Area-weighted Mean Shape Index Research Articles

The Influence of Spatial Heterogeneity of Urban Green Space on Surface Temperature

Urban green space (UGS) has been recognized as a key factor in enhancing the urban ecosystem balance, particularly in arid areas. It is often considered an effective means to mitigate the urban heat island (UHI) effect. In this study, the reference comparison method was utilized to optimize the process of nighttime lighting data; the random forest classification method was employed to extract UGS data; and the radiative transfer method was applied in land surface temperature (LST) inversion. Additionally, moving window analysis was conducted to assess the robustness of the results. The objective of this research was to analyze the spatial distribution characteristics of UGS and LST and to explore their bivariate local spatial autocorrelations by calculating four landscape metrics, including the aggregation index (AI), edge density (ED), patch density (PD), and area-weighted mean shape index (Shape_am). It was found that the distribution of UGS in the study area was uneven, with higher temperatures in the eastern and western regions and lower temperatures in the central and southern regions. The results also revealed that ED, PD, and Shape_am were negatively correlated with LST, with correlation coefficients being −0.469, −0.388, and −0.411, respectively, indicating that UGS in these regions were more effective in terms of cooling effect. Conversely, AI was found to be positively correlated with LST (Moran’ I index of 0.449), indicating that surface temperatures were relatively higher in regions of high aggregation. In essence, the fragmented, complex, and evenly distributed green patches in the study area provided a better cooling effect. These findings should persuade decision makers and municipal planners to allocate more UGS in cities for UHI alleviation to improve quality of life and enhance recreational opportunities.

How Does the 2D/3D Urban Morphology Affect the Urban Heat Island across Urban Functional Zones? A Case Study of Beijing, China

Studying driving factors of the urban heat island phenomenon is vital for enhancing urban ecological environments. Urban functional zones (UFZs), key for planning and management, have a substantial impact on the urban thermal environment through their two-dimensional (2D)/three-dimensional (3D) morphology. Despite prior research on land use and landscape patterns, understanding the effects of 2D/3D urban morphology in different UFZs is lacking. This study employs Landsat-8 remote sensing data to retrieve the land surface temperature (LST). A method combining supervised and unsupervised classification is proposed for UFZ mapping, utilizing multi-source geospatial data. Subsequently, parameters defining the 2D/3D urban morphology of UFZs are established. Finally, the Pearson correlation analysis and GeoDetector are used to analyze the driving factors. The results indicate the following: (1) In the Fifth Ring Road area of Beijing, the residential zones exhibit the highest LST, followed by the industrial zones. (2) In 2D urban morphology, the percentage of built-up landscape (built-PLAND) and Shannon’s diversity index (SHDI) are the main factors influencing LST. In 3D urban morphology, building density, the sky view factor (SVF), and the area-weighted mean shape index (shape index) are the main factors influencing LST. Therefore, low-density buildings with simple and dispersed shapes contribute to mitigating LST, while fragmented distributions of trees, grasslands, and water bodies also play important roles in alleviating LST. (3) In the interactive detection results, all UFZs show the highest interaction detection results with the built-PLAND. (4) Spatial variations are observed in the impact of different UFZs on LST. For instance, in the residential zones, industrial zones, green space zones, and public service zones, the SVF is negatively correlated with LST, while in the commercial zones, the SVF exhibits a positive correlation with LST.

Spatial-temporal changes of landscape and habitat quality in typical ecologically fragile areas of western China over the past 40 years: A case study of the Ningxia Hui Autonomous Region.

