Table of Content

    20 March 2015, Volume 30 Issue 3 Previous Issue    Next Issue
    Expert's Forum
    2050 Energy Consumption Projection for China
    SHEN Lei, LIU Li-tao, WANG Li-mao, CHEN Feng-nan, ZHANG Chao, SHEN Ming, ZHONG Shuai
    2015, 30 (3):  361-373.  doi: 10.11849/zrzyxb.2015.03.001
    Abstract ( )   HTML ( )   PDF (5252KB) ( )   Save

    As fossil fuels consumption and global warming are closely associated with each other, energy consumption has attracted great attention around the world. Especially when China overtook the U.S. as the world's biggest energy consumer in 2010, the time and value for China's peak energy consumption become the focus of world attention. Based on a brief review of existing peak energy consumption methods and models, population and economic development selected as two major driving factors, and using the variation rule of per capita energy consumption during economic development in developed countries as reference, the future energy consumption for China was projected up to 2050. The results showed that: 1) China has great potential to increase per capita energy consumption and the cumulative per capita energy consumption. The probable per capita energy consumption range for China is 4.75-9.31 tce/cap in 2050, the upper limit equivalent to only 76% of the United States' per capita consumption peaks. And the probable energy consumption range for China is 6.19-12.13 billion tce in 2050. While the probable range of cumulative per capita energy consumption for China for 1870-2050 is 207-294 tce,the upper limit equivalent to only 46% of the United States' (56% of Germany and 57% of United Kingdom) cumulative per capita consumption during 1870-2012. 2) Currently, most studies showed that the probable energy consumption peak range for China will be in 2035-2040, with the peak value range of 6.2-7.9 billion tce. This paper argues that in addition to the United States, United Kingdom and Germany Scenarios, the other national scenarios will be unlikely peaked. 3) Under France Scenario the “zero” growth of China's energy consumption will occur around 2040, while Japan, South Korea and Baseline scenarios project that a slow growth period of China's energy consumption will occur after 2035, with growth rate about 2%. To sum up, France, Japan and South Korea scenarios are more reasonable and China's energy consumption is likely to enter a slow growth period since 2035. At present, the level of GDP per capita in China is not high, and the level of per capita energy consumption especially for cumulative per capita energy consumption is low, so it would put ourselves in a passive position in climate change negotiations if we are too optimistic about China's peak energy consumption time and value. Based on national conditions of China, we need to leave more energy consumption space for China's social economic development. Last but not least, actively promoting energy-efficient production and adopting an energy-efficient lifestyle will be the key for China's sustainable socio-economic development, energy security and respondence to global climate change.

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    Resource Economics
    Period of Organic Conversion in Agricultural Heritage Sites —Taking Paddy Rice of Hani Terrace in Honghe County of Yunnan Province as an Example
    ZHANG Yong-xun, LIU Mou-cheng, MIN Qing-wen, YUAN Zheng, LI Jing, FAN Miao
    2015, 30 (3):  374-383.  doi: 10.11849/zrzyxb.2015.03.002
    Abstract ( )   HTML ( )   PDF (1928KB) ( )   Save

    As highly efficient agricultural technologies are used widely, efficiency of labor got improved, and grain yield was on the increase, but so many negative effects appeared such as environmental problem, food safety and disappearance of traditional agricultural culture. As a GIAHS, the system of forest-village-paddy-river in Hani terrace, which had formed for a long time in history, has multiple values that include ecologic value, productive value and landscape value, therefore, it is of great significance to protect agricultural system of Hani terrace from being destroyed. The purpose of protecting agricultural system of Hani terrace will be achieved, if the price of agricultural products from Hani terrace region is improved by organic planting for the farmers going on planting paddy rice. However, it must go through a stage of organic conversion from non-organic production to organic production. In this stage, the agricultural products produced by organic planting are not brought at the price of organic products due to not having organic label. Therefore, the local government should give some compensation to the farmers who planted rice by organic production during organic conversion for the agriculture products per unit weight, so that the income of the farmers cannot be lost. In this paper, questionnaire and interview were used for gaining the information about input-output of agriculture in organic planting during organic conversion, earnings of farmers from work in city in Hani terrace region, and input-output of modern agricultural planting. By analyzing, contrasting and computing those informations, we had results as follows: 1) The directly input of organic planting of paddy rice in Hani terrace region is more than modern planting, but paddy rice yield from organic planting is lower than modern planting; 2) labors of young adults prefer to work or live in cities for higher income, therefore, the opportunity cost is higher; and 3) extra compensation of paddy rice from organic planting at 2.84 yuan/kg is reasonable for protecting terrace landscape and traditional planting pattern in Hani terrace region.

