Landscape Pattern Changes Research Articles

Combining catastrophe technique and regression analysis to deduce leading landscape patterns for regional flood vulnerability: A case study of Nanjing, China

Urbanization leads to changes in land use, and the expansion of impervious surfaces leads to an increase in flood vulnerability. Predicting and analyzing these landscape pattern changes are important in the early stages of urban planning. In practice, the threshold for obtaining comprehensive and detailed hydrological and meteorological data is high, which makes it difficult for landscape and urban planners to quickly evaluate urban floods. To compensate for these trends, we took Nanjing, China, as the study site and discussed the leading flood vulnerability landscape patterns based on quantitative assessments. We introduced catastrophe theory to integrate three indicators and seven subfactors for flood vulnerability assessment: exposure, including precipitation; sensitivity, including elevation, slope, soil and drainage density; and adaptability, including land use and forest coverage. Then, we calculated the landscape pattern metrics (shape index, fractal dimension index, related circumscribing circle, contiguity index and landscape division index) at the class level. Finally, we divided the city into four subregions, established regression models for the subregions and the whole city, and deduced the leading flood vulnerability landscape patterns in each region and the whole city. We found that the leading landscape patterns varied among different regions. According to the research results, the landscape pattern indexes identified in this paper can be interpreted intuitively, which can provide a reference for modifying the planning layout of regional green infrastructure, optimizing the vulnerability of urban floods, and providing a basis for further improving Nanjing urban planning and alleviating the urban flood vulnerability. The methods proposed herein also will benefit land use and green infrastructure management in other regions lacking meteorological and hydrological data.

Temporal and spatial variation of ecosystem service value and its response to landscape pattern change in Guizhou Province, China.

Guizhou Province is a test area of ecological civilization in China, and one of the most typical areas of karst landform development in the world. Exploring the change of ecosystem service value and its spatial correlation distribution characteristics with landscape pattern is conducive to formulating ecological environment improvement and protection measures according to local conditions. We analyzed the spatial and temporal variations of landscape pattern and ecosystem services in Guizhou Province from 2005 to 2018 and constructed a geographically weighted regression model to explore the spatial changes of their correlation coefficients. The results showed that the transfer of landscape types in Guizhou Province from 2005 to 2018 mainly occurred in the five landscapes of construction land, forest, water, grassland, and cropland. The landscape fragmentation and diversity increased. The value of ecosystem services was increasing year by year. Forests were the main contributors to the value of ecosystem services in Guizhou Province, with regulation services as the main ecosystem services. For high-value landscape types, the increase of diversity and the reduction of fragmentation were conducive to the increases of ecosystem service value. In the area with concentrated low-value landscape types, it showed the opposite effect. The direction of landscape transfer and the spatial distribution of diversity and fragmentation of different landscape types should be adjusted according to the characteristics of ecological environment in different regions of Guizhou Province, to realize the increases of ecosystem service value.

Changes in Vegetation Coverage and Migration Characteristics of Center of Gravity in the Arid Desert Region of Northwest China in 30 Recent Years

Vegetation coverage is important in global landscape change patterns, but research on temporal and spatial dynamic changes and analysis of vegetation landscape pattern is relatively lacking. The present study aimed to investigate the dynamic changes of vegetation coverage in the arid desert region of Northwest China and analyze the characteristics of its center of gravity migration. The normalized difference vegetation index (NDVI) and pixel binary model were used to calculate the vegetation coverage to analyze the vegetation distribution characteristics and vegetation migration in the arid desert area in Northwest China in 1990, 1995, 2000, 2005, 2015 and 2020. The results showed that from 1990 to 2020, the proportion of light and severe vegetation coverage in the arid desert region of Northwest China increased, while the proportion of medium vegetation coverage decreased. The distribution types of medium- and high-grade vegetation generally migrate to the southeast and south, which may be mainly due to the humid climate conditions and higher population density in this direction. The vegetation center of gravity migration is mainly concentrated in the southeast-south direction. Vegetation degradation occurs in the northwest region, and vegetation improvement is the main trend in the southeast and south region. The direction of vegetation migration may be affected by precipitation and soil humidity. This study provides a theoretical basis and has certain guiding significance for desertification control, ecological sustainable management, ecological restoration, and protection in the arid desert region of Northwest China.

