Author:

Lei Wenfang (Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029)

Title:

Characteristics, concentration and size distribution of desert aerosols over the Heihe region

Publisher:

Plateau Meteorology. 12(2): 170-179

Date:

1993

Language:

Chinese

Classification:

2B, 2Eb

Region:

Gansu, China

Summary:

In the Heihe region the concentration of desert aerosols is usually low; fine particles are predominant. Striking increases in dust concentration can be observed during dust blowing periods, particularly coarse particles (diameter {D} of between 2.0 and 10.0 m) which increase more than 20 times. They account for 9.6 percent of the total number of particles, much higher than on clear days (1.9 percent). Moderate precipitation removal is the most effective for desert particles with D3/4 4.0 | Ìm (90 percent), but is not as effective with all particles, specially to those with D£3/40.4 | Ìm. Therefore desert aerosols with 0.5£1/4D£1/44.0 | Ìm may be transported on long-distances. Movements of large-scale air masses may greatly change the concentration of desert aerosols. The diurnal variation of background desert aerosol is mainly controlled by air dispersion or dilution. There are three sources of background desert aerosols: global background aerosols, large-range background dust and local soil dust. The measured size distribution of desert aerosols is characterized by three modes, which can be fitted into the sum of three log-normal distribution functions.

Author:

Li Houqiang and Ai Nanshan

Title:

The intermittence, stable distribution and characteristics of wind-sand turbulent flow

Publisher:

Journal of Desert Research. 13(1):11-20

Date:

1993

Language:

Chinese

Classification:

2B

Summary:

Based on the heterogeneity and intermittence of wind-sand turbulent flows this report discusses the relationship between percentages of sand and height of flow. The formula M (h>Ho)=Ch^-D is derived from the stable contribution theory. This results in the factual dimension D=2.36 (h > 10 cm), D= 1.465 (h < 10 cm), the velocity distribution w(lul)=921ul-D/2-1 and the sand particle diffusion <l x (t)l > µ t^2/D. According to the travelling solution of the kdv Burgers equation, the scaling law for wind-sand flow v/bx, +Dlnh=A was found; it reveals the inherent relation among the dissipation v, dispersion b wind velocity x, and height h. In addition, the starting radius of sand particles, the starting wind velocity and the multifractal characteristics of wind-sand flow are calculated and discussed.

Authors:

Li Jiangteng (Editor)

Title:

Papers on the environment and regional development in arid and semi-arid regions in China

Publisher:

Vientiane Press pp. 268

Date:

1990

Language:

Chinese

Available:

Chinese Academy of Forestry

Classification:

6Aa, 6Ab, 6Ac, 6Ad

Region:

China

Summary:

In this collection of papers recent research achievements on the environment, geography, meteorology, hydrology, desert science, glacier geology, ecology and air pollution of arid and semi-arid regions in China are presented. The formation and development of arid geographical environments including land degradation trends and improvement strategies in relation to both natural factors and human activities are discussed. Regional desertification and drought intensification predictions are also made and key issues for regional development and environmental improvement of arid regions in this century are identified. The papers contain a series of important theoretical and practical solutions to desertification control, ecological maintenance and regional development for arid and semi-arid regions in China.

Author:

Li Jin

Title:

Model for developing artificial vegetation in Horqin Sandy Land

Publisher:

Chinese Journal of Applied Ecology. 5(1):46-71

Date:

1994

Language:

Chinese

Classification:

3Ab, 6Cd

Region:

Inner Mongolia, China

Summary:

Horqin Sandy Land is a typical sandy soil steppe in northern China which covers 40 000 km². Annual precipitation varies between 320 and 460 mm and falls mostly from June to August; moisture content is 0-180 cm and the shifting sand layer ranges from three to tour percent. According to the research of Liu Yingxin, et al. the succession series of psammophytes in sandyland are as follows: Agriophyllum spuarrosum, Salix gordejevii, Artemisia halodendron, Perennial herba, e.g. Agropyron cristatum, shrubs, e.g. Ephedra sinica, Prunus sibirica and trees (sparse Ulmus pumila grassland). Based on the above-mentioned site conditions, model artificial vegetation should include: a landscape of sparse wood grassland with shrubs as main species and trees as secondary species; interdune depressions with a water table higher than four to five meters suitable for planting Pinus sylvestris var. mongolica; windward slopes of sand dunes suitable for Artemisia halodendron, Caragana microphylla and leeward slopes of sand dunes suitable for Salix gordejevii.

