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2011 Vol.9 No.3
Published 2011-06-30
Articles
1
FAN Qing-Cheng, WANG Fei, MU Xin-Min, LIU Zhen-Dong, LI Dui
Impact of conservation tillage on soil wind erosion
Conservation tillage could reduce soil wind erosion effectively on farmland. An experiment of soil wind erosion on farmland in northern Loess Plateau was designed with wind tunnel tests under different conservation treatments including straw mulch, stubble and ridge tillage. The results indicated that straw mulch and stubble could reduce the soil wind erosion rate, and the soil wind erosion rate under straw mulch with 4210kg/hm
2
was decreased by 62.8% compared with CK(no conservation treatment), which was less than that under other conservation tillage. The ridge tillage which was perpendicular to the wind could reduce soil wind erosion rate in low wind velocity, the direction of ridge also affected soil wind erosion, and the soil wind erosion rate under ridge tillage with the same direction as the wind was more than others. With increasing straw mulch and height of stubble, the soil wind erosion rate decreased in the same velocity. The soil wind erosion rate had a significant power function to wind velocity under conservation tillage treatments. In the height of 0-60cm, the total volume of sediment discharge under straw mulch was the least, while the largest under ridge tillage. The most of sand concentrate in the height of 45-60cm under ridge tillage that direction was perpendicular to the wind, and concentrate in the height of 0-15cm under other treatments. The sediment discharge percent in the height of 0-15cm increased with increasing wind speed. The sediment discharge percent decreased with decreasing height of stubble and with the increasing amount of straw mulching. It is suggested that the straw mulching 20cm and both of them should be suitable for preventing soil wind erosion.
2011 Vol. 9 (3): 1-5 [
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6
ZHANG Ying
Calculation on water conservation price of forest with optimal control method in China
In order to better carry out the study on water conservation of forest and serve for the forest management, as well as to promote the development of forest ecological compensation, based on the theory of economic cybernetics and optimal control method, the accounting model of water conservation of forest was established and verified by collecting the data of forest area, rainfall, evaporation, runoff and gross domestic product (GDP) in 7 major river basins in China from 1999 to 2008. The calculated results show that the optimal water conservation price of forest was 1.043 RMB Yuan/m
3
. This accounting model had statistical significance and economic meanings by testing. It can be concluded that the results in this paper have significant guidance for ecological benefit compensation of forest and water resources management in China.
2011 Vol. 9 (3): 6-12 [
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13
TUN Yu-Fu, TU Bin, MA Yu, ZHANG Hui-Hui, CHU Qing-Ming, LI Li
Debris flow of Shuangyangzi gully, Dujiangyan City in Wenchuan earthquake area
In 2010, the intense rainstorm on 13 August induced debris flow hazard in Dujiangyan City, Sichuan Province, the affecting area of Wenchuan earthquake. This debris flow is the result of both rainfall and earthquake. Therefore, it is significant to make clear of the development characteristics of debris flows by studying its formation and movement process in high seismic intensity area. For discussing the starting way of debris, this paper analyzed the watershed, especially the gully channel characteristics of Shuangyangzi gully based on field survey after the Wenchuan earthquake. Earthquake induced acitive development of disasters as collapse, landslide and provided abundant incompact solid matters, in addition, there are several drop water dams and rockfill dams in the gully. After the H1 landslide on the right bank of Shuangyangzi gully slided and blocked gully channel in case of heavy rainfall under the inducement of the flood, debris flow outburst. It can be concluded that the debris flow could outburst again in the next heavy rainfall.