Linkages between soil erosion and long-term changes of landscape pattern in a small watershed on the Chinese Loess Plateau

Understanding the response of soil erosion to the changes of land use and landscape pattern is valuable for the optimization of soil and water conservation measures in a watershed. This study selected a typical hilly-gully watershed of the Chinese Loess Plateau, the Zhifanggou watershed, to assess its long-term land use changes from 1938 to 2020 and their impacts on sediment yield by using the spatially distributed soil erosion model WaTEM/SEDEM with an average annual rainfall erosivity of 2000–2010. The results indicated that the main land use types in the Zhifanggou watershed were cropland, forest and grassland, and experienced two changing periods: rapid agricultural reclamation during 1938–1958 and vegetation restoration during 1958–2020. The average annual sediment yields varied consistently with land use changes, showing evident changes from 51.84 t ha−1 y−1 in 1938 to 254.1 t ha−1 y−1 in 1958 and then to 4.27 t ha−1 y−1 in 2020. Correlation analysis suggested that sediment yield was closely related to the landscape indices of interspersion and juxtaposition index and Perimeter-area fractal dimension. The results indicated that increased vegetation cover and high spatial heterogeneity of landscapes could alter sediment transport pathways, reduce sediment connectivity, and induce less sediment discharged into the river. Our findings could provide a good reference for optimizing soil and water conservation measures in the watershed.

Ecological Assessment of Terminal Lake Basins in Central Asia under Changing Landscape Patterns

Climate change and anthropogenic activities drive the shrinkage of terminal lakes in arid areas to varying degrees. Ecological water conveyance (EWC) projects have emerged globally to restore the ecology of terminal lakes. However, there remains a lack of qualitative evaluation of the benefits of EWC on terminal lakes. This study compared the Taitema Lake Basin with the Aral Sea Basin in Central Asia, representative of terminal lake basins with and without EWC, respectively. The results show that the water area of Taitema Lake increased by 7.23 km2/year due to EWC (2000–2019), whereas that of the Aral Sea Basin decreased by 98.21% over the entire process of natural evolution (1972–2019). Land use changes before and after the EWC (1990–2019) included an increase and decrease in desert land and water bodies in the Aral Sea Basin, and a decrease and increase in desert land and arable land in the Tarim River Basin, respectively. The normalized difference vegetation index (NDVI) and actual evaporation (ETa) are the main factors influencing the change in the water area of the Aral Sea Basin with the changing environment, while EWC is the main factor influencing the change in the water area of Taitema Lake. The results confirm that EWC is a feasible measure for achieving ecological restoration of a terminal lake watershed in an arid area.

Landscape Change Analysis: Ecosystem Services in the Peri-urban Agriculture of Bangkok

Over the past decades, Bangkok peri-urban has been transformed from agricultural villages to urban development communities. Within the flat terrain and poor drainage characteristic of Chao Phraya Lower Floodplain, peri-urban agricultures are considered to be one of landscape patches and areas that creating and adding ecosystem services and values for mega urban areas. The significant loss of agricultural landscape of Bangkok peri-urban means that the loss of seasonal water retention areas, productive landscapes, as well as habitat for urban wildlife. This research classifies and analyzes landscape transformations especially agricultural landscape structures and functions of eight selective sites surrounded by the urban fringe of Bangkok. By tracing over the landscape change patterns backs form 1952 to 2018, the study areas include; 1) Rangsit Klong Sam and Klong Si, Pathumthani 2) Bang Kradi, Patumthani, 3) Lum Lukka Klong Hok Wa, Patumthani, 4) Klong Chorakea Noi and Klong Lat Krabang, Bangkok, 5) Bang Pla, Samut Prakarn, 6) Kok Kham, Samutsakorn, 7) Tha Mai, Samutsakorn, and 8) Klong Mahasawat, Nakorn Pathom. It is also critical linking and discussing on the ecosystem functions and services toward sustainable landscape management. This paper concludes the research gap between the lack of policies to practices for promoting the ecosystem services linking to the preserving and focusing on peri-urban agriculture landscape of Bangkok.