Author:

Li Qusheng (Changchun Institute of Geography, Academia Sinica)

Title:

The formation of Songnen Sandy Land and changes in the environment

Publisher:

Journal of Desert Research. 11(3)

Date:

1991

Language:

Chinese

Classification:

2B, 4Aa

Region:

Northeast of China

Summary:

The paper studies formation factors of sandyland, characteristics of grains, composition of heavy minerals and the surface micro-structure of quartz. Songnen Sandy Land is believed to have come from the alluvial sand of Songhua Jiang and Nen Jiang Plain through wind erosion, transportation and deposition. There are two or three layers of paleosol in the sandyland. The results of Thermoluminescene, 14C and archaeological analysis indicate that this sandyland experienced tour fixed periods and tour shifting periods after it formed in the early Holocene. Paleo-environments in the west Songhua Jiang and Nen Jiang Plain during the Holocene were reconstructed according to changes in sandyland and pollen characteristics of the paleosol.

Author:

Li Shenggong

Title:

A preliminary study of vegetation and desertification control in the Shiquanhe River Valley

Publisher:

Arid Zone Research. 11(2):46-52

Date:

1994

Language:

Chinese

Classification:

3Ad, 6Cd, 6Ec

Region:

Qing Zang Plateau, China

Summary:

Shiquanhe River at the elevation of 4 250 m is surrounded by mountains which block humid air currents; the climate is dry and cold, with an annual average temperature of -0.2 °C. The frost-tree period is 80-100 days/year and annual average precipitation 73.7 mm. The Shiquanhe River Valley belongs to the sub-alpine desert vegetation and alpine steppe zones. Moor and meadow are distributed on banks of the Shiquanhe River and other seasonal rivers, which are dominated by Kobresia spp and Carex spp., accompanied by Triglochin palustris and Chenopodium glaucum. Abundant species and high yield grasses have made the meadow grasslands a major grazing ground, now heavily overgrazed. In the river valley the shrub meadow, which consisted of Myficatia elegans before the 1960s, has been damaged. Typical xerophytes such as Caragana versicolor, Ceratoides latens and Aiania gracilis grow toward the center of valley where only Myricaria elegans shrubbery grew some years ago, indicating that the habitat of the valley is becoming arid. Once the vegetation was destroyed, wind erosion action intensified, causing loss of water and soil and desertification. Measures aimed at ecological restoration and desertification control should protect existing vegetation and establish artificial vegetation in the valley.

Author:

Li Shuandi

Title:

A preliminary study on the formative periods of Kumkury Desert

Publisher:

Arid Zone Research. 9(2):27-32

Date:

1992

Language:

Chinese

Classification:

3D, 4Aa

Region:

Tibet, China

Summary:

Kumkury Desert (36°32'-36°53'N and 88°40'-89°50'E) has an elevation of 3 900-4 800 m and covers an area of 1 662 km². Two fresh water lakes, Xiaoshazi Lake and Shazi Lake, are located in the central part of the desert. Based on the chronological, sedimentological, geochemical and mineralogical studies of the lacustrine section of Xiaoshazi Lake, this paper analyses the relationship between lacustrine section construction and Kumkury Desert development. It concludes that the desert, which appeared 6 000 years ago, was not formed until after construction of the lacustrine section.

Author:

Li Shuanke (Institute of Geography, Academia Sinica, Beijing)

Title:

A preliminary study of the formation age of Hobq Sandy Land - the highest sandyland in the China

Publisher:

Journal of Desert Research. 11(3)

Date:

1991

Language:

Chinese

Classification:

2B, 3C, 4Aa

Region:

Tibet, China

Summary:

Based on analyses of chronology, sedimentology, geochemical characteristics and mineralogy in the lacustrine of Xiaoshazhi Lake, this paper addresses the relationship between lacustrine construction and sandyland development. This sandyland did not appear during the construction of the lacustrine section; formation of the Hobq Sandy Land was after 600 yr.B.P.

Authors:

Li Shugang and Cheng Xingjun (Xinjiang Institute of Biology, Pedology and Desert Research, Academia Sinica, Urumqi)

Title:

A revised scheme for systematic aridisols classification in Xinjiang

Publisher:

Arid Zone Research. 10(4): 1-3

Date:

1993

Language:

Chinese

Classification:

2Eb

Region:

Northwest Asia

Summary:

The aridisols of Xinjiang form a vast aridisol zone in central Asia- Kazakstan, Uzbecksitan and Turkinenstan. Sub-orders of aridisols are divided as follows. G1 is a cold temperature regime (altoeryicaridisol); G2 refers to the upper limit of the subsurface layer to 100 cm (a calcic layer, calcic aridisol); G3 has an upper limit of the subsurface layer to 100 cm (luvic argillic, oralkalic argillic layer, argillic aridisol); G4 classifications possesses at least one of the following layers: secondary argillic layer, haplo layer, residual salic layer, or gypsic layer (outhic aridisol).

