A case study on Landscape Component Niche based on Landscape Pattern Indices: Yanchi,Ningxia Province,China

Yanchi County is located in the agro-pastoral ecotone and belongs to the ecologically fragile area of Northwest China.It is important to study the evolution of landscape pattern to curb its environmental degradation.In order to intuitively show how the landscape pattern of the study area changes over time,Landsat Thematic Mappers(TM)and Landsat Operational Land Imager(OLI)data of 1991,2000,2010 and 2017 were used.This paper attempts to apply niche theories and methods into landscape ecology,and constructs a niche model of landscape components by using"n-dimentional hypervolume niche theory"and landscape pattern indices.By evaluating the spatial and temporal evolution of niche from the perspective of two-dimensional space to reflect the changes of landscape pattern in the study area over the past 26 years,new theories and methods were introduced for the characterization of landscape pattern.The results indicate that:1)The larger the attribute and dominance value of landscape components,the higher the ecological niche and the stronger the control effect on the overall landscape.2)The ecological niche of each landscape component was significantly different,just as its control effect on the overall landscape.3)The dynamic change of the ecological niche of each landscape component was different,with grassland,unused land and arable land always in a high dominant position,although the ecological niche of construction land and water area was always low.In general,the introduction of niche theory into the landscape ecology provided a new method to study the changes in regional landscape pattern.     

Land cover changes in the rural-urban interaction of Xi＇an region using Landsat TM/ETM data

Landsat ETM/TM data and an artificial neural network （ANN） were applied to analyse the expansion of the city of Xi＇an and land use/cover change of its surrounding area between 2000 and 2003. Supervised classification and normalized difference barren index （NDBI） were used respectively to retrieve its urban boundary. Results showed that the urban area increased by an annual rate of 12.3%, with area expansion from 253.37 km^2 in 2000 to 358.60 km^2 in 2003. Large areas of farmland in the north and southwest were converted into urban construction land. The land use/cover changes of Xi＇an were mainly caused by fast development of urban economy, population immigration from countryside, great development of infrastructure such as transportation, and huge demands for urban market. In addition, affected by the government policy of “returning farmland to woodland”, some farmland was converted into economic woodland, such as Chinese goosebeerv garden, vineyard etc.     

西安市土地利用与环境关系的协调研究

In this paper we adopt annual land use conditions change data, land sifting data, social, economic and population data and environment information of nine districts and four counties in Xi＇an city from 1980 to 2000 to analyze its structural and degree change of land use since the 1980s, and calculate the benefits and transformation of land use type. The results show that the non-agricultural land increased rapidly, especially the urban and rural residential spots and industrial and mining （RIM） land use increased mostly rapidly, an increase of 64%. Meanwhile, the intensity of land exploitation was accelerating, land was transformed to industries with better benefit and areas experiencing faster urbanization process. By analyzing the harmonious degree of land exploitation in economic and environmental aspects, we find out that the land use imbalance mainly existed in the municipal area of Xi＇an, and the imbalance index of land use based on GDP and non-agricultural population were respectively 12.37 and 14.67 in 2000, which were far higher than those in other regions. Nevertheless the environmental harmonious degree in the municipal area of Xi＇an ranges between 0.6 and 0.8, which was better than that of suburban area. Some proposals addressing to the problems of harmonious level in all scales, resources utilization, projects management and feasibility analysis and intensive urbanization are also put forward.     

熵视角下的广州城市生态系统可持续发展能力分析(英文)

The urban ecosystem possesses dissipating structures that can absorb substances and energy from the external environment and export products and wastes to maintain order within the system. Given these circumstances, this paper analyzed the ability of the urban ecosystem in Guangzhou City to sustain development from the perspective of entropy. The research was carried out in three steps. First, an evaluation index system that considers the ability of the urban ecosystem for sustainable development was formed based on the structures and functions of the urban ecosystem and the change in the entropy of the urban socioeconomic ecosystem. Second, the sustainable development ability assessment model for the urban ecosystem was built using information entropy. Last, by combining the time series variation of the evaluation indicators with the entropy weights, this paper analyzed the influence of the combined factors on the sustainable development ability of the urban ecosystem in Guangzhou and suggested some measures to promote the sustainable development of the urban ecosystem in Guangzhou. The conclusions of this study can be summarized as follows: (1) The urban ecosystem has developed in an orderly and healthy direction, with effective control over the urban environmental pollution problems in Guangzhou between 2004 and 2010. (2) The sustainable development ability of the urban ecosystem had been on an upward trend in Guangzhou during the study period. The ability of the natural urban ecosystem to support the urban socioeconomic ecosystem increased continuously, and the improved ecoenvironment enhanced the harmony and vitality of the urban ecosystem in Guangzhou.     

