Taking social statistic data as basic data,this paper extended the meaning of urban land uses,highlighted the meaning of urban land uses in modern urbanization,which includes direct,indirect and induced land uses,quan...Taking social statistic data as basic data,this paper extended the meaning of urban land uses,highlighted the meaning of urban land uses in modern urbanization,which includes direct,indirect and induced land uses,quantitatively simulated the indirect and induced land uses by the substitution method of agricultural consumption and urban carbon emission and then,analyzed the spatiotemporal evolution of urban land uses in China during 1952–2005 by spatial analysis tool of Geographic Information System. The results indicate that the area of urban land use in China had been increasing since 1952,showing an inversed pyramid structure,i.e.,the direct<the indirect<the induced. Specifically,Chinese urban land use has changed from concentrated distribution in Northwest China to balanced spatial distribution,and the eastern coastal area is under great pressure. Moreover,the northeastern region has moved into the induced dominant stage,while the western region remains at the indirect dominant stage. Finally,it is proposed that in order to guarantee the future demand of urban land use in China,ensuring the induced land use in the eastern region should be taken as a priority goal of Chinese developing policy.展开更多
[Objective] This study was to provide basis for the scientific management of land use in Haihe River Basin (HRB) through the quantitative exploration of the land use conversion, changes of intensity and spatial dist...[Objective] This study was to provide basis for the scientific management of land use in Haihe River Basin (HRB) through the quantitative exploration of the land use conversion, changes of intensity and spatial distribution in this region. [Method] With the support of remote sensing technology and geographic information technology, the land use maps of the study area in 40 years (1970-2010) were in- terpreted and plotted. Four kinds of tupu, namely, land use change tupu, process tupu, arising tupu and evolution mode tupu were built through the spatial overlay of the land use maps to analyze the change rules of land use patterns. [Result] The conversion of arable land to construction land was the main characteristics of land use changes in HRB for the 40 years; the area of non-stable region accounted for 35% of the total, indicating that the land use changed remarkably, thus, it was nec- essary to strengthen the scientific land management in HRB; the new conversions to all land use patterns were all the lowest in 1980-1990, indicating that land use changed slowly during this period. [Conclusion] The results indicate that, compared with conventional transfer matrix method, geo-information tupu has obvious advantage in analyzing land use changes that it can demonstrate the spatial distribution of interest region, display the multi-dimensional spatial information.展开更多
The Loess Plateau of China has experienced a lengthy drought and severe soil erosion.Changes in precipitation and land use largely determine the dynamics of runoff and sediment yield in this region. Trend and mutation...The Loess Plateau of China has experienced a lengthy drought and severe soil erosion.Changes in precipitation and land use largely determine the dynamics of runoff and sediment yield in this region. Trend and mutation analyses were performed on hydrological data(1981–2012) from the Yanwachuan watershed in the Loess Plateau Gully Region to study the evolution characteristics of runoff and sediment yield. A time-series contrasting method also was used to evaluate the effects of precipitation and soil and water conservation(SWC) on runoff and sediment yield. Annual sediment yield declined markedly from 1981 to 2012 although there was no significant change in annual precipitation and annual runoff. Change points of annual runoff and annual sediment yield occurred in 1996 and 1997,respectively. Compared with that in the baseline period(1981–1996), annual runoff and annual sediment yield in the change period(1997–2012)decreased by 17.0% and 76.0%, respectively, but annual precipitation increased by 6.3%. Runoff decreased in the flood season and normal season, but increased in the dry season, while sediment yield significantly declined in the whole study period. The SWC measures contributed significantly to the reduction of annual runoff(137.9%) and annual sediment yield(135%) and were more important than precipitation. Biological measures(forestland and grassland) accounted for 61.04% of total runoff reduction, while engineering measures(terraces and dams) accounted for 102.84% of total sediment yield reduction. Furthermore, SWC measures had positive ecological effects. This study provides a scientific basis for soil erosion control on the Loess Plateau.展开更多
基金Under the auspices of Key Program of National Natural Science Foundation of China (No. 40535026)
文摘Taking social statistic data as basic data,this paper extended the meaning of urban land uses,highlighted the meaning of urban land uses in modern urbanization,which includes direct,indirect and induced land uses,quantitatively simulated the indirect and induced land uses by the substitution method of agricultural consumption and urban carbon emission and then,analyzed the spatiotemporal evolution of urban land uses in China during 1952–2005 by spatial analysis tool of Geographic Information System. The results indicate that the area of urban land use in China had been increasing since 1952,showing an inversed pyramid structure,i.e.,the direct<the indirect<the induced. Specifically,Chinese urban land use has changed from concentrated distribution in Northwest China to balanced spatial distribution,and the eastern coastal area is under great pressure. Moreover,the northeastern region has moved into the induced dominant stage,while the western region remains at the indirect dominant stage. Finally,it is proposed that in order to guarantee the future demand of urban land use in China,ensuring the induced land use in the eastern region should be taken as a priority goal of Chinese developing policy.