Author:

Li Sinj

Title:

Desertification control objectives, measures and engineering proposals in the central "One-River-Two Tributaries" basin in Tibet

Publisher:

Journal of Desert Research. 14(2):55 -63

Date:

1994

Language:

Chinese

Classification:

6Db

Region:

Tibet

Summary:

The central "One-River-Two-Tributaries" basin in Tibet is one of the most severely decertified areas in China. Based on comprehensive development planning and analysis of actual conditions in the region, desertification control objectives, measures and engineering proposals are put forth. According to the suggested objective, 84 600 ha. of decertified lands will be brought under control in the eighth and ninth five-year plan periods. Once this project has been completed, a comprehensive index of economic, ecological and social benefits is expected to rise by 33.7 percent compared to 1990 data.

Authors:

Li Xianglan, Tian Jixin and Zhang Chengge (Northwest Institute of Soil and Water Conservation, Academia Sinica)

Title:

A study on the effects of forest types on the physical properties of soil in the Loess Plateau area

Publisher:

Scientia Silvae Sinicae. 28(2):98-108

Date:

1992

Language:

Chinese

Classification:

2Ec, 3Ab

Region:

Loess Plateau, China

Summary:

In two districts of the Loess Plateau studies were conducted on the effects of different types of natural forests on the physical properties of soil. Results indicated that (1) in both districts the average content of coarse (1.0-0.5 mm in diameter), medium (0.5-0 2.5 mm) and fine sand (0.25-0.05 mm) in the top layer of the soil showed the following sequence: forestland > bushland > farmland. Similar sequences were obtained in soil profiles despite varying soil depth. (2) The average content of coarse silt in the top layer of soil showed the following order: bushland > forestland, young stands > middle-aged stands > mature stands, while the content of medium and fine silt was adverse. (3) The average content of physical particles of clay in the top layer of the soil was in the order of forestland > bushland, mature forest stands > middle-aged stands. (4) The content of soil moisture was arranged in the following sequence: forestland > bushland > farmland.

Author:

Li Yonghong (Institute of Botany, Chinese Academy of Sciences)

Title:

Degradation model for grazing on the main steppe rangelands in Inner Mongolia and considerations for establishing a computerized rangeland monitoring system

Publisher:

ACTA Phytoecologica Sinica. 18(4)

Date:

1994

Language:

Chinese

Classification:

2Cd, 4Bd, SAb

Region:

Inner Mongolia

Summary:

Grazing degradation trajectories for the main steppe rangelands in Inner Mongolia are studied by combining site-specific experiments in typical steppe areas and overall investigation of the total region. The study concludes that: (1) Plant species can indicate both positive and negative, and qualitative and quantitative vegetation changes as a result of grazing. Species which can tolerate moderate grazing pressure are noted. (2) Restoration of degraded steppe rangeland demonstrated that rhizomatic grasses rehabilitate more quickly than tussock grasses. The restoration process was in a monostable state; restoration dynamics corresponded generally to spatial changes along the grazing gradient. (3) The main steppe rangeland communities dominated by Stipa gobina, S. breviflora, S. krylovii, S. grandis. S. baicalensis and Aneurolepidium chinese will converge into Artemisia frigida community under sustained grazing influence. A. frigida is the most effective quantitative indicator species of grazing pressure. fit is also a fine forage species and an important species for resisting steppe degradation. (4) The concept of steppe degradation is discussed. the difference and relationship between steppe retrogression and rangeland degradation are analyzed. The grazing retrogression of steppes is divided into two succession stages: rangeland utilization (improvement) and degradation. The quantitative criteria for rangeland degradation are established. A computerized system for steppe rangelands decision-making is suggested which includes monitoring and assessment.

Authors:

Li Zhenshan and Wang Yimou

Title:

The basic theory of desertification assessment

Publisher:

Journal of Desert Research. 14(2): 84-89

Date:

1994

Language:

Chinese

Classification:

2B, 6Aa

Region:

China

Summary:

Types and degrees of desertification are closely related to natural, social and economic conditions. Desertification assessment refers to evaluation and classification of desertification degrees based on selected indicators. These include natural and artificial factors influencing desertification and historical and recent processes of desertification, including development trends and ecological and reversing processes. Indicators may be single-element or compound, present status, development degree or hazard indicators. The development degree of desertification can be divided into light, moderate, severe or very severe. A complete set of assessment criteria and degree of desertification must be established before making an evaluation.