Spatio-temporal Evolution and Optimization of Landscape Ecological Risk in Karst Mountainous Areas

[Objective]The ecological vulnerability and landscape ecological risk of karst mountainous areas have increased as a result of enhanced disturbance of natural resources by human activities.This paper aimed to explore the characteristics of ecological risk evolution under different landscape patterns in the region,with a view to providing reference for land classification protection,sustainable use of resources and regional ecological risk optimization in karst mountainous areas.[Method]Taking Huangping County,a typical karst mountainous area,as an example,eight evaluation factors of natural and landscape patterns were selected to construct a landscape ecological risk evaluation model,to quantitatively explore the spatio-temporal evolution of landscape ecological risk and the trend of risk level transfer in the study area from^(2)010-2018,and to reveal the complex relationship between ecological risk and topography in karst mountainous areas.[Result]①From 2010 to 2018,land use types changed to different degrees,with the most amount of woodland transferred out(1627.37 hm^(2))and the most amount of construction land transferred in(1303.93 hm^(2));a total of 3552.31 hm^(2) of land was transferred,with a change ratio of 2.13%,and there was a significant conversion between construction land,arable land,and woodland.②From 2010 to 2018,the landscape ecological risk in the study area changed significantly,and the landscape ecological risk index decreased from 0.3441 to 0.1733,showing an upward and then downward trend;the landscape ecological risk of the whole region was dominated by low-risk and lower-risk zones,and the ecological risk level generally shifted from a high level to a low level,and the ecological environment was improved.③There was a negative correlation between ecological risk and topographic position,and high-risk zones were mainly distributed among low topographic zones;with the change of time,the advantage of risk level for the selection of topography was gradually weakened,and the influence of anthropogenic factors on the ecological risk of the landscape was becoming more and more prominent.[Conclusion]This paper can provide theoretical basis for land use optimization and ecological protection in karst mountainous areas.

Changes of landscape pattern and its influence on environment in Dongling District，Shenyang City，China

Dongling District of Shenyang City is an ecotone between city and countryside. Human disturbance causes serious changes of the landscape pattern studed by using indices of landscape pattern: proportion in land cover types,average area and number of patches,fractal dimension of patches,indices of diversity, dominance and contagion and index of human disturbance.There are many changes of the landscape pattern of Dongling District for the last 30 years.The landscape pattern is breaking, the diversity is increasing and the dominance is decreasing.There are different fractal dimension and contagion in distinct geomorphological unit.The changes of landscape pattern bring some beneficial results but causes deterioration of ecological environment.

Landscape pattern and its effect on ecosystem functions in Seoul Metropolitan area:Urban ecology on distribution of the naturalized plant species

During land transformation process in the human history, naturalized plants were introduced to several land use patterns by the different ways of plant itself. Including some naturalized plants that had been contribute to land restoration, many naturalized plants have been invaded to original habitat or landscape for native plants. Once the plants were colonized, they extend their area and population size. Urban developed areas often give an important role of source habitat for naturalized plants and expanding their population size. In recent, this situation is appearing as one of environmental problems about the urban landscape management controlling the naturalized plants that invaded in the developed area and conserving the native vegetation. This paper is focusing on relationships between distribution of habitat of naturalized plants and landscape patch in urban area in Seoul. Gangdong-Gu, one of the administrative areas in Seoul was selected for this study. We examined the recent land use change using LANDSAT TM data and spreading of the representative naturalized plants (Robinia pseudoacacia and Eupatorium rugosum) by Seoul Biotope Mapping Project and field survey in 1999. As a result, these two species were often occurred in the same habitat and distributed in forest edge disturbed by man. Their distribution patterns were related to landscape indices (patch size and shape) in the forest edge.

