The objectives of this study are to assess land s ui tability and to predict the spatial and temporal changes in land use types (LUTs ) by using GIS-based land use management decision support system. A GIS databas e w...The objectives of this study are to assess land s ui tability and to predict the spatial and temporal changes in land use types (LUTs ) by using GIS-based land use management decision support system. A GIS databas e with data on climate, topography, soil characteristic, irrigation condition, f ertilizer application, and special socioeconomic activities has been developed a nd used for the evaluation of land productivity for different crops by integrati ng with a crop growth model-the erosion productivity impact calculator (EPIC). International food policy simulation model (IFPSIM) is also embedded into GIS fo r the predictions of how crop demands and crop market prices will change under a lternative policy scenarios. An inference engine (IE) including land use choice model is developed to illustrate land use choice behavior based on logit models , which allows to analyze how diversified factors ranging from climate changes, crop price changes to land management changes can affect the distribution of agr icultural land use. A test for integrated simulation is taken in each 0.1° by 0.1° grid cell to predict the change of agricultural land use types at globa l level. Global land use changes are simulated from 1992 to 2050.展开更多
Spatial scaling for net primary productivity （NPP） refers to the transferring process of establishing quantitative correlation between simulated NPP derived from data at different spatial resolutions. How to transfe...Spatial scaling for net primary productivity （NPP） refers to the transferring process of establishing quantitative correlation between simulated NPP derived from data at different spatial resolutions. How to transfer NPP at one scale by the algorithm with smaller error to at another is the urgent problem. Nonlinearity and effects from land cover type are two main problems in NPP scaling. In this paper, the contextural approach based on mixed pixels and support vector machine （SVM） algorithm are used to make the scaling model from the fine resolution （TM） to the coarse resolution （MODIS）. Spatial scaling from NPP retrieved from fine resolution data to NPP derived from coarse resolution images is performed, and the correction of scale effect to NPP retrieved from coarse resolution data of MODIS is accomplished. The result shows that the correlation between Rj_coereted of the correction factor for scale effect and 1-Fmiddle dessity grassland estimated by SVM regression model is higher （R2=0.81）. Before the correction for scale effect, the correlation between NPPMODIS and NPPTM is lower （R2=0.69; RMSE=3.47）, while the correlation between NPPTM and corrected NPPMODIS_corrected is higher （R2=0.84; RMSE= 1.87）. Therefore, NPP corrected for scale effect has been greatly improved in both correlation and error.展开更多
Land use structure optimization(LUSO) is an important issue for land use planning. In order for land use planning to have reasonable flexibility, uncertain optimization should be applied for LUSO. In this paper, the r...Land use structure optimization(LUSO) is an important issue for land use planning. In order for land use planning to have reasonable flexibility, uncertain optimization should be applied for LUSO. In this paper, the researcher first expounded the uncertainties of LUSO. Based on this, an interval programming model was developed, of which interval variables were to hold land use uncertainties. To solve the model, a heuristics based on Genetic Algorithm was designed according to Pareto Optimum principle with a confidence interval under given significance level to represent LUSO result. Proposed method was applied to a real case of Yangzhou, an eastern city in China. The following conclusions were reached. 1) Different forms of uncertainties ranged from certainty to indeterminacy lay in the five steps of LUSO, indicating necessary need of comprehensive approach to quantify them. 2) With regards to trade-offs of conflicted objectives and preferences to uncertainties, our proposed model displayed good ability of making planning decision process transparent, therefore providing an effective tool for flexible land use planning compiling. 3) Under uncertain conditions, land use planning effectiveness can be primarily enhanced by flexible management with reserved space to percept and hold uncertainties in advance.展开更多
Remotely sensed data are capable of providing spatial and temporal information on land use land cover(LULC)over a large extent of land.The Sidoarjo District in East Java Province has recently been extensively explored...Remotely sensed data are capable of providing spatial and temporal information on land use land cover(LULC)over a large extent of land.The Sidoarjo District in East Java Province has recently been extensively explored for economic development opportunities.This paper examines the use of multi-temporal Landsat images in deriving information for LULC maps,changes of land development and natural ecosystems such as mangrove forest within particular economic reform areas.Results suggest a minimum accuracy(baseline)for LULC mapping using Landsat multispectral reflectance data of 74% for the overall accuracy(OA)and 0.70 for the kappa coefficient of agreement(kappa).On average an acceptable accuracy(OA=88% and