Evaluation of land-use pattern change in West Bhanugach Reserved Forest,Bangladesh,using remote sensing and GIS techniques

A study was conducted to investigate the land-use pattern change over a period of 18 years （1988-2006） by using remote sens- ing and Geographical Information System （GIS） technologies, in the West Bhanugach Reserved Forest, a hill forest, in Sylhet Forest Divi- sion of Bangladesh, The images were processed using ERDAS Imagine software. Both supervised and unsupervised approaches were ap- plied and ground control points were collected using a GPS. Maps were prepared using GIS software. Results showed that vegetation cover drastically decreased from the year 1988 to 1996 （l 826 ha to l 714.85 ha）, but increased gradually from the year 1996 to 2006 （l 714.85 ha to l 847.83 ha） due to the initiation of co-management practice involving local communities. Change in bare land was inversely proportionate to the amount of vegetation cover changes unless any other land-uses were converted into bare land. The area of water bodies increased from the year 1988 to 1996 （307.67 ha to 379.53 ha）, but decreased from the year 1996 to 1997, then remained invariabile from the year 1997 to 2006. Some recommendations were also made for applying the RS and GIS techniques to study the land-use pattern change in the Bhanugach Reserved Forest and to create a GIS data base for the study area.

Detection of Land-Use and Surface Temperature Change at Different Resolutions

Understanding the relationship between land-use/land-cover change (LULCC) and environment is seriously important to manage arid land. However, information on how environmental factors influence the LULCC patterns at different scales in arid area is lacking. This paper investigates the application of RS/GIS for detecting LULCC and assessing its impact on surface temperature in the Ismailia Governorate, Egypt. Landsat images have been utilized to quantify the changes from 1984 to 2011. The images were pre-processed using calibration techniques and the geometric and atmos- pheric corrections were performed. Different ratios, indices, and optimized index factor were implemented to decide the best band combination. Supervised classification using Maximum Likelihood technique and spatial reclassification have been employed. Six land-use/land-cover categories (urban, vegetation, waterlogged 1 and 2, bare land, and water) were identified. The highest overall accuracy and Kappa coefficient is 93.04% and 80.65%, respectively. The integration of RS and GIS was further applied to examine the impact of land-use change on surface temperatures. The results revealed a notable land-use change in the study area. The Built-up area has rapidly increased in Ismailia during the 27 years pe- riod. The built-up area (37.65?C in 1984 and 43.876?C in 2011) and Barren land (37.34?C in 1984 and 42.801?C in 2011) exhibit the highest surface radiant temperature, while vegetated surfaces (28.73?C in 1984 and 32.96?C in 2011), water (25.94?C in 1984 and 27.32?C in 2011), waterlogged1 (34.54?C in 1984 and 35.60?C in 2011) recorded low radiant temperature respectively. Waterlogged2 is the class that shows an unexpected radiant temperature (26.38?C in 1984 and 27.75?C in 2011). The urban development between 1984 and 2011 has given rise to an average of 6.23?C in surface radiant temperature. During 27 years, the change rate of land-use types which are decreased are barren land (1.12% an- nually) and waterlogged1 and 2 (0.76 and 6.61% annually). The area of vegetation, water, and built-up are increased by 0.98%, 0.82%, and 0.61% per year, respectively.

FARMLAND AND URBAN AREA DYNAMICS MONITORING INCHINA USING REMOTE SENSING AND SPATIALSTATISTICS METHODOLOGY

With the need in the global change research project for the land -use/land-cover change information, most international and regional research organization or groups have put amounts of efforts to improve of the dynamics monitoring and database updating techniques. With the pressure on nature environment from increasing population and decreasing farmland be- coming significant more and more in China, the farmland urban dynamics in historical and current times, even the change trends in the future, should be monitored and analyzed serving for regional and national social, economic and environmental sustain- able development in the long future. Based on spatial and temporal series of land -use/land-cover database resources, Chinese Academy of Sciences designed a sampling framework for monitoring farmland and urban area dynamics in regional and national level. In order to test the accuracy of the sampling schema for national and regional level, we took two provinces area into overall covered change detecting process with TM images data through being inter’Preted by digitalization on the screen. The result shows that our stratified random sampling schema is suitable for monitoring land -use/land-cover change at national and regional level with quick response, high accuracy and low expenses. The land-use/land-cover change (LUCC) information can update the LUTEA database for global change research during certain period so that the forecasting process and evaluating analysis on land resources and environment under human and natural driving force will get essential data and produce valuable conclusions.