基金Supported by the Key Technology R&D Program of Hebei Province (10277105D)the Funds of the Chinese Academy of Sciences for Key Topics in Innovation Engineering(KSCX-EW-J-5)~~
文摘[Objective] This study was to provide basis for the scientific management of land use in Haihe River Basin (HRB) through the quantitative exploration of the land use conversion, changes of intensity and spatial distribution in this region. [Method] With the support of remote sensing technology and geographic information technology, the land use maps of the study area in 40 years (1970-2010) were in- terpreted and plotted. Four kinds of tupu, namely, land use change tupu, process tupu, arising tupu and evolution mode tupu were built through the spatial overlay of the land use maps to analyze the change rules of land use patterns. [Result] The conversion of arable land to construction land was the main characteristics of land use changes in HRB for the 40 years; the area of non-stable region accounted for 35% of the total, indicating that the land use changed remarkably, thus, it was nec- essary to strengthen the scientific land management in HRB; the new conversions to all land use patterns were all the lowest in 1980-1990, indicating that land use changed slowly during this period. [Conclusion] The results indicate that, compared with conventional transfer matrix method, geo-information tupu has obvious advantage in analyzing land use changes that it can demonstrate the spatial distribution of interest region, display the multi-dimensional spatial information.
基金supported by the National Natural Science Foundation of China (51239009, 41171034)Shaanxi Provincial Natural Science Foundation of China (Key) Project (2013JZ012)+1 种基金Shaanxi Provincial Key Laboratory Project of Department of Education (14JS059)Shaanxi Provincial Water Conservancy Science and Technology Project (2016slkj-11)
文摘The Loess Plateau of China has experienced a lengthy drought and severe soil erosion.Changes in precipitation and land use largely determine the dynamics of runoff and sediment yield in this region. Trend and mutation analyses were performed on hydrological data(1981–2012) from the Yanwachuan watershed in the Loess Plateau Gully Region to study the evolution characteristics of runoff and sediment yield. A time-series contrasting method also was used to evaluate the effects of precipitation and soil and water conservation(SWC) on runoff and sediment yield. Annual sediment yield declined markedly from 1981 to 2012 although there was no significant change in annual precipitation and annual runoff. Change points of annual runoff and annual sediment yield occurred in 1996 and 1997,respectively. Compared with that in the baseline period(1981–1996), annual runoff and annual sediment yield in the change period(1997–2012)decreased by 17.0% and 76.0%, respectively, but annual precipitation increased by 6.3%. Runoff decreased in the flood season and normal season, but increased in the dry season, while sediment yield significantly declined in the whole study period. The SWC measures contributed significantly to the reduction of annual runoff(137.9%) and annual sediment yield(135%) and were more important than precipitation. Biological measures(forestland and grassland) accounted for 61.04% of total runoff reduction, while engineering measures(terraces and dams) accounted for 102.84% of total sediment yield reduction. Furthermore, SWC measures had positive ecological effects. This study provides a scientific basis for soil erosion control on the Loess Plateau.