kappa=0.86)can be achieved by integrating multispectral reflectance and green normalized difference vegetation index(GNDVI)to support vector machine classification.The economic reform in the Sidoarjo District made a significant change to LULC and mangrove distribution.From 1995 to 2015,25% of crop land and 15% of bare land changed to become built-up areas,and 8% of wetland and 22% of mangroves changed to crop land.A remarkable decrease of mangrove forest occurred in the interior land along the river systems over the whole district.Fortunately,the coastal mangroves areas saw a significant increase due to the Lumpur Sidoarjo(LUSI)-caused mud flow sediments near the estuary of the river.The impact of extensive economic activities and development on the natural mangrove forests was partially compensated for by the LUSI events and also newly developed local community oriented conservative management.展开更多
Primary productivity of ecosystem is important indicator about ecological assessment. Remote sensing technology has been used to monitor net primary productivity （NPP） of ecological system for several years. In this...Primary productivity of ecosystem is important indicator about ecological assessment. Remote sensing technology has been used to monitor net primary productivity （NPP） of ecological system for several years. In this paper, the remotely sensed NPP simulation model of alpine vegetation in Qinghai Province of Tibet Plateau was set up based on the theory of light use efficiency. Firstly a new approach based on mixed pixels and Support Vector Machine （SVM） algorithm were used to correct simulated NPP values derived from Moderate Resolution Imaging Spectroradiometer （MODIS） data. Finally, spatial distribution and monthly variation characteristics of NPP in Qinghai Province detail. The result showed in 2006 were analyzed in that NPP of vegetation in Qinghai Province in 2006 ranged from o to 422 gC/m2/a and the average NPP was 151 gC/m2/a. NPP gradually increased from northwest to southeast. NPP of different vegetation types were obviously different. The average NPP of broad-leaved forest was the largest （314 gC/m2/a）, and sparse shrub was the smallest （101 gC/m2/a）. NPP in Qinghai Province significantly changed with seasonal variation. The accumulation of NPP was primarily in the period （from April to September） with better moist and heat conditions. In July, the average NPP of vegetation reached the maximum value （43 gC/m2）. In our model, the advantage of traditional LUE models was adopted, and our study fully considered typicalcharacteristics of alpine vegetation light use efficiency and environmental factors in the study area. Alpine vegetation is the most important ecological resource of Tibet Plateau, exactly monitoring its NPP value by remote sensing is an effective protection measure.展开更多
BACKGROUND: Symptoms of Post-Traumatic Stress Disorder (PTSD) have often been found in studies on homeless people, due to high rates of traumatic experiences. Most research on homelessness has been conducted in North ...BACKGROUND: Symptoms of Post-Traumatic Stress Disorder (PTSD) have often been found in studies on homeless people, due to high rates of traumatic experiences. Most research on homelessness has been conducted in North America and Western Europe. However there are many social and cultural factors which can impact the prevalence and number of PTSD symptoms. AIMS: This study sought to determine the prevalence and predictors of trauma and PTSD symptoms among homeless adults in an Eastern European nation (Poland). METHOD: Randomly chosen residents of shelters were interviewed (N = 200). The respondents were asked about symptoms of PTSD, alcohol abuse/dependence, depression symptoms and perceived social support. RESULTS: The data indicated that 30% of the homeless sample were victims of traumatic events, 22% showed at least one PTSD symptom, and 7% met criteria for a lifetime diagnosis of PTSD. Symptoms of PTSD were the most common among those who had symptoms of alcohol abuse/ dependence and depression. CONCLUSION: The study’s findings support the need to attend to mental disorders such as PTSD when addressing the array of needs of homeless people.展开更多
文摘The objectives of this study are to assess land s ui tability and to predict the spatial and temporal changes in land use types (LUTs ) by using GIS-based land use management decision support system. A GIS databas e with data on climate, topography, soil characteristic, irrigation condition, f ertilizer application, and special socioeconomic activities has been developed a nd used for the evaluation of land productivity for different crops by integrati ng with a crop growth model-the erosion productivity impact calculator (EPIC). International food policy simulation model (IFPSIM) is also embedded into GIS fo r the predictions of how crop demands and crop market prices will change under a lternative policy scenarios. An inference engine (IE) including land use choice model is developed to illustrate land use choice behavior based on logit models , which allows to analyze how diversified factors ranging from climate changes, crop price changes to land management changes can affect the distribution of agr icultural land use. A test for integrated simulation is taken in each 0.1° by 0.1° grid cell to predict the change of agricultural land use types at globa l level. Global land use changes are simulated from 1992 to 2050.