In this paper, we use the InVEST model and five periods of land use data from 1980 to 2020 to assess the habitat quality of the Ningxia Hui Autonomous Region in Western China, which has characteristics of a typical fragile ecosystem. We further analyse the spatial and temporal characteristics of habitat quality evolution and its relationship with land use and landscape pattern indices to explore the close relationship between regional habitat quality changes and human natural resource conservation and utilization. The research results show that the overall habitat quality of Ningxia Hui Autonomous Region was stable and at a moderate level (0.57-0.60) during the 40 years from 1980 to 2020; Habitat patches (2020) with low (24.89%), high (22.45%) and very high (29.81%) quality occupy a larger proportion of the area, followed by very low (13.31%) and moderate levels (9.54%). Over the past 40 years, there have been 275 sample sites in Ningxia where habitat quality has deteriorated, 1593 sample sites where the habitat quality has remained stable, and 184 sample sites where the habitat quality has increased. From 1980 to 2020, the Mean Patch Area of landscape types in Ningxia decreased by 25.9 hm2. The Patch Density increased by 0.06 /hm2. The Largest Patch Index decreased by 15.69%. The Edge Density increased by 2.5 m/hm2. The Contagion Index decreased by 2.99%. The Area-Weighted Mean Patch Fractal Dimension remained basically unchanged (0.01). The Landscape Shape Index showed a trend of first increasing and then decreasing, increasing by 13.94. The Area-Weighted Mean Shape Index has been reduced by 9.45. The Shannon Diversity Index and Shannon Evenness Index both show an increasing trend, but the amplitude is relatively small, with 0.09 and 0.04, respectively. There was a significant spatial aggregation of high and low habitat quality in Ningxia, with high values usually distributed in the northern and southern areas with good natural conditions and low values distributed in areas with frequent human activities and poor natural conditions. The decrease in habitat quality in Ningxia was mainly due to the expansion of cultivated land and construction land, the increase in landscape fragmentation and the resulting decrease in connectivity. On the other hand, due to the implementation of ecological protection measures, such as the project of returning farmland to pasture and grass to forest, the quality of habitats in Ningxia increased. The conclusions of this study support the idea that the conservation of habitat quality in ecologically fragile areas should fully preserve the original natural habitats and reduce the interference of human activities to increase the habitat suitability of the landscape and the habitat connectivity between patches. At the same time, targeted ecological protection policies should be developed to restore the areas where the habitat quality has been damaged and ultimately maintain the stability of biodiversity and ecosystems in ecologically fragile areas. Meanwhile, for ecologically fragile areas with similar ecological characteristics to those of Ningxia, our research supports the idea of increasing the protection of the stability of the original habitats, increasing the proportion of ecological restoration projects, financial investment and seeking cooperation with local community managers and residents will help to improve the quality of the regional habitats and the enrichment of the biodiversity, and ultimately promote the harmonious coexistence of human beings and nature in the modernized sense of the word.

From “separation” to “Integration”: Analyzing the functional transformation of the urban greenbelt in Beijing from the perspective of “parkization”

The Urban greenbelt (UGB), vital for curbing urban expansion, experiences shifts in function across diverse development stages. Unfortunately, UGB functional transformation process, especially its social utilization of ecological functions, often receives insufficient attention, impacting urban ecosystem health enhancement and residents' well-being. The UGB park, combining ecology and social benefits, holds significance in studying varied UGB functions and their transformation. Thus, tracking park development trends (“parkization”) aids in analyzing UGB functional evolution. We employed high-precision land use/land cover (LULC) data (less than1m) from Beijing to explore UGB functional transformation law, focusing on UGB park dynamics and their ecological benefits (Park Ecological Land Use/Land Cover (PLULC) percentage (PPELULC), mean patch size (MPS), edge density (ED), area-weighted mean shape index (AWMSI), patch size standard deviation (PSSD)), and social benefits (per capita park area (PCP), per capita PLULC area (PCPELULC), accessible park service scope). Results revealed that as UGB park construction slowed, park ecological space displayed an “increasing and dispersing” trend, signifying weakened UGB park ecological benefits. Simultaneously, park social services collectively exhibited improvement, suggesting the UGB functional transformation from solely ecological protection to holistic environmental and social safeguarding. This transformation was more notable within the first greenbelt (UGB1), predominantly driven by comprehensive and natural amusement parks. The “parkization”-based UGB function evaluation method not only illuminated the functional transformation mechanism but also underscored the integrated needs of ecology and society, which is essential to the subsequent scientific formulation and implementation of ecological management strategies that meet the needs of urban environmental protection

RELAÇÕES ENTRE DIVERSIDADE AVIÁRIA E HETEROGENEIDADE DA PAISAGEM AGRÍCOLA

ABSTRACT Studies on birds and their habitats are usually conducted in natural areas (protected areas, forests, wetlands, etc.). In this study, the relationship between agricultural landscape diversity and the species diversity of birds was investigated in an agricultural zone surrounded by natural and forested areas. Observations were carried out in 60 sample grid squares. Presence/absence data for birds and cultivated plants at each sample site were recorded. The Shannon-Wiener diversity index for bird species and landscape metrics for agricultural areas were used in the sample site. A multiple linear regression analysis was performed to explain the correlation between agricultural landscape diversity and bird species diversity. According to the results, the area-weighted mean shape index (AWMSI) and the number of patches (NP) were found to be particularly effective at predicting bird species diversity (R2 = 0.66). In addition, as the patch number and patch shape ratio increased in a sample area, the diversity of bird species (R = 0.83) expanded. It can be concluded that agricultural zones consisting of small, different patches are rich areas for bird species diversity. Bird species diversity is lessened in agricultural areas with uniform or similar landscape structures consisting of large patches. If the NP in the area is high, but not distributed in a mosaic pattern, then the diversity of bird species is considered weak. Despite the increasing NP and patch types, bird species diversity declines if there is intense human activity in the area.