The role of landscape pattern analysis in understanding concepts of land cover change

Landscape ecology and landscape pattern analysis are important components of national-scale programs to identify trends in land cover change because: 1) Statistics on changes in land cover proportions are not spatial. A change matrix derived from GIS provides useful information, but it does not show the spatial form of change in the landscape. Landscape pattern metrics reveal spatial pattern. 2) A growing body of literature has shown that a change in landscape pattern might indicate important changes in ecological functions: forest connectivity and species movements, number and size of farm patches, effects on water quality. Spatial pattern is important in structuring ecological communities and in maintaining existence of competitors. Spatial pattern may be determined by disturbance and may in turn, determine how disturbances propagate through the system. 3) Sometimes landscape pattern may not significantly change, even though land cover proportions do change. Or, vice-versa, sometimes landscape pattern can significantly change, even though land cover proportions don't significantly change. 4) Landscape pattern is an inherent and important part of describing landscapes: based on the literature, one of the most important descriptive characteristics of a landscape is its texture. The objectives of this paper are to: 1) Explain the importance of the role of landscape ecology and landscape pattern analysis in land cover change studies; 2) Review the literature that specifically incorporates landscape ecology into land cover change studies; and 3) List the theoretical and technical issues involved and suggest solutions for them.

Landscape pattern dynamics of water body in Kaifeng city in the 20th century

Landscape spatial pattern mainly refers to the distribution of patches, which are different in size and shape in space owing to the interaction of various ecological activities. In landscape ecology study, landscape pattern has been one of the key study areas. Water body landscape plays an important role in the development history of a city, but at present city water body landscape in many cities has been destroyed, hence protecting water body in the city is becoming more and more important. In order to protect city water body landscape reasonably, the precondition is to probe the dynamics of water body landscape. Based on historical data and remote sensing data, six indexes including patch number, patch area, landscape dominance index, fractal dimension, patch density and connectivity index etc. were used to analyze landscape pattern dynamics of water body in Kaifeng city since the end of the Qing Dynasty (in the 20th century). The results showed: (1) Since the end of the Qing Dynasty, landscape area of water body in Kaifeng city increased first and then decreased from 1898 to 2002AD; the landscape dominant degree had the same changing tendency with the area. (2) Patch number of water body landscape in Kaifeng city had an increase from 1898 to 2002, but maximum area of patch, minimum area of patch and average area of patch decreased, which resulted in an increase in landscape fragment degree. (3) Connectivity index decreased and fractal dimension increased from 1898 to 2002. The reasons for these changes were the repeated overflows and flooding of the Yellow River and the influence of human activities.

Regional agricultural landscape pattern changes along the Yellow River in Henan Province from 1987 to 2002

Agricultural landscape along the riparian zones is designated as important landscape components for partly controlling water quality, biodiversity, as well as for their aesthetic role in landscapes. Therefore, the change of agricultural landscape along the riparian zones is at the top of the agenda for many policy makers and landscape planners. As a basis for conservation management, sufficient information about landscape structure should be provided. In the present study, we reconstructed the former landscape structure and elucidated the changes in landscape patterns during a period of about 15 years. Two sets of maps were used： a landsat-5 TM image （1987） and landsat-7 ETM image （2002）. The frequency index, landscape diversity index and landscape fragmentation index were calculated for analyses. The results showed that： （1） the areas of the irrigated land, river, forest and beach landscape classes presented a decreasing trend while the areas of landscape classes of pool, paddy fields, dry land and construction land increased. （2） Disturbed by human activity, landscape diversity index increased but landscape fragmentation index decreased. In short, Human activities have had important influences on agricultural landscape of the riparian zones along the Yellow River in Henan Province.

Land Use of the Three Gorges Reservoir Area and the Effect on Its Landscape Pattern in the Recent 50 Years

The paper makes detailed analysis on the changing processes of the main types of land use in Three Gorges Reservoir Area through the techniques of RS （Remote Sense） and GIS （Geography Information System）. Based on the theory of landscape ecology, many types of landscape pattern indexes are calculated and made correlation analysis. The results indicate that： in 1995 the ecological environment of Three Gorges Reservoir Area was the most vulnerable in the recent 50 years, but resumed in 2002; the landscape pattern diversity index, fractal dimension index and fragmentation index has close correlation with the area of land use/cover change （LUCC）. The research also releases that the increase of the cultivated land, grassland and construction land deteriorates the landscape ecological pattern, while the increase of forest land area will help restore the landscape ecological pattern to its original state. The rapid change of grassland is an important index of the change of landscape pattern, because it has the most effect on change of landscape pattern index.

