Human-land System Research Articles

Evaluating potential landing sites for the Artemis III mission using a multi-criteria decision making approach

The selection of a landing site within the Artemis Exploration Zone (AEZ) involves multiple factors and presents a complex problem. This study evaluates potential landing sites for the Artemis III mission using a combination of Geographic Information Systems (GIS) and Multi-Criteria Decision Making (MCDM) methodologies, specifically the TOPSIS algorithm. By integrating topographic, illumination, and mineralogy data of the Moon, we assess 1247 locations that meet the Human Landing System (HLS) requirements within 13 candidate regions and Site 004 near the lunar south pole. Criteria considered include surface visibility, HLS-astronaut line of sight, Permanently Shadowed Regions (PSRs), sunlight exposure, direct communication with Earth, geological units, and mafic mineral abundance. Site DM2 (Nobile Rim 2), particularly the point at latitude 84°12’5.61”S (−84.20156°) and longitude 60°41’59.61”E (60.69989°), is the optimal location for landing. Sensitivity analysis confirms the robustness of our approach, validating the suitability of the best location despite the MCDM method employed and variations in criteria weightings to prioritize illumination and PSRs. This research demonstrates the applicability of GIS-MCDM techniques for lunar exploration and the potential benefits they can bring to the Artemis program.

The coupling characteristics and influencing factors of the "homestead-cultivated land system" in the Three Gorges Reservoir Region of China: A farmer perspective

Homesteads and cultivated land are crucial elements of the rural territorial system. Their coupling characteristics and changing patterns are essential for understanding the evolution of rural human-land systems and for developing coordinated rural development strategies. This study takes Huilong Village and Pingba Village in the TGRR, employing methods such as GIS spatial analysis, comprehensive index evaluation, coupling coordination degree model, and geographic detector model. The analysis focuses on the coupling characteristics and influencing factors of the “HCS” in these villages and proposes optimization strategies to provide scientific guidance for village planning, selection of high-quality rural development paths, and strategy design. The main findings are as follows: (1) The spatial distribution of homesteads and cultivated land in typical villages exhibits clear traffic directionality. The spatial coupling of the “HCS” demonstrates significant convergent evolution and adjacent distribution characteristics. (2) The utilization coupling of the “HCS” in Huilong Village and Pingba Village is predominantly high, with 98.72% and 94.62% of farmers, respectively, being highly coupled. However, the degree of coupling coordination is mostly barely coordinated. (3) The primary factors influencing the coordinated development of the “HCS” in the study area include the utilization conditions of homestead and cultivated land, labor status, and economic status. These factors can be categorized into four types: labor factor restrictions, nonagricultural development disturbance, agricultural development, and lagging farming conditions. Differentiated development strategies are proposed for each type. This research enhances the understanding of the coupling between homestead land and cultivated land, offering valuable insights for regional village planning, high-quality development path selection, and government decision-making.

The complexity of religious land use: Mosques, titling and informality in China (1949–2023)

In considering complex human-land systems, the land use and planning for places of worship is perhaps not an issue that may first come to mind. Simultaneously, however, it has become an increasingly critical and researched topic due to rising ethnic and cultural tensions in the West. Contrarily, the topic is virtually terra incognita for the Chinese context. This article aims to make up for that shortfall, and examines the way how the space for religious sites in China is acquired, planned and governed. It focuses on one of the more prominent places of worships often contested in the West: the mosque, and particularly those belonging to the Hui minority. The study relies on surveys, in-depth interviews, participant observation and rare documents hitherto unavailable in English, such as (informal) contracts, ownership titles, and historical court rulings. A dual finding is reported: 1) over time, the Chinese state’s envisioned ownership for religious property in general, and Islamic property in particular, has evolved into common property slightly comparable to condominium; 2) despite stated intentions to formalize religious planning, mosques’ land use has remained largely informal. Markedly, local planning authorities continue upholding a grey zone in which Hui Muslim sites of worship are tacitly condoned. Although there are caveats, this “tolerance of informality” offers leeway for religious praxis while providing space to a revolutionary past of complex, contested and convoluted property rights.

