Accompanying the development of social economy,the land use model of mountainous area,typically eco-weak area,is changing gradually. Here the establishment of eco-friendly land use model in mountainous area,will pione...Accompanying the development of social economy,the land use model of mountainous area,typically eco-weak area,is changing gradually. Here the establishment of eco-friendly land use model in mountainous area,will pioneer the model of sustainable development in that area. Concerning Qianjiang District of Chongqing Municipality,huge change of land use model,mainly embodied in the unceasing increase of construction land and gradual decrease of agricultural use land,has taken place in recent years. To explore the eco-friendly land use model in mountainous area,Qianjiang District was chosen as the study object in the present study. Via analyzing the changes in land use model,we found that related eco-environment restrictive factors mainly regional climatic change,soil texture,hydrological environment as well as soil erosion and land degradation,etc. And based on these results,we further analyzed the effect of land use change on eco-environment and the factors restricting the maintenance of eco-environment and regional development,finally put forward the counter measures for balancing land use and co-environment in mountainous area. The results will be important for the development of social economy and eco-system construction in Qianjiang District.展开更多
The present paper investigates the asymmetrical variability of the location of the north and the south equatorial ionization anomaly(EIA) crests in the East-Asian sector,along with their association with simultaneous ...The present paper investigates the asymmetrical variability of the location of the north and the south equatorial ionization anomaly(EIA) crests in the East-Asian sector,along with their association with simultaneous observations of equatorial electrojet(EEJ) strength,geomagnetic activity index,and solar flux index during the 2002-2003 sudden stratospheric wanning(SSW) event.Analysis of these observations indicates the existence of a large-scale quasi 16-day periodic meridional movement in both EIA crests,and also reveals a strong correlation between the quasi 16-day oscillation in geomagnetic latitudes of the EIA crest and EEJ strength.The latitude of the northern/southern EIA crest and the EEJ strength indicate that obvious synchronous periodic oscillations were in-phase in the northern and southern hemisphere when the SSW occurred.In addition,it is also found that both the EIA crest location and amplitude of the periodic movement of the EIA locations exhibit hemispheric asymmetry.The amplitude of the periodic movement of the EIA location in the southern hemisphere is larger than that of the northern hemisphere,and the southern EIA crest is further off from the equator than the north one.Understanding these asymmetries requires a combination of mechanisms that involve at least trans-equator meridional winds and the position of a sub-solar point;however,potential disturbances in neutral winds associated with the SSW may additionally complicate the equatorial ionospheric dynamics.展开更多
文摘Accompanying the development of social economy,the land use model of mountainous area,typically eco-weak area,is changing gradually. Here the establishment of eco-friendly land use model in mountainous area,will pioneer the model of sustainable development in that area. Concerning Qianjiang District of Chongqing Municipality,huge change of land use model,mainly embodied in the unceasing increase of construction land and gradual decrease of agricultural use land,has taken place in recent years. To explore the eco-friendly land use model in mountainous area,Qianjiang District was chosen as the study object in the present study. Via analyzing the changes in land use model,we found that related eco-environment restrictive factors mainly regional climatic change,soil texture,hydrological environment as well as soil erosion and land degradation,etc. And based on these results,we further analyzed the effect of land use change on eco-environment and the factors restricting the maintenance of eco-environment and regional development,finally put forward the counter measures for balancing land use and co-environment in mountainous area. The results will be important for the development of social economy and eco-system construction in Qianjiang District.
基金supported by the National Natural Science Foundation of China(Grant Nos.41274156, 41464006 & 41674157)Guangxi Natural Science Foundation(Grant No.2014GXNSFAA118282)+1 种基金L.Goncharenko and S R.Zhang have been supported through US National Science Foundation(Grant No. AGS-1132267)the Haystack Observatory was also supported through a cooperative agreement(Grant No.AGS-1242204) between the US National Science Foundation and MIT
文摘The present paper investigates the asymmetrical variability of the location of the north and the south equatorial ionization anomaly(EIA) crests in the East-Asian sector,along with their association with simultaneous observations of equatorial electrojet(EEJ) strength,geomagnetic activity index,and solar flux index during the 2002-2003 sudden stratospheric wanning(SSW) event.Analysis of these observations indicates the existence of a large-scale quasi 16-day periodic meridional movement in both EIA crests,and also reveals a strong correlation between the quasi 16-day oscillation in geomagnetic latitudes of the EIA crest and EEJ strength.The latitude of the northern/southern EIA crest and the EEJ strength indicate that obvious synchronous periodic oscillations were in-phase in the northern and southern hemisphere when the SSW occurred.In addition,it is also found that both the EIA crest location and amplitude of the periodic movement of the EIA locations exhibit hemispheric asymmetry.The amplitude of the periodic movement of the EIA location in the southern hemisphere is larger than that of the northern hemisphere,and the southern EIA crest is further off from the equator than the north one.Understanding these asymmetries requires a combination of mechanisms that involve at least trans-equator meridional winds and the position of a sub-solar point;however,potential disturbances in neutral winds associated with the SSW may additionally complicate the equatorial ionospheric dynamics.