2011 Vol. 9 (3): 13-17 [
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18
LV Meng-Quan, WANG Ji-Jun, JIANG Jing-Long, ZHANG Fu, HAO Xiao-Dong
Temporal and spatial variability of soil erosion in Dongbeigou Watershed in northern mountainous area, Hebei Province, based on Land Use/Cover Change(LUCC)
Land-use has a direct effect on the change of soil erosion intensity through changing vegetation cover, soil property and runoff velocity. The Dongbeigou Watershed with an area of 19.34km
2
was chosen as the study area. Based on climate, vegetation coverage, soil, land-use survey and Quickbird image data in 1990 and 2009, the change characteristics of land-use and soil erosion were revealed by means of the shift matrix of land-use and Revised Universal Soil Loss Equation (RUSLE) supported by GIS. The results showed: the forestland increased from 38.56% in 1990 to 55.83% in 2009 compared to the decrease of grassland, cropland and barren land. The main conversion happened between forestland and grassland. The annual average soil erosion modulus decreased from 5136.13t/(km
2
·a) in 1990 to 1823.30t/(km
2
·a) in 2009. The soil erosion intensity decreased significantly. The area where the slight soil erosion (200-2500t/(km
2
·a)) happened constituted 32.78%, and the area where the moderate soil erosion (2500-5000t/(km
2
·a)) happened constituted 28.49% in 1990, whereas, in 2009 the area where slight soil erosion happened constituted 33.25%, and where little slight erosion soil erosion (<200t/(km
2
·a)) happened constituted 28.49%. The average soil erosion modulus of different land use types declined greatly, but there were great differences among the soil erosion modulus of different land use types. The soil loss rate happening in forestland and residential land was low, but the soil loss rate happening in barren land was high. The barren land is the key area of soil and water conservation in future.
2011 Vol. 9 (3): 18-25 [
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26
CHE Xiao-Li, WANG Wen-Long, GUO Jun-Quan, HAN Fang-Fang
Effects of up-slope runoff and sediment on ephemeral gully erosion sediment and hydraulic parameters
The ephemeral gully erosion was an important issue and had great distribution in the Loess Plateau. The runoff and sediment from up-slope had great impacts on slope soil erosion. In this paper, its effect on down-slope ephemeral gully erosion sediment yield and hydrodynamic parameters were analyzed by water discharge scouring experiments in fields, with the designed discharge 5L/min,10L/min and 15L/min on the slope of 26°. The results indicated that the runoff from up-slope increased the flow velocity. The Reynolds number, Froude number, stream power and shearing force increased by 33%-76%, 21%-47%, 29%-72%, 18%-42% respectively, and the Daycy-Weisbach coefficient decreased by 11%-13%, which caused the increasing sediment of the ephemeral gully erosion. Except the flow velocity and Froude number, the other hydrodynamic parameters increased over the water discharge scouring time. There was a power relationship between ephemeral gully relative increment sediment yield caused by up-slope runoff and relative increment of the stream power and shearing force.
2011 Vol. 9 (3): 26-31 [
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32
TANG Wen, YANG Ai-Min, ZHANG Hong-Jian, TANG Ke-Wang
Evolution tendency of runoff in Shenyang City, Liaoning Province, China
The river flow of basin has already varied significantly affected by the global climate change and human activity. Based on 28-year (1980-2007) measuring data of river flow, the developing rules of river flow in Shenyang City was studied with mathematically statistics. Results show that the runoff of major rivers in Shenyang City has a decreasing tendency in the past 28 years. The reduction of runoff modulus is between 108-12093m
3
/(km
2
·a) with average 2061m
3
/(km
2
·a). Pu River has the maximum contribution, Raoyang River the minimum. The mean reduction percentage of 23.11% was caused by human utilization, Liao River, Hun River and Liu River has the more contribution due to more intense human events, Yangximu River the minimum.
2011 Vol. 9 (3): 32-35 [
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36
LI Guo-Hua, ZHANG Jian-Feng, DIAO Xiu-Hai, SHU Jin-Zhao, YUE Ceng-Bi
Application of seed-base for afforestion of
Morus alba
Linn on raised field in coastal serious saline land
Coastal saline land in Tangshan City was taken as the research object, and some experiments were carried out in Nanbao salt field. Seed-base technique and some measures of site preparation were applied to test the survival rate and growing state of
Morus alba
Linn seedling when planting in serious saline soils. Results indicated that the seed-base technique performed better effects on improving soil and cutting off the salt flow. After the seed-base technique was employed, most of the seedlings survived and grew well in heavy saline soils compared to the control. This experiment implies that the seed-base technique could create better growing environment for
Morus alba
Linn seedlings, which will increase survival rate and improve trees growing. It can be concluded that the integrated technique is effective and practical in serious coastal saline land in gulf of Bohai Sea, which will offer afforestation technique for Tangshan City and advance the afforestation development in heavy saline soils.
