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Spatial distribution of surface rock fragment on hillslopes in a small catchment in wind-water erosion crisscross region of the Loess Plateau

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Science china Earth sciences 2008年第6期51卷 862-870页

作者： ZHU YuanJun1,2.. shao MingAn1 1 {2. of Soil and Water Conservation, {2..Academy of sciences and Ministry of Water resources, Northwest Agriculture and Forestry University, Yangling 712..0, china 2..1} of geographical sciences and natural resources research, {2..Academy of sciences, beijing 100101, china institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water Resources Northwest Agriculture and Forestry University Yangling China institute of geographical {{2.and natural resources research Chinese Academy of Sciences Beijing China

The cover and size distributions of surface rock fragment in hillslopes were investigated by using digital photographing and treating technique in a small catchment in wind-water erosion crisscross region of the Loess Plateau. The results indicated that the maximal cover of rock fragment was pre-sented at mid-position in steep hillslope. Rock fragment presented a general decreasing-trend along the hillslope in gentle hillslope. Rock fragment cover was positively related to gradient, rock fragment size decreased generally along the hillslope, and the size reduced with the gradient. The mean size of rock fragment was at a range of 6―2..mm in the steep hillslope, rock fragment size > 50 mm was rarely presented. The covers of rock fragment at different positions were markedly related to the quantities of rock fragment he area of rock fragment of 2..0 mm accounted for 60% or more of the total area, dominating the distribution of rock fragment in the hillslopes.

关键词： wind-water erosion crisscross region of the Loess Plateau small catchment hillslope surface rock fragment cover and size

Temperature variations recovered from tree-rings in the middle Qilian Mountain over the last millennium

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Science china Earth sciences 2005年第4期48卷 521-529页

作者： LIU Xiaohong1,2..QIN Dahe1, shao xuemei , CheN Tuo1 & REN Jiawen12... Cold and Arid Regions Environmental and Engineering {2..institute, chinese Academy of sciences, Lanzhou 730000, china 2..institute of geographical sciences and natural resources {2.. chinese Academy of sciences, beijing 100101, china Cold and Arid Regions Environmental and Engineering research institute Chinese Academy of Sciences Lanzhou China institute of geographical {{2.and natural resources research Chinese Academy of Sciences Beijing China

Based on the cross-dated tree-ring samples collected from the middle Qilian Moun- tain, a standard ring-width chronology had been developed, which covered the period AD 1000 to 2..0. The correlations between the chronology and climatic records from the nearby meteorological stations indicated that temperature was the dominant climatic factor for tree growth at upper timberline, and the most important climatic factor for the tree growth in the area was the mean temperature from previous December to current April. The temperature variations recovered from the ring-width data showed a cold period during the “Little Ice Age” and the con- tinuous warming during the twentieth century. Comparison between the ring-width chronology and δ18O records from the Dunde ice core in the Qilian Mountain indicated that there was a con- sistent trend in both time series. A significant correlation existed between our ring-width chro- nology and the Northern hemispheric temperature, suggesting that the climate changes in the Qilian Mountain were not only driven by regional factors, but also responsive to the global cli- mate.

关键词： middle Qilian Mountain, tree-ring width chronology, temperature variations.

Water Security Problem in North china: research and Perspective

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Pedosphere 2005年第5期15卷 563-575页

作者： XIA Jun LIU Meng-Yu JIA shao-Feng Key Laboratory of Water Cycle ＆Related Land Surface Processes Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 （China） State Key Laboratory of Water resources ＆ Hydropower Engineering sciences Wuhan University Wuhan 430072（China） Center for Agricultural resources research Institute of Genetic and Developmental Biology Chinese Academy of Sciences Shijiazhuang 050021 （China）

This paper addresses the emergence of water security problems in North china with the aim of highlighting key waterresources management and water security issues for the long-term development of North china. Three key problemsrelated to water resources and security issues in North china in the 2..t century are addressed, namely 1) the watercycle under environmental change, 2..agricultural water saving, and 3) water security. Development of international{12. related to these issues is also reviewed. The {12. plan developed recently by the chinese Academy of sciences(CAS) is discussed and suggestions on {12. and development of water resources science in North china are *** to focus on experimental catchments and dedicated {12. stations, a detailed knowledge of the water cycle onNorth china farmland has been compiled. A range of techniques that include isotope tracers has been used to acquirehydrologic data. Much {12. has been devoted to developing distributed hydrological models at different scales. In thewell irrigation district, five different water saving irrigation regimes have been investigated, and these regimes have hadwidespread application, and reduced water use 60-150 mm while they increased water use efficiency (WUE) by 2..-30%.Furthermore, preventing water pollution is the most essential step to ensure North china’s water security.