Do Forest Landscape Pattern Planning and Optimization Play a Role in Enhancing Soil Conservation Services in Mountain Areas of Western China?

The relationship between landscape patterns and soil conservation,as well as the need for nature-based soil erosion control and landscape pattern optimization,have increasingly gained attention in the scientific and political community in the past decade.With the implementation of a series of afforestation/reforestation projects in the western China,the optimization and management of forest landscape patterns will become more important for soil conservation.In this study,the Bailongjiang Watershed(BLJW),in the western China,was used as a case study to explore the relationship between the forest landscape pattern and soil conservation services using mathematical and spatial statistics methods.A spatially-explicit model called the sediment delivery ratio(SDR)model of the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)was used to assess the soil conservation service in each sub-basin of BLJW in 1990,2002,and 2014,and landscape indices were used to describe changes in forest landscape patterns in each sub-basin.Nine forest landscape indices,including the percentage of landscape(PLAND),largest patch index(LPI),edge density(ED),landscape shape index(LSI),mean patch shape(SHAPEMN),patch cohesion index(COHESION),landscape division index(DIVISION),splitting index(SPLIT)and aggregation index(AI),were significantly correlated to the soil conservation service.PLAND,AI,LSI and SPLIT of forestland were determined to be the more important landscape indicators.The results also indicated that soil conservation was substantially scale-dependent.The results demonstrated that landscape type diversity greatly affected watershed soil conservation and can be used for forest landscape restoration and management.Furthermore,spatial statistics analysis indicated that the Spatial Lag Model(SLM)was superior to the Ordinary Least Squares(OLS)for soil conservation regressions in 1990 and 2014,while OLS was more appropriate for the regression in 2002.These findings will be useful for enhancing soil conservation and for optimizing mountainous forest landscape patterns for afforestation/reforestation and regional development.Future planning and implementation of ecological restoration should focus more on strategic spatial planning and integrated landscape management with full consideration of future climate,water availability/consumption,hydrological regime,topography,and watershed features,especially on afforestation and revegetation projects in western mountainous China,where the socio-ecological system is fragile and poor.

Forest landscape patterns dynamics of Yihe-Luohe river basin

Based on the information from forest resources distribution maps of Luoning County of 1983 and 1999, six indices were used to analyze spatial patterns and dynamics of forest landscapes of the typical region in the middle of the Yihe-Luohe river basin. These indices include patch number, mean patch area, fragment index, patch extension index, etc. The results showed that: (1) There was a rapid increase in the number of patch and total area from 1983 to 1999 in the study area. The fragment degree became very high. (2) The area of all the forest patch types had witnessed great changes. The fractal degree of each forest patch type became big from 1983 to 1999. The mean extension index of Robinia pseudoacacia forest, non-forest, shrub forest, sparse forest, and Quercus species forest increased rapidly, but that of economic forest became zero. The fractal dimension each showed that forest coverage has been promoted. (3) The changes of landscape patterns were different in different geomorphic regions. From 1983 to 1999 the vegetation cover area, the gross number and the density of patch, diversity and evenness of landscape were all reduced greatly in gullies and ravines, but the maximum area and the mean area of patch types were increased. In hilly region, both the forest cover area and the number of patch increased from 1983 to 1999, but the mean area of patch was reduced greatly. In mountain region, even though the area under forest canopy reduced from 1983 to 1999, the patch number was increased greatly, the mean area of all patch types was reduced, the extension index, diversity index and evenness index of landscape were all increased. Furthermore, because of different types of land use, human activity and terrain, the vegetation changes on northern and southern mountain slopes were different. According to these analyses, the main driving forces, such as the policies of management, market economy, influence of human activities etc. are brought out.

