Supported by RS and GIS, the land use change from 1982 to 2003 were analyzed and the impacts of land use changes on pH value, organic matter, total N, total P, total K, available N, available P, and available K in soi...Supported by RS and GIS, the land use change from 1982 to 2003 were analyzed and the impacts of land use changes on pH value, organic matter, total N, total P, total K, available N, available P, and available K in soil of Xiaojiang watershed, a typical karst agricultural region of Yunnan Province, Southwest China were assessed. The following aspects are concluded. （1） The total land use converted during the past 20 years in Xiaojiang watershed covers an area of 610.12 km^2, of which 134.29 km^2 of forestland was converted into cultivated land, and 210 km^2 of.unused land was converted into cultivated land. （2） The rapid growth of population and the economic development were the main driving forces of land use change. （3） With the change in land use, the soil properties have been changed significantly. The pH, organic matter, total N, total P, total K, available N, available P and available K in soil in 1982 were 6.3, 38.02 g·kg^-1, 1.86 g·kg^-1, 1.63 g·kg^-1, 10.94 g·kg^-1, 114.42 g·kg^-1, 11.65 mg·kg^-1 and 64.69 mg·kg^-1g, respectively; and those in 2003 were 6.73, 25.26 g·kg^-1, 1.41 g·kg^-1, 0.99 g·kg^-1, 12.6 g·kg^-1, 113.43 mg·kg^-1, 11.11 mg·kg^-1 and 151.59 mg·kg^-1, respectively. Pared samples t-test of the tested indices of soil properties indicate that those indices have changed significantly during the last 20 years. But the soil properties changed differently, due to the differences in land use change. （4） Also, with the change in land use and management measures of soil, the modifications in soil properties which developed from carbonate rocks were more sensitive than those in the soil developed from sandstone.展开更多
Firstly,this paper analyzed current situations,major practice and existing problems of under-forest economy in Henan Province.Then,it made an in-depth discussion of guiding thought,principle and objectives,constructio...Firstly,this paper analyzed current situations,major practice and existing problems of under-forest economy in Henan Province.Then,it made an in-depth discussion of guiding thought,principle and objectives,construction task and safeguarding measures of the underforest economic development plan. Besides,it analyzed benefits of the under-forest economic development plan. By 2017,the area of underforest economic land will reach 1. 60 million hm2,create output value of 155. 2 billion yuan( accounting for more than 20% of forest output value),provide 3. 27 million jobs,and will greatly increase ecological carrying capacity of construction and development of the Central Plains Economic Region( CPER).展开更多
[Objective] The research aimed to analyze a regional rainstorm weather process in north-central Henan Province. [Method] Based on the conventional meteorological observation data and the rainfall data of Henan Meteoro...[Objective] The research aimed to analyze a regional rainstorm weather process in north-central Henan Province. [Method] Based on the conventional meteorological observation data and the rainfall data of Henan Meteorological Station, the diagnostic analysis of atmospheric thermodynamics and dynamics on a rainstorm weather process in north-central Henan Province on July 19, 2010 was carried out. The characteristics of physical quantity field and the evolution of weather situation in north-central Henan Province when the rainstorm happened were studied. [Result] Western Pacific subtropical high strengthened to extend westward. The dynamic uplifting of low vortex at the middle and low layers, the strong water vapor transportation of southwest low-level jet caused the regional rainstorm weather process in north-central Henan Province. The diagnostic results of physical quantity showed that the deep, thick wet layer and the sustained water vapor convergence provided the abundant water vapor for rainstorm generation. The positive vorticity advection center developed and spread from northwest to southeast, which was favorable for the development of vertical movement. The structure maintenance of positive vorticity at the middle and low layers, negative vorticity at the middle and high levels provided the power condition for the regional rainstorm generation. The pumping effect of convergence at the middle and low layers, divergence at the high layer was favorable for the strengthening of vertical ascending motion at the low layer. The uplifting effect of dew point front at the middle and low layers triggered the release of unstable energy. The confrontation of warm and cold air was one of the important reasons for the regional rainstorm. TBB characteristic analysis showed that TBB was from -60 to -50 ℃ in north-central Henan Province in the whole strong precipitation time, and the moving speed was equivalent to that of southwest vortex. The low-value belt of TBB corresponded with the rainstorm occurrence zone in Henan, and the minimum-value center of TBB was basically consistent with the strongest center of precipitation. [Conclusion] The research provided the scientific basis for the short-term forecast of rainstorm.展开更多
Background:Regional ecosystem health assessments are the basis for the sustainable development of society.However,an ecosystem is a complex integration of ecosystem mosaics and subsystems that influence each other,mak...Background:Regional ecosystem health assessments are the basis for the sustainable development of society.However,an ecosystem is a complex integration of ecosystem mosaics and subsystems that influence each other,making it difficult to evaluate them using traditional assessment methods of linear and explicit functions.We introduce a back-propagation neural network model optimized by a genetic algorithm to evaluate ecosystem health in 16 districts in Yunnan Province.Result:(1)The model required fewer inputs to evaluate complex and nonlinear systems,avoided the need for subjective weights,and performed well in this practical application to regional ecosystem health assessment.(2)The ecosystem health in Yunnan Province was increasing,and there was a significant positive spatial autocorrelation during 2000-2020,showing that districts with high Ecosystem Health cluster together and the ecological protection policy of the region has produced a diffusion effect,leading to continuous improvement of the ecological health of the surrounding areas.High-low outlier areas of ecosystem health should be paid more attention,because of the increasing instability of local health levels.Conclusion:This study provides a methodological exploration for assessing spatial mosaics of different ecosystems at a regional scale.展开更多
