framework integrating ecosystem service importance and ecological risk to delineate ecological protection and restoration zones. During the quantification process, certain constraints became apparent. Firstly, the assessment of ecosystem service importance was restricted to only four critical service functions, which inadequately capture the full complexity and multidimensionality of ecosystem services. This narrow scope may obscure other vital functions, thereby potentially compromising the accuracy and applicability of the zoning outcomes. Secondly, the ecological risk quantification was constrained by data availability, resulting in the exclusion of several potentially significant risk indicators. Consequently, the depth and comprehensiveness of the risk evaluation were limited, impeding precise characterization of the spatial distribution and intensity of ecological risks. Another limitation is the estimation of ecological water demand relied primarily on vegetation water requirements as a proxy, which does not fully capture the diversity of ecosystem water needs and thus limits the comprehensiveness of the assessment. Moreover, due to the lack of high-resolution data, some key parameters were derived from literature-based estimates, which may reduce the precision and reliability of the results.

Future research should prioritize the optimization of indicator selection and data integration. This includes broadening the scope of ecosystem service assessments to systematically include a wider array of service categories—such as cultural and regulatory services—to more fully reflect ecosystem complexity and diversity, thereby improving the precision and scientific robustness of zoning results. Moreover, strengthening the ecological risk assessment framework by leveraging multi-source, multi-temporal, and multi-spatial ecological monitoring data, alongside incorporating additional potential risk factors—such as climate change stressors and biodiversity loss—will deepen and expand risk evaluation capabilities, enabling more accurate delineation of the spatial patterns and magnitudes of ecological risks. What’ more, ecological water demand assessments should move beyond vegetation proxies to encompass broader ecosystem water needs. With the growing availability of high-resolution data, future research should prioritize integrated, spatially explicit, and context-sensitive frameworks to support precise and resilient ecological planning under environmental change.

Conclusions

(1) The Shiyang River Basin exhibits pronounced spatial differentiation across its mountain, oasis, and desert systems along a southwest-to-northeast gradient. The mountain system, covering the largest area with substantial vegetation coverage, constitutes the core region for ecological barriers and ecosystem service provision. The oasis system, though occupying the smallest area, sustains intensive human activities and represents the zone of most acute ecological-economic conflicts. The desert system, extensively distributed across the northwest, presents the greatest ecological vulnerability and restoration challenges.

(2) From 1990 to 2020, ecosystem service importance across the basin demonstrated an overall upward trajectory, maintaining a spatially stable pattern characterized by “high values in the southwest, low values in the northeast.” Areas of high and relatively high importance concentrate primarily within mountain and oasis systems, reflecting robust ecological foundations and service capacity. While this trend indicates enhanced ecosystem service functionality, high-value areas comprise only 36.82% of the basin, underscoring persistent spatial heterogeneity that warrants attention to differential development potential and ecological carrying capacity among regions.

(3) Ecological risk levels remain elevated overall, exhibiting a slight increasing trend with spatial patterns following a “mountain-low, oasis-moderate, desert-high” gradient. Mountain systems maintain the lowest risk levels, while oasis systems demonstrate moderate risk with notably intensifying pressures. Desert systems present the highest risk levels, reflecting imbalanced relationships among human activity intensity, ecological vulnerability, and restoration capacity. This necessitates strengthened risk prevention and ecological stability mechanisms in oasis-desert transition zones.

(4) Total ecological water demand for the Shiyang River Basin in 2020 reached 34.043 billion m³, displaying a spatial distribution pattern of “high in the south, low in the north.” Vegetation ecological water demand concentrates primarily in ecological core zones, restoration areas, and wilderness protection zones, while per-unit-area vegetation water demand peaks in ecological set-aside and buffer zones.

(5) Based on ecosystem service importance and ecological risk assessments, the Shiyang River Basin ecological protection and restoration zoning comprises five distinct zones: ecological core zones, ecological buffer zones, ecological restoration zones, wilderness protection zones, and ecological set-aside zones. This framework achieves integrated coordination between ecological function maintenance and ecological risk management. The spatial distribution of each zone aligns closely with mountain-oasis-desert system characteristics, providing clear ecological management orientations and scientific foundations for differentiated zonal policies.