Trend surface analysis of forest landscape pattern in Guandishan forest region of Shanxi,China

１ＩｎｔｒｏｄｕｃｔｉｏｎＡｌｍｏｓｔａｌｏｆｌａｎｄｓｃａｐｅｓａｒｅｓｐａｔｉａｌｙｈｅｔｅｒｏｇｅｎｅｏｕｓｍｏｓａｉｃｓｏｆｌａｎｄｃｏｖｅｒｏｒｈａｂｉｔａｔ（Ｆｏｒｍａｎ，１９９５）．Ｔｈｅｓｐａｔｉａｌａｒａｎｇｅｍｅｎｔｏｒｓｐａｔ...

Impacts of land use change on landscape patterns in mountain human settlement:The case study of Hantai District(Shaanxi,China)

Mountain area is an important geographical unit of land,and its ecology is sensitive and fragile.Over the past few decades,human activities have caused dramatic changes in land use in mountainous areas,which caused changes in landscape patterns and impacts on the ecological environment.It is unknown how the mechanism of land use affects the landscape pattern at different scales.The Hantai District,a typical human settlement in the mountain area in Shaanxi,China,was chosen as the study area.Based on the remote sensing images,the mathematical models and landscape indexes were adopted to evaluate the impact of land use change from 1998 to 2017 on the landscape pattern at different scales,and its main driving forces were analyzed.The results showed that the urbanized land expanded largest from 15.39%to 24.30%,and cultivated land experienced the largest decline from 43.54%to 35.35%.Changes in land use have made the patch morphology of most land types developed from a natural random to a sawtooth shape,and its spatial pattern evolved from a ruleset to a fragmented expansion.This reflects the continuous strengthening of human intervention in the process of regional development.Under the jurisdiction of Hantai District,the biggest change in landscape pattern is in Hanzhong City and Qili Town.The improved economy and increasing population and urbanization rate were the main factors that cause these changes.This research could provide necessary information for understanding the evolution mechanism of land resources in mountainous human settlements for mountainous areas with significant geomorphic differentiation.

Study on Landscape Pattern in the Jinshajiang Xerothermic Valley Using RS and GIS-Taking Yuanmou of Yunnan as an Example

Based on the data of Landsat-TM in 1986 and 2000 and with the applied indices of landscape pattern, an analysis is carried out on the landscape pattern with its evolution in Yuanmou County of Yunnan Province inside the Jinshajiang Xerothermic valley area and a forecast is given on the changing tendency of the landscape pattern in the county with Markov Chain Model. The result shows that the production landscape like irrigated farmland and construction land in town and country as well as ecological building landscape in boondocks were enlarged during 1986-2000. Also the patch shape was regularized and the patch shape index and dimensionality were degraded. The landscape pattern was tattered and the heterogeneity index and Evenness degree were increased but the dominance degree was degraded. The key elements with lower stability cover grassland. water body and bush land. The future transformation of landscape pattern will centralize in construction land's occupation in irrigated farmland, non-irrigated farmland and grassland, the transformation of non-irrigated farmland to irrigated farmland,forest and sparse wodland or orchard,construction land's occupation in grassland and cultivation of it into sloping non-irrigated farmland and forest's degeneracy to bush land, sparse woodland and grassland. The main measures to improve virtuous development of landscape in the xerothermic valley are suggested.