Study on ecosytem service function change of island based on remote sensing

Based on the interpretation of the remote sensing data presented by the resource satellite, this paper states the fact that the land-use area in Donghai Island, which is located in the south of Zhanjiang, Guangdong Province, had expanded by 576.71 hm2 in the 25 years from 1986 to 2010 because of human activities such as land reclamation; in the meantime, great changes in types of land cover on the island have occurred. The definite change in land use leads to the remarkable transition in its ecosystem service value. Therefore, by applying the Costanza method in this paper to quantificationally analyze the changes in its ecosystem services on this island; the Costanza method is a calculation technique that shows the service value per unit area of island. It is found that from 1986 to 2010, especially in the recent years, due to the rapid development in the petrifaction, steel and port industries, the areas of cultivated land, woodland, grassland and desert have decreased in different degrees, while the lands for residence, industry and traffic construction and the areas of water and wetlands have increased. Consequently, compared with the number of RMB 547.57x10^6 yuan per year in 1986, the ecosystem service value of Donghai Island was greatly reduced to RMB 493.94x10^6 yuan per year in 2010. As for the spatial distribution, it presents a feature that it is higher in the west and low in the east. The results manifest that it is of great significance to analyze the changes in the ecosystem service function on the basis of the service value of the island presented by the remote sensing data in a quantificational way, which will contribute to the promotion of ecological compensation.

Spatiotemporal characteristics, patterns, and causes of land-use changes in China since the late 1980s

Land-use/land-cover changes （LUCCs） have links to both human and nature inter- actions. China＇s Land-Use/cover Datasets （CLUDs） were updated regularly at 5-year inter- vals from the late 1980s to 2010, with standard procedures based on Landsat TM／ETM＋ im- ages. A land-use dynamic regionalization method was proposed to analyze major land-use conversions. The spatiotemporal characteristics, differences, and causes of land-use changes at a national scale were then examined. The main findings are summarized as fol- lows. Land-use changes （LUCs） across China indicated a significant variation in spatial and temporal characteristics in the last 20 years （1990-2010）. The area of cropland change de- creased in the south and increased in the north, but the total area remained almost un- changed. The reclaimed cropland was shifted from the northeast to the northwest. The built-up lands expanded rapidly, were mainly distributed in the east, and gradually spread out to central and western China. Woodland decreased first, and then increased, but desert area was the opposite. Grassland continued decreasing. Different spatial patterns of LUC in China were found between the late 20th century and the early 21st century. The original 13 LUC zones were replaced by 15 units with changes of boundaries in some zones. The main spatial characteristics of these changes included （1） an accelerated expansion of built-up land in the Huang-Huai-Hai region, the southeastern coastal areas, the midstream area of the Yangtze River, and the Sichuan Basin; （2） shifted land reclamation in the north from northeast China and eastern Inner Mongolia to the oasis agricultural areas in northwest China; （3） continuous transformation from rain-fed farmlands in northeast China to paddy fields; and （4） effective- ness of the ＂Grain for Green＂ project in the southern agricultural-pastoral ecotones of Inner Mongolia, the Loess Plateau, and southwestern mountainous areas. In the last two decades, although climate change in the north affected the change in cropland, policy regulation and economic driving forces were still the primary causes of LUC across China. During the first decade of the 21st century, the anthropogenic factors that drove variations in land-use pat- terns have shifted the emphasis from one-way land development to both development and conservation. The ＂dynamic regionalization method＂ was used to analyze changes in the spatial patterns of zoning boundaries, the internal characteristics of zones, and the growth and decrease of units. The results revealed ＂the pattern of the change process,＂ namely the process of LUC and regional differences in characteristics at different stages. The growth and decrease of zones during this dynamic LUC zoning, variations in unit boundaries, and the characteristics of change intensities between the former and latter decades were examined. The patterns of alternative transformation between the ＂pattern＂ and ＂process＂ of land use and the causes for changes in different types and different regions of land use were explored.

