Authors:

Ci Longjun

Title:

Land use classification for desertification control in Mu Us Sandy Land, Inner Mongolia, China

Publisher:

The Faculty of the Graduate School of Cornell University.

Date:

1992

Language:

Chinese

Classification:

2B, 6Ee

Region:

Inner Mongolia, China

Summary:

China has only seven percent of the world's cultivated land of the world, but feeds 22 percent of the world's population. Therefore land is of critical importance to China. According to Chinese government information (28 August 1991), the population in China increases by 16 million per year, while cultivated land decreases by 4 600 ha due to water and soil erosion, desertification and nonuse of agricultural land. Decertified land occupies 13.4 percent of China's total area and is increasing every year. Land use and land degradation issues are of critical concern to China. Mu Us Sandy Land is a typical, seriously decertified land area. Different types of sand land are scattered over 77 percent of the total sandyland area. Population growth and environmental degradation are increasing the need to find new solutions and approaches to the desertification problem. Control of land desertification can only be achieved by changing land use planning methods. Land evaluation is a systematic way of assessing land use suitability from which plans can be developed to control human misuse of lands. In this volume land suitability analyses are based on the automated land evaluation system (ALES) and geographical information system (GIS) methodologies. The authors obtained data from investigations of 3 810 field survey plots, l 200 soil profiles and 604 tree trunk analyses; there are ten (GIS) maps. The computerized methods are in conformity with the FAO's framework for Mu Us Sandy Land evaluation.

Author:

(Commission for Integrated Survey of Natural Resources, Chinese Academy of Sciences)

Title:

The impact of global change on desertification in China

Publisher:

Journal Of Natural Resources. 9(4): 289-303

Date:

1994

Language:

Chinese

Classification:

2B, 3D, 4Aa

Region:

China

Summary:

This article discuss the impact of global climate change on desertification in China based on predictions of increasing CO₂ concentrations (which could double by the year 2030) and mean annual temperatures if current industrial patterns remain unchanged. The analysis adopts UNEP's aridity index (ratio of annual precipitation to potential evapotranspiration) which ranges from 0.05 to 0.65, excluding arctic and sub-arctic regions. The potential evapotranspiration is obtained from Thornthwaite's formula. Research results are based on 30 years of data from more than 700 meteorological stations in China. (1) Under the impact of global change, China's arid zones will expand and land desertification will develop. Currently, China's arid, semi-arid and dry sub-humid areas cover 2.976 million km², plus extreme arid areas of 697 000 km². Total size of arid and extreme arid areas is 3.673 million km² or 38.3 percent of China's total land mass, including 2.08 million km² of desertificated land area. After CO₂ concentrations double and mean annual temperatures increase by 4 °C, China's arid area will expand to 4.63 million km or 48.3 percent of China's total area. including 2.67 million km² of desertification land. The increasing rate of land desertification will be 6 941 km²/year. (2) Under the impact of global change, China's arid zone will become warmer and drier. According to data gathered over 40 years from more than 160 meteorological stations in China, during 1951-1991, the ten-year running mean temperature of arid (semi arid and dry sub-humid) areas has shown a tendency to increase since the 70s. Ten-year running precipitation data also increased since the 70s, but more slowly. The annual mean temperature of China's arid areas increased insignificantly; winter temperatures increased but summer temperature deceased. The annual precipitation in arid areas increased prominently after the 70s. In semi-arid areas temperature increased since the 70s, especially in winter; precipitation decreased as compared to the 50s and 60s.

Author:

Cui Wangcheng

Title:

Oases processes and desertification of the Yarkant River and the Kagar River Valley

Publisher:

Arid Zone

Research.