基金Foundation： Chinese Liaoning Province Education Bureau General Science Research Project （No. L2010226） Chinese Education Ministry Humanities and Social Sciences Key Research Base Project （No.08JJD790142）+1 种基金 Chinese Liaoning Province Education Bureau Innovation Team Project （No. 2007T095） Chinese Special Funds for Major State Basic Research Project （No. 2007CB714406）.
文摘Spatial scaling for net primary productivity （NPP） refers to the transferring process of establishing quantitative correlation between simulated NPP derived from data at different spatial resolutions. How to transfer NPP at one scale by the algorithm with smaller error to at another is the urgent problem. Nonlinearity and effects from land cover type are two main problems in NPP scaling. In this paper, the contextural approach based on mixed pixels and support vector machine （SVM） algorithm are used to make the scaling model from the fine resolution （TM） to the coarse resolution （MODIS）. Spatial scaling from NPP retrieved from fine resolution data to NPP derived from coarse resolution images is performed, and the correction of scale effect to NPP retrieved from coarse resolution data of MODIS is accomplished. The result shows that the correlation between Rj_coereted of the correction factor for scale effect and 1-Fmiddle dessity grassland estimated by SVM regression model is higher （R2=0.81）. Before the correction for scale effect, the correlation between NPPMODIS and NPPTM is lower （R2=0.69; RMSE=3.47）, while the correlation between NPPTM and corrected NPPMODIS_corrected is higher （R2=0.84; RMSE= 1.87）. Therefore, NPP corrected for scale effect has been greatly improved in both correlation and error.
基金Under the auspices of National Natural Science Foundation of China(No.41401627,41471144)Foundation Research Project of Jiangsu Province(No.BK20140236)
文摘Land use structure optimization(LUSO) is an important issue for land use planning. In order for land use planning to have reasonable flexibility, uncertain optimization should be applied for LUSO. In this paper, the researcher first expounded the uncertainties of LUSO. Based on this, an interval programming model was developed, of which interval variables were to hold land use uncertainties. To solve the model, a heuristics based on Genetic Algorithm was designed according to Pareto Optimum principle with a confidence interval under given significance level to represent LUSO result. Proposed method was applied to a real case of Yangzhou, an eastern city in China. The following conclusions were reached. 1) Different forms of uncertainties ranged from certainty to indeterminacy lay in the five steps of LUSO, indicating necessary need of comprehensive approach to quantify them. 2) With regards to trade-offs of conflicted objectives and preferences to uncertainties, our proposed model displayed good ability of making planning decision process transparent, therefore providing an effective tool for flexible land use planning compiling. 3) Under uncertain conditions, land use planning effectiveness can be primarily enhanced by flexible management with reserved space to percept and hold uncertainties in advance.