2011 Vol. 9 (3): 36-39 [
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40
YAN Xiao-Lin, DING Guo-Dong, ZHANG Wei-Cheng
Effects of rainfall and salt layers on water and salt movement in coastal saline land
In order to discover the effects of different salt layers on water and salt movement in coastal saline land, slag and sand were designed as salt layers in
Fraxinus chinensis
forests to compare and study the seasonal change rules of soil moisture and soil salinity at different depths. Results show that the soil moisture and salinity are affected by different factors at the surface and different depths of soil. At the surface, soil moisture and salinity are mainly affected by rainfall and evaporation, while at the lower depths, groundwater table is another affecting factor. In the rainy season, high intensity rainfall has great leaching function on the soil surface, but there is no obvious difference between two salt layers. However, for the soil at 30cm depth, the salt layers with slag and sand has a strong effect on inhibition of return effect of soil. The conductivity of salt layers decreased from 591ms/m in May to 493ms/m in October with slag and from 558ms/m down to 501ms/m with sand. For the soil at 60cm depth, the conductivity of salt layers decreased from 810ms/m in May to 582ms/m in October with slag and from 607ms/m to 560ms/m with sand. It is also found that the slag has better effect on inhibition of conductivity than sand.
2011 Vol. 9 (3): 40-44 [
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45
MENG Jie, BO Chong-Feng, LI Chi, ZHANG Xin-Chang, SUN Tie-Feng, ZHANG Xiao-Jun
Effects of biological soil crust on slope soil carbon and nitrogen under erosion conditions
In order to reveal the effects of biological soil crust (BSC) on the distribution of soil carbon and nitrogen on slope under erosion conditions, by experimenting on field plots and in laboratory, this study investigated the distribution pattern of soil organic matter, total nitrogen and nitrate nitrogen contents with BSC treatment and without crust group. The results indicated that: biological soil crust played significant role in soil carbon and nitrogen accumulation. In the same position on slope, soil organic matter, total nitrogen and nitrate nitrogen contents of BSC treatment in soil profile of 0-20cm depth were higher than those without crust group. On the whole, the accumulation effect of BSC on soil carbon and nitrogen was mainly concentrated in the 0-10cm soil layer. Compared with no crust, the average storages of soil organic matter, total nitrogen, nitrate nitrogen and ammonium nitrogen were increased by 44.7%, 18.2%, 39.2% and 4.33%, respectively. BSC could significantly increase soil nitrate nitrogen content of 0-2cm and 2-5cm soil layers (
P
<0.05), which may be explained by that BSC could control nitrate nitrogen loss by effectively reducing soil erosion and also release some amount of nitrate nitrogen during the studying period. Due to the loss characteristics of soil ammonium nitrogen were different from nitrate nitrogen, the effect of BSC on soil ammonium nitrogen was not obvious. Correlation analysis showed that there were highly significant or significant positive correlations between soil organic matter and total nitrogen, nitrate nitrogen and ammonium nitrogen (respectively
P
<0.01,
P
<0.05). Therefore, it can be concluded that the presence of biological soil crust would have favorable effects on soil carbon and nitrogen accumulation under erosion conditions, which indicate BSC could be of great positive significance to restoration and reconstruction of degraded ecosystem in research area.
2011 Vol. 9 (3): 45-51 [
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52
DONG Ba-Jian, HUANG Shua-Rui, JIA Meng-Rui
Short-term response of litter of degraded
Larix pricipis-rupprechtii
forest to close-to natural management
Taken the degraded
Larix pricipis-rupprechtii
man-made forest in the mountain area of north Hebei Province as objects, the short-term response of water-holding characteristics to different management measures in three years were studied, which could provide theoretical base for the research of the impact of close-to nature management measure on soil and water conservation function of forest. Results showed that: 1) In clear-cut strips (blockading + clear cut in strips + manual promote renew), litter storage increased firstly and then decreased, but in leave strip (blockading only), it increased continuously. 2) The increasing range for maximum water holding rate was clear cut strip 15m (72.54%)> clear cut strip 30m (49.54%)> leave strip (27.03%), for effective retention rate occurred clear cut strip 15m (110.13%)> clear cut strip 30m (83.27%)> leave strip (40.64%), and for maximum water holding capability was leave strip(175.96%)> clear cut strip 15m (70.39%)> clear strip 30m (47.01%), and for effective water retention was leave strip (204.99%)> clear cut strip 30m (141.96%)> clear strip 15m (50.37%). 3) The litter mass, maximum water holding capability and effective water retention of afforestation land of
Betula platyphylla
Suk were larger than those of afforestation land of
Larix principis-rupprechtii
and
Quercus mongolica
Fischer ex Ledebour. It can be concluded that close-to nature management measure would significantly enhance the water conservation function of forest land in the short-term and it was effective measures for the restoration of ecological function of degraded
Larix principis-rupprechtii
forest.