11(3): 52-57

Date:

1994

Language:

Chinese

Classification:

2Ed, 3Aa, 4Ba, 4Bc, 4Be, 6Ee

Region:

Xinjiang, China

Summary:

Drainage areas of the Yarkant and Kagar Rivers are major regions of agricultural production in the southern part of Xinjiang. Typical arid desert climate, geologic structures and geomorphic features predominate. In oasis areas two interrelated processes occur simultaneously, i.e. destruction of the desert ecosystem and establishment of artificial oases. In the interior of an oasis, the ecosystem is becoming more stable; on the frontier of an oasis, exploration and exploitive utilization of oasis resources have caused ecological degradation and desertification. Desertification in troth river systems is characterized by the following phenomenon. (1) Mobile sand and desert are expanding because of water shortages in farmland areas and simultaneously strong winds. (2) Natural vegetation had been damaged due to lack of water or overcutting of fuelwood. (3) Grassland degradation is the result of overgrazing and digging Licorice. (4) Sand is accumulating on both sides of irrigation channels or in ditches. Before 1974, the Yarkant River recharged the Tarim River throughout the year; after 1979, the Yarkant River no longer recharged. With increased human activities lack of water has became so severe that hydrographic structures have changed. Poplar trees covering large areas have died. Environmental degradation of the desert is advancing at such a pace that inhabitants are migrating.

Authors:

Dong Guangrong, Li sen, Li Baoshengg, Wang Yao and Yan Mancun (Institute of Desert Research, Academia Sinica, Lanzhou)

Title:

A preliminary study of the formation and evolution of deserts in China Publisher: Journal of Desert Research. 11(4)

Date:

1991

Language:

Chinese

Classification:

2Ec, 3 C. 4Aa

Region:

North China

Summary:

During the past ten years, these authors and others discovered paleoeolain sands and associated sandy sediments of the Cenozoic Era in desert areas of China, which provide evidence of the formation and evolution of these deserts. On the basis of the feature analysis, pattern division, dating, and petrofeature/petrofacies comparisons of the paleoeolian sand strata, a striate graphical sequence in desert areas of northern China was established and the curliness of desert formations and their evolution in early or late Tertiary and Quaternary periods, reconstructed. Development patterns and desert types in the Quaternary period are discussed.

Authors:

Dong Yanqing, Zhangsun and Zhenpeng (Shaanxi Academy of Agricultural Sciences)

Title:

Agronomic efficacy of furrow seeding in marginal farm land

Publisher:

Agricultural Research in the Arid Areas. 1991(2): 32-39

Date:

1991

Language:

Chinese

Classification:

6Ea

Region:

North China

Summary:

Furrow seeding with applied fertilizer to resist drought, cold and injury from salinisation and to improve wheat responses to fertilizer is a traditional agricultural practice in parts of northern winter growing areas of China. Mechanized 2BFG-6(S) fertilizing and furrow seeding implements for grains now intensify the process. This is beneficial in dry and humid years. A production increase of 14.7-20 percent can be expected. A 2BFG-6(S) furrow seeder combined with a 8.8-11 Kilowatt tour-wheeled tractor for use at the Weibei Rainfed Highland (an area of low productivity and salinisation) fulfilled the essential agricultural requirements for furrow seeding of grains and intensive fertilization.

Authors:

Dong Yuxiang

Title:

Analysis of agroecosystem functions in decertified areas

Publisher:

Journal of Desert Research. 13(3):39-46

Date:

1993

Language:

Chinese

Classification:

2Ee, 3Ab, 4Ba, 4Bb, 4Bc, 4Be, 6Ee

Region:

Inner Mongolia

Summary:

This paper examines how local agroecosystems function, using Baiyintala village as an example. Baiyintala is situated in the central Horqin Sandy Land which experiences an annual rainfall of 362.3 mm, annual evaporation of 1 935 mm, and annual mean wind velocity of 3.4 m/s, with a maximum of 18.7 m/s. Baiyintala's agroecosystem consists of five subsystems, i.e. farrowland, forestland, grassland, and inhabitant and livestock areas. Total area is 4 944 ha of which farmland occupies 2737.3 ha, forestland of 2 472 ha and grassland, 33 360 ha. Energy inputs for the agroecosystem include solar, industrial, biological and man and animal power. Energy outputs include biological energy, grain, oil and animal products. Material inputs are precipitation, chemical fertilizer and manure. Based on analyses of energy and material flows, agroecosystem functions in decertified areas can be characterized as follows: scale and amount of energy flow and material flow are small and energy and material passages are few. It is a low-input, low-output, low-benefit agroecosystem.