Impact of LCZs spatial pattern on urban heat island: A case study in Wuhan, China

Based on World Urban Database and Access Portal Tools (WUDAPT), this study mapped Local Climate Zones (LCZs) in Wuhan in 2020 and detected surface urban heat island intensity (SUHII) within LCZs in day/night of all seasons through Moderate Resolution Imaging Spectroradiometer (MODIS) land products. Four landscape metrics were used to explore spatial heterogeneous effects of LCZs on SUHII by Geographically weighted regression (GWR) model. Results showed that LCZs map can be used to describe the thermal environment in Wuhan. SUHII difference among LCZs was stronger in spring and summer, while less in winter. SUHII difference of the same LCZ was found in three districts in Wuhan. SUHII of most other built classes in Hankou were higher than Wuchang and Hanyang. SUHII within LCZ G in Wuchang was the lowest in daytime of all seasons but the highest at night of all seasons. LCZ 2, LCZ 4, LCZ 5, LCZ 8 and LCZ H had strong positive correlation with SUHII and LCZ D and LCZ G had significant negative correlation with SUHII. Percentage of landscape (PLAND) of LCZs had stronger impact on SUHII than Contagion index (CONTAG), Shannon's diversity index (SHDI) and Area-weighted mean shape index (SHAPE_AM) of LCZs. PLAND of LCZ 8 had strong impact on increasing SUHII in daytime of all seasons, while PLAND of LCZ 2, LCZ 4 and LCZ 5 showed obvious influence on increasing SUHII at night of all seasons. LCZ D had strong impacts on decreasing SUHII in daytime of all seasons and less cooling impacts at night of all seasons. LCZ G showed strong cooling impacts on SUHII in day/night time of all seasons except winter nighttime. SHDI richness of LCZs in analysis unit helped alleviate SUHII. High CONTAG of LCZ with high LST increase SUHII, while High CONTAG of LCZ with low LST decrease SUHII. Very regular shape of LCZ built classes increased the SUHII, while less fragmented of LCZ land cover classes decreased the SUHII.

Analysis of Landscape Composition and Configuration Based on LULC Change Modeling

Land cover changes threaten biodiversity by impacting the natural habitats and require careful and continuous assessment. The standard approach for assessing these changes is land cover modeling. The present study investigated the spatio-temporal changes in Land Use Land Cover (LULC) in the Gorgan River Basin (GRB) during the 1990–2020 period and predicted the changes by 2040. First, a change analysis employing satellite imagery from 1990 to 2020 was carried out. Then, the Multi-Layer Perceptron (MLP) technique was used to predict the transition potential. The accuracy rate, training RMS, and testing RMS of the artificial neural network, MLP, and the transition potential modeling were computed in order to evaluate the results. Utilizing projections for 2020, the prediction of land cover change was made. By contrasting the anticipated land cover map of 2020 with the actual land cover map of 2020, the accuracy of the model was evaluated. The LULC conditions in the future were predicted under two scenarios of the current change trend (scenario 1) and the ecological capability of the land (scenario 2) by 2040. Seven landscape metrics were considered, including Number of Patches, Patch Density, the Largest Patch Index, Edge Density, Landscape Shape Index, Patch Area, and Area-Weighted Mean Shape Index. Based on the Cramer coefficient, the most critical factors affecting LULC change were elevation, distance from forest, and experimental probability of change. For the 1990–2020 period, the LULC change was shown to be influenced by deforestation, reduced rangeland, and expansion of agricultural and residential areas. Based on scenario 1, the area of forest, agriculture, and rangeland would face −0.8, 0.5, and 0.1% changes in the total area, respectively. In scenario 2, the area of forest, agriculture, and rangeland would change by 0.1, −1.3, and 1.3% of the total area, respectively. Landscape metrics results indicated the destructive trend of the landscape during the 1990–2020 period. For improving the natural condition of the GRB, it is suggested to prioritize different areas in need of regeneration due to inappropriate LULC changes and take preventive and protective measures where changes in LULC were predicted in the future, taking into account land management conditions (scenario 2).

