Land use and land cover change on slope in Qiandongnan prefecture of Southwest China

This study uses DEM(Digital Elevation Model) data and remote sensing maps of the study area in 1993, 1999, and 2009 to analyze the slope gradient change of land use patterns in Qiandongnan Prefecture, Guizhou province, China. The land use data were classified into five types, forest, farmland, grassland, water and built-up, the slope gradients were divided into four grades. Indices for analyzing land use features were defined by their proportions, transformation matrixes, land use degree and changes.The results showed that all land use types can be found at every gradient. Generally, with the slope degree increased, the area of forest being augmented as well, while the area of the other land use types(farmland, grassland and build-up) declined. Moreover, a mass of farmland were shifted from other land use types from 0° to 25°, while a quantity of forest were transformed from the other land use types on 25° from 1993 to 2009. In terms of land use degree and changes, the area of farmland and buildup land use types decreased when slope degree increased. Finally, we calculated the five landscape pattern metrics: Patch Density(PD) value, Largest Patch Index(LPI), Shannon's Diversity Index(SHDI), Area-Weighted Mean Shape Index(AWMSI) and Contagion Index(CONTAG). The results of metricsanalysis showed that PD values, SHDI values and CONTA values had a similar variation trend, that is, they decreased when slope degree increased. There was no obvious variation trend on LPI value.     

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.     

Characteristics of rock fragments in different forest stony soil and its relationship with macropore characteristics in mountain area,northern China

Rock fragments have major effect on soil macropores and water movement. However, the characteristics of rock fragments and their relationship with macropore characteristics remain elusive in forest stony soils in northern mountainous area of China. The objectives of this study are to (1) use Industrial Computed Tomography (CT) scanning to quantitatively analyze rock fragment characteristics in intact soil columns in different forest lands and (2) identify the relationship between characteristics of rock fragments and that of the macropores. Intact soil columns that were 100 mm in diameter and 300 mm long were randomly taken from six local forest stony soils in Wuzuolou Forest Station in Miyun, Beijing. Industrial CT was used to scan all soil column samples, and then the scanned images were utilized to obtain the three-dimensional (3D) images of rock fragments and macropore structures. Next, the parameters of the rock fragments and macropore structure were measured, including the volume, diameter, surface area, and number of rock fragments, as well as the volume, diameter, surface area, length, angle, tortuosity and number of macropores. The results showed that no significant difference was found in soil rock fragments content in the 10-30 cm layer between mixed forest and pure forest, but in the 0-10 cm soil layer, the rock fragments in mixed forest were significantly less than in pure forest. The number density of macropores has significant negative correlation with the number of rock fragments in the 0-10 cm soil layer, whereas this correlation is not significant in 10-20 cm and 20-30 cm soil layers. The volume density of macropore was not correlated with the volume density of rock fragments, and there is no correlation between the density of macropore surface area and the density of rock fragment surface area. Industrial CT scanning combined with image processing technology can provide a better way to explore 3D distribution of rock fragments in soil. The content of rock fragments in soil is mainly determined by parent rocks. The surface soil (0-10 cm) of forest contains fewer rock fragments and more macropores, which may be caused by bioturbation, root systems, gravitational settling and faunal undermining.     

Land use/cover changes and environmental consequences in Songnen Plain, Northeast China

The Songnen Plain in Northeast China, one of the key national bases of agricultural production, went through remarkable land use/cover changes in recent years. This study aimed to explore the long-term land use/cover changes and the effects of these changes on the environment. The Landsat-based analysis showed that, during 1986–2000, cropland, built-up land and barren land had increased, among which cropland had the largest increase of 9,198km² with an increase rate of 7.5%. Woodland, grassland, water body and swampland had decreased correspondingly, among which grassland had the most dramatic decrease of 6,127km² with a decrease rate of 25.6%. The transition matrix results revealed that grassland, woodland and swampland were the three main land use types converted to cropland. Climate warming created the potential environment for the conversion of grassland and swampland into cropland. Land resources policy made by central and provincial governments of China affected the pattern and intensity of land use. Land use/cover changes accompanied by climatic variation brought out a series of environmental consequences, such as sand desertification of land, land salinization and alkalinization, grassland degradation, and more frequent floods. Under this circumstance, optimized land use structure and restoration measures are needed.     

