Carbon storage in desertified lands: A case study from North China     

Feng Qi  Cheng Guodong  Endo Kunihiko 《GeoJournal》2000,51(3):181-189

Based on the organic and carbonate carbon levels of the top 1 m of soil from desertified soils of Northern People's Republic of China, climatic and vegetative cover zones have been derived for some 334000 km² of desertification-prone lands. Regional accumulations of pedogenic carbonates were examined relative to precipitation, altitude, and temperature. The largest accumulations of pedogenic carbonates were found in Calcic soils in warm, arid areas. Accumulated organic carbon predominated in soils under Betula platyphylla. In the naturally desertified lands of China, for example, the top 1.0-m soil layer contains some 7.84 Pg of organic carbon and 14.9 Pg of carbonate carbon. Total stored carbon, including carbonate carbon, is 1.8-fold more than organic carbon alone. The carbon released through land desertification in China may be an important factor affecting changes in concentrations of greenhouse gases worldwide.  相似文献   

Influences of local factors on permafrost occurrence and their implications for Qinghai-Xizang Railway design   总被引：6，自引：0，他引：6  

CHENG Guodong State Key Laboratory of Frozen Soil Engineering  Cold  Arid Regions Environmental  Engineering Research Institute  Chinese 《中国科学D辑(英文版)》2004,47(8):704-709

Permafrost is a product of long-term energy ex-change between the atmosphere and the ground. Macro-scale distribution of permafrost is controlled overall by climate. However, site-specific variables such as terrain conditions, snow cover, soil/rock type, and moisture content can significantly modify the ef-fect of climate, resulting in localized anomalies in permafrost distribution[1,2]. These factors cause distur-bances to normal thermal regimes and can determine the presence and absence of p…  相似文献   

青藏高原多年冻土区路基工程地质研究   总被引：24，自引：0，他引：24       下载免费PDF全文

程国栋 《第四纪研究》2003,23(2):134-141

回顾了青藏高原多年冻土区近年来所开展的路基工程地质研究工作,指出冻土工程地质勘探在方法上有很大进展,总结出了一整套冻土区工程地质勘察的暂行规定和细则.近年来的工作特别注重了对冻土地温和含冰量的研究,这是冻土工程地质中特有的十分重要的参数.在大量观测试验的基础上,总结出了有关路基稳定性的若干重要结论.据此提出,在气候转暖的背景下,高温冻土区筑路必须采用"冷却路基"的方法.为寻求气候转暖的对策,冻土工程地质预报的研究也取得了很大的进展,对冻土区路基工程地质的研究方向提出了新的建议.  相似文献   

影响青藏高原植被生理过程与大气CO2浓度及气候变化的相互作用   总被引：11，自引：0，他引：11  

范广洲  程国栋 《大气科学》2002,26(4):509-518

利用一陆面过程模式,初步模拟研究了青藏高原夏季风盛行期植被生理过程与大气CO2浓度及气候变化的相互作用。结果表明,气候以及大气CO2浓度变化对青藏高原地区的植被生理过程有较明显的影响,高温、高温和高CO2浓度将加强高原植被的光合作用和呼吸作用,有利于植被生长。高原植被也可通过生理过程,产生净CO2呼收,降低大气CO2含量,起到调整温室效应的作用,从而影响全球气候变化;当气温升高、大气CO2增加时,这种作用更加有效。青藏高原地区大气CO2浓度加倍,对高原地区气候的直接影响不明显。植被的存在也会影响区域气候变化,并可通过改变高原热源,进而影响高原及其周边地区气候变化。文中还归纳出了植被生理与气候相互作用的简单概念模型。  相似文献   

Magnetic investigation of heavy metals contamination in urban topsoils around the East Lake, Wuhan, China   总被引：2，自引：0，他引：2  

Tao Yang  Qingsheng Liu  Lungsang Chan  Guodong Cao 《Geophysical Journal International》2007,171(2):603-612