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    Research on Rural Energy Consumption Pattern Based on Farmers' Livelihood: A Case Study in Jinsixia Rural Tourist Destination
    LI Xin, YANG Xin-jun, CHEN Jia, WU Wen-heng
    2015, 30 (3):  384-396.  doi: 10.11849/zrzyxb.2015.03.003
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    According to the sustainable livelihood theory, a research idea of “rural tourism development-farmers' livelihood changes-optimization of rural energy consumption in mountainous rural tourism destination” is established in this paper. Taking Jinsixia rural tourist destination as an example, the transformation of the livelihood, energy consumption patterns and comprehensive benefits of energy consumption are analyzed. Firstly, through household surveys and interviews, the local farmer households were divided into five types by the energy consumption-livelihood diversity model. Secondly, based on the energy consumption diversity model and benefits evaluation method, the energy consumption structures and comprehensive benefits of farmers who have different types of livelihood strategies are interpreted. Thirdly, with the method of grey correlation analysis, the study identifies the main livelihood capital factors that affect the farmers' energy consumption, and summarizes the driving mechanism of the transformation of farmers' energy consumption patterns. The results are as following: 1) Farmers' livelihood diversity level has an impact on the energy consumption diversity level, the latter will raise as the former goes up inside the non-tourism enterprises and tourism enterprises. 2) Compared with the farmers who are not engaged in tourism, the commercial energy consumption of farmers who are engaged in tourism increases significantly, which reflects the fact that the tourism causes the increase of new energy, the decrease of traditional energy consumption, and speeds the optimization and commercialization of farmers' energy consumption patterns. 3) There is a sharp distinction in energy consumption comprehensive benefits among different types of farmers, that the energy consumption comprehensive benefits of farmers who are engaged in tourism (16.96 yuan/kgce) are significantly greater than the farmers who are not engaged in tourism (13.53 yuan/kgce), which indicates that the former benefits more from the energy consumption. 4) Physical capital, human capital and financial capital are the main factors that affect the farmers' energy consumption pattern. Farmers' livelihood change which is brought by the tourism development is the important driver leading to the energy consumption transformation in rural tourism destination. To further improve the environmental policy and optimize the energy utilization, this paper puts forward the corresponding countermeasures and suggestions.

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    Resource Ecology
    Sources and Sinks of Carbon Caused by Forest Land Use Change from 1975 to 2005 in Central Asia
    CHEN Yao-liang, LUO Ge-ping, YE Hui, WANG Yuan-gang, HUANG Xiao-tao, ZHANG Qi, CAI Peng
    2015, 30 (3):  397-408.  doi: 10.11849/zrzyxb.2015.03.004
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    The contribution of forest land use change to the carbon source has been researched in most tropical regions, but it is poorly documented for arid forest ecosystem. Using Bookkeeping model, we estimated the sources and sinks of carbon caused by forest land use change between 1975 and 2005 in Central Asia. The results indicated that: The forest land use change performed as carbon sink overall, with total carbon sequestration of 3.07 Tg. The accelerated afforesting led to a strong carbon sequestration (12.97 Tg), while the deforestation was a main carbon source, releasing 5.80 Tg. The woodland transfer also performed as carbon source, releasing 4.10 Tg. We recommend that some efficient measures should be taken on increasing the quality and quantity of forest resources in the future to enhance the forestry carbon sequestration in Central Asia. Therefore, this can offset the carbon loss caused by industrial activities, so as to provide sufficient space for the sustained and healthy development of the economy in Central Asia. This study is conducive to profoundly understand the influence of human activities on global carbon balance.

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    Application of Partial Least Squares (PLS) Regression Method in Attribution of Vegetation Change in Eastern China
    HOU Mei-ting, HU Wei, QIAO Hai-long, LI Wei-guang, YAN Xiao-dong
    2015, 30 (3):  409-422.  doi: 10.11849/zrzyxb.2015.03.005
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    Vegetation change is generally caused by the combined effects of various climate variables, which is further complicated by the impacts of human activities. Assessing the importance of each explanatory variable is critical for the study of vegetation change attribution. The responses of vegetation to temperature and precipitation in eastern China have been widely explored in previous studies. However, less attention has been paid to the influence of other climate variables in vegetation change. In this study, we introduced a statistical method called partial least squares (PLS) to investigate the relative importance of different climate variables. ThePLS regression, combining features of principal components analysis (PCA) and multiple regression, overcomes the multicollinearity problem which arises when two or more explanatory variables in a multiple regression model are highly correlated. Using GIMMS NDVI products and PLS method, we first investigated the relative effects of different climate variables (temperature, precipitation, sunrise, relative humidity, wind) on vegetation change in eastern China from the period 1982 to 2006. Then, the relative contribution of anthropogenic factors on the vegetation change was quantified in the region of Jiangsu Province where vegetation shows distinctive changes. The results indicated that: 1) there were distinct north -south differences among interannual variations of monthly NDVI in eastern China in the period of 1982-2006. A significant increase of NDVI was found in December through May in some areas north to the Huaihe River, while the drop of NDVI occurred in June through October in some areas south to the Huaihe River; 2) in the areas with significantly increased NDVI, the greatest contributor was temperature and it had the most significant effect on the increase of NDVI. In particular, the temperature rise could play a dominant role in driving the increase of NDVI in the Huang-Huai-Hai Plain in late winter and early spring (February-March). The decrease in NDVI, by contrast, might not be attributed to climate factors in many areas. However, it should be noted that there was no obvious change in NDVI trends in many parts of eastern China compared with the areas suffering significant NDVI change; 3) Jiangsu Province was mainly characterized by a significant decline of NDVI in June from 1982 to 2006. However, such large regional concentration of NDVI change was not observed in other months and regions. Statistical analysis showed that the agricultural structural adjustment played a key role in controlling the NDVI change in June in Jiangsu Province. The decline of NDVI in June was mainly attributed to the decrease in sown area of cotton across a large spatial extent.