2011 Vol. 9 (3): 52-58 [
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59
LI Dun-Yang, LI Su-Qing, HAN Jin-Chao
Changes of water quality in typical sites along upstream of Fen River
In order to reveal the effect of water quality along upstream of Fen River on regular water supply to residents in Taiyuan, the capital city of Shanxi Province, the history of water quality over 25 years from 1985 to 2010 was investigated in this study. The water samples were collected from five sites, four villages (Toumaying, Ninghua, Dongzhai, and Hecha) along the river and Fen River Reservoir upstream. Single factor evaluation method and index method were used to evaluate the water quality. Results showed that：1）The water quality deteriorated significantly in the upstream area around 2002. For most water samples, quality grade increased from level II or III to level IV or above. High percentage of samples around Ninghua and Hecha areas showed grade lower than level III, whereas Fen River Reservoir showed water quality around level II or III. The deterioration of water quality was mainly due to the increase of concentration of salt permanganate index, BOD
5
and NH
+
4
-N resulted from coke burning, coal washing and heavy use of fertilizers. 2) Salt permanganate index and NH
+
4
-N showed increasing trend for the water quality upstream of Fen River, mainly due to the low efficiency of decomposition of inorganic and organic pollutants caused by high concentration of nitrite in the water. 3) The general change of the water quality in the upstream area of Fen River occurred to the concentration and varieties of organic pollutants, showing increased level of eutrophication and water hardness, mainly due to increased consumption of water and inappropriate waste treatment. In general, the water quality upstream of Fen River has been deteriorating, it should be the main focus to take all measures to protect the water environment upstream of Fen River.
2011 Vol. 9 (3): 59-64 [
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65
GENG Gui-Dun, BAI Gang-Shuan, DU She-Ni, XU Jian, LI Man
Effects of super absorbent with different application methods on soil moisture, soil salinity and
Lycopersicon esculentum
growth
In order to determine the effects of BJ2101-L super absorbent with various application methods, field experiments were conducted to investigate their effects on soil moisture, soil salinity and
Lycopersicon esculentum
growth in Hetao irrigation district, Inner Mongolia. In this paper, BJ2101-L super absorbent was applied with four treatments of furrowing, mixing, holing and broadcasting. The results showed that furrowing, holing, mixing significantly increased soil moisture in 0-80cm soil layer, particularly there were significant effects during
Lycopersicon esculentum
fruit-setting stage, and soil moisture in furrowing, mixing and holing treatments increased by 12.66%, 9.40% and 7.50% in 0-80cm soil layer compared to the control respectively. BJ2101-L super absorbent inhibited the accumulation of soil salinity and could improve the survival rate of
Lycopersicon esculentum
seedlings. The yields in furrowing, mixing, holing and broadcasting treatments increased by 37.70%,30.93%, 26.35% and 12.87% compared to the control, and water use efficiency increased by 56.58%, 44.98%, 32.58% and 24.05% against the control respectively. Optimum application method of BJ2101-L super absorbent should be furrowing application in Hetao irrigation district in
Lycopersicon esculentum
production.
2011 Vol. 9 (3): 65-70 [
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71
ZHONG Xi-Jun, XIE Chuan, HUANG Qian-Ru, ZHANG Xin-Liang, WU Lin, SUN Yong-Meng, QIN Jiang-Chao
Benefit analysis of different soil and water conservation measures at sloping
Arachis hypogaea
land with red soil
Taking conventional cultivation of
Arachis hypogaea
as control, effects of different soil and water conservation measures were analyzed at sloping
Arachis hypogaea
land with red soil by using runoff plot experiment. The measures are
Arachis hypogaea
+ grass hedge,
Arachis hypogaea
+ cover + grass hedge, and
Arachis hypogaea
+ cover. This experiment began in April after determination of
Arachis hypogaea
planting, and ended in August after
Arachis hypogaea
harvest. Results showed that: 1) The surface runoff of three kinds of measures increased with the increase of daily rainfall; 2) the surface runoff and soil erosion of three kinds of measures differed significantly with control (
P
<0.01). That
Arachis hypogaea
+ cover + grass hedge should be the effective
Arachis hypogaea
soil and water conservation measure at sloping
Arachis hypogaesa
with red soil.