流域空间结构指标与药物污染水平的关系研究

PDF HTML阅读 XML下载 导出引用 引用提醒 流域空间结构指标与药物污染水平的关系研究 DOI: 10.5846/stxb202111123174 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31971489） Quantifying relationships between watershed characteristics and pharmaceutical pollution in aquatic environment Author: Affiliation: Fund Project: the National Natural Science Foundation of China (31971489) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:流域地表特征与土地利用结构同流域水环境质量关系密切。流域空间结构指标能够表征流域空间结构特征和生态功能，主要包括流域特征指标和景观格局指数等。为探讨海湾流域生态系统结构与药物污染特征之间的关系，以浙江象山湾为研究区域，采用固相萃取、超高效液相色谱质谱联用等分析手段，研究流域水环境中药物的污染水平、分析其分布特征与流域特征指标和景观结构的关系。结果表明，象山湾22个流域共有22种药物检出，总检出浓度范围为n.d.-220.2 ng/L，主要包括林可霉素、大环内酯类、喹诺酮类、抗癫痫药物、β受体阻滞剂、抗抑郁药物，其中林可霉素、大环内酯类和抗癫痫药物的检出率高达100%，检出浓度分别为2.36-29.1 ng/L、n.d.-35.8 ng/L和n.d.-37.5 ng/L。流域地貌结构指标与水环境药物污染关系密切，其中平均坡度（MS）与药物总浓度、面积高程曲线斜率（SAEC）与β受体阻滞剂都呈显著负相关关系（P<0.01）；流域景观结构也与水环境药物污染紧密相关，其中景观蔓延度指数（CONTAG）、城镇用地面积加权平均形状因子（IsSHAPE-AM）、林地最大斑块景观面积比（fLPI）与药物总浓度呈显著负相关关系（P<0.05），Shannon均匀度指数（SHEI）与药物总浓度呈显著正相关关系（P<0.05）。通过明确药物与流域空间结构指标的关系，可为应用景观生态措施进行流域管理提供科学依据。 Abstract:Watershed characteristics play a significant role in improving water pollution at watershed scale. Understanding the relationships between watershed characteristics and water quality is of great significance for watershed management. Pharmaceuticals are of increasing concern for their ubiquitous detection and potential threat to aquatic environment. However, little is known about the relationships between watershed characteristics and pharmaceutical pollution in the aquatic environment. To study the relationships between watershed characteristics and pharmaceutical pollution in the aquatic environment, we investigated the occurrence of 29 pharmaceuticals and their quantifying relationships with watershed characteristics in Xiangshan Bay, Eastern China. Pharmaceuticals were extracted by using solid-phase extraction (SPE) and analyzed by ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The redundancy analysis and regression modeling were used to explore the correlation between watershed characteristics and pharmaceutical concentrations. The results showed that 22 target pharmaceuticals were detected in the surface water samples, with the detected concentrations ranged from not detected (n.d.) to 220.20 ng/L. Lincomycin (100% of samples), macrolides (100% of samples), antiepileptic drugs (100% of samples), beta-blockers (95% of samples), antidepressant drugs (77% of samples) were the predominant compounds with concentration of 2.36-29.1 ng/L, n.d. -35.8 ng/L, n.d. -37.5 ng/L, n.d.-15.0 ng/L, and n.d.-3.49 ng/L, respectively. Redundancy analysis revealed that the concentrations of pharmaceuticals in the watersheds were positively correlated to topographical features of watersheds. Correlation analysis also showed that the total pharmaceutical concentrations had a significantly negative correlation with mean slope (MS) (P<0.01), and beta-blockers had a significantly negative correlation with slope of area elevation curve (SAEC) (P<0.01). The landscape pattern is also a crucial factor for determining pharmaceutical pollution in the aquatic environment. We have also found that the total pharmaceutical concentrations were negatively correlated with contagion (CONTAG) (P<0.05) and positively correlated with Shannon's evenness index (SHEI) (P<0.05). Furthermore, the area-weighted mean shape index of urban land (IsSHAPE-AM) and the largest patch index of forest (fLPI) had significantly negative correlation with total pharmaceutical concentrations (P<0.05). Overall, the watershed characteristics had significant influences on the pharmaceutical pollution. According to pharmaceutical pollution in the watersheds, the study of the watershed characteristics' correlation to water pollution will help better understanding the influences of the surrounding characteristics on the water quality of surface water at watershed scale. These findings can provide scientific support for improving the water pollution control in surface water at watershed scale from the perspective of sustainable landscape management. 参考文献 相似文献 引证文献