Landscape Pattern Analysis of International Livable Communities Based on Satellite Images of Wenjiang District, Chengdu City

This paper used Google Earth satellite maps of Wenjiang District, Chengdu City in 2008, 2012 and 2015 as basic data sources, and field investigation data in recent years, and employed Photoshop and Auto CAD to analyze landscape pattern of urban and suburban areas of Wenjiang District—the international livable communities. The results showed that urban forest patches accounted for the absolute dominance in the study area, the overall landscape fragmentation index in 2008 was 0.0054, landscape diversity index 1.3603, landscape dominance index 0.2937, and evenness index 0.8452. From 2008 to 2012, patch density index reduced by 7.04, landscape fragmentation index increased by 0.0014, diversity index reduced by 0.043, evenness index reduced by 0.0269, landscape dominance index increased by 0.0027. From 2012 to 2015, patch density index increased by 1.22, landscape fragmentation index kept stable, diversity index reduced by 0.024, evenness index reduced by 0.0149, landscape dominance index increased by 0.0196. Through analyzing quantitative indexes of urban landscape pattern, and exploring basic features of the international livable communities from the perspective of landscape eco-pattern, this paper put forward suggestions for city management and green space system protection of Wenjiang as the references for the future researches on maintenance and operation of landscape eco-pattern.

Characterization of landscape pattern based on land economic niche change: A case study in Ganzhou,Gansu Province, China

Land use change has a profound impact on biodiversity and ecological processes, and is closely related to changes in landscape patterns. This paper introduces the theory and method of land economic niche into landscape ecology, which provides a new method for spatial characterization of urban and rural spatial landscape patterns. Based on this theory, this paper analyzes the landscape pattern of Ganzhou District by using Landsat images as data source in 1995, 2000, 2005, 2010 and 2015. We calculated the land economic niche by applying the niche potential theory. Combined with the theory of landscape ecology, we explored the effects of the land economic niche change on the landscape pattern at a county scale. The results show that economic niche of construction land, watershed and farmland increased during 1995-2015, and grassland declined significantly. The economic niche of farmland, construction land, watershed and grassland show a negative correlation with the number of patches （NP）, fragmentation index （FN） and the fractal dimension index （FD）, and had a positive correlation with the aggregation index （AI）. There was no significant correlation between the forest land economic niche and landscape metrics. The change of land economic niche has a driving effect on the landscape pattern of the county, which can represent the economic development direction of Ganzhou District. The land economic niche is closely related to the landscape type which can directly obtain an economic benefit.

Simulation of Landscape Pattern of Old Growth Forests of Korean Pine By Block Kriging

The study area was located in Liangshui Natural Reserve. Xaoxing'an Mountains. Northeastern China. Korean pine forests are the typical forest ecosystems and landscapcs in this region. It is a high degrees of spatial and temporal hetcrogeneity at different scales, which effected on landscape pattern and processes. In this paper we used the data of 144 plots and semivariogram to analyze spatial heterogeneity of old growth forests of Korean pine in landscape level. Model for forest variations by isotropic semivariogram is linear with sill. The spatial heterogeneity is dependent on scales and dircctions in Korean pine forests. Patterns of forest types in space were resulted from complex interactions between physical and biological forces. We uscd 20 metres for interpolation interval to cstimate the values of unsampled area. Comparing the results with field data, block kriging and mapping are an cffective techniques to simulate landscape pattern.

Landscape Pattern Optimization of Chengdu Based on Modern Garden City

TOptimization of regional landscape pattern is significant for improving function and value of ecosystem,and restraining the expansion of urban layout.Taking Chengdu City for example,this paper applied RS and GIS techniques,landscape indexes and ecological service function evaluation to further analyze the temporal and spatial characteristics of landscape pattern and spatial differences of regional ecological functions,and on this basis,identified the spatial distribution of ecological source lands.Based on the long-term objective of building Chengdu into a modem garden city,this paper applied the accumulative cost distance model and introduced garden city theory to construct regional ecological corridors and ecological nodes,and explored the approaches of optimizing landscape pattern of modem garden city.The results showed that a great deal of arable land has been transferred to construction land in the urbanization;intensity of regional ecological functions showed obvious spatial differences;ecological source lands were mainly distributed in the Longmen Mountain,the Qionglai Mountain,the Changqiu Mountain and the Longquan Mountain;according to actual conditions of the study area,the road ecological corridors,river corridors and agricultural corridors in the layout of "four rings and six radial corridors" were constructed;ecological nodes dominated by intersection,wetland and forest park were formed.This research method and results are significant references for building Chengdu into a modem garden

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.