Effect of human settlements on urban thermal environment and factor analysis based on multi-source data: A case study of Changsha city

In view of the lack of comprehensive evaluation and analysis from the combination of natural and human multi-dimensional factors, the urban surface temperature patterns of Changsha in 2000, 2009 and 2016 are retrieved based on multi-source spatial data(Landsat 5 and Landsat 8 satellite image data, POI spatial big data, digital elevation model, etc.), and 12 natural and human factors closely related to urban thermal environment are quickly obtained. The standard deviation ellipse and spatial principal component analysis(PCA) methods are used to analyze the effect of urban human residential thermal environment and its influencing factors. The results showed that the heat island area increased by 547 km~2 and the maximum surface temperature difference reached 10.1℃ during the period 2000–2016. The spatial distribution of urban heat island was mainly concentrated in urban built-up areas, such as industrial and commercial agglomerations and densely populated urban centers. The spatial distribution pattern of heat island is gradually decreasing from the urban center to the suburbs. There were multiple high-temperature centers, such as Wuyi square business circle, Xingsha economic and technological development zone in Changsha County, Wangcheng industrial zone, Yuelu industrial agglomeration, and Tianxin industrial zone. From 2000 to 2016, the main axis of spatial development of heat island remained in the northeast-southwest direction. The center of gravity of heat island shifted 2.7 km to the southwest with the deflection angle of 54.9° in 2000–2009. The center of gravity of heat island shifted to the northeast by 4.8 km with the deflection angle of 60.9° in 2009–2016. On the whole, the change of spatial pattern of thermal environment in Changsha was related to the change of urban construction intensity. Through the PCA method, it was concluded that landscape pattern, urban construction intensity and topographic landforms were the main factors affecting the spatial pattern of urban thermal environment of Changsha. The promotion effect of human factors on the formation of heat island effect was obviously greater than that of natural factors.The temperature would rise by 0.293℃ under the synthetic effect of human and natural factors. Due to the complexity of factors influencing the urban thermal environment of human settlements, the utilization of multi-source data could help to reveal the spatial pattern and evolution law of urban thermal environment, deepen the understanding of the causes of urban heat island effect, and clarify the correlation between human and natural factors, so as to provide scientific supports for the improvement of the quality of urban human settlements.     

城市暴雨内涝情景模拟与灾害风险评估

Scenario modelling and the risk assessment of natural disasters is one of the hot-spots in disaster research.However,up until now,urban natural disaster risk assessments lack common procedures and programmes.This paper selects rainstorm waterlogging as a disaster to research,which is one of the most frequently occurring hazards for most cities in China.As an example,we used a small-scale integrated methodology to assess risks relating to rainstorm waterlogging hazards in the Jing’an District of Shanghai.Based on the basic concept of disaster risk,this paper applies scenario modelling to express the risk of small-scale urban rainstorm waterlogging disasters in different return periods.Through this analysis of vulnerability and exposure,we simulate different disaster scenarios and propose a comprehensive analysis method and procedure for small-scale urban storm waterlogging disaster risk assessments.A grid-based Geographical Information System (GIS) approach,including an urban terrain model,an urban rainfall model and an urban drainage model,was applied to simulate inundation area and depth.Stage-damage curves for residential buildings and contents were then generated by the loss data of waterlogging from field surveys,which were further applied to analyse vulnerability,exposure and loss assessment.Finally,the ex-ceedance probability curve for disaster damage was constructed using the damage of each simulated event and the respective exceedance probabilities.A framework was also devel-oped for coupling the waterlogging risk with the risk planning and management through the exceedance probability curve and annual average waterlogging loss.This is a new explora-tion for small-scale urban natural disaster scenario simulation and risk assessment.     