Temporal and spatial differentiation characteristics of ecosystem service values based on the ecogeographical division of China: a case study in the Yellow River Basin, China.

The identification of spatiotemporal changes in ecosystem service values (ESVs) and their drivers is the basis for ecosystem service administration and decision-making. This research focuses on the Yellow River Basin (YRB). With a multitemporal land use and land cover (LULC) dataset (1995-2018), the equivalence coefficient method with spatiotemporal dynamic correction and exploratory spatial data analysis methods were used to evaluate ESV changes due to LULC changes and their spatial characteristics. The contributions of the ESV driving factors and their mutual effects were also investigated via geographic detectors. The results revealed that (1) the land use structure of the YRB, mainly grassland and cultivated land, was stable from 1995 to 2018. However, the transition between land use types was dramatic, including urban expansion accompanied by losses of farmland, grassland, and unused land; increased forestland; and significant increases in water bodies and wetland areas. (2) During the study period, the overall ESV of the YRB increased, and hydrological regulation and climate regulation services dominated the change in the ESVs in the study area. The ESV exhibited obvious ecogeographical pattern differentiation and evident positive spatial autocorrelation. High values were concentrated in the southern part of the study area, including the southeastern part of the Qinghai-Tibet Plateau region and the central part of the East Asian monsoon region. Low values were concentrated in the northwestern arid zone, dominated by desert and grassland ecosystems. (3) Because of the fragility of the regional ecological background, the spatial differentiation of the ESVs in the YRB is dependent on natural factors; however, anthropogenic factors such as the degree of land use and the human activity intensity also lead to ESV differentiation. The synergistic effects of human activities, landscape pattern changes, and natural factors result in the spatial differentiation of the ESVs in the research region. Therefore, human activities affecting the ecological environment should be controlled, nature-based solutions should be advocated, patch diversity should be increased, landscape fragmentation should be reduced, LULC ecosystem service functions should be improved, and the relationship among economic, social, and ecological landscape resources should be coordinated.

Research on temporal and spatial evolution of land use and landscape pattern in Anshan City based on GEE

Frequent mining activities can bring about problems such as soil erosion and environmental pollution, which are detrimental to the efficient use of land and the sustainable development of cities. Existing studies have paid little attention to mining areas and lack comparative analysis of landscape changes in multiple mining pits. In this paper, the main urban area of Anshan City, where the mining areas are concentrated, was used as the research area, and the Landsat TM/OLI surface reflectance (SR) data of the Google Earth Engine (GEE) platform and the random forest algorithm were used to map the land use in 2008, 2014, and 2020. On this basis, land use dynamics and landscape pattern indices were used to analyze the changes in land use and landscape patterns in the Anshan City area. In addition, a moving window method was combined to further analyze and compare the landscape changes between different pits. The results show that:1. From 2008 to 2020, the construction land in Anshan urban area continued to decline, the forest land continued to expand, and the construction land was shifted to the forest land and cultivated land. Mining land increased before 2014 and remained almost unchanged after 2014, which is in line with the actual situation. 2. During the study period, the landscape fragmentation degree and landscape heterogeneity in the urban area of Anshan kept increasing. The high value areas of landscape fragmentation were the urban-rural combination areas and the mining areas. Among them, the reclamation of Dagushan and Donganshan is better, while the reclamation of Anqian, Yanqianshan and Xiaolingzi mines needs to be strengthened. 3. The random forest algorithm based on GEE shows a high degree of accuracy for land use classification. The overall classification accuracy in 3 years exceeds 90% and the kappa coefficient exceeds 0.85. The study results can be used as an essential reference for optimizing the urban ecological environment and provide technical backing for the urbanization construction and rational use of land in Anshan City.