Ecological resilience in water-land transition zones: A case study of the Dongting Lake region, China

Water-land transition zones (WLTZs) are quintessential, complex human-land systems where aquatic and terrestrial environments intermingle, playing a pivotal role in bolstering global ecological resilience (ER). Human terrestrial production activities have encroached upon ecologically sensitive aquatic areas, weakening the inherent ER patterns in WLTZs. To address these issues, we developed an ER assessment process chain across the disturbance-carrying-recovery (D-C-R) dimensions. Applied it to the Dongting Lake region, this model diagnosed the spatiotemporal variations in ER from 2000 to 2020 and revealed the stress mechanisms of various driving factors. The results indicate: (1) The ER spatial pattern in the Dongting Lake region featured a radiating enhancement structure originating from a low-value core in the central plain’s lake network area, displaying distinct water-land gradient variations. Areas with declining ER levels were mainly distributed around the main body of the lake, water system runoff areas, and near governmental centers. (2) The spatiotemporal differentiation effects of ER manifested as an east–west axial development trend, tending toward polarization. The spatiotemporal aggregation effect appeared as L-L clustering and cold spots in the north, gradually expanding toward the peripheral forest areas. (3) Factors related to land use were the dominant drivers of spatiotemporal changes in ER. Simultaneously, the nonlinear interaction intensity among these driving factors showed a significant annual increase. This research framework can be extended to assess ER in similar regions, potentially offering policy recommendations for the ecological protection and sustainable management of WLTZs.

Spatial and temporal distribution characteristics and influencing factors of tourism eco-efficiency in the Yellow River Basin based on the geographical and temporal weighted regression model.

With economic progression in China, Yellow River Basin serves as a critical economic belt, which has also been recognized as a cradle of Chinese culture. A watershed is a complex structure of social, economic, and natural factors, and the diversity of its components determines its complexity. Studies on the spatiotemporal distribution characteristics and factors influencing the tourism eco-efficiency at the watershed scale are crucial for the sustainable regional socio-economic development, maintaining a virtuous cycle of various ecosystems, and comprehensively considering the utilization and coordinated development of various elements. Based on tourism eco-efficiency, the coordination degree of regional human-land system and the sustainable development levels can be accurately measured. With the tourism eco-efficiency in the Yellow River Basin from 2009 to 2019, the present study considers 63 cities in the Yellow River Basin as the research area by adopting the super-efficiency slacks-based measure (Super-SBM) model. Methods such as trend surface analysis, spatial autocorrelation analysis, elliptic standard deviation analysis, and hot spot analysis were used to explore their spatiotemporal distribution and evolution characteristics. The geographical and temporal weighted regression (GTWR) model was used to determine the factors influencing the tourism eco-efficiency value. The findings are as follows: ①The level of tourism eco-efficiency in the Yellow River Basin is not high, exhibiting a fluctuating upward trend. ②The tourism eco-efficiency in the Yellow River Basin shows significant spatial interdependence and agglomeration. Furthermore, the track of the center of gravity moves from northeast to southwest. ③ The tourism eco-efficiency in the Yellow River Basin is affected by various factors, with the economic development level having the greatest influence.

Assessing the coupling coordination dynamics between land use intensity and ecosystem services in Shanxi's coalfields, China

The land use and cover changes (LUCC) caused by strong coal-mining activities and ecological restoration practices have seriously interfered with the ecosystem services (ESs) in the mining area. However, little attention has been paid to how to explore and improve the coordinated relationship between LUCC and ESs in mining areas. This study investigated the crucial relationship between ESs and land use intensity (LUI) in coal-mining areas, emphasizing the significance of understanding this interdependence for balanced human–land system development. Employing a coupling coordination degree (CCD) model, this research examined the evolving relationship across various reclamation stages of coalfields in Shanxi, China, spanning from 1986 to 2020. Additionally, stepwise and geographically weighted regressions were utilized to investigate the primary factors influencing CCD and their respective impacts. Notably, the comprehensive ecosystem service index (CESI) exhibited an upward trend between 1986 and 2020, whereas the LUI initially increased and subsequently declined during the reclamation stages. Moreover, the CCD between the LUI and CESI gradually evolved from mildly maladjusted to reluctant coordination throughout the various reclamation stages, gradually improved over time. Geographically, the region exhibited a coordinated level gradually expanded. Precipitation, slope, coal mining intensity, and industrial output emerged as primary CCD influencers. Coal mining intensity exerted negative impacts, whereas the impact of industrial output was minimal. Based on our findings, we recommend the timely and judicious reclamation of coalfields, taking into consideration the land's bearing capacity.