Spatiotemporal patterns and characteristics of land-use change in China during 2010–2015

Land use/cover change is an important theme on the impacts of human activities on the earth systems and global environmental change. National land-use changes of China during 2010–2015 were acquired by the digital interpretation method using the high-resolution remotely sensed images, e.g. the Landsat 8 OLI, GF-2 remote sensing images. The spatiotemporal characteristics of land-use changes across China during 2010–2015 were revealed by the indexes of dynamic degree model, annual land-use changes ratio etc. The results indicated that the built-up land increased by 24.6×10~3 km^2 while the cropland decreased by 4.9×10~3 km^2, and the total area of woodland and grassland decreased by 16.4×10~3 km^2. The spatial pattern of land-use changes in China during 2010–2015 was concordant with that of the period 2000–2010. Specially, new characteristics of land-use changes emerged in different regions of China in 2010–2015. The built-up land in eastern China expanded continually, and the total area of cropland decreased, both at decreasing rates. The rates of built-up land expansion and cropland shrinkage were accelerated in central China. The rates of built-up land expansion and cropland growth increased in western China, while the decreasing rate of woodland and grassland accelerated. In northeastern China, built-up land expansion slowed continually, and cropland area increased slightly accompanied by the conversions between paddy land and dry land. Besides, woodland and grassland area decreased in northeastern China. The characteristics of land-use changes in eastern China were essentially consistent with the spatial govern and control requirements of the optimal development zones and key development zones according to the Major Function-oriented Zones Planning implemented during the 12 th Five-Year Plan(2011–2015). It was a serious challenge for the central government of China to effectively protect the reasonable layout of land use types dominated with the key ecological function zones and agricultural production zones in centraland western China. Furthermore, the local governments should take effective measures to strengthen the management of territorial development in future.

Land-Use Changes and Human Driving in and Near the Yangtze River Delta from 1995–2015

We analyzed the characteristics and trends of land-use change in and near the coastal zone of the Yangtze River Delta(YRD) during five periods(1995, 2000 2005, 2010, and 2015) using remotely sensed Landsat imagery. Using automatic supervised classification combined with visual interpretation, we obtained land-use information for five study areas(Nantong, Shanghai, Jiaxing, Ningbo, and Zhoushan). Significant land-use changes have occurred in this area between 1995 and 2015, characterized in particular by large reductions in cultivated land and rapid increases in urbanized land. In addition, land reclamation was very active in this period as an effective supplement to the increased demand for land development: since 1995, 1622 km^2 of land was reclaimed from near-coastal regions in the study area. This increase in urbanization was jointly driven by population, economic, transportation, and policy factors. Urban areas expanded from the center outward in concentric rings, with infrastructure guiding the radial expansion of development along transportation corridors, thus forming a network of connections. Due to the influence of national land regulation policies, the expansion rate of development in the YRD gradually diminished after 2010. This indicates that the area's resource and environmental carrying capacity has reached a saturation stage in which urbanization has transitioned from broad and incremental expansion to the intensive use of land resources.

Interpretation and Compilation of Landsat TM Imagery for Land-use and Site Classification Mapping in the Korqin Sandy Lands, NE China

For the purpose of of forestation, planning and development in the Three-North Region, a series of 6 Landsat TM scenesfrom 1996 to 1997 were used to classify land-use conditions in the whole Korqin Sandy Lands at eastern part of Inner Mongolia, China, with an area of about 430×306 square kilometers. Later on, Site classiflcation was made and mapped for the 4 southern sandy counties. The annotation symbol for each agglomeration of site condition is comprised of six parts: land unit, land use pattern, soi...

Urban Heat Island Assessment for a Tropical Urban Airshed in India

There has been paucity of field campaigns in India in past few decades on the urban heat island intensities (UHI). Remote sensing observations provide useful information on urban heat island intensities and hotspots as supplement or proxy to in-situ surface based measurements. A case study has been undertaken to assess and compare the UHI and hotspots based on in-situ measurements and remote sensing observations as the later method can be used as a proxy in absence of in-situ measurements both spatially and temporally. Capital of India, megacity Delhi has grown by leaps and bounds during past 2 - 3 decades and strongly represents tropical climatic conditions where such studies and field campaigns are practically non-existent. Thus, a field campaign was undertaken during summer, 2008 named DELHI-I (Delhi Experiments to Learn Heat Island Intensity-I) in this megacity. Urban heat island effects were found to be most dominant in areas of dense built up infrastructure and at commercial centers. The heat island intensity (UHI) was observed to be higher in magnitude both during afternoon hours and night hours (maximum up to 8.3?C) similar to some recent studies. The three high ranking urban heat island locations in the city are within commercial and/or densely populated areas. The results of this field campaign when compared with MODIS-Terra data of land surface temperature revealed that UHI hotspots are comparable only during nighttime. During daytime, similar comparison was less satisfactory. Further, available relationship of maximum UHI with population data is applied for the current measurements and discussed in the context of maximum UHI of various other countries.