Determination of 137Cs reference inventories in a large-scale region: A case study in the central-eastern Inner Mongolia Plateau

In isotope 137 Cs tracing studies, it is a premise to determine suitable 137 Cs reference inventory（CRI） plots and the CRI values. Owing to the heterogeneous spatial distribution of 137 Cs deposition in the ground and diverse, or even irregular, operations in sampling and testing procedures, CRI determination is usually faced with many difficulties and uncertainties. In addition, more difficulties occur in an investigation of a large-scale region because of time constraints and measurement cost limitations. In this study, traditional CRI acquiring methods were summarized first, and then a new complex scheme was established, involving seven core steps and coupling the model estimate and sample measurement. The above CRI determination methodology was implemented in the central-eastern Inner Mongolia Plateau. The case study results showed that the CRI in the dark chestnut soil sub-region, located in the east and south of Xing＇an City, exhibited 2447 Bq·m–2; the CRI in the aeolian sandy soil sub-region, positioned in the south central Tongliao City and central Chifeng City, showed 2430 Bq·m–2; the CRI in the sandy chernozem soil sub-region, situated in the northwestern Chifeng City, presented 2384 Bq·m–2; and the CRI in the chestnut soil sub-region, in the southern Xilin Gol City, was 2368 Bq·m–2. The newly proposed CRI determination scheme was proved effective, and the determined CRI plots and CRI values were convincing. The methodology offered a framework for 137 Cs tracing studies in large-scale regions or long-distance transects.     

1984-2008年北京湿地景观格局驱动机制(英文)

The landscape pattern of Beijing wetlands has undergone a significant change as a result of natural and artificial elements.Supported by remote sensing and GIS technology,using multi-temporal TM images from 1984 to 2008 in Beijing,this paper analyzed the dynamic characteristics of wetlands landscape pattern through selected typical indices including patch area,patch average area,fractal dimension index,diversity,dominance,contagion indices and the spatial centroids of each wetlands type were calculated.Finally,the paper explored the evolution mode and driving factors of wetland landscape pattern.The results were obtained as follows:the total wetland area increased during the period 1984-1996,then decline from 1996 to 2004.The wetland area in 1994 accounted for only 47.37% of that in 2004.The proportion of artificial wetland area was larger than that of natural wetland.The proportion of reservoir wetland was 33.50% to 53.73% and had the maximum average area.pond and paddy field wetland type with the least average area accounted for 16.46% to 45.09% of the total wetland area.The driving forces of the natural river wetland were mainly natural elements;its fractal dimension index was greater than the others.The Shannon diversity index of wetland landscape increased from 1.11 in 1992 to 1.34 in 2004,indicating that the difference between proportions of each wetland type decreased and areas of each wetland type were evenly distributed.The contagion index went down from 65.59 to 58.41,indicating that the connectivity degraded.Miyun Reservoir had the largest area and its area change had a great impact on the location of the centroid.Wetland resources degenerated gradually from the joint effects of natural and artificial factors.During the period 2006-2008,the precipitation increased and the drought condition was relieved.The government implemented series of positive policies to save water resources,and the wetland area increased.     

Soil and plant responses to degradation of alpine grassland in source region of the Yellow River

Land degradation has been rapidly taking place in source region of the Yellow River in China. This study was conducted during 2008 in Maduo County to investigate soil and plant changes in relation to land degradation. Several results were derived from this work. First, the soil organic carbon (SOC) and total nitrogen (TN) decreased significantly on the extremely degraded land comparing with the natural grassland. Second, soil bulk density increased as land degradation worsened. Soil bulk density of the extremely degraded land was significantly greater than that of the grassland. Third, pH showed no obvious variation pattern. Finally, aboveground biomass decreased from grassland to the moderately degraded land. But aboveground biomass increased on the extremely degraded land and very extremely degraded land with most aboveground biomass inedible for livestock.     