Changing mountain farmscapes: vulnerability and migration drivers in the Paute River watershed,Southern Ecuador

Abrupt changes in land use/land cover have often characterized Andean rural landscapes. This is particularly notorious in the Paute River watershed in southern Ecuador. We seek to show how, under tenets of the global economy, rural mountain landscapes suffer constant modifications due to the agricultural practices of dwellers and migrants. Erosion of arable slopes takes center stage in analyzing vulnerability due to the high erodibility factor found in this watershed. By using remote sensing and GIS applications, we analyzed the potential erodibility with intersections of rural development constraining of ecosystem services, including the production of water, food, and cultural values in the Paute River watershed. We found six sources of migratory flows and analyzed topographic and elevation effects in potential erodibility indexes of agroecological options to ameliorate the environmental stress. We identified factors associated with migration trends observed in the area and assessed vulnerability issues of resource management that could prevent deforestation, soil erosion, and acculturation amidst the pressures of development in the region. We conclude that sustainable development options can be implemented with a watershed management approach oriented to diminish emigration. This approach shall be integrative, inclusive, and respectful of the rich biocultural diversity heritage conservation of southern Ecuador.     

Land cover change and carbon stores in a tropical montane cloud forest in the Sierra Madre Oriental,Mexico

Tropical montane cloud forest is one of the ecosystems with the highest biomass worldwide, representing an important carbon store. Globally its deforestation index is –1.1%, but in Mexico it is higher than –3%. Carbon estimates are scarce globally, particularly in Mexico. The objective of this study was to simulate future land-cover scenarios for the Sierra Madre Oriental in Mexico, by analyzing past forest cover changes. Another objective was to estimate stored carbon in the two study areas. These objectives involve the generation of information that could be useful inputs to anti-deforestation public policy such as the REDD+ strategy. Remote sensing was used to measure land cover change and estimate carbon stocks. Satellite images from 2015, 2000 and 1986 were used, and Dinamica EGO freeware generatedmodels of future projections. Between 1986 and 2015, 5171 ha of forest were converted to pasture. The annual deforestation rates were –1.5% for Tlanchinol and –1.3% for the San Bartolo Tutotepec sites. Distance to roads and marginalization were highly correlated with deforestation. By 2030, an estimated 3608 ha of forest in these sites will have been converted to pasture. Stored carbon was estimated at 16.35 Mg C ha-1 for the Tlanchinol site and 12.7 Mg C ha-1 for the San Bartolo site. In the Sierra Madre Oriental deforestation due to land cover change(–1.4%) is higher than levels reported worldwide. Besides having high values of stored carbon(14.5 Mg C ha-1), these forests have high biodiversity. The models' outputs show that the deforestation process will continue if action is not taken to avoid the expansion of livestock pasturing. This can be done by paying incentives for forest conservation to the owners of the land. The results suggest that REDD+ is currently the most viable strategy for reducing deforestation rates in tropical montane cloud forests in Sierra Madre Oriental.     

LAND USE／COVER CHANGE AND DRIVING FORCES IN SOUTHERN LIAONING PROVINCE SINCE 1950S

1IN TR O D U CTIO N Land isthemost essentiaplhysicalresource asnd mate- rialbasisforpeople'slif e(LIU,1996).Land use/cover change(LUCC ) isa key aspectofglobalenvironment change, andindicatetsheinfluencoefhuman activiti on physicaelnvironment.As we allkno…     

Spatial patterns of interprovincial mountain geographical names in China and implications for regional governance

Suffering from fragile environment, poor accessibility and infrastructure, as well as social, political and economic marginality, the interprovincial mountain geographical entities are difficult areas for the regional governance in China. By analyzing the spatial patterns and the influencing factors of the interprovincial mountain geographical names (IMGNs), the goal of this research is to clarify the geographical features of IMGNs and offer alternatives for the management of interprovincial mountain regions in China. The spatial visualization, the analysis of spatial agglomeration and the influencing factors of IMGNs were all implemented under a geographical information system. Results showed that there were 6869 IMGNs in China according to the database of “China’s Second National Survey of Geographical Names (2014–2018)”, including 4209 mountain geographical names, 1684 mountain peak geographical names and 976 the other mountain geographical names. Hunan Province had the largest number of names while Shanghai had the smallest number of names. In addition, the spatial variance of the mountain peak names and the mountain names were larger than that of the other mountain geographical names, and the IMGNs showed a significant clustering phenomenon in the southern part of China. The relative elevation and the population had an impact on the distribution of the IMGNs. The largest number of the names occurred where the relative elevation was between 1000–2000 m and where the population was between 40–50 million. Density of unnamed interprovincial mountain geographical entities declined from west to east in China. The analysis of generic names of different types of IMGNs implied that the naming of IMGNs is inconsistent. Based on these analyses, it is suggested that the government should take the IMGNs as management units, strengthen the naming of unnamed interprovincial mountain geographical entities, standardize the generic names of IMGNs and identify areas of poverty based on the survey of IMGNs.     