Analysis of the Spatiotemporal Variation of Landscape Patterns and Their Driving Factors in Inner Mongolia from 2000 to 2015

Understanding the spatiotemporal changes in landscape patterns and their driving factors in Inner Mongolia can benefit land use and ecological environment management in this region. This study used the county landscape index and multiple regression analysis to reveal the temporal and spatial evolutions of landscape patterns and their driving factors in Inner Mongolia from 2000 to 2015 with multitemporal land use data. The results showed that (1) grassland was the main landscape type in Inner Mongolia. Grassland and unused land decreased, and cropland expanded from 2000 to 2015. Grassland degradation has slowed since 2005. (2) At the class level, the dominance of grassland decreased, and the degree of landscape fragmentation of cropland, forestland, and grassland increased gradually. At the landscape level, the landscape shape was more complex, the landscape connectivity was worse, and the landscape diversity gradually enhanced. (3) This study revealed that climatic factors influenced the evolution of landscape patterns, and human activities were the key driving factors of landscape-level metrics. The results of this study provide scientific bases for land management strategies.

Impacts of Sand Mining Activities on the Wetland Ecosystem of Poyang Lake (China)

Increasing anthropogenic activities are threatening freshwater ecosystems worldwide. Sand mining in Poyang Lake has significantly impacted the wetland ecosystem over the past 20 years, yet a quantitative analysis of these impacts remains insufficient. Here, we used 63 Landsat images taken from 2000 to 2020 along with the support vector machine (SVM) method and a retrieval model of suspended sediment concentration (SSC) to identify sand mining vessels and areas affected by sand mining. Then, we analyzed the changes in landscape patterns in the areas affected by sand mining. The potential impact of underwater noise generated by sand mining vessels on Yangtze finless porpoises was analyzed by a sound propagation model. The number of sand mining vessels in Poyang Lake during the flood, normal, and dry seasons increased from 2000 to 2016 but rapidly decreased from 2017 to 2020. Sand mining vessels were mainly distributed in the northern channel from 2000 to 2006, moved toward the center of the lake from 2007 to 2010, then moved northward in 2017. Within the areas affected by sand mining, water and mudflats declined, grassland and sandbars increased, and the landscape discontinuity increased. The habitat of the Yangtze finless porpoise affected by underwater noise from sand mining vessels in all seasons has significantly increased overtime. The mean area of the affected habitats was 70.65% (dry), 64.48% (normal), and 63.30% (flood) of the total habitat areas. The porpoise habitats in the northern channel and the west branch of the Ganjiang River are more seriously affected by the underwater noise of sand mining vessels than the southern lake. The impact of sand mining activities on wetland landscape and aquatic species demands systematic investigation in the future.

Identifying Ecosystem Service Trade-Offs and Their Response to Landscape Patterns at Different Scales in an Agricultural Basin in Central China

Identifying relationships among multiple ecosystem services (ESs) at different scales and the factors affecting such relationships is the foundation for sustainable ecosystem management. A case study was conducted in the Sihu Lake Basin, an agricultural basin in Central China, to examine the interactions among ESs across different scales and the responses to landscape pattern changes (2000–2020). The results indicate that (1) agricultural land and wetlands were converted into construction land and gradually decreased in size; forestland and artificial channels gradually increased in size. (2) ESs had spatial heterogeneity in their strength at the grid and county scales. (3) Most relationships between ESs were synergistic at the grid and county scales, and most correlations increased as the scale increased due to landscape consistency. (4) The landscape metrics explained approximately 45.56–61.06% of the variations in ESs, and the main influencing factor was agricultural land. Our results demonstrated that the construction of rivers and channels, dense and widely distributed agricultural land and construction land were more positively correlated with increasing crop production and nitrogen export, whereas forestland exhibited a stronger contribution to increasing carbon storage and water yield. These findings explore appropriate management methods for agricultural development and ecological conservation in agricultural basins.

Analysis of Landscape Pattern Evolution and Driving Forces Based on Land-Use Changes: A Case Study of Yilong Lake Watershed on Yunnan-Guizhou Plateau