Dynamic simulation and projection of land use change using system dynamics model in the Chinese Tianshan mountainous region, central Asia

A critical step in alleviating the contradiction between human activities and land systems is to project and analyze land use change traits in various scenarios to furnish a basis for formulating economic development and ecological conservation strategies. However, few studies have examined land use change using the system dynamics (SD) model and patch-generating land use simulation (PLUS) model in the Chinese Tianshan mountainous region (CTMR) affected by different economic growth patterns and climate change contexts. Therefore, based on the Shared Socioeconomic Pathways and Representative Concentration Pathways (SSPs-RCPs) scenarios, we attempted to construct a regional SD model (RSDM) including population, economic, land, and climate subsystems. Then, the coupled model by combining RSDM and PLUS was employed to simulate and project land use/cover changes (LUCC) in the CTMR at the regional level to explore the spatial distribution of land and its pattern of change in different climate contexts. The SD model is an effective method that can simulate the nonlinear behavior of a complex system and predict its evolution through the interactions and feedback relationships between different influencing factors. The PLUS model is an effective tool that can be used to simulate the evolution of land patches and capture the extent to which the driving factors contribute to LUCC. The relative errors were less than 5%, and the total accuracy of PLUS model was 91.77%. The above results demonstrated the effectiveness of RSDM and PLUS model in modeling LUCC across the CTMR. From 2005 to 2020, there was an expansion trend in the area of forest and construction land as well as in the area of cultivated land, while the grassland area displayed a significant decline. By 2040, the area of unused land, grassland, and water is expected to demonstrate a decreasing trend while other land types increase, with construction land showing the most significant increase of 101.37% under the SSP585 scenario. It is anticipated to expand mainly to cultivated land and grassland around cities. The cultivated land is expected to primarily encroach on the regions of unused land and grassland under the three scenarios, reaching the expansion demand. As opposed to the scenarios of SSP126 and SSP245, the SSP585 scenario distribution of the cultivated land patches will be more compact and denser. The SSP126 and SSP245 scenarios will exhibit similar patterns of future spatial distribution of land. The SSP585 scenario is anticipated to display marked differences. According to the three scenarios, grassland degradation will be severe and require increased grassland protection. The findings can offer novel perspective concepts with regard to future ecological and environmental management, judicious distribution of land resources, and sustainable progression in the CTMR.

Identifying Spatiotemporal Patterns of Multiscale Connectivity in the Flow Space of Urban Agglomeration in the Yellow River Basin

The United Nations Sustainable Development Goals (SDGs) and the rise of global sustainability science have led to the increasing recognition of basins as the key natural geographical units for human–land system coupling and spatial coordinated development. The effective measurement of spatiotemporal patterns of urban connectivity within a basin has become a key issue in achieving basin-related SDGs. Meanwhile, China has been actively working toward co-ordinated regional development through in-depth implementation of the Yellow River Basin’s ecological protection and high-quality development. Urban connectivity has been trending in urban planning, and significant progress has been made on different scales according to the flow space theory. Nevertheless, few studies have been conducted on the multiscale spatiotemporal patterns of urban agglomeration connectivity. In this study, the urban network in the Yellow River Basin was constructed using Tencent population migration data from 2015 and 2019. It was then divided into seven distinct communities to enable analysis at both the basin and community scales. Centrality, symmetry, and polycentricity indices were employed, and the multiscale spatiotemporal patterns of urban agglomerations in the Yellow River Basin were identified using community detection, complex networks, and the migration kaleidoscope method. Community connectivity was notably concentrated at the basin scale with a centripetal pattern and spatial heterogeneity. Additionally, there was a symmetrical and co-ordinated relationship in population migration between the eastern and western regions of the basin, as well as between the internal and external parts of the basin. At the community scale, there was significant variation in the extent of central agglomeration among different communities, with few instances of similar-level, long-distance, and interregional bilateral links. The utilization of multiscale spatiotemporal patterns has the potential to enhance the comprehension of economic cooperation between various cities and urban agglomerations. This understanding can aid decision-makers in formulating sustainable development policies that foster the spatial integration of the basin.