Spatial disparity patterns of green spaces and buildings in arid urban areas

Urban green spaces are a crucial component in regards to the quality of life, ecosystem balance and recreational services of populations, particularly in arid and semi-arid regions. This study aimed to explore spatial patterns of accessibility to public parks on a neighbourhood scale in the Sohar Wilayat, Oman. Utilising GIS techniques and landscape metrics, we investigated the spatial variations of green patches relevant to other land use types predominantly residential buildings in each local area. The entropy index, the landscape shape index (LSI) and the area-weighted mean shape index (AWMSI) were calculated to analyse landscape spatial patterns of urban green spaces across the study area. The results of this study indicated that the large numbers of green space patches in the majority of neighbourhoods were associated with large population size. In measuring spatial accessibility to public parks, the central neighbourhoods were characterised by low scores and long distances from green spaces, while neighbourhoods in the south and north showed short distances and high scores for residents’ accessibility to the nearest park. High rates of fragmentation and irregular shapes, particularly within marginal and inner neighbourhoods, can be attributed to rapid urbanisation and sprawl, which has extensively transformed urban green spaces and vacant land into dwellings. Our findings suggest that a spatial quantification and identification of green space distribution patterns and the accessibility of public parks could provide decision-makers and municipality planners with invaluable guidelines for allocating green parks and recreational amenities equitably and efficiently to urban residents.

Multiscale analysis of the effects of urban green infrastructure landscape patterns on PM2.5 concentrations in an area of rapid urbanization

Urban green infrastructure (UGI) is considered to be an effective tool for mitigating PM2.5 (particulate matter with an aerodynamic diameter of less than 2.5 μm) pollution in urban areas. However, long and continuous time series analyses of the relationships between the UGI landscape and PM2.5 pollution remain a challenge. In the present study, then we analyzed the PM2.5 variations and their relationships with the UGI landscape patterns at the urban agglomeration (the urban area of CLUA) and neighborhood scales (6 neighborhood zones with radii ranging from 500 m to 3000 m around the sampling point.). The results illustrated PM2.5 concentration increased slightly in the urban expansion areas and decreased in some old urban areas, but the changing trend was not significant. The PM2.5 concentrations were different among the four seasons in this area, and the lowest and highest concentrations occurred in winter (66.79 μg/m³) and summer (24.32 μg/m³), respectively. At the urban agglomeration scale, just a very small proportion of the PM2.5 variations in the CLUA during this study period could be attributed to the UGI landscape pattern, wind speed and relative humidity; PM2.5 concentrations were affected more strongly by wind speed and relative humidity than by UGI landscape patterns; the LSI (landscape shape index) and bridges served as the main landscape indicators affecting the PM2.5 concentrations among the UGI landscape patterns factors. At the neighborhood scale, the LPI (largest patch index), AWMSI (area-weighted mean shape index), AI (aggregation index), Core and Loop served as the main UGI landscape indicators influencing PM2.5 and had different degrees of influence on the PM2.5 concentrations; the seasonal and scale effects of UGI landscape patterns on PM2.5 concentrations at neighborhood scales were observed. Comparatively, the effects of the UGI landscape patterns on PM2.5 concentration seem more significant at the neighborhood scale than at the urban agglomeration scale. The findings of this multiscale analysis can provide new insights into understanding the relationships between UGI landscape patterns and urban air pollution at different scales, and provide a scientific reference for urban planning and air pollution control.

Class and landscape level habitat fragmentation analysis in the Bale mountains national park, southeastern Ethiopia

The changes of natural habitat structure and function due to human interference is hastening worldwide, and it is compulsory to preserve biological resources in a protected system. This study aims to measure the landscape ecological structure and the extent of habitat fragmentation in the Bale mountains national park. The land use/land cover change was determined by interpreting the 1985, 1995, 2005 and 2017 Landsat images with ArcGIS 10.3, and the selected landscape structural metrics was analyzed using FRAGSTATS 4.2.1. All land cover classes showed a declining trend, except the farmland, and grassland depicted the highest area reduction. From 1985 to 2017 grassland, Erica, forestland, and afro-alpine were decreased by 9.36 %, 0.26 %, 0.06 %, and 0.01 %, respectively. Whereas, farmland was increased by 43.67 %. The study area was characterized as progressively fragmented since it was signified by the escalated value of patch number (40.22 %), area-weighted mean shape index (18.84 %), and edge density (22.27 %) and a declined value of mean patch size (28.68 %) and core area (10.60 %) over the study period. Considering this result, there was a high loss in area available for core dependent species, particularly for Mountain nyala in the grasslands and woodlands, Ethiopian wolf in afro-alpine regions, and Bale monkey in the bamboo forest. Both forestland and grassland need a conservation priority since these habitats were the most fragmented and habitat lost area.