关键词： environmental change North china water cycle water resources water security

Current situation and trend of arable land change in china

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Journal of geographical sciences 2000年第3期10卷 28-34页

作者： Received date: 1999-11-02..ENG Xiang-jing1 , JIA shao-feng 2..1.institute of Population {2.. People’s University of china, beijing 100872..3} 2..institute of Geographic sciences and natural {12. {2.. chinese Academy of sciences, Beiji 中国人民大学北京中科院地理科学与资源所北京

How to protect arable land in the process of economic development and urbanization is a critical issue in china. In this paper, an attempt is made to analyze the situation of arable land change in china and it's relationship with population growth, economic development and urbanization. In depth analysis is also made in different regions. Forecasting is conducted to show the trend of arable land change in china based on the results of correlation analysis. Some suggestions are put forward for the policy making of reasonable utilization and protection of arable land in the future.

关键词： arable land change population growth economic development urbanization

The Climatic Signals in Tree-ring Chronologies of Qilian Juniper and Qinghai Spruce With Reference to the Aspects in Qinghainan Mountain in Northeast Tibetan Plateau

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The Climatic Signals in Tree-ring Chronologies of Qilian Jun...

research progress of socio-economic water cycle in china

第四届青藏高原国际学术研讨会

作者： Liang Eryuan~(1,2..shao {2.~(1,2..1 {2..of geographical sciences and natural resources research, chinese Academy of sciences, {12., 100101 2..2..of Tibetan Plateau research, chinese Academy of sciences, {12., 100085

Qilian juniper (Sabina przewalskii Kom.) and Qinghai spruce (Picea crassifolia Kom.) are endemic and widespread species in northeast Tibetan Plateau. The existence of mixed forests of two species provides a rare opportunity to compare their growth behaviour and climate-tree growth relationships under the same environment. herein, two mixed forests at western (H1 and H2..and eastern (H3 and H4) aspects of Qinghainan Mts. (37°2..05 98°40.007, 3736-3800 m) in the east margin of Qaidam Basin were selected. H1, 3 and H2..4 are Qilian juniper and Qinghai spruce forests sites, respectively.

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Journal of geographical sciences 2002年第1期12卷 114-120页

作者： JIA shao-feng, WANG Guo, ZHANG Shi-feng, YU Gui-rui, WANG Jin-xia, XIA Jun (institute of Geographic {{2.and natural resources research, CAS, beijing 100101,china) institute of Geographic sciences and {{2.resources research CAS 北京 100101

china has made great progress in the study of socio-economic water cycle. She has completed national water resources appraisement and medium to long-term water supply planning. She has been engaging in study on water-deficient regions in North{2..and Northwest{2..for about half a century. For solving water shortage problem in northern{2.. she has put forward the famous South-to-North Water Transferring Projects, which has been set as one of the four biggest national projects in the Tenth Five-Year-Plan period although there are still debates. For promoting water use efficiency,{2..has been reforming her water management system, including water right system and water price system. There has already been a case of water right purchase.{2..has also done a lot of research on the interaction between human activity, water and ecosystem. For meeting the need of sustainability and coordinating water resources development and environmental protection, the study of ecological water requirement became very hot in recent years. There are three focuses of socio-economic water cycle study now in{2.. water transfer projects from the south to the north, water resources management and ecological water requirement.

关键词： water cycle socio-economic water cycle sustainable water resources management water security

Estimation of soil organic carbon reservoir in china

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Journal of geographical sciences 2001年第1期11卷 3-13页

作者： WANG shao-qiang1, ZHOU Cheng-hu1, LI Ke-rang1, ZHU Song-li{2.HUANG Fang-hong1 (1.The State Key Laboratory of resources and Environment Information System, {{2.of Geographic sciences and natural resources research, CAS, beijing 100101, china The State Key Laboratory of resources and Environment Information System Institute of Geographic Sciences and Natural Resources Research CAS Beijing China institute of Environment Science Beijing Normal University Beijing China