Spaceflight Logistics Approach to Modeling Aggregated Vehicle Concepts

As space exploration moves toward long-duration, sustainable campaigns, operations such as in-space rendezvous, multiple launches, and in-space rendezvous or In-Situ Resource Utilization plants complicate campaign planning. The field of spaceflight logistics has been developed to perform the logistical planning for these new campaigns in an automated manner. Though previous tools have included aggregated vehicle concepts consisting of multiple vehicles, they have key limitations that may not be able to assess campaigns with more complex vehicle architectures and mission operations. This works aims to address these limitations by formulating a method to include independently operating vehicles that can also operate as an element within a larger stack across various different mission segments. Because of the use of the path-arc formulation, the optimizer has the flexibility to decide to use the independent vehicle stages independently, or within a stack. To prove the usefulness of this formulation, the methodology will be applied to a sample case that uses some of these aggregated space vehicles. In particular, a case study of a government reference Human Landing System mission will be used due to its inclusion of aggregated space vehicles.

Identification and structural characteristics of urban agglomerations in China based on Baidu migration data

Scope identification and structural characteristics are the basis of studies on urban agglomeration. The scope planned by central and local governments, as well as the existing structural models, mainly focuses on social-economic statistics, which rarely considers the links between cities. Population mobility network is a crucial driving factor of the human-land system evolution. Herein, we proposed a new analysis framework, including the new scope identification algorithm and the new structure representation model based on urban network. Results show that population flow network showed a diamond, and is consistent with the “Heihe-Tengchong Line”, which was similar to the population distribution; We found 20 urban agglomerations in China, which was much smaller than that planned, and the adjacent distribution was obvious; China's urban network consisted of four subnets, with Yangtze River Delta, Hebei-Beijing-Tianjin, Pearl River Delta and Chengdu-Chongqing as the center, respectively; Urban agglomerations were divided into single-core, dual-core and multi-core types, mainly in single-core structure; The internal intensities of the four top urban agglomerations were the highest, and the imbalance between inflow and outflow intensities caused either accumulation or loss of population. We further proposed some policy suggestions for sustainable development.

Food-water-land-ecosystem nexus in typical Chinese dryland under different future scenarios

Healthy coupling of the food-water-land-ecosystem (FWLE) nexus is the basis for achieving sustainable development (SD), and FWLE in drylands is frontier scientific issues in the study of coupled human land systems. To comprehensively safeguard the future food, water, and ecological security of drylands, this study examined the implications for FWLE linkages in a typical Chinese dryland from the perspective of future land-use change. First, four different land-use scenarios were proposed using a land-use simulation model with a gray multi-objective algorithm, including an SD scenario. Then, the variation of three ecosystem services was explored: water yield, food production, and habitat quality. Finally, redundancy analysis was used to derive the future drivers of FWLE and explore their causes. The following results were obtained. In the future in Xinjiang, under the business as usual scenario, urbanization will continue, forest area will decrease, and water production will decline by 371 million m3. In contrast, in the SD scenario, this negative impact will be substantially offset, water scarcity will be alleviated, and food production will increase by 1.05 million tons. In terms of drivers, the anthropogenic drivers will moderate the future urbanization of Xinjiang to some extent, with natural drivers dominating the sustainable development scenario by 2030 and a potential 22 % increase in the drivers of precipitation. This study shows how spatial optimization can help protect the sustainability of the FWLE nexus in drylands and simultaneously provides clear policy recommendations for regional development.

Putting a Price on Nature: Ecosystem Service Value and Ecological Risk in the Dongting Lake Area, China.