Author:

Dong Yuxiang (Institute of Desert Research, Academia Sinica, Lanzhou)

Title:

Study of the function of human factors in desertification

Publisher:

Journal of Desert Research. 12(1)

Date:

1992

Language:

Chinese

Classification:

2B, 4Ba, 4Bb, 4Bc, 4Bd

Region:

North China

Summary:

The areas of Xijingzi, Naritu, Baiyintala and Jiangjia Ravine are to study human factors in the desertification process, applying qualitative and quantitative methods developed by other experts. Comparative analysis of desertification criteria and quantitative studies of recent desertification processes show that the influences of human factors on desertification are comprehensive and dominant. In historical periods desertification was determined by natural factors, especially climate change. Dry climate changed the environment into desert, including large areas of shifting dunes. An unstable society and economy developed. In recent times, desertification is caused by human activities, particularly population increases and livestock pressure. Although recent desertification is largely a man-made process, natural processes are still at work. In Naritu human factors account for 60 percent of the desertification process while natural factors account for 40 percent. The development speed of man-made desertification is about ten times greater than natural processes.

Authors:

Dong Yuxiang and Chen Kelong

Title:

The degree and regionalization of sandy desertification in China

Publisher:

Journal of Desert Research. 15(2):170-174

Date:

1995

Language:

Chinese

Classification:

2B, 5B

Region:

North China

Summary:

Based on regional differences in desertification development processes, the authors establish criteria for assessing degrees of desertification. Their system includes six criteria: percentage of decertified land in an area, percentage of severely decertified lane in an area, productivity reduction percentages, mean increasing percentage of decertified land, annual percentage of expanding decertified land and annual percentage of productivity reduction. Degrees of desertification are slight, moderate and severe. According to degree and regional continuity, China's decertified lands can be divided into 20 regions. Eight have slight desertification (such as the central plain of northeast China), seven have moderate desertification (such as Bashang in Hebei province) and five have severe desertification (such as northern Shaanxi province). This research provides a foundation for developing distinct plans to combat desertification.

Authors:

Dong Yuxiang and Liu Yihua

Title:

Study of the sandy desertification process of the Hunshandake Sandy Land during the last 5 000 Years

Publisher:

Arid Land Geography 16(2):45-51

Date:

1993

Language:

Chinese

Classification:

2Cb, 3Aa, 3C, 4Ab

Region:

Inner Mongolia

Summary:

Concepts differ on the origin and development of sandy desertification in the historical periods. This paper uses a comparative method based on climatic variations and stratum profiles to study the historical processes of sandy desertification. The analytical results based on climatic variations in historical periods show that dry and humid phases alternated. The Yaoshitu profile in Hongshandake includes three layers of dark sandy soil and three layers of yellow aeolian sand, which indicate that Hunshandake Sandy Land experienced three stages of stabilized dunes and mobilized aeolian sand, respectively. The area is presently in the third (during the last 5 000 years) mobilizing aeolian sand stage. Historical processes of sandy desertification in the Hongshandake Sandy Land were primarily due to climate change.

Authors:

Fan Shengyne and Xu Jianhua

Title:

Preliminary approach to a general mathematical model of human effects in soil erosion and desertification system

Publisher:

Scientia Geographical Sinica. 12(4):305-312

Date:

1992

Language:

Chinese

Classification:

2Cd, 4Ba, 4Bb, 4Bc, 4Bd 4Be

Region:

North China

Summary:

Using an analysis of the dynamics of soil erosion and desertification in relation to landform evolution, a general mathematics model of soil erosion and desertification was established: Y=CMf (x₁...x_n). The formula for the change in velocity of human effects is obtained by the following:

The concept and method for calculating the input elements and their characteristic value in an area are proposed. A quantitative analysis of human effects can become an important index for analyzing the cause of soil erosion and desertification processes, and provides a scientific basis for soil and water conservation and desertification control.

Author:

Feng Futang

Title:

Desert control and revegetation experiments on typical steppe in Hulun Buir grassland

Publisher:

Grassland of China. (4):38-40

Date:

1993

Language:

Chinese

Classification:

6Cb, 6Cd

Region:

Inner Mongolia, China

Summary:

The sandy steppe of Hulun Buir Grassland is situated in the northeastern part of Inner Mongolia. Total area is three million ha. Experimental studies were carried out on a sand belt in the dry steppe zone with a dry climate, minimal rainfall, open vegetation and a mobile sand field. Soils are fixed sand and semi-fixed sand. Protophytes have been heavily damaged by human beings and overgrazing creating uncovered surfaces and wind erosion that seriously threatens people's livelihood. In order to fix mobile sand, big-technical methods such as drilling and straw checkerboard wind-breaks are employed on mobile sandyland. A combination of shrubs and grasses can be used for establishing biological windbreaks; grasses can protect the surface from wind erosion. Over five years vegetation coverage increases were calculated as 0 to ten percent to 25 percent to 85 percent; soil fertility also improved.