The influence of urban form on surface urban heat island and its planning implications: Evidence from 1288 urban clusters in China

There is a growing demand for urban form optimization to mitigate urban heat island (UHI) effect. Nevertheless, how UHI responds to various urban morphological patterns is still limitedly understood, especially for cities in developing countries. Here, based on 1288 urban clusters identified automatically across China, we created a consistent analytical environment to recognize both homogeneity and heterogeneity of the relationship. Specifically, urban form was characterized from aspects of size, shape, and centrality, respectively measured using metrics of urban size, area-weighted mean shape index (AWMSI) and dispersion index (DI), entropy and Moran’s I. Then, relationships between the metrics and surface UHI (SUHI) were modelled using the ordinary least squares (OLS). Results reveal that in nighttime when stronger relationships were observed than in daytime, centrality, a feature of intra-urban development structure largely neglected by previous studies, dominated as the most influential aspect. The relationships also varied across climate zones. A two-step OLS regression further reveals them to be size-dependent. As city expanded, the rising shape irregularity created a cooling impact, while the rising centrality leaded to urban warming. Overall, this study suggests that, in addition to controlling urban expansion, the optimal urban form for SUHI mitigation is moderately dispersed, polycentric, and decentralized.

The woody plant diversity and landscape pattern of fine-resolution urban forest along a distance gradient from points of interest in Qingdao

Points of interest (POIs) are closely related to urbanization and human mobilities, and would consequently affect the spatial distribution of urban forest and its species diversity. However, the issue on what the relationships between POIs and urbanization, and how do POIs affect urban forest was rarely mentioned in previous studies. In our research, a total of 82,978 POI records (reclassed to 7 categories of catering and restaurants, commercial areas, educational and institutional areas, public services, residential areas, scenic spots and shopping areas) were collected to analyze their influence on woody plant diversity and urban forest landscape metrics according to a distance gradient using field measurements of diversity and imagery delineated urban forest patches. The results revealed that the urbanization intensity (computed as impervious surface area proportion) was linearly decreased with the increase of distance from POIs except for scenic spots. When it close to POIs, the woody plant species richness, Shannon-Wiener diversity and evenness gradually increased, whereas the Simpson’s diversity decreased. Meanwhile, the urban forest patches delineated from fine-resolution images got smaller, less shape complexity and fragmented with mean patch area (AREA_MN), area-weighted mean shape index (SHAPE_AM) and area-weighted mean contiguity index (CONTIG_AM) decreased and patch density (PD) increased. This study can improve our understanding on the diversity, distribution of urban forest and its relationship with human activities, and guide us in urban forest planning and management.

Landscape metrics to analyze the forest fragmentation of Chitteri Hills in Eastern Ghats, Tamil Nadu

Chitteri Hills of Eastern Ghats is primarily covered by evergreen forests and deciduous forests. Forest Management, change in landuse and rapid economic development has caused a minor change in the landscape of Chitteri. In the current study the forest fragmentation was assessed using the Fragstat 4.0 software for different classes using specific metrics. Fragstats 4.0 spatial pattern analysis was applied for different landuse classes that was derived from landuse and landcover maps prepared using the Landsat 8 digital data. The results from the above analysis have shown that there was more fragmentation in the Chitteri Hills. Class Area (CA), Percentage of Landscape (PLAND), Largest Patch Index (LPI), Number of Patches (NP), Patch Density (PD), Area Weighted Mean Shape Index (AWMSI) at the class level was quantified in the present study. These spatial metrics were found to be very simple and helpful in quantification of the complex spatial processes and can be used as an effective means for monitoring the Chitteri Landscape.