In order to explore the landscape pattern evolution and driving forces of the Yilong Lake watershed, the combined method of supervised classification with manual visual interpretation based on the landsat5TM/8OLI remote sensing image data sources was used to establish a high-precision spatial distribution information database of the Yilong Lake watershed. Landscape index was used to analyze the distribution and spatial pattern change characteristics of various land-use types. Based on correlation and principal component analysis, we discuss the relationship between the change characteristics of land-use type, distribution and spatial pattern, and the interference of local socio-economic development and natural factors. The results show that: (1) In the past 30 years, the land-use types of the Yilong Lake watershed are mainly forest, garden plot and cultivated land. The forest area decreased significantly by 30.45 km2, of which the fastest reduction stage was from 2000 to 2005, with a total reduction of 20.56 km2. The garden plot conversion is relatively large, with a total of 181.69 km2 transferred out, of which 28.84 km2 has become unused land, respectively. (2) In the past 30 years, the maximum patch index decreased by 9.94% and the patch density index increased by 14.25%, indicating that the landscape fragmentation in the whole basin increased. The Shannon diversity index showed an increasing process; the aggregation index showed a decreasing process. (3) The change in landscape pattern in the watershedwas closely related to economic growth, population growth, social affluence and agricultural development. Natural factors, social factors and economic indicators are significantly positively correlated with patch density, edge density, landscape shape index and Shannon diversity index, and significantly negatively correlated with the largest patch index and the contagion index. On the whole, the wetlands in the basin are shrinking and the landscape diversity is changing. Reducing the excessive impact of human activities on the watershed ecosystem is a key factor for the local protection of wetland resources and the maintenance of wetland ecological functions.

Landscape pattern change and its correlation with influencing factors in semiarid areas, northwestern China

The West Liaohe Plain (WLP) is a typical crop-pastoral ecotone of the semiarid area in Northwestern, China. Land use/cover change (LUCC) of the WLP might endanger this ecosystem, triggering long-lasting environmental concerns. LUCC data for China (1980–2020) and hydrometeorological data were analyzed to reveal factors contributing to change and explore sustainable development opportunities. The results show that characteristics of the main land-use types in the WLP have changed significantly, especially cultivated land area, which increased by 15.2% and 6.79% during the periods 1980–1995 and 2000–2020, respectively. Response relationships were observed due to natural (precipitation, temperature, and runoff) and anthropogenic (economy) factors and LUCC. Between 2000 and 2020, the impact of anthropogenic factors on cultivated land was stronger than on grassland at the class and landscape level, using the landscape indices which were selected, including percent of landscape (PLAND), number of patches (NP), largest patch index (LPI), and Shannon's evenness index (SHEI). Expansion of cultivated land from 1990 to 1995 was not only related to anthropogenic factors but also to hydrological & climatic factors. The results of this study have the potential to influence sustainable land resource development.

The Evaluation of Urban Green Space Landscape Changes and Ecosystem Services in Beijing

As a very important part of the urban ecosystem, the urban green space system plays an active role in maintaining the urban ecosystem stability, providing ecosystem services, and improving the quality of the urban environment. In order to deal with the problems brought about by the deterioration of the urban ecological environment, it is necessary to study and analyze the spatial distribution pattern, evolutionary characteristics and ecosystem services of urban green space to maximize its ecological benefits and comprehensive functions. In this study, we took Beijing urban area as an example, and based on the spatial distribution data of urban green space and remote sensing data, we first calculated the urban green space type transition matrix, landscape pattern index and ecosystem services. Then, we analyzed the changes in urban green space landscape patterns, ecosystem services and their spatial distributions from 2000 to 2020, and studied the interactive relationships between landscape changes and changes in ecosystem services. The results showed three key findings. (1) Beijing's urban green space construction has achieved remarkable results from 2000 to 2020. The area of green space has increased by 77.41%, mainly from cultivated land and construction land. (2) From 2000 to 2020, the amounts of dust retention, SO2 absorption, NO2 absorption, cooling and humidification, carbon fixation and oxygen release, and rainwater runoff reduction in Beijing's urban green space have shown continuous increases in general. (3) There is a close relationship between urban green space landscape changes and green space ecosystem services, and total area (TA) has the highest correlation with ecosystem services. Except for rainwater runoff reduction, the correlation coefficients between TA and ecosystem services are all higher than 0.85. This research can provide theoretical guidance for optimizing Beijing's green space and determining how to maximize the effect of green space for improving the ecological environment, and ultimately provide a scientific basis for the construction of Beijing's ecological environment.