文摘Remotely sensed data are capable of providing spatial and temporal information on land use land cover(LULC)over a large extent of land.The Sidoarjo District in East Java Province has recently been extensively explored for economic development opportunities.This paper examines the use of multi-temporal Landsat images in deriving information for LULC maps,changes of land development and natural ecosystems such as mangrove forest within particular economic reform areas.Results suggest a minimum accuracy(baseline)for LULC mapping using Landsat multispectral reflectance data of 74% for the overall accuracy(OA)and 0.70 for the kappa coefficient of agreement(kappa).On average an acceptable accuracy(OA=88% and kappa=0.86)can be achieved by integrating multispectral reflectance and green normalized difference vegetation index(GNDVI)to support vector machine classification.The economic reform in the Sidoarjo District made a significant change to LULC and mangrove distribution.From 1995 to 2015,25% of crop land and 15% of bare land changed to become built-up areas,and 8% of wetland and 22% of mangroves changed to crop land.A remarkable decrease of mangrove forest occurred in the interior land along the river systems over the whole district.Fortunately,the coastal mangroves areas saw a significant increase due to the Lumpur Sidoarjo(LUSI)-caused mud flow sediments near the estuary of the river.The impact of extensive economic activities and development on the natural mangrove forests was partially compensated for by the LUSI events and also newly developed local community oriented conservative management.
基金funded by the National Natural Science Foundation of China (Grant No.41271421)the Humanities and Social Sciences Research Project of the Ministry of Education in China (Grant No. 10YJCZH156)
文摘Primary productivity of ecosystem is important indicator about ecological assessment. Remote sensing technology has been used to monitor net primary productivity （NPP） of ecological system for several years. In this paper, the remotely sensed NPP simulation model of alpine vegetation in Qinghai Province of Tibet Plateau was set up based on the theory of light use efficiency. Firstly a new approach based on mixed pixels and Support Vector Machine （SVM） algorithm were used to correct simulated NPP values derived from Moderate Resolution Imaging Spectroradiometer （MODIS） data. Finally, spatial distribution and monthly variation characteristics of NPP in Qinghai Province detail. The result showed in 2006 were analyzed in that NPP of vegetation in Qinghai Province in 2006 ranged from o to 422 gC/m2/a and the average NPP was 151 gC/m2/a. NPP gradually increased from northwest to southeast. NPP of different vegetation types were obviously different. The average NPP of broad-leaved forest was the largest （314 gC/m2/a）, and sparse shrub was the smallest （101 gC/m2/a）. NPP in Qinghai Province significantly changed with seasonal variation. The accumulation of NPP was primarily in the period （from April to September） with better moist and heat conditions. In July, the average NPP of vegetation reached the maximum value （43 gC/m2）. In our model, the advantage of traditional LUE models was adopted, and our study fully considered typicalcharacteristics of alpine vegetation light use efficiency and environmental factors in the study area. Alpine vegetation is the most important ecological resource of Tibet Plateau, exactly monitoring its NPP value by remote sensing is an effective protection measure.
文摘BACKGROUND: Symptoms of Post-Traumatic Stress Disorder (PTSD) have often been found in studies on homeless people, due to high rates of traumatic experiences. Most research on homelessness has been conducted in North America and Western Europe. However there are many social and cultural factors which can impact the prevalence and number of PTSD symptoms. AIMS: This study sought to determine the prevalence and predictors of trauma and PTSD symptoms among homeless adults in an Eastern European nation (Poland). METHOD: Randomly chosen residents of shelters were interviewed (N = 200). The respondents were asked about symptoms of PTSD, alcohol abuse/dependence, depression symptoms and perceived social support. RESULTS: The data indicated that 30% of the homeless sample were victims of traumatic events, 22% showed at least one PTSD symptom, and 7% met criteria for a lifetime diagnosis of PTSD. Symptoms of PTSD were the most common among those who had symptoms of alcohol abuse/ dependence and depression. CONCLUSION: The study’s findings support the need to attend to mental disorders such as PTSD when addressing the array of needs of homeless people.