Evaluation and sensitivity analysis of the ecosystem service functions of haze absorption by green space based on its quality in China

Evaluation of the ecosystem service functions of haze absorption by green space is important for controlling haze. In this study, the ecosystem service functions of haze absorption by green space in China in 2001, 2004, 2007, 2010, 2013, 2016 and 2018 are analyzed based on green space quality and sensitivity using a geographic information system (GIS) and Moderate Resolution Imaging Spectroradiometer (MODIS) imagery. The results showed that the benchmark ecosystem service functions of haze absorption by green space when considering only the area of green space showed a trend that increases first and then decreases in 2001–2018, with 9000458.55 million Kg, 9145110.75 million Kg and 7734526.75 million Kg in 2001, 2013 and 2018, respectively. However, the corrected functions based on green space quality were 7724215.34 million Kg, 8320301.79 million Kg and 6510132.55 million Kg in the corresponding years. This indicated large differences between ecosystem service functions of haze absorption based on the quality and area of green space; only considering the area of green space to evaluate ecosystem service functions will result in overestimation. In terms of the spatial distribution of the ecosystem service functions of haze absorption by green space, there were greater differences in the benchmark and corrected functions, and the spatial distributions of the maximum, intermediate and minimum ecosystem service functions were notably different. However, the benchmark and corrected functions all showed a consistent trend in the rank of their contribution rates and ecosystem service functions as well as consistent distribution trends: the spatial distribution of ecosystem service functions of haze absorption by green space was very different in the same year, but there was little difference among different years. The change coefficients for the ecosystem service functions of haze absorption by arable land and grass land remained stable, whereas the coefficient of sensitivity for forest cover was elastic. Patch density (PD) and the ecosystem service functions of SO2 absorption, NOx absorption, dust retention and total ecosystem services showed a significant negative correlation, with correlation coefficients of -0.407, -0.511, -.330 and -0.332, respectively. In contrast, the area-weighted mean shape index (SAPE_AM) and ecosystem service functions exhibited significant positive relationships with correlation coefficients of 0.650, 0.634, 0.568 and 0.570, respectively. The results provide an improved method for evaluating the ecosystem service functions of haze absorption by green space as well as a reference for the prevention and control of haze and the coordinated development of regional societies, the economy and the environment.

Analysis of the Habitat Fragmentation of Ecosystems in Belize Using Landscape Metrics

Landscape metrics have been of game changing importance in the analysis of ecosystems’ composition and landscape cohesion. With the increasing urban and agricultural expansion, the natural flora and fauna of many highly diverse areas have been degraded. Fragmentation of ecosystems and habitats have stressed the biodiversity of Belize. To understand the dynamics of this change, a study was conducted using three moderately separate years of ecosystem landscape data. The metrics used for the analysis were area-weighted mean shape index (AWMSI), mean shape index (MSI), edge density (ED), mean patch size (MPS), number of patches (NUMP), and class area (CA). These metrics were produced for the years 2001, 2011, and 2017. The classes of agricultural use, lowland savannas, mangroves and littoral forests, urban, and wetlands were the subjects for analysis. Using the GIS extension Patch Analyst, parametric runs were performed. From these results, a one-way ANOVA test of the NUMP, Tukey HSD test, and Scheffé Multiple Comparison test were performed. The results indicate that there has been significant habitat fragmentation, especially from the years 2001 to 2011. Agricultural areas increased by 19.37% in just 10 years, with the NUMP of some habitats increasing by 284%. The results also show fluctuation in ED and a decrease in overall MPS, all indicating high fragmentation. These changes have been mostly induced due to the expansion of agricultural activities and urbanization, especially in the northern parts of Belize. It is imperative that additional policies be implemented to deter the effects of habitat fragmentation upon the existing ecosystems of Belize and elsewhere.

Land use alteration strategy to improve forest landscape structural quality in Radhanagar forest range under Bankura district

Such kind of human necessities restructured the existing landscape pattern which brings imbalance in regional biodiversity. Radhanagar Forest Range (RFR) in Bankura district has been faced same kind of activates since 1960. As a result, forest patch becomes isolated and structurally complex in nature which is an important cause for extinction of wild animal. To control this damage forest department increased forest area through several plantation schemes in vacant or barren land. But plantation areas were not appropriate in the question of structural forest quality in this region. The present study seems that forest structural quality is a vital consideration for balancing biodiversity, in concern of several ecological processes like species movement, connectivity, colonization and edge contrast. Suitable forest patch structure may possible when appropriate areas i.e. forest encroached areas will be select for plantation. To prove this statement, study considers two types of landuse alteration into forest land i) all barren land altered into forest and ii) selected encroached areas altered into forest land in RFR. ArcGIS 10.3 version software is used for technical map editing and preparing these spatial alteration maps. After that several landscape ecological indexes like Total Core Area Index (TCAI), Mean Core Area (MCA) at 300 m specified edge depth, Total Edge (TE), Edge Density (ED), Area Weighted Mean Shape Index (AWMSI), Area Weighted Mean Patch Fractal Dimension (AWMPFD) and Mean Patch Size (MPS) are calculated using FragStat 4.2 version software to compare both spatial alteration forest qualities. Comparison analysis explains that encroached areas alteration into forest land is qualitative to improve forest structural quality. It is interesting to know that less area will be planted in encroached area to get utmost forest structural qualities.