Spatio-temporal patterns of intra-urban land use change in Beijing, China between 1984 and 2008

Urban internal structure is essential information for urban geography researchers and urban planners or managers. This research aims to examine the spatial structure changes of internal urban land use based on the interpreted datasets of 1984 and 2008. Spatio-temporal patterns of internal land use conversion and urban expansion are analyzed, and then dominant driving factors (e.g., social economy, population growth and urban planning) were identified. The results indicate that Beijing′s intra-urban layout has experienced tremendous adjustment from compact to disperse configure, otherwise its function objects have shifted from the major economic and industrial development before the 1990s to the combination with cultural, high-technological and inhabitable city at present. The dominant urban land use transformations include the relocation of industrial lands from core districts to suburban or other provinces, and the accelerating expansion of residential areas and green spaces for supplying the demand of housing and ecological protection. Although Beijing′s urban planning has experienced three major adjustments and improvement since the 1980s, its optimization of urban internal patterns still remains a challenge.     

Effects of rainfall and rocky desertification on soil erosion in karst area of Southwest China

Monitoring and evaluating the evolution of rocky desertification timely and studying the characteristics of soil erosion under different rainfall patterns are of great scientific significance for regional soil and water conservation, rocky desertification control and ecological environment construction. Four periods of remote sensing image data from 2005 to 2020 were selected to study the evolution characteristics of rocky desertification and its impact on soil erosion in the controlled boundary...     

Mountain Land Use Planning of Metropolitan Suburbs： the Case of the Jinyun Mountain and Its Surrounding area, Chongqing, China

Open space of metropolitan suburbs in mountain region, has been increasingly becoming the coupling mosaic structure of industrial actions and landscape behaviors. However, the local governments, when making land use planning, often aim at economic development, and rarely refer to the coordination of compatibilities and conflicts between industrial actions and landscape behaviors in the mosaic structure. In this study land use in the Jinyun Mountain and its surrounding area, Chongqing is adjusted by gray multi-objective programming approach and local-level decision-making process to cope with conflicts between objectives for human welfare and objectives for landscape conservation. The results indicate that： 1） the compatibilities and conflicts among different behavior characters and different landscape types result in the compatibilities of landscape to human behavior; 2） a land use planning in the study area is produced based on the sustainable land use and social-eco development, which pays more attention to the resources and environment constraints and economic objectives, and follows the distribution law of rare resources; 3） in the study area, cultivated land of 1,207.27 ha can meet the demands for food and byproducts by the residents there, orchard land and forestland of 632.55 ha, 2,276.61 ha, respectively can provide enough spaee for the local people to improve their living structure and meet their demands for reereational activities, and urban residential land, rural residential land, mining land and transportation land of 1107.60 ha, 120.27 ha, 162.48 ha, 100.91 ha, respeetively can satisfy the resident＇s eeonomie development and infrastructures; 4） the equilibrium among industrial actions, landscape accessibility and ecological conservation can be obtained by analyzing the possible impaets of human activities on landscape eeologieal proeess in open spaee of metropolitan suburbs in mountain areas.     

LAND COVER CHANGES AND LANDSCAPE DYNAMICS ASSESSMENT IN LOWER REACHES OF TARIM RIVER IN CHINA

The Tarim River Basin, located in the typical arid region, is one of the key regions of LUCC research in China and plays an important role in maintaining the sustainable development of the westem China. In recent years, the ecological environment of the Tarim River Basin has degraded greatly. In the lower reaches, in particular,the riverbed has been dried up for more than 20 years, which accelerated the desertification and has been a great threat to people‘s lives. Taking the section of the Tarim River between Qiala Lake and Taitema Lake as a typical region, an investigation on land cover changes was carried out with the support of remote sensing information of 1988 and 2000 respectively. The changes of land cover in this region were obtained: 1) Cropland tended to increase. 2)Urban or Built-up Area in 2000 was 324.4ha more than that in 1988.3) Waters expanded by 3476.51ha. 4) Woodland and Grassland decreased, while Barren Land increased by 3824.9ha. The total amount of land use/land cover change between 1988 and 2000 is small, which is only 0.355% of the total area. It shows that the developmental pace of the lower reaches of the Tarim River is relative slow. Based on these results, the authors assessed the landscape dynamics of this region and pointed out that the degree of desertification was strengthened and the landscape dominated by sand land was further characterized by salt desert.     