基金The open foundation of physical geography of Southwest University, No.250-411109 Foundation of Science and Technology Committee of Chongqing, No.20027534+1 种基金 No.20048258 Project of Ministry of Land and Resources, No.200310400024
文摘Supported by RS and GIS, the land use change from 1982 to 2003 were analyzed and the impacts of land use changes on pH value, organic matter, total N, total P, total K, available N, available P, and available K in soil of Xiaojiang watershed, a typical karst agricultural region of Yunnan Province, Southwest China were assessed. The following aspects are concluded. （1） The total land use converted during the past 20 years in Xiaojiang watershed covers an area of 610.12 km^2, of which 134.29 km^2 of forestland was converted into cultivated land, and 210 km^2 of.unused land was converted into cultivated land. （2） The rapid growth of population and the economic development were the main driving forces of land use change. （3） With the change in land use, the soil properties have been changed significantly. The pH, organic matter, total N, total P, total K, available N, available P and available K in soil in 1982 were 6.3, 38.02 g·kg^-1, 1.86 g·kg^-1, 1.63 g·kg^-1, 10.94 g·kg^-1, 114.42 g·kg^-1, 11.65 mg·kg^-1 and 64.69 mg·kg^-1g, respectively; and those in 2003 were 6.73, 25.26 g·kg^-1, 1.41 g·kg^-1, 0.99 g·kg^-1, 12.6 g·kg^-1, 113.43 mg·kg^-1, 11.11 mg·kg^-1 and 151.59 mg·kg^-1, respectively. Pared samples t-test of the tested indices of soil properties indicate that those indices have changed significantly during the last 20 years. But the soil properties changed differently, due to the differences in land use change. （4） Also, with the change in land use and management measures of soil, the modifications in soil properties which developed from carbonate rocks were more sensitive than those in the soil developed from sandstone.
文摘Firstly,this paper analyzed current situations,major practice and existing problems of under-forest economy in Henan Province.Then,it made an in-depth discussion of guiding thought,principle and objectives,construction task and safeguarding measures of the underforest economic development plan. Besides,it analyzed benefits of the under-forest economic development plan. By 2017,the area of underforest economic land will reach 1. 60 million hm2,create output value of 155. 2 billion yuan( accounting for more than 20% of forest output value),provide 3. 27 million jobs,and will greatly increase ecological carrying capacity of construction and development of the Central Plains Economic Region( CPER).
文摘[Objective] The research aimed to analyze a regional rainstorm weather process in north-central Henan Province. [Method] Based on the conventional meteorological observation data and the rainfall data of Henan Meteorological Station, the diagnostic analysis of atmospheric thermodynamics and dynamics on a rainstorm weather process in north-central Henan Province on July 19, 2010 was carried out. The characteristics of physical quantity field and the evolution of weather situation in north-central Henan Province when the rainstorm happened were studied. [Result] Western Pacific subtropical high strengthened to extend westward. The dynamic uplifting of low vortex at the middle and low layers, the strong water vapor transportation of southwest low-level jet caused the regional rainstorm weather process in north-central Henan Province. The diagnostic results of physical quantity showed that the deep, thick wet layer and the sustained water vapor convergence provided the abundant water vapor for rainstorm generation. The positive vorticity advection center developed and spread from northwest to southeast, which was favorable for the development of vertical movement. The structure maintenance of positive vorticity at the middle and low layers, negative vorticity at the middle and high levels provided the power condition for the regional rainstorm generation. The pumping effect of convergence at the middle and low layers, divergence at the high layer was favorable for the strengthening of vertical ascending motion at the low layer. The uplifting effect of dew point front at the middle and low layers triggered the release of unstable energy. The confrontation of warm and cold air was one of the important reasons for the regional rainstorm. TBB characteristic analysis showed that TBB was from -60 to -50 ℃ in north-central Henan Province in the whole strong precipitation time, and the moving speed was equivalent to that of southwest vortex. The low-value belt of TBB corresponded with the rainstorm occurrence zone in Henan, and the minimum-value center of TBB was basically consistent with the strongest center of precipitation. [Conclusion] The research provided the scientific basis for the short-term forecast of rainstorm.
基金This work was supported by the National Natural Science Foundation of China[52078160]。
文摘Background:Regional ecosystem health assessments are the basis for the sustainable development of society.However,an ecosystem is a complex integration of ecosystem mosaics and subsystems that influence each other,making it difficult to evaluate them using traditional assessment methods of linear and explicit functions.We introduce a back-propagation neural network model optimized by a genetic algorithm to evaluate ecosystem health in 16 districts in Yunnan Province.Result:(1)The model required fewer inputs to evaluate complex and nonlinear systems,avoided the need for subjective weights,and performed well in this practical application to regional ecosystem health assessment.(2)The ecosystem health in Yunnan Province was increasing,and there was a significant positive spatial autocorrelation during 2000-2020,showing that districts with high Ecosystem Health cluster together and the ecological protection policy of the region has produced a diffusion effect,leading to continuous improvement of the ecological health of the surrounding areas.High-low outlier areas of ecosystem health should be paid more attention,because of the increasing instability of local health levels.Conclusion:This study provides a methodological exploration for assessing spatial mosaics of different ecosystems at a regional scale.