2011 Vol. 9 (3): 71-74 [
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75
FAN Jian-Rong, WANG Nian-Zhong, CHEN Guang, JIAO Jian, XIE Yun
Practice factor of soil and water conservation in Northeastern China
Soil erosion is a severe onging problem in Northeastern China. To give basis to soil and water conservation plan and soil erosion prediction, the effects of different conservation practices on runoff and sediment reduction are urgently to be studied. From 17 runoff plots in four watersheds, runoff and sediment records of 343 soil erosion events were collected to estimate the effects of soil and water conservation practices. The practice factors of seven soil and water conservation types were calculated, and they were 0.020 for engineering-control factor for terrace, 0.061 for cut-off drain, 0.054 for biological-control factor of shrubs, 0.363 for natural ecosystem rehabilitation, 0.624 for tillage factor for up-down slope tillage with soybeans, 0.257 for contour tillage with soybeans, and 0.186 for counter ridge combing with vegetation stripes. The results of this study could be applied in soil erosion prediction by using soil erosion model.
2011 Vol. 9 (3): 75-78 [
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79
MO Long, MA Qin, ZHANG Jian-Jun, FU Yan-Ling, ZHANG Xiao-Ping
Precise comparison of spatial interpolation for precipitation using KRIGING and TPS (Thin plate smoothing spline) methods in Loess Plateau
Loess Plateau covers large area in China, where precipitation shows complicated spatiotemporal variability. The interpolation method is an integral component for analyzing the spatial and temporal characteristics of precipitation in Loess Plateau, as well as they are crucial conditions for obtaining reliable results of hydrological and erosion modeling. In this paper, the precise of KRIGING and TPS (Thin plate smoothing spline) methods,were compared and analyzed according to the observed data including average annual rainfall, yearly and monthly rainfall for 20 years from 1981 to 2000 from 50 meteorological stations in the He-Long Section and the nearby regions. The performance of the two different algorithms, KRIGING and TPS, were verified and compared by cross-validation test based on the data of 27 stations. The results indicated that: 1) For the interpolation of the average annual precipitation, yearly and monthly precipitation, both the KRIGING and TPS methods can reflect the spatial distribution of precipitation in the He-Long Section. The absolute value difference of average
A
(the index of agreement) for whole period for both of the methods are less than ±0.01. There is no significant difference for the precipitation interpolation precision between the KRIGING and TPS methods. 2) The differences of the interpolation precision for both of the methods at different time scales show nearly the same trend. The average
A
for the average annual precipitation is better than that of April about 14%, better than that of the annual precipitation and the July about 19%, 35% respectively.
2011 Vol. 9 (3): 79-87 [
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88
ZHANG Jing-Ai, GUAN Wei, SUN Ping, JI Xiu-Juan
Automatic water bodies extraction model based on K-T transformation
Threshold method and spectral relationship method are traditional methods for water body information extraction, the two methods, however, could not distinguish cloud shadow from water body, which leads to lower precision. For achieving a optimal model, the K-T transformation（Kauth-Thomas transformation）was applied to the TM image firstly, and then the improved model of water bodies extraction was found using the six new wave bands of the TM image after K-T transformation. It can be concluded that only when the spectral curve of water body occurred with W shape, could the new model of water body information extraction, Greenness 〈Wetness〉 Fourth, eliminate the influence of all shadow and extract the water body with higher precision.
2011 Vol. 9 (3): 88-92 [
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93
LI Ji, ZHOU Chun-E, LIANG Zhi-Yang, MIAO Jing
Impacts of drought stress on physiological characteristics of
Aconitums
Using fuzzy membership method, transplanted seedlings of five
Aconitums
（
Acotinitum kusnezoffii
Reichb.,
A. sinomontanum
Nakai,
A. smithii
Hand.-Mazz.,
A. barbatum
Pers. var.
puberulum
Ledeb,
A. soongaricum
Stapf var.
angustius
W.T.Wang）were selected to study the effects of drought stress on their physiological characteristics,aiming at providing a method and basis for selection of draught-resistance plants. Three soil moisture levels were designed in the experiment: control（CK）,moderate water stress（T1）,and severe water stress （T2）. The results showed: 1) The cell membrane permeability of
A. sinomontanum
and
A. soongaricum
var.