Spatial and temporal patterns of soil nitrogen distribution under different land uses in a watershed in the hilly area of purple soil, China

Quantification of soil spatial and temporal variability at watershed scale is important in ecological modeling, precision agriculture, and natural resources management. The spatio-temporal variations of soil nitrogen under different land uses in a small watershed (12.10 km²) in the hilly area of purple soil at the upper reaches of the Yangtze River in southwestern China were investigated by using conventional statistics, geostatistics, and a geographical information system in order to provide information for land management and control of environmental issues. A total of 552 soil samples (0 to 15 cm) from 276 sites within the watershed were collected in April and August of 2011, and analyzed for soil total nitrogen (STN) and nitrate nitrogen (NO3-N). We compared spatial variations of STN and NO3-N under different land uses as well as the temporal variations in April (dry season) and August (rainy season). Results showed that STN contents were deeply affected by land-use types; median STN values ranged from 0.94 to 1.27 g·kg^?1, and STN contents decreased in the following order: paddy field > forestland > sloping cropland. No significant difference was found for STN contents between April and August under the same land use. However, NO3-N contents were 23.26, 10.58, and 26.19 mg·kg^?1 in April, and 1.34, 8.51, and 3.00 mg·kg^?1 in August for the paddy field, sloping cropland and forestland, respectively. Nugget ratios for STN indicated moderate spatial dependence in the paddy field and sloping cropland, and a strong spatial dependence in forestland. The processes of nitrogen movement, transformation, absorption of plant were deeply influenced by land use types; as a result, great changes of soil nitrogen levels at spatial and temporal scales were demonstrated in the studied watershed.     

Spatial patterns and driving forces of land change in Tibetan-inhabited Three Rivers Headwaters region,China

The Three Rivers Headwaters Region(TRHR) plays a key role in regulating water supply and climate of East Asia. A comprehensive understanding of the processes and driving forces of the long-term land use dynamics of the TRHR is needed to guide sustainable land resource management and regional ecological conservation strategies. This study examined long-term land change patterns in the TRHR and investigated the driving forces of the change. First, Landsat TM/ETM+ images covering TRHR of four time points from 1987 to 2016 were used to derive land use patterns, and statistical metrics were applied to quantify the spatial and temporal changes. Second, Principal Component Analysis and correlation analysis were employed to analyze environmental and social-economic data to identify the driving forces of land use change. Third, potential influences of the religion of Tibetan Buddhism on land use change were explored using GIS analysis, questionnaire survey and field observation. Results showed that areas of barren land, agricultural land, and built-up land largely increased, while areas of grassland and forest greatly decreased, with the highest change rate occurring in the most recent decade of analysis(from 2007 to 2016). Among the three headwater regions, the Yellow River Headwater Region showed an overall higher changing speed than the other two headwater regions. The regional driving forces of change in TRHR includedsocial-economic development, climatic condition, pressure of population growth, and environmental protection activities. It was also found that Tibetan Buddhism can help slow down the changes caused by human activities.     

Impacts of global warming on patterns of temperature change in China

Global climate change has a wide range of impacts, and this paper presents an investigation on how global warming has changed the relationship between air temperature and latitude ＆ altitude using the meteorological data obtained from 160 stations in China. The investigation indicates that there are very distinct seasonal differences in patterns of temperature variation as a function of latitude and altitude： a very significant latitude effect in winter and a very significant altitude effect in summer. However, with global warming, the latitude effect in winter is weakening and the altitude effect in summer is strengthening. This pattern of change in the relationship between temperature and latitude ＆ altitude is helpful in efforts to reconstruct and explain the past temperature patterns and variations.     

Land use and land cover change within the Koshi River Basin of the central Himalayas since 1990

Land change is a cause and consequence of global environmental change.Land use and land cover have changed considerably due to increasing human activities and climate change,which has become the core issue of major international research projects.This study interprets land use and land cover status and the changes within the Koshi River Basin(KRB)using Landsat remote sensing(RS)image data,and employs logistic regression model to analyze the influence of natural and socioeconomic driving forces on major land cover changes.The results showed that the areas of built-up land,bare land and forest in KRB increased from 1990 to 2015,including the largest increases in forest and the highest growth rate in construction land.Areas of glacier,grassland,sparse vegetation,shrub land,cropland,and wetland all decreased over the study period.From the perspective of driving analysis,the role of human activities in land use and land cover change is significant than climate factors.Cropland expansion is the reclamation of cropland by farmers,mainly from early deforestation.However,labor force separation,geological disasters and drought are the main factors of cropland shrinkage.The increase of forest area in India and Nepal was attributed to the government’s forest protection policies,such as Nepal’s community forestry has achieved remarkable results.The expansion and contraction of grassland were both dominated by climatic factors.The probability of grassland expansion increases with temperature and precipitation,while the probability of grassland contraction decreases with temperature and precipitation.     