Landscape Pattern of Ancient Terraces in Huangping County and Slopeto-Terrace Strategy

Formation and development of ancient terraces proves that slope-to-terrace project is a signifi cant measure for conserving water and soil in mountainous areas. UAV remote sensing technology was applied to obtain RS images with a resolution ratio of 0.1–0.5 m, Arc GIS was applied for data processing, and Fragstats3.3 was used to calculate characteristic indexes, to study landscape pattern of 4 ancient terraces in Huangping County, Guizhou Province. The results showed that terrace landscapes and woodland landscapes in the study area account for nearly 80% of the whole landscape(terrace 30%, woodland 50%); mean area of single fi eld is mainly concentrated between 100 m^2 and 200 m^2, and height between 0.7 m and 1.7 m, breadth 0.5 m and 0.6 m; most terraces have a gradient of 5–25°, accounting for 70% of the total number of fi eld. The water and soil conservation concept in the ancient terraces provides references for the slope-to-terrace project and the water and soil loss control of slope farmland.

Relationship Between Watershed Landscape Pattern Change and Runoff-Sediment in Wind-Water Erosion Crisscross Region

This paper selected the typical wind-water erosion crisscross region Xiliugou watershed for research to reveal the impact of the landscape pattern change of the underlying surface in wind-water erosion crisscross region where soil erosion is most serious on rainfall and runoff as well as erosion and sediment.Based on the Landsat TM image data and measured data of runoff-sediment in that watershed,the paper analyzed the characteristics of watershed landscape pattern change and runoff-sediment and explored the relationship between landscape index and runoff-sediment yield by means of GIS and Fragstats.The results were included as follows.(1)Grassland was the dominant landscape.In terms of the number of patches and area change rate,from 1985 to 2010,cultivated land,forest land and construction land were most stable,followed by unused land.Unused land,grassland and cultivated land experienced the most dramatic conversion and maximally affected by human activities.(2)The inter-annual difference between annual runoff and annual sediment load was significant.Compared with the annual sediment load,the trend of decreasing runoff was more obvious.The correlation coefficient of runoff-sediment was 0.67,representing a significant correlation.(3)There was a significant correlation between the landscape index and runoff-sediment.The runoff was negatively correlated with the largest patch index,patch cohesion index,aggregation index and contagion index,but positively correlated with landscape morphology index and landscape division index.And the sediment was negatively correlated with the contagion index,aggregation index and plaque cohesion index,but positively correlated with other landscape indexes.The results indicate that with the increase of the largest patch index,patch cohesion index and aggregation index,the rainfall infiltration capacity increase obviously and the soil erosion reduce significantly.Therefore,increasing the largest patch index,patch cohesion and aggregation index of the watershed landscape can enhance the function of water storage and soil conservation as well as ecological optimization in the windwater erosion crisscross region.The results can provide theoretical support for the ecological environment construction and comprehensive utilization of water and soil resources.

Study on Landscape Pattern Based on Landsat-8 in the Center of Chengdu City, China

Study on landscape spatial pattern in the center of Chengdu City is based on the Landsat-8 image by using 3S technique and spatial pattern analysis software Fragstats 3.3. The results showed that there covered an area of 193.92 km2 in the center of Chengdu City. 55.24% of the total area was made up of buildings, covering an area of 107.12 km2, and the overall landscape of impervious ground-based. There were 22,666 patches;29.67% of the patches were roads. The human interference of buildings, roads and green space was a maximum;fragmentation of the highest was green space. The fragmentation of overall urban landscape was high;the diversity was low;the value of Shannon’s diversity index was 0.63;the value of Shannon’s evenness index was 0.70. All kinds of landscape distribution were not balanced, and lack of connectivity. This research puts important reference for creating good urban landscape space and restoring the natural ecological environment in the western regions of China.