Coupling analysis of landscape pattern and thermal fields after the afforestation in Beijing plain area

Under the positive human land use regulation (e.g. afforestation), understanding the impacts of landscape pattern changes on urban and rural thermal fields can provide reference data for future construction and optimization of urban afforestation projects and bring new insights for future landscape patterns and thermal fields environment related research. Under the context of "One Million Mu Plain Afforestation Project" in Beijing plain area, we applied remote sensing technology and geographic information system and used transfer-matrix method and coupling analysis to evaluate the impacts of plain afforestation on thermal field environment and to explore the correlation between changes in landscape patterns resulted from urban afforestation projects and urban land surface temperature. Our results showed that the percentage of landscape (PLAND) of forests and parks increased by 7.6% and 0.5% after the afforestation project in Beijing plain area, respectively. The heat island intensity decreased by 19.2% of entire plain area, and by 23.3% of suburban area, however, it increased by 23.5% of city area. Spanning urban to urban-rural interface, the PLAND of forests and parks, the mean patch size (MPS) of forests and wetlands were significantly negatively correlated with the changes in landscape surface temperature (LST). In city area, the area-weighted mean shape index (AWMSI) of forests was significantly positively correlated with the changes of LST. In suburban area, the MPS and AWMSI of forests showed significantly negative correlation with changes of LST, which was contrary to parks. After the implementation of afforestation project in Beijing plain area, the increased urban forests and urban parks had mitigated thermal fields to some extent. The scale of mitigation was limited and most areas with decreased heat island intensity were concentrated in newly planted sites in suburban area. The more connected the forests and wetlands, the better the relief of the thermal fields in the plain area. Impacted by the grain size, time, topography, human activities and other factors, the change in landscape patterns caused by the control of land use structure showed non-linear correlation with the change of LST.

Detecting urban land-use configuration effects on NO2 and NO variations using geographically weighted land use regression

Land use regression (LUR) has been used to predict NO2 and NO distribution. However, previous studies overlooked the possibility that the effect of land-use configuration on NO2 and NO may not always be constant across the study domain. The objective of this study was to depict the spatially varying effect so as to better predict NO2 and NO. First, a LUR model was adopted to screen the land-use factors for NO2 and NO predictions. Then, a geographically weighted regression (GWR) model was developed to delineate the spatial non-stationarity in the relationship. The results show that the GWR model improved NO2 and NO prediction accuracy, with increases of 29.3% and 6.9%, respectively. The road ERSD (i.e., shortest distance to express road) factor had a negative effect on NO2. The impervious AWMSI (i.e., area-weighted mean shape index) factor had a larger effect on NO in the northwest of Foshan, due to more uneven and dense distribution of impervious patches. NO had a steeper distribution gradient than NO2, which implies that NO is more localized. The relationships between land-use configuration, NO2 and NO concentrations are not constant in space. This means that the predictive abilities of land-use factors for NO2 and NO are different across Foshan. Overall, our approach can obtain a higher estimation accuracy than the LUR at city scale. It could also be applied easily for other air pollutants and in cities worldwide.

Decreased Landscape Ecological Security of Peri-Urban Cultivated Land Following Rapid Urbanization: An Impediment to Sustainable Agriculture

The sustainable management of peri-urban agriculture requires cultivated land to not only be a source of food production, but also contribute ecological resources. This paper presents a method for assessing the landscape ecological security (LES) of peri-urban cultivated land that considers both cultivated landscape and interactions with the surrounding landscape. The situation in Changchun City was assessed at three time nodes. Furthermore, its spatiotemporal variations in several landscape characteristics were also measured. The results suggest that the peri-urban cultivated landscape was affected to varying extents by urbanization. The metrics of PD (patch density), ED (edge density), AWMSI (area-weighted mean shape index), FRAC (fractal dimension) and DIVISION (landscape division index) progressively increased during urbanization for cultivated land within 20 km of the urban gravity center. Elevated fragmentation and vulnerability of the cultivated landscape was also detected. The traditional method for quantifying LES of cultivated land neglects interactions with other landscape types. When the impacts of the ecological and construction landscapes were included, the results better reflected the dynamics of cultivated landscape in a peri-urban area. Decreased LES of cultivated land poses an impediment to the sustainable peri-urban agriculture, and better management practices should be applied for maintaining the LES of peri-urban cultivated land resources.