Spatio-temporal pattern of net primary productivity in Hengduan Mountains area,China: impacts of climate change and human activities

Net primary productivity(NPP), a metric used to define and identify changes in plant communities, is greatly affected by climate change, human activities and other factors. Here, we used the Carnegie-Ames-Stanford Approach(CASA) model to estimate the NPP of plant communities in Hengduan Mountains area of China, and to explore the relationship between NPP and altitude in this region. We examined the mechanisms underlying vegetation growth responses to climate change and quantitatively assessed the effects of ecological protection measures by partitioning the contributions of climate change and human activities to NPP changes. The results demonstrated that: 1) the average total and annual NPP values over the years were 209.15 Tg C and 468.06 g C/(m2·yr), respectively. Their trend increasingly fluctuated, with spatial distribution strongly linked to altitude(i.e., lower and higher NPP in high altitude and low altitude areas, respectively) and 2400 m represented the marginal altitude for vegetation differentiation; 2) areas where climate was the main factor affecting NPP accounted for 18.2% of the total research area, whereas human activities were the primary factor influencing NPP in 81.8% of the total research area, which indicated that human activity was the main force driving changes in NPP. Areas where climatic factors(i.e., temperature and precipitation) were the main driving factors occupied 13.6%(temperature) and 6.0%(precipitation) of the total research area, respectively. Therefore, the effect of temperature on NPP changes was stronger than that of precipitation; and 3) the majority of NPP residuals from 2001 to 2014 were positive, with human activities playing an active role in determining regional vegetation growth, possibly due to the return of farmland back to forest and natural forest protection. However, this positive trend is decreasing. This clearly shows the periodical nature of ecological projects and a lack of long-term effectiveness.     

SPATIALIZATION MODEL OF POPULATION BASED ON DATASET OF LAND USE AND LAND COVER CHANGE IN CHINA

The spatialization of population of counties in China is significant.Fistly,we can gain the estimated val-ues of population density adaptive to different kinds of regions.Secondly,we can integrate effectively population data with other data including natural resources,environment,society and economy,build 1km GRIDs of natural resources re-serves per person,population density and other economic and environmental data,which are necessary to the national manage-ment and macro adjustment and control of natural resources and dynamic monitoring of population.In order to establish population information system serving national decision-making,three steps ought to be followed:1)establishing complete geographical spatial data foundation infrastructure including the establishment of electric map of residence with high resolu-tion using topographical map with large scale and high resolution satellite remote sensing data,the determination of at-tribute information of housing and office buildings,and creating complete set of attribute database and rapid data update-ing;2) establishing complete census systems including improving the transformation efficiency from census data to digital database and strengthening the link of census database and geographical spatial database,meanwhile,the government should attach great importance to the establishment and integration o population migration database;3)considering there is no GIS software specially seving the analysis and management of population data,a practical approach is to add spe-cial modules to present software system,which works as a bring actualizing the digitization and spatialization of popula-tion geography research.     

Spatio-temporal dynamic patterns of rural area development in eastern coastal China

The aim of this study is to evaluate the current state of rural area development at the county level in the eastern coastal China. An evaluation index system including 18 factors was developed, and a rural development index (RDI) was constructed to evaluate rural development state in 2000, 2004, and 2008. The quantitative evaluation indicated the following results. 1) This study derived four dominating components by means of principal component analysis, which can explain 78.2% of the total information, namely agricultural production input, the basic condition of agriculture, the comparative effectiveness of grain production, and the household′s own basic conditions. 2) Since the turn of the new millennium, the rural area in the eastern coastal China has experienced a rapid development in general. Well developed, developed, moderately developed and undeveloped rural areas respectively occupied 29.32%, 22.33%, 21.91%, and 10.51% in 2008. 3) The countryside had maintained a sound momentum of developing trend between 2000 and 2008, while the rural development in the eastern coastal China lacked sustainability. And 4) industrialization, urbanization, original economic basis, and location are four major driving forces of the disparity of rural area development in the eastern coastal China. Given these results, the strategies and policies for the improvement of each rural group were put forward.     

THE DRIVING FORCES OF LAND USE/COVER CHANGE INTHE UPSTREAM AREA OF THE NENJIANG RIVER

IINTRODUCTION niques in China（ZHANG。t al，1999； CHEN et al，2000b）．Since the early 1990s，he acceleration of land With its abundant forest，land and water re－use／cover change（LUL乙）has spurred renewed con－sources，the area of the Nenjlang River valley Is one ofcerns about the role ofland use change Indrlvingmany the lmpoFtant lumber products and commodity grainenvironmental problems．Research on the causes and ba…