青藏高原青海湖流域环境与经济协调性评价(英文)

Qinghai Lake Watershed (QLW) is a hot place of a series of ecological restoration and environmental remediation programs nowadays.However,little information is available on change of ecosystem service and economic practice in this area.As ecosystem service and natural capital are closely related with social and economic development,an index of concordance between environment and economy (ICEE) has been proposed to compare the annual variation rate of ecosystem service value (RESV) with that of gross domestic product (RGDP).Using this Index,we have assessed concordance between environment and economy (CEE) for the QLW in the period 1977-2004.The result showed that from 1977 to 2004,the ecosystem service value in the QLW descended from 128.81×10 8 yuan to 127.32×10 8 yuan;In contrast,the GDP increased from 0.931×10 8 yuan to 8.856×10 8 yuan.The values of the I CEE were -1.14,-0.22,and -0.14 in the stages of 1977-1987,1987-2000 and 2000-2004,respectively.The result indicated that during the first stage 1977-1987,the relationship between environment and economy in the QLW was not concordant but at a high conflict;from 1987 to 2004,there was a low conflict between environment and economy,and the CEE appeared to increase slowly.Analysis of the assessment results showed that the national policies and industrial adjustment practice play an important role in the CEE changes.     

1958-2017年长江流域气候变化的时空特征与热点区域

The Yangtze River Watershed in China is a climate change hotspot featuring strong spatial and temporal variability;hence, it poses a certain threat to social development. Identifying the characteristics of and regions vulnerable to climate change is significantly important for formulating adaptive countermeasures. However, with regard to the Yangtze River Watershed, there is currently a lack of research on these aspects from the perspective of natural and anthropogenic factors. To address this issue, in this study, based on the temperature and precipitation records from 717 meteorological stations, the RClim Dex and random forest models were used to assess the spatiotemporal characteristics of climate change and identify mainly the natural and anthropogenic factors influencing climate change hotspots in the Yangtze River Watershed for the period 1958-2017. The results indicated a significant increasing trend in temperature, a trend of wet and dry polarization in the annual precipitation, and that the number of temperature indices with significant variations was 2.8 times greater than that of precipitation indices. Significant differences were also noted in the responses of the climate change characteristics of the sub-basins to anthropogenic and natural factors;the delta plain of the Yangtze River estuary exhibited the most significant climate changes, where 88.89% of the extreme climate indices varied considerably. Furthermore, the characteristics that were similar among the identified hotpots, including human activities(higher Gross Domestic Product and construction land proportions) and natural factors(high altitudes and large proportions of grassland and water bodies), were positively correlated with the rapid climate warming.     

Vulnerability of natural ecosystem in China under regional climate scenarios:An analysis based on eco-geographical regions简

Assessment of vulnerability for natural ecosystem to climate change is a hot topic in climate change and ecology, and will support adapting and mitigating climate change. In this study, LPJ model modified according to features of China＇s natural ecosystems was em- ployed to simulate ecosystem dynamics under A2, B2 and A1B scenarios. Vulnerability of natural ecosystem to climate change was assessed according to the vulnerability assessment model. Based on eco-geographical regions, vulnerability of natural ecosystem to climate change was analyzed. Results suggest that vulnerability for China＇s natural ecosystems would strengthen in the east and weaken in the west, but the pattern of ecosystem vulner- ability would not be altered by climate change, which rises from southeast to northeast gradually. Increase in ecosystem vulnerable degree would mainly concentrate in temperate humid/sub-humid region and warm temperate humid/sub-humid region. Decrease in eco- system vulnerable degree may emerge in northwestern arid region and Qinghai-Tibet Plateau region. In the near-term scale, natural ecosystem in China would be slightly affected by cli- mate change. However, in mid-term and long-term scales, there would be severely adverse effect, particularly in the east with better water and thermal condition.     