angustius
clearly increased only under T2,while that of
A. smithii
and
A. barbatum
var.
puberulum
greatly increased under both T1 and T2 treatments. The cell membrane permeability of
A. kusnezoffii
significantly decreased under T1 but increased under T2. 2) The MDA contents of
A. sinomontanum
,
A. barbatum
var.
puberulum
and
A. soongaricum
var.
angustius
were all greatly increased under the drought stress treatments,while that of
A. smithii
and
A. kusnezoffii
increased obviously only under T2 and T1 respectively. 3) The Chla contents of the Aconitums,except for
A. barbatum
var.
puberulum
,were significantly lower than that of CK. The Chlb contents of the five Aconitums varied greatly under the draught stress treatments. 4) The Pn of both
A. kusnezoffii
and
A. sinomontanum
largely decreased under T1 and T2 treatments,but there was no significant difference between those two treatments. The Pn of
A. smithii
decreased grealty only under T2,whereas that of
A. barbatum
var.
puberulum
increased by T1 and T2 treatments. The Pn of
A. soongaricum
Stapf var.
angustius
had no significant change under the treatments. (5) The drought tolerant ability of the five Aconitum species was determined according to the subordinate function value as:
A. kusnezoffii>A. sinomontanum>A. smithii>A. soongaricum
Stapf var.
angustius
>
A. barbatum
var.
puberulum
.
2011 Vol. 9 (3): 93-100 [
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101
GAO Guo-Xiong, TUN Fa-Qi, ZHOU Mi-Jing
Specialized course framework for Soil and Water Conservation based on the questionnaire survey and analysis
The establishment of the course framework is the kernel of the specialty characteristics for the major of Soil and Water Conservation and Desertification Combating. Discussion, questionnaire by e-mail and other forms were employed to survey the opinion on the course framework setting, including the direction of undergraduate eduction, curriculum types, class hours alloting contents of practicing, the ability of students etc.. The results showed that for undergraduate students of the major of Soil and Water Conservation and Desertification Combating in Northwest A & F University, the course framework is reasonable to some extent to meet the basic needs of social practice. The students have a good grasp on theory knowledge, however, their ability to adapt to the practical work should be improved further. Therefore, according to the opinion in surveys, the course framework was reset to meet the needs of practice to a large extent. The new course framework gives the optimal adjustment with the compression of six courses and increase of class hours for the main course.
2011 Vol. 9 (3): 101-105 [
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1737
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106
WANG Xiu-Ying, GAO Xiao-Fei, LIU He-Beng, LU Bing-Jun
Review of analytical methods for aggregate size distribution and water-stability of soil macro-aggregates
Wet-sieving method is a classical and still the most prevalent procedure for testing the water stability of soil aggregates. Three main mechanisms are attributed to the breakdown of soil aggregates during wetting including slaking (breakdown caused by the compression of entrapped air in the soil pores), differential swelling and physic-chemical dispersion. The existing wetting methods can be divided into fast wetting and slow wetting according to the velocity of wetting, and atmospheric pressure wetting and high-vacuum wetting according to the barometric condition of soil sample when wetting. When soil samples are fast wetted under atmospheric pressure, water penetrates the soil mass at a high rate along capillaries, and compressing entrapped air causes a series of miniature explosions and breaks down soil aggregates, while wetting soil samples slowly or in vacuum gives high aggregation. In order to investigate the soil aggregate size distribution and water-stability comprehensively, it is recommended that fast wetting under atmospheric pressure and slow wetting (or wetting in vacuum) should be taken respectively with equivalent soil samples. During wet-sieving, the sieves should not shake too rapidly, and the number and aperture of sieves can be selected according to analytical purpose.
2011 Vol. 9 (3): 106-113 [
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114
WANG Yan, WANG Li
A review of research on ecological footprint
Since 1992 the theory of ecological footprint model has been concerned by more and more researchers. In recent twenty years, a great progress has been made in the study of ecological footprint all over the world, especially in China. In this paper we briefly introduced the concept and the calculation methods of ecological footprint, stated its weakness and advantage, and reviewed its research progress abroad and at home. Finally, we argued the possible future research directions of ecological footprint.
2011 Vol. 9 (3): 114-120 [
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