Understanding the relationship between ecosystem service value and ecological risk evolutions holds great theoretical and practical significance, as it helps to ensure the quality management of ecosystems and the sustainable development of human-land system interactions. We analyzed this relationship in the Dongting Lake area in China from 1995 to 2020 using data from remote sensing-interpreted land use with ArcGIS and Geoda. We used the equivalent factor method to estimate the ecosystem service value, constructed a landscape ecological risk index to quantitatively describe the ecological risk of Dongting Lake, and analyzed their correlation. The results show that: (1) over the last 25 years, the ecosystem service value decreased by 31.588 billion yuan, with higher values in the middle of the area and lower values in the surroundings-the highest value was found in forested land and the lowest was for unutilized land; (2) the ecological risk index also decreased slowly over time, from the perspective of single land use type, the ecological risk value of construction land was the lowest, followed by woodland, grassland, and cultivated land, with water area being the highest-the ecological risk level presents the distribution state of whole piece and local aggregation; and (3) the ecological risk index in Dongting Lake area demonstrated positive spatial correlation, and the spatial agglomeration of land with similar risk levels showed a decreasing trend. Areas with strong partial spatial correlations between ecosystem service value and ecological risk index are mainly distributed in the central water areas and their surrounding areas. This study investigates the rational utilization of land resources, and the sustainable development of regional ecological security in Dongting Lake area.

A Simulation-Based Study on the Coupling Coordination of Farmers’ Livelihood Efficiency and Land Use: A Pathway towards Promoting and Implementing the Rural Development and Rural Revitalization Strategy

The interaction process between farmers’ livelihood and land use is a core link between the interaction and the coupling of the human–land system. It is a complex evolutionary process that involves several issues such as resource-intensive utilization and economic development. This study first constructs a dynamic model of the coupling system of farmers’ livelihood efficiency and land use and designs two types of 31 scenarios based on the farmer’s livelihood mode and land use. This study further simulates the coupling coordination relationship in different scenarios and then proposes suggestions for sustainable development. The findings of our study show that with the development of time, the livelihood capital, livelihood output, and land use level first showed a decline and then an increase. The results also reveal that livelihood efficiency and coordination degree are related to the livelihood mode and land use mode of farmers, while the land use level is not significantly associated with the livelihood mode of farmers. Pure-agriculture farmers have the lowest livelihood efficiency and coordination degree when they have no planting and breeding poultry, while part-time farmers have the highest land use level and coordination degree when they plant cash crops and breeding livestock. Besides, non-agriculture farmers have the highest livelihood efficiency and the lowest land use level when they neither plant crops nor breed livestock. To improve the level of coupling coordination, it is necessary not only to flexibly adjust the farmer’s livelihood and land use mode but also to optimize the allocation of various resources to promote the coordinated and sustainable development of farmers.

Spatiotemporal differences of land use pattern between mountainous areas and basin areas at township scale: A case study of Yuxi City

Land use/land cover change is an important carrier for the study of human-land relationship. Yuxi City is a typical area of with alternating mountain and basin landforms, forming a special human-land system with “mountains” and “basins” as the core elements. Taking 75 towns in Yuxi City, Yunnan Province as a case study, this paper uses a comprehensive evaluation model of land use/land cover change and related analysis methods to analyze the changes of land use pattern in mountainous areas and basin areas respectively from 1995 to 2018, and to reveal their spatial differences and its influencing factors. The results show that: 1) The dynamic evolution of land use in the mountainous area and the basin area presented obvious stage characteristics. From 1995 to 2005, the average comprehensive dynamic degree of land use in the mountainous area was 1.7861, which was significantly higher than the 1.7033 in the basin area. The average comprehensive dynamic degree of land use in mountainous areas from 2005 to 2018 was 1.1284, which was significantly lower than 1.9427 in the basin area. 2) From 1995 to 2018, the land use degree and the comprehensive dynamic degree of land use continued to rise in the basin area, while the mountainous area showed a trend of rising first and then falling. The overall change trend of land use depletion in the mountainous area was consistent with that in the basin area, but the mountainous area was always higher than that in the basin area. 3) The land use change in mountainous areas and basin areas was mainly reflected in the difference of natural factors and socio-economic fators. The radiation and agglomeration functions of the basin area have always attracted people to migrate from the mountains to the basin, which was beneficial to the ecological restoration of the vegetation in the mountains. Since the mountainous area and the basin area are geographically adjacent, the coupling and coordination of the two is the premise and foundation for the sustainable development of the region. This causal relationship of land use changes provides a reliable basis for the regulation of mountain-basin human-land coupling relationship.

