In this paper, introducing new remote sensing and geographic information technology to solve the problem of data collection and analysis, this makes the study of ecological risk assessment very quick and accurate. Tak...In this paper, introducing new remote sensing and geographic information technology to solve the problem of data collection and analysis, this makes the study of ecological risk assessment very quick and accurate. Taking the Shan Xin mining area of the tin mine in Lengshuijiang of Hunan Province as the research object, using the remote sensing image data of three periods in 2005, 2010 and 2015, the remote sensing image is classified carefully and the landscape classification map of the mining area is obtained. The ecological risk index is introduced and the ecological risk values are sampled and interpolated on the ArcGIS platform. The ecological risk spatial distribution map based on the landscape pattern index was obtained. The ecological risk was divided into 5 levels by using the Jenks natural classification method, and each ecological risk grade area was counted. The research results show that: from year 2005 to year 2010, landscape ecological risk trend of the mining area is growing up;the trend rising area of landscape ecological risk is mainly in the southwest and northeast of the Shan Xin mining field;the area of higher and high ecological risk is increasing year by year;and the trend of dispersed development in space is obvious;the development trend of ecological risk in the mining area is rapidly increasing;in 2010 - 2015, the higher and high ecological risk area decrease slightly with the increasing of area of grassland and residential low vulnerability of landscape types;the ecological risk area showed a slow decreasing trend. The research results provide an objective reference for decision making of ecological environment governance.展开更多
The Liupan Mountains is located in the southern Ningxia Hui Autonomous Region of China, which forms an important dividing line between landforms and bio-geographic regions. The populated part of the Liupan Mountains r...The Liupan Mountains is located in the southern Ningxia Hui Autonomous Region of China, which forms an important dividing line between landforms and bio-geographic regions. The populated part of the Liupan Mountains region has suffered tremendous ecological damages over time due to population pressure, excessive demand and inappropriate use of agricultural land resources. In this paper, datasets of land use between 1990 and 2000 were obtained from Landsat TM imagery, and then spatial models were used to characterize landscape conditions. Also, the relationship between the population density and land use/cover change (LUCC) was analyzed. Results indicate that cropland, forestland, and urban areas have increased by 44,186ha, 9001ha and 1550ha, respectively while the grassland area has appreciably decreased by 54,025ha in the study period. The decrease in grassland was most notable. Of the grassland lost, 49.4% was converted into cropland. The largest annual land conversion rate in the study area was less than 2%. These changes are attributed to industrial and agricultural development and population growth. To improve the eco-economic conditions in the study region, population control, urbanization and development of an ecological friendly agriculture were suggested.展开更多
The Liupan Mountains are located in the southern Ningxia Hui Autonomous Region of China,that forms an important divide between landforms and biogeographic regions.The populated part of the Liupan Mountain Region has s...The Liupan Mountains are located in the southern Ningxia Hui Autonomous Region of China,that forms an important divide between landforms and biogeographic regions.The populated part of the Liupan Mountain Region has suffered tremendous ecological damage over time due to population pressure,excessive demand and inappropriate use of agricultural land resources.To present the relationship between land use/cover change and spatio-temporal variation of soil erosion,data sets of land use between the late 1980s and 2000 were obtained from Landsat Thematic Mapper(TM)imagery,and spatial models were used to characterize landscape and soil erosion conditions.Also,soil erosion in response to land use and land cover change were quantified and analyzed using data from geographical information systems and remote sensing.Soil erosion by water was the dominant mode of soil loss,while soil erosion by wind was only present on a relatively small area.The degree of soil erosion was classified into five severity classes:slight,light,moderate,severe,and very severe.Soil erosion in the Liupan Mountain Region increased between the late 1980s and 2000,both in terms of acreage and severity.Moderate,severe,and very severe eroded areas accounted for 54.86%of the total land area.The lightly eroded area decreased,while the moderately eroded area increased by 368817 ha(22%)followed by severe erosion with 146552 ha(8.8%),and very severe erosion by 97067.6 ha(5.8%).Soil loss on sloping cropland increased with slope gradients.About 90%of the cropland was located on slopes less than 15°.Most of the increase in soil erosion on cropland was due to conversion of steep slopes to cropland and degradation of grassland and increased activities.Soil erosion was severe on grassland with a moderate or low grass cover and on dry land.Human activities,cultivation on steep slopes,and overgrazing of pastures were the main reasons for the increase in erosion severity.展开更多
文摘In this paper, introducing new remote sensing and geographic information technology to solve the problem of data collection and analysis, this makes the study of ecological risk assessment very quick and accurate. Taking the Shan Xin mining area of the tin mine in Lengshuijiang of Hunan Province as the research object, using the remote sensing image data of three periods in 2005, 2010 and 2015, the remote sensing image is classified carefully and the landscape classification map of the mining area is obtained. The ecological risk index is introduced and the ecological risk values are sampled and interpolated on the ArcGIS platform. The ecological risk spatial distribution map based on the landscape pattern index was obtained. The ecological risk was divided into 5 levels by using the Jenks natural classification method, and each ecological risk grade area was counted. The research results show that: from year 2005 to year 2010, landscape ecological risk trend of the mining area is growing up;the trend rising area of landscape ecological risk is mainly in the southwest and northeast of the Shan Xin mining field;the area of higher and high ecological risk is increasing year by year;and the trend of dispersed development in space is obvious;the development trend of ecological risk in the mining area is rapidly increasing;in 2010 - 2015, the higher and high ecological risk area decrease slightly with the increasing of area of grassland and residential low vulnerability of landscape types;the ecological risk area showed a slow decreasing trend. The research results provide an objective reference for decision making of ecological environment governance.