ANALYSIS OF THE EXPANSION OF THE BUILT-UP AREA OF DALIAN CITY

With the astounding development and gradual improvement of remote sensing technology,as an advanced science technology,it is used to pro vide multi-temporal,large scope re al-time information for land-use dynamic change,and also is one of the best efficient m ethods for studying the earth resour ces and environment.Remote sensing image has its characteristics of ample inform ation and reflecting the objective r ealities.The paper uses multi-temp oral TM images in1986,1996and 2000,and relevant sta tistic data to analyze land-use chan ges of Dalian City in Liaoning Provin ce of Chi-na over ten years by means of the corre lation analysis method.The results have shown that two methods could con-formably reflect the present land-u se change.Urbanization is closely c orrelative to natural factors and ec onomic develop-ment.Especially in recent 20years,under the influence of the reform and open-up policy,Dalian,as a specifi c coast city,is becoming an international m etropolis.

A landscape management analysis framework and its preliminary application in Ejina Oasis, Northwest China

The implementation of integrated landscape management to support local and regional human well-being is crucial in arid regions,but its application to date is very limited.Although analytical frameworks have been established to maximize ecosystem services via trade-offs between different landscape configurations,consumption factors such as water resources are rarely and weakly considered in such frameworks.In this paper,an improved integrated landscape-management analysis framework,called the Consumption-integrated Landscape Management to Ecosystem Service(CLMES),is proposed.In this framework,consumption factors are integrated at the same level as ecosystem services.The improved analytical framework is then used to assess and optimize landscape design in the Ejina Oasis,an extremely arid region in western China.Three landscape conditions(past,current,and future)are evaluated,based on the CLMES.Our results indicate that the Heihe River water-allocation program effectively promoted ecosystem services in the Ejina Oasis from 2000 to 2011.However,the excessive expansion of cropland led to a slight decline in habitat quality.An optimized landscape configuration and policy suggestions are proposed,which may be beneficial to the improvement of total water-use efficiency,oasis stability,and resilience of the ecological?social system in the Ejina Oasis.

The Effect of the Land Use/Cover Changes on the Floods of the Madarsu Basin of Northeastern Iran

In order to understand the effect of the land use/cover change on the hydrologic regime of the Madarsu Basin in Golestan province of Iran, we selected the two floods of June 1964 and June 2003 with equal amount of rainfall but different rate of runoff. For these floods the closest time images of MODIS were selected. On these images we analyzed the land use/cover types and calculated their area and change rate between two floods. We also calculated the Curve Number (CN) for each land use/cover type according to the US Soil Conservation System (SCS) model. The results showed that: the intensity of the peak floods has increased from 1960 to 2002, and the natural lands of forests, rangelands, and bare lands have been decreased from 1960 to 2002. While the agricultural lands showed increase during the same period. The CN value has also increased during the study period causing the decrease of moisture retention capacity of the soil. As a result, despite the equal rainfall, the discharge rate of 2003 flood was about 10 times larger than that of the 1964 flood, which is the direct effect of the land use/cover change from the stable forests and rangelands to the unstable agricultural lands on the both soil moisture retention capacity and run off rate.