The paper respectively adopted physio-chemical properties of every soil stratum from {2.3 soil profiles of the second national soil survey. The corresponding carbon content of soils is estimated by utilizing conversion coefficient 0.58. In the second soil survey, the total amount of soil organic carbon is about 9{2.18xl08t and carbon density is about 10.53 kgC/m{2.n china according to the area of 877.63x106hm{2.urveyed throughout the country. The spatial distribution characteristics of soil organic carbon in china is that the carbon storage increases when latitude increases in eastern china and the carbon storage decreases when longitude reduces in northern china. A transitional zone with great variation in carbon storage exists. Moreover, there is an increasing tendency of carbon density with decrease of latitude in western china. Soil circle is of great significance to global change, but with substantial difference in soil spatial distribution throughout the country. Because the structure of soil is inhomogeneous, it could bring some mistakes in estimating soil carbon reservoirs. It is necessary to farther resolve soil respiration and organic matter conversion and other questions by developing uniform and normal methods of measurement and sampling.

关键词： terrestrial ecosystem global change soil carbon reservoir carbon cycle

Flooding 1990s along the Yangtze River, has it concern of global warming?

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Journal of geographical sciences 2001年第1期11卷 43-52页

作者： GONG Dao-yi1, ZHU Jin-hong2..WANG shao-wu2..1. Key Laboratory of Environmental Change and natural Disaster, {2..of resources Science, beijing Normal University, beijing 100875, china 2..Department of Geophysics, Peking University, beijing 100871, Key Laboratory of Environmental Change and natural Disaster Institute of Resources Science Beijing Normal University Beijing China Department of Geophysics Peking University Beijing China

There were a series of severe floods along the middle to lower reaches of the Yangtze River (Changjiang River) in china during the 1990s. The extensive summer (June, July and August) precipitation is mostly responsible for the flooding. The summer rainfall in the 1980s and the 1990s is much higher than that in the previous 3 decades. The means for 1990–1999 is +87.62..m above normal, marked the 1990s the wettest decade since the 1950s. Six stations with a time span of 1880–1999 are selected to establish century-long rainfall series. This series also shows that the 1990s is the wettest decade during the last 12..years. In the wettest 12..ears, four occurred in the 1990s (1991, 1996, 1998 and 1999). Both global and china’s temperature show there is a relative lower air temperature during the 1960–1970s, and a rapid warming in the 1980–1990s. Comparisons of rainfall between 1960–1979 and 1980–1999 show there are dramatic changes. In the cold period 1960–1979, the summer rainfall along the Yangtze River is 3.8 % to 4.7 % below the normal, during the warm period 1980–1999, over 8.4 % to 18.2.. of summer rainfall occurs. Over the whole eastern china, the summer rainfall shows opposite spatial patterns from the 1960–1970s to 1980–1990s. The consistent trend toward more rainfall with global warming is also presented by the greenhouse scenario modeling. A millennial Drought/flood Index for the middle to lower reaches of the Yangtze River showed that although the surplus summer rainfall in the 1990s is the severest during the past 150 years, it is not outstanding in the context of past millennium. Power spectra of the Drought/flood Index show significant interdecadal periods at 33.3 and 11.8 years. Thus, both the {52. interdecadal variations and the global warming may play important roles in the frequent floods witnessed during the last two decades.

关键词： summer rainfall Yangtze River global warming interdecadal variation

Spatial Characteristics of Soil Organic Carbon Storage in china's Croplands

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Pedosphere 2005年第4期15卷 417-423页

作者： WANG shao-Qiang YU Gui-Rui ZHAO Qian-Jun NIU Dong CheN Qing-Mei WU Zhi-Feng institute of Geographic sciences and {{2.resources research Beijing 10010 （China）. Guangdong institute of Eco-Environment and Soil Science Guangzhou 510650 （China）

The soil organic carbon (SOC) pool is the largest component of terrestrial carbon pools. With the construction of a geographically referenced database taken from the second national general soil survey materials and based on 1546 typical cropland soil profiles, the paddy field and dryland SOC storage among six regions of china were systematically quantified to characterize the spatial pattern of cropland SOC storage in china and to examine the relationship between mean annual temperature, precipitation, soil texture features and SOC content. In all regions, paddy soils had higher SOC storage than dryland soils, and cropland SOC content was the highest in Southwest china. Climate controlled the spatial distribution of SOC in both paddy and dryland soils, with SOC storage increasing with increasing precipitation and decreasing with increasing temperature.

关键词： carbon storage cropland soil organic carbon spatial characteristics