基金Under the auspices of the National Key Science and Technology Support Program of China (No. 2006BCA01A07-2)National Natural Science Foundation of China (No. 40671153)+1 种基金Hunan Land Resource Bureau Program (No. 2007-15)Hunan Educa-tion Bureau Program (No. 08C348)
文摘The Liupan Mountains is located in the southern Ningxia Hui Autonomous Region of China, which forms an important dividing line between landforms and bio-geographic regions. The populated part of the Liupan Mountains region has suffered tremendous ecological damages over time due to population pressure, excessive demand and inappropriate use of agricultural land resources. In this paper, datasets of land use between 1990 and 2000 were obtained from Landsat TM imagery, and then spatial models were used to characterize landscape conditions. Also, the relationship between the population density and land use/cover change (LUCC) was analyzed. Results indicate that cropland, forestland, and urban areas have increased by 44,186ha, 9001ha and 1550ha, respectively while the grassland area has appreciably decreased by 54,025ha in the study period. The decrease in grassland was most notable. Of the grassland lost, 49.4% was converted into cropland. The largest annual land conversion rate in the study area was less than 2%. These changes are attributed to industrial and agricultural development and population growth. To improve the eco-economic conditions in the study region, population control, urbanization and development of an ecological friendly agriculture were suggested.
基金This research was supported by program of the State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Water and Soil Conservation,Chinese Academy of Sciences and Ministry of Water Resources(No.10501-298)National Key Basic Research Program(2007CB407200)Open Research Fund of State Key Laboratory of Remote Sensing Science,Jointly Sponsored by Beijing Normal University and the Institude of Remote Sensing Applicantions of Chinese Academy of Sciences(2009KFJJ019).
文摘The Liupan Mountains are located in the southern Ningxia Hui Autonomous Region of China,that forms an important divide between landforms and biogeographic regions.The populated part of the Liupan Mountain Region has suffered tremendous ecological damage over time due to population pressure,excessive demand and inappropriate use of agricultural land resources.To present the relationship between land use/cover change and spatio-temporal variation of soil erosion,data sets of land use between the late 1980s and 2000 were obtained from Landsat Thematic Mapper(TM)imagery,and spatial models were used to characterize landscape and soil erosion conditions.Also,soil erosion in response to land use and land cover change were quantified and analyzed using data from geographical information systems and remote sensing.Soil erosion by water was the dominant mode of soil loss,while soil erosion by wind was only present on a relatively small area.The degree of soil erosion was classified into five severity classes:slight,light,moderate,severe,and very severe.Soil erosion in the Liupan Mountain Region increased between the late 1980s and 2000,both in terms of acreage and severity.Moderate,severe,and very severe eroded areas accounted for 54.86%of the total land area.The lightly eroded area decreased,while the moderately eroded area increased by 368817 ha(22%)followed by severe erosion with 146552 ha(8.8%),and very severe erosion by 97067.6 ha(5.8%).Soil loss on sloping cropland increased with slope gradients.About 90%of the cropland was located on slopes less than 15°.Most of the increase in soil erosion on cropland was due to conversion of steep slopes to cropland and degradation of grassland and increased activities.Soil erosion was severe on grassland with a moderate or low grass cover and on dry land.Human activities,cultivation on steep slopes,and overgrazing of pastures were the main reasons for the increase in erosion severity.