Assessing Cultivated Land–Use Transition in the Major Grain-Producing Areas of China Based on an Integrated Framework

The cultivated land-use transition (CLUT) is the morphological result of changes in the cultivated land-use mode over time, and the result of the interaction and mutual restriction of the human land system. This paper applies a “spatial–functional” integrated framework to understand the structure and functioning of CLUTs, and quantitatively evaluates and visualizes CLUTs in the major grain-producing area in southern China. The results show that (1) the comprehensive CLUT index in the middle and lower reaches of the Yangtze River changed from 0.0480 to 0.0711 from 2001 to 2019 and indicated significant differences in the transition index between different regions. (2) The CLUT identified a positive aggregation effect under a 5% significance during the period, and the agglomeration degree of the spatial and functional transitions strengthened, which increased from 0.3776 to 0.4673 and from 0.2127 to 0.2952, respectively. (3) The gravity center of the CLUT demonstrated a pattern of migration from the southwest to the northeast, and the migration speed of the gravity center decreased from 2.9401 km/year to 1.2370 km/year. The migration direction of the gravity center for the spatial transition is opposite to the functional transition, and the migration speed of the gravity center for the spatial and functional transitions decreased from 8.3573 km/year to 1.0814 km/year, and from 3.2398 km/year to 1.0254 km/year, respectively. To address this transition, policymakers should formulate differentiated policies to promote the sustainable use of cultivated land through the spatial and functional transition of major grain-producing areas.

Link Ecological and Social Composite Systems to Construct Sustainable Landscape Patterns: A New Framework Based on Ecosystem Service Flows

Integrating the flow of supply and demand of ecosystem services (ESs) into the ecological security pattern (ESP) of coastal ecosystems with extremely fragile ecological backgrounds and contradictory human–land relationships is beneficial to the coordinated development of human–land systems. However, existing studies ignore the issue of scales of supply–demand linkages, making the ESP not properly guide sustainable development. Based on ESs delivery chain theory and landscape ecology approaches, we developed a sustainable development framework consisting of coupled microscopic natural–social systems. The method was tested using data from the Liao River Delta. In this study area, the natural supply potential and demand mapping distribution of key ESs were assessed to identify ecological sources in the Liao River Delta, a typical coastal zone in northern China. The resistance surface based on land use type assignment was modified using hydrological connectivity frequency and nighttime light intensity. Ecological corridors were extracted and optimized using a minimum cumulative resistance model and connectivity evaluation. The study found that the high supply area and the high demand reflection area are not consistent in location and supply level. Ecological source areas are evenly distributed, accounting for 12% of the total area. The ecological corridors are mainly concentrated in the west and southeast and do not cross the built-up areas in the east. This ESP framework safeguards the local demand for natural products and the natural potential to maintain services over the longer term and to a larger scale while informing the development of environmental management measures.

Modeling Analysis on Coupling Mechanisms of Mountain–Basin Human–Land Systems: Take Yuxi City as an Example

The result of a human–land relationship in geographical environment systems is a human–land coupling system, which is a comprehensive process of interaction and infiltration between human economic and social systems and the natural ecosystem. Based on the recognition that the human–land system is a nonlinear system coupled by multiple factors, a time delay fractional order dynamics model with a Holling-II-type transformation rate was constructed, the stability analysis of the system was carried out, the transformation times of different land classes were clarified, and the coupled dynamics model parameters of mountainous areas and basin areas were obtained by using the land-use change survey data and socio-economic statistical data in Yuxi City, respectively: the transformation parameter of the production and living land to the unused land in mountainous areas and basin areas (aM, 0.0486 and aB, 0.0126); the transformation parameter of unused land to production and living land in mountainous areas and basin areas (bM 0.0062 and bB, 0.0139); the transformation parameter of unused land to the forest and grass land in mountainous areas and basin areas (sM, 0.0051 and sB, 0.0028); the land area required to maintain the individual unit in mountainous areas and basin areas (hM, 0.0335 and hB, 0.0165); the average reclamation capacity in mountainous areas and basin areas (dM, 0.03 and dB, 0.05); the inherent growth rate of populations in mountainous areas and basin areas (rM, 0.0563 and rB, 0.151). Through analyzing the coupling mechanisms of human–land systems, the countermeasures for the difference between mountainous areas and basin areas in the future development are put forward. The mountainous area should reduce the conversion of forest and grass land to production and living land by reducing the average reclamation or development capacity, reducing the excessive interference of human beings on unused land, and speeding up its natural recovery and succession to forest and grass land. In addition to reducing the average reclamation or development capacity in basin areas, the reclamation or development rate of the idle land and degraded land should be increased, and the conversion of idle land and degraded land into productive and living land should be encouraged by certain scientific and technological means.