Author:

Feng Qi

Title:

Preliminary study on the dry sand layer of sandyland in semi-humid regions

Publisher:

Arid Zone Research. 11(1):24-27

Date:

1994

Language:

Chinese

Classification:

2Eb, 3Ac, 6Ee

Region:

Shandong province, China

Summary:

Yuchen county in Shandong province lies in the semi-humid zone where stabilized and semi-stabilized sand dunes exist. Sand grain size varies between 0.05-2 mm. In order to study features of the dry sand layer of sandyland four plots were selected at the top of mobile dunes. The tour plots, 2 m x 2 m in area, include: bare mobile sand land, irrigated bare sand land, irrigated peanut field and irrigated grassland. A series of observations and analyses were conducted in September when sunshine intensity is lower and time shorter. Results suggest that daily changes in dry sand layer thickness in semi-humid sandyland coincide periodically with daily soil temperature and air temperature changes. Thickness development velocity of dry sand layers covered with vegetation is slow; on the contrary, the thickness development velocity of bare sand layers is fast. The development velocity of the dry sand layer in crop fields is faster than in grassland. The moisture under dry sand layers changes slowly with air moisture when dry sand reach seven to eight centimetres.

Author:

Fu Bojie (Research Centre for Eco-Environmental Science, Academia Sinica)

Title:

Spatial pattern analysis of agricultural landscape in the loess area

Publisher:

Acta Ecological Sinica. 15(2):113-120

Date:

1995

Language:

Chinese

Classification:

2Cd, 6Ee

Region:

North China

Summary:

Agricultural landscape is a mosaic of' natural and human activities arranged in a variety of patterns and on a variety of scales. The spatial quality of' the landscape can influence ecological phenomena and is a critical component in understanding ecological dynamics. Geographic Information System (GIS), fractal analysis and statistical methods were used to examine the spatial patterns of agricultural landscape in the loess area of China. A land use map on a scale of 1:10 000 was digitized to cover ten land use categories: irrigated farmland, check-dam farmland, terrace farmland, slope farmland, orchard, grassland, bush, forest, reservoir and residential land. The size and fractal dimension of patches, patch elongation index, diversity, dominance, relative richness and the fragmentation index of landscape of gullies were calculated using models and the GIS. Along with the increases in "human-managed" patches the shape of farmland and forest patches tend to change from simple to complex. The shape of grassland patches vary at random. The authors suggest planting buffers between hill tops and hill slopes and between hill and gully slopes to control soil erosion and improve landscape connectivity.

Author:

Fu Hua

Title:

Study on the characteristics of chemical elements of forage species in three types of rangeland in Alxa Desert

Publisher:

Journal of Desert Research. 14(2):37-41

Date:

1994

Language:

Chinese

Classification:

2Ec, 3Aa, 6Ee

Region:

Northwest of China

Summary:

Alxa Desert is located between 37°24'-42°25'N and 97°10'-106°12'E at an altitude of 1 000-1 700 m. Constructive species of the desert are of Chenopodiaceae, Zygophyllaceae, Compositae, Rosaceae, Tamaticaceae and Gramineae, with coverage ranging from one to 20 percent. This study analyses the macro-elements and trace elements of 44 forage species in nine families on slightly warm-arid rangeland, slightly warm super-arid rangeland and warm-super-arid rangeland. Results show that all forage species are deficient in Mo except for grass forages. Forages of the Tribulus family, Leguminosae and Chenopodinceae are Ca-rich and Gramineous forages are Ca-poor; all contain a medium level of nitrogen. As a whole, plant species of Zygoghyllaceae have a higher enrichment ability to Ca, N and Zn; plant species of Compositae have a higher enrichment ability to Cu. Zn and Mn; and plant species of Rosaceae have a higher enrichment ability to Fe, Cu. Mn and Co.