The Landscape Pattern Evolution of Typical Open-Pit Coal Mines Based on Land Use in Inner Mongolia of China during 20 Years

As the province most abundant in mineral resources in China, Inner Mongolia has more than 200 open-pit coal mines. The coal mining activities seriously hinder the sustainable use of regional land and the improvement of residents’ wellbeing. Taking 13 typical open-pit coal mines of Inner Mongolia as the study area, combining remote sensing images and the Google Earth Engine (GEE) platform, the trend features of spatial and temporal evolution of land use and landscape patterns from 2001 to 2020 were analyzed by transfer matrix and landscape pattern index methods. According to the mining plan and reclamation measures of the “Land Reclamation Plan”, the impacts of ecological restoration projects on land-use structure and landscape patterns were evaluated. The results showed that the following: (1) The landscape types of typical open-pit coal mining areas were mainly grassland, cropland, and industrial landscapes. The change trend of landscape pattern was obvious over the past 20 years, and the changes in grassland and mining land were relatively large, which decreased by 56.51 km2 and increased by 60.42 km2, respectively. (2) Land reclamation and ecological restoration projects had positive impacts on landscape pattern changes. With the transformation from mining activities to land reclamation activities beginning in 2007, nearly 70% of the study area showed a decreasing trend in landscape fragmentation, indicating a better landscape pattern of mining area. (3) Positive policy orientation of mine ecological restoration promoted more reasonable landscape patterns.

Spatial-temporal characteristics of cultivated land use eco-efficiency under carbon constraints and its relationship with landscape pattern dynamics

With China’s rapid urbanization and socioeconomic development, cultivated land has been experiencing continuous reduction, spatial shift, and ecological degradation in the past few decades, coupled with the decreasing and aging agricultural labor force, thus improving cultivated land utilization efficiency while minimizing associated environmental impacts is one of the major challenges facing China. This study first establishes an index system to access the eco-efficiency of cultivated land use (EECLU) considering both carbon sequestration and carbon emissions, next, employs the Super-SBM model to evaluate the spatial–temporal characteristics of EECLU, then, uses landscape metrics to describe landscape pattern dynamics of cultivated land, and finally conducts panel data analysis to investigate the relationship between landscape pattern changes and the EECLU variations. This framework was applied to Jiangsu Province, a major grain-producing area with a developed economy. The results showed that the average EECLU of the counties in rural Jiangsu from 2000 to 2020 slightly decreased, most counties were in the medium–low efficiency range (0.6–0.8), and Southern Jiangsu generally has the lowest EECLU values while Central Jiangsu has the highest. The total area and the average patch sizes of cultivated land have significantly positive impacts on EECLU, while the shape complexity and patch fragmentation have significantly negative impacts on EECLU. Therefore, comprehensive low-carbon strategies and better management and technology in the agricultural sector are needed to further improve EECLU. On the premise of protecting the total area of cultivated land, larger and more aggregated land patches should be promoted in the land consolidation process, and the cultivated land targeted for occupation or compensation should be able to simplify the overall shape of cultivated land patches.

The dynamics of tea plantation encroachment into forests and effect on forest landscape pattern during 1991–2021 through time series Landsat images

Tea plantations encroachment into forests has occurred in the major tea planting area of Yunnan province, China in the past decades. However, the dynamics of tea plantation encroachment into forests and the effect on forest landscape pattern is not clear. In this study, we proposed a method to evaluate the dynamic effects of tea plantation encroachment on forest landscape pattern change by using time series Landsat 5/7/8 data from 1991 to 2021 on the Google Earth Engine (GEE) platform. First, a pixel- and phenology-based algorithm was applied to generate tea plantations encroachment into forests maps for seven historical periods. Second, three indices including the tea plantations encroachment index (TPEI), the growth area of tea plantations encroachment into forests (GATEF), and the growth index of tea plantations encroachment into forests (GITEF) were used to quantify the tea plantations encroachment into forests of seven historical periods. Third, the effects of forests landscape pattern resulting from tea plantations encroachment were evaluated in class metrics and landscape metrics respectively. Our results show a total of 13,721 ha of GATEF from the early 1990s to the early 2020s. The GITEF increased from the early 1990s to the early 2010s and decreased from the early 2010s to the early 2020s in our study area. And the TPEI indicates that the edge encroachment mode dominated in our study period. Correlation analysis indicates that tea plantations encroachment level had significant correlation coefficients with landscape pattern indices (such as CONTAG (r = −0.91), ED (r = 0.95), DIVISION (r = 0.85), and SHEI (r = 0.86)), which indicates that the level of tea plantations encroachment affects significantly the forest landscape pattern. This study provides a promising approach to quantifying the effect of forest landscape pattern results from tea plantations encroachment.