An EcoCity model for regulating urban land cover structure and thermal environment： Taking Beijing as an example

Urban land-use/cover changes and their effects on the eco-environment have long been an active research topic in the urbanization field. However, the characteristics of urban inner spatial heterogeneity and its quantitative relationship with thermal environment are still poorly understood, resulting in ineffective application in urban ecological planning and management.Through the integration of "spatial structure theory" in urban geography and "surface energy balance" in urban climatology, we proposed a new concept of urban surface structure and thermal environment regulation to reveal the mechanism between urban spatial structure and surface thermal environment. We developed the EcoCity model for regulating urban land cover structure and thermal environment, and established the eco-regulation thresholds of urban surface thermal environments. Based on the comprehensive analysis of experimental observation, remotely sensed and meteorological data, we examined the spatial patterns of urban habitation, industrial, infrastructure service, and ecological spaces. We examined the impacts of internal land-cover components(e.g., urban impervious surfaces, greenness, and water) on surface radiation and heat flux. This research indicated that difference of thermal environments among urban functional areas is closely related to the proportions of the land-cover components.The highly dense impervious surface areas in commercial and residential zones significantly increased land surface temperature through increasing sensible heat flux, while greenness and water decrease land surface temperature through increasing latent heat flux. We also found that different functional zones due to various proportions of green spaces have various heat dissipation roles and ecological thresholds. Urban greening projects in highly dense impervious surfaces areas such as commercial, transportation, and residential zones are especially effective in promoting latent heat dissipation efficiency of vegetation, leading to strongly cooling effect of unit vegetation coverage. This research indicates that the EcoCity model provides the fundamentals to understand the coupled mechanism between urban land use structure and surface flux and the analysis of their spatiotemporal characteristics. This model provides a general computational model system for defining urban heat island mitigation, the greening ratio indexes, and their regulating thresholds for different functional zones.

Land use and land cover changes and Soil erosion in Yezat Watershed,North Western Ethiopia

Soil erosion affects land qualities and water resources.This problem is severe in Ethiopia due to its topographic features.The present research was aimed to estimate spatiotemporal changes in land-use/land-cover pattern and soil erosion in the Yezat watershed in Ethiopia.This study was carried out by using landsat imageries of 2001,2010 and 2015.Ilmages were classified into categories using supervised classification by maximum likelihood algorithm.They were also classified into different biomass levels by using Normalized Difference Vegetation Index(NDVI)analysis.Revised Universal Soil Loss Equation modeling was applied in a GIS environment to quantify the potential soil erosion risk.The area under grassland,woodland and homesteads have increased by 610.69(4%),101.69(0.67%)and 126.6 ha(0.83%)during 2001-2015.The extent of cultivated land and shrub/bushland was reduced by 323.43(0.02%)and 515.44 ha(3.41%),respectively,during the same period.The vegetation cover in the watershed decreased by 91% during 2001-2010,and increased by 88% during 2010-2015.Increase of NDVI values indicates better ground cover due to implementation of integrated watershed development program in the region.The estimated annual soil losses were 7.2 t ha^(-1) yr^(-1) in 2001,7.7t ha^(-1) yr^(-1) in 2010 and 4.8t ha^(-1) yr^(-1) in 2015.Management interventions are necessary to improve the status and utilization of watershed resources in response to sustainable land management practices for sustainable livelihood of the local people.

Contribution of phytoecological data to spatialize soil erosion:Application of the RUSLE model in the Algerian atlas

Among the models used to assess water erosion,the RUSLE model is commonly used.Policy makers can act on cover(C-factor)and conservation practice(P-factor)to reduce erosion,with less costly action on soil surface characteristics.However,the widespread use of vegetation indices such as NDVI does not allow for a proper assessment of the C-factor in drylands where stones,crusted surfaces and litter strongly influence soil protection.Two sub-factors of C,canopy cover(CC)and soil cover(SC),can be assessed from phytoecological measurements that include gravel-pebbles cover,physical mulch,annual and perennial vegetation.This paper introduces a method to calculate the C-factor from phytoecological data and,in combination with remote sensing and a geographic information system(GIS),to map it over large areas.A supervised classification,based on field phytoecological data,is applied to radiometric data from Landsat-8/OLI satellite images.Then,a C-factor value,whose SC and CC subfactors are directly derived from the phytoecological measurements,is assigned to each land cover unit.This method and RUSLE are implemented on a pilot region of 3828 km^(2) of the Saharan Atlas,composed of rangelands and steppe formations,and intended to become an observatory.The protective effect against erosion by gravel-pebbles(50%)is more than twice that of vegetation(23%).The C-factor derived from NDVI(0.67)is higher and more evenly distributed than that combining these two contributions(0.37 on average).Finally,priorities are proposed to decision-makers by crossing the synthetic map of erosion sensitivity and a decision matrix of management priorities.