Altitude pattern of carbon stocks in desert grasslands of an arid land region

For estimating the altitude-distribution pattern of carbon stocks in desert grasslands and analyzing the possible mechanism for this distribution, a detailed study was performed through a series of field vegetation surveys and soil samplings from 90 vegetation plots and 45 soil profiles at 9 sites of the Hexi Corridor region, Northwestern China. Aboveground, belowground, and litter-fall biomass-carbon stocks ranged from 43 to 109, 23 to 64, and 5 to 20 g/m2, with mean values of 80.82,44.91, and 12.15 g/m2, respectively. Soil-carbon stocks varied between 2.88 and 3.98 kg/m2, with a mean value of 3.43 kg/m2 in the 0–100-cm soil layer. Both biomass-and soil-carbon stocks had an increasing tendency corresponding to the altitudinal gradient. A significantly negative correlation was found between soil-carbon stock and mean annual temperature, with further better correlations between soil-and biomass-carbon stocks, and mean annual precipitation. Furthermore, soil carbon was found to be positively correlated with soil-silt and-clay content, and negatively correlated with soil bulk density and the volume percent of gravel. It can be concluded that variations in soil texture and climate condition were the key factors influencing the altitudinal pattern of carbon stocks in this desert-grassland ecosystem. Thus, by using the linear-regression functions between altitude and carbon stocks, approximately 4.18 Tg carbon were predicted from the 1,260 km2 of desert grasslands in the study area.     

基于InVEST生境质量模型与景观格局指数的山地植物多样性变化研究——以甘肃白龙江流域为例（英文）

Mountains in western China, hosted rich biodiversity and millions of people and inhabitant with vital ecosystem services, had experienced the most serious biodiversity loss with fragile ecological problems. Even though increasing attentions had been paid to this issue, we still lacked efficient methods to assess the change of plant biodiversity at medium/large scale due to the poor data and co-existing multiple habitat types. This study proposed an integrated method combining InVEST-habitat quality model, NPP and landscape pattern indexes to analyze the spatial heterogeneity of plant biodiversity and its spatiotemporal change on raster cell scale. The results indicated that plant biodiversity service was high in Bailongjiang watershed with obvious spatial pattern variations. The land area containing higher plant biodiversity were 3161 km2, which mainly distributed in the National Nature Reserve and forestry area. While the areas with lower plant biodiversity accounted for 37.67% and mainly distributed in the valleys between Zhouqu-Wudu-Wenxian County, the valley of Minjiang in Tanchang County and alpine mountain snow-covered regions. During 1990–2010, plant biodiversity level tended to increase and the higher plant biodiversity area increased from 14.13% to 17.15% due to ecological restoration and afforestation, while plant biodiversity decreased in the area with intensive human activities, such as cultivated land, urban and rural land. The results showed that combining InVEST-habitat quality model, NPP and landscape pattern indexes can effective reveal mountain plant biodiversity change. The study was useful for plant biodiversity conservation policy-making and human activity management for the disaster-impacted mountainous areas in China.     

Relationship analysis between livelihood assets and livelihood strategies: A Heihe River Basin example

The security and quality of the livelihood of farmers is of paramount concern in rural areas of China. Livelihood stability would force the related polity to act coordinately while eradicating poverty and promoting resource sustainability. For this study, the livelihood approach was used as a framework of analysis that is based upon Sustainable Livelihoods Framework, the core of which is livelihood assets. Livelihood capitals provide substantial contributions to the well-being of numerous rural dwellers. However, the level and degree of reliance on livelihood capital differ across households. Factors that contribute to the economic reliance of households on a particular economic activity in general and on livelihood capital in particular may vary depending upon the type of resource endowment, household demographic, and economic characteristic as well as exogenous factors such as markets, prices, policies, and technologies. This study identifies factors that influence a household’s livelihood strategy choice with a particular focus on livelihood assets. The study applies a preliminary investigation concerning the relationship between livelihood assets and livelihood strategies, that is, the allocation of assets. Environmentally augmented household livelihood assets were collected from 300 sample households within the Heihe River Basin. Results show that physical assets possess a maximum value (0.609) for farmers and human assets possess a relatively high value (0.516) followed by social assets (0.354). Besides, financial and natural assets possess relatively low values (0.286 and 0.241, respectively). An increment of one unit should reduce the occurrence of choosing non-agricultural activities for natural capital while an increment of one unit should increase the occurrence of choosing non-agricultural activities for financial capital, while other variables remain constant. Governments, therefore, should enhance funding and technological support to achieve livelihood diversity and strengthen the facility of farmers by way of establishing relevant polity. It would enable farmers and provide themselves with the ability and asset reserves to transition from agricultural production to secondary and tertiary industries in order to improve the livelihood of farmers overall.