Spatial-Temporal Driving Factors of Urban Landscape Changes in the Karst Mountainous Regions of Southwest China: A Case Study in Central Urban Area of Guiyang City

Rapid urban expansion has significantly altered the regional landscape pattern, posing a serious threat to the sustainable development of natural and social ecosystems. By using landscape patterns indices and an area transfer matrix, this study analyzed the spatial-temporal changes of landscape patterns in the karst mountainous cities of southwest China from 2000 to 2020, by taking the central urban area of Guiyang City (CUAG) as the study area. This study explored the spatial and temporal driving factors of landscape pattern changes by using stepwise multiple linear regression and geographic detector methods. The results show: (1) CUAG’s landscape types altered changed drastically, with the area of forestland and construction land rapid increment and cultivated land decrement significantly. (2) The patches of construction land and forestland tended to be aggregated, the degree of fragmentation was reduced, and the shape was complex; cultivated land fragmentation was intensified. The connectivity of the landscape was improved, while the level of landscape diversity declined, the trend of landscape homogenization was obvious. (3) Socioeconomic and geographical endowment drivers have determined landscape pattern changes. The findings of this study may be used to interpret other similar landscapes worldwide and may imply the protection of urban ecosystem and sustainable development.

Monitoring landscape fragmentation and aboveground biomass estimation in Can Gio Mangrove Biosphere Reserve over the past 20 years

Over the past 20 years, the mangrove landscape of Can Gio Mangrove Biosphere Reserve (MBR) has undergone drastic changes in space and time. However, we know very little about changes in mangrove landscape model characteristics from analysis of different aspects based on landscape fragmentation. In the present study, the temporal and spatial changes of landscape pattern of land use/land cover (LULC) over the past 20 years in Can Gio Mangrove Biosphere Reserve (MBR), southern Vietnam were analyzed based on remote sensing data, with high classification accuracy (overall accuracy >85%, Kappa >0.8). The present study selected representative landscape indexes and built an integrated landscape index to examine the spatial-temporal changes of landscape patterns. Overall, over the past 20 years, the degree of fragmentation has gradually increased, mainly occurring in the transition zone of MBR. These changes are intended to reflect the significant temporal variation of the MBR, where the ecosystem is strongly disturbed by the intensity of human activities. We then investigate the effectiveness of principal component analysis (PCA)-based machine learning techniques in estimating the mangrove AGB, and applying landscape indices to assess impacts in Can Gio MBR. It reveals that the ANN model obtained the highest prediction accuracy (R2train = 0.785), followed by GPR (R2train = 0.703), and SVM (R2train = 0.671). As a result of applying the ANN model, the predicted mangrove AGB in 2000 and 2020 in the study site ranged from 6.531 to 368.163 Mg ha−1, and 13.749 to 320.295 Mg ha−1, respectively. These results support the application of the model as a tool to support LULC management and protection in the study site, and to contribute insights into the future mangrove research in other regions of the world.

Spatial and Temporal Evolution of Urban Green Space Pattern Based on GIS Sensors and Remote Sensing Information: Taking Xi’an as an Example

In order to solve the practical application of the continuously developing remote sensing technology in urban planning, this paper proposes a method of temporal and spatial evolution of urban green spatial pattern based on GIS remote sensing information. Based on the Landsat Image data of the main urban area of Xi’an from 2000 to 2012, different classification methods are used to extract the urban green space information and compare the accuracy. The classification results with high accuracy are selected to analyze the temporal and spatial evolution law of urban green space and the change of landscape pattern in the study area. In this paper, the change of vegetation coverage can be divided into five levels: significant degradation: <-0.006; slight degradation: -0.006~-0.002; stable: -0.002~0.002; slight improvement: 0.002~0.006; and significant improvement: >0.006. The results of this paper prove that this method can be used to understand and evaluate the ecological consequences of urbanization and improve our quality of life. At the same time, it can provide basic information for decision-making.