Magnetic measurements and heavy metal analyses were performed on 133 samples from the urban soils around the East Lake in Wuhan, China. Samples were collected from four areas with different environmental settings: a heavy industrial area well known for thermal power generation and steel works; villages located in the downwind area of the industrial area; a main road with heavy traffic and roads around the East Lake. Results show that concentrations of magnetic particle and heavy metals in urban topsoils are significantly elevated due to the input of coarser-grained magnetite from industrial (e.g. power generation and steel production) and other anthropogenic activities (e.g. vehicle emissions). Concentration-related magnetic parameters, for example, magnetic susceptibility, saturation isothermal remanent magnetization and anhysteretic remanent magnetization, significantly correlate with the concentration of heavy metals. Moreover, in terms of grain sizes, the magnetic particles of different origins can be efficiently discriminated at the studied region. Therefore, magnetic measurements provide a basis for discrimination and identification of different contamination sources, and can be used as an economic alternative to chemical analysis when mapping heavy metal contamination in urban soil around the East Lake region, Wuhan, China.  相似文献   

反求水文地质参数的SWIFT法     

刘国东 《地球科学与环境学报》1990,(2)

单纯形与罚函数相结合的SWIFT方法应用于水文地质计算,可反求具有界限约束的水文地质参数。通过实例计算,找到了一个较好的初始单纯形的步长乘子V和单纯形缩小因子rv,从而减少目标函数的计算次数,节省机时。  相似文献   

Simulation of energy and water balance in Soil-Vegetation-Atmosphere Transfer system in the mountain area of Heihe River Basin at Hexi Corridor of northwest China   总被引：17，自引：2，他引：15  

KANG Ersi  CHENG Guodong  SONG Kechao  JIN Bowen  LIU Xiande & WANG Jinye . Cold  Arid Regions Environmental  Engineering Research Institute  Chinese Academy of Sciences  Lanzhou  China  . State Key Laboratory of Frozen Soil Engineering  Chinese Academy of Sciences  Lanzhou  China  . Academy of Water Resources Conservation Forest of Qilian Mountains  Gansu Province  Zhangye  China 《中国科学D辑(英文版)》2005,48(4):538-548

Under the background of global water cycle, theregional water cycle systems of the arid inland regionsof northwest China are characterized by the fact thatthe area is composed of various relatively independentinland river basins, each of which is a system of inter-related climate, hydrology, water resources, ecologyand environment. An inland river basin consists of amountain area and the plain and basin area in front ofthe mountains. The vertical landscape zonality of aninland river basin can …  相似文献   

中国冻土研究近今进展   总被引：13，自引：4，他引：9  

程国栋 《地理学报》1990,45(2):220-224

近年来,在南极和青藏高原发现了多种成因的厚层地下冰。冰土的水分迁移、冻胀、成冰机制、强度和蠕变等的研究进一步深化。冻土改造和利用兴起,在寒区砂金矿开采、热桩利用等方面有了良好的开端。  相似文献   

中国生态足迹、多样性与承载力的计算与分析   总被引：2，自引：2，他引：0  

徐中民  程国栋  张志强  Paul H Templet  Yongyuan YIN 《地理学报(英文版)》2003,13(1)

The ecological footprint of China's provinces is calculated in this paper. In general,China's development is not sustainable because its ecological footprint is beyond its bio-capacity. Thesustainability status of each province in China is presented. Ulanowicz's development capacityformula was introduced to discuss the relationship of development and ecological footprint's diversity.The diversity of ecological impacts is related to the efficiency with which an economy uses thesource and sink services of the environment and, in this view, should be a factor in economic output.Development capacity, calculated from the ecological footprint and its diversity, is used to examinethe relationship of economic output with the structure of the ecological footprint. China and itsprovinces are presented as a case study to investigate this relationship. The analysis shows thatfootprint capacity is significant in predicting economic output. Increasing the ecological footprint'sdiversity is presented as another way to increase development capacity.  相似文献   

Studies on frozen ground of China   总被引：5，自引：0，他引：5  

ZHAO Lin  CHENG Guodong  DING Yongjian 《地理学报(英文版)》2004,14(4):411-416

1ThestatusoffrozengroundinChinaBased on previous studies, Zhou and Guo (1982) summarized the distribution characteristics of permafrost in China and indicated that the permafrost area in China is about 215×104 km2, in which about 163.4×104 km2 is on the Tibetan Plateau. After mapping and zonation of frozen ground in 1983, Xu and Wang suggested that the areas of permafrost, seasonally frozen ground and temporal frozen ground in China were 206.8×104 km2, 513.7×104 km2 and 229.1×104 km2 …  相似文献