Space for Challenges: NASA’s Protest Process Makes Procurement Fairer and More Transparent

This article examines the National Aeronautics and Space Administration (NASA) procurement system broadly, starting from the top down with further examination of the protest process. It asks whether the protest process ensures fairness and transparency in the competition between commercial companies to win the contracts solicited by NASA. As a case study on the protest process, and to help answer the question, the article examines the recent Blue Origin protest regarding the Human Landing System and the SpaceX lunar lander contract award. Finally, the article concludes that the protest procedure is vital in ensuring the procurement process is fair and that NASA is held accountable for its decisions when it comes to spending public funds. NASA Procurement System, NASA, SpaceX, Blue Origin, Protest Process

Coupling responses of landscape pattern to human activity and their drivers in the hinterland of Three Gorges Reservoir Area

Human activities and landscape patterns are important representations of two major elements in the human-land system. Therefore, analyzing coupling characteristics of human activity intensity and landscape patterns is of great significance to reveal the evolution of regional human-land relationships. To fill the hole on the coupling response of human activity intensity and landscape pattern, the mountainous human activity intensity and landscape pattern coupling model was constructed, and the comprehensive dominant-recessive human activity intensity index (CHAI) was proposed. Moreover, based on the AHP and cumulative index method, we quantitatively evaluated the human activities intensity of Fengjie County in the hinterland of Three Gorges Reservoir Area (TGRA) from 2000–2020, and analyzed spatial coupling patterns between CHAI and landscape pattern through the local spatial autocorrelation model. Finally, factors influencing the type of coupled change in CHAI and landscape pattern were explored by a binary logistic regression model. The results show: (1) There are no obvious changes in CHAI of Fengjie County, but the spatial change shows the characteristics closely related to the terrain gradient and the level of economic development of Fengjie County with an overall contraction while local enhancement. (2) The spatial coupling between CHAI and landscape pattern in Fengjie County shows four types: Coordination type, antagonism type, gradually coordinated type, gradually antagonistic type. (3) The important impact factors of the coupling between CHAI and landscape pattern are distance to county administrative center, distance to the town government, and landform, etc., which reflects socio-economic factors were the main factors in the evolution of the regional social ecosystem. (4) There are diverse and special coupling responses between human activity intensity and landscape patterns in the hinterland of TGRA. In general, the hinterland of TGRA has achieved a win-win situation for the ecology and economy through partial disharmony in exchange for overall coordination. Moreover, the research results reveal the uniqueness of China's mountainous landscape pattern in response to human activities in recent years.

Towards Multi-Scale Space-Time Characteristics of Air Quality and Population Exposure Risk

In order to formulate policies to control regional air pollution and promote sustainable human–land system development, it is crucial to study the space–time distribution of air pollution and the population exposure risk. Existing studies are limited to individual fine particulate pollutants, which does not fully reflect the comprehensiveness of air quality. In addition, the spatiotemporal distribution of air quality and population exposure risk at different scales need to be further quantified. In this study, we used air monitoring station data and population spatial distribution data to analyze the spatiotemporal characteristics of air quality, including seasonal variations, variations before and during heating periods, and the occurrence frequency of priority pollutants in the traditional industrial areas of Northeast China in 2015. The population exposure–air pollution risk (PE-APR) model was used to calculate the population exposure risk at different spatial scales. The results suggest that GIS methods and air monitoring data help to establish a comprehensive air quality analysis framework, revealing spring–summer differentiation and the change trend of air quality with latitude. There are significant clustering features of air quality. A grid-scale population exposure–air pollution risk map is not restricted by administrative boundaries, which helps to discover high-risk areas of the main regional economic corridors and differences between inner cities and suburbs. This study provides a reference for understanding the space–time evolution of regional air pollution and formulating coordinated cross-regional air pollution strategies.