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    Resource Evaluation
    Runoff Renewability in the Middle Yellow River in Response to Human Activity and Climate Change
    XU Jiong-xin
    2015, 30 (3):  423-432.  doi: 10.11849/zrzyxb.2015.03.006
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    Runoff renewability is an important topic in the study of water cycle, and the knowledge of it is important for sustainable utilization of water resources in arid and semi-arid climate areas. Based on hydrological and meteorological data and the information related with human activity including soil and water conservation and water diversion, and using statistical method, we have studied the temporal variation in runoff renewability (Irr) and its formative cause in the middle Yellow River basin. We found that at the time scale of 59 year, Irr shows a decreasing trend superposed by some secondary fluctuations, which divides the variation into four stages. Although the correlations of Irr with three climate variables in the same year such as annual precipitation (Pm), air temperature (Tm) and summer monsoon intensity (SMI) are relatively low, we found significant time-lag effect of the variation in Pm, Tm and SMI on Irr, based on which the characteristic length of time-scale (Lt) can be determined. The correlation coefficients of Irr with N-year moving averages of a climate variable were calculated and then plotted with N. TheNassociating with the turning point is determined as Lt. We found that the Lt for the influence of Pm, Tm and SMI on Irr are 11, 9 and 4 years respectively. There is close negative correlation between Irr and the area of each type of soil and water conservation measures, and the total area. The large-scale implementation of ecological restoration centering on“conversion of degraded farm land into forest and grass land ”since 1998 has resulted in a further reduction in Irr. A regression equation between Irr and the index (Iwd,5m) of warming and dryness and the total area (Asw) of soil and water conservation measures was established which indicates that Irr decreases with Iwd and Asw.
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    Research on AgricultureWater Pricing in the Yellow River Basin Based on Static Multi-region CGE Model
    ZHAO Yong, DOU Shen-tang, LAI Rui-xun
    2015, 30 (3):  433-445.  doi: 10.11849/zrzyxb.2015.03.007
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    Agricultural water plays an important role in water usage of the Yellow River Basin (YRB) and China. Therefore, how to quantitatively analyze the relationship between irrigation water price/usage and social economic variables is an interesting problem. First, based on the Australian TERM model and the bottom-up method, we construct a multi-regional statically computable general equilibrium (CGE) model of the YRB. This model focuses on irrigation water of 47 sectors, in which six are agriculture planting sectors. Then, we apply this CGE model to study the agricultural irrigation water price in different provinces of the YRB. This is done under five scenarios that the irrigation water consumption is reduced by 10%, 15%, 20%, 30% and 50% respectively. We also study the social and economic change under five scenariosof increasing the water price by 10%, 15%, 20%, 30% and 50% respectively. The results show that: 1) The price of agricultural irrigation increases with the decrease of the quantity of irrigation water (the scarcity of water resources is being more and more important). With 15% reduction in irrigation water, the irrigation water price in Qinghai, Gansu, Ningxia, Inner Mongolia, Shaanxi, Shanxi, Henan and Shandong provinces are 0.13, 0.28, 0.07, 1.41, 0.59, 0.80, 0.97 and 0.77 yuan/m3 respectively. With 30% reduction in irrigation water, the final prices of irrigation water in above provinces are 0.28, 0.57, 0.11, 3.34, 1.26, 1.69, 2.19 and 1.78 yuan/m3 respectively. In addition, it indicates that the current price of agriculture irrigation water is relatively low. 2) In all the five scenarios that increase the water price by 10%, 15%, 20%, 30% and 50%, the actual GDP reduces. The maximum reduction is in Ningxia, and the minimum is in Inner Mongolia in all five cases. The GDP of Ningxia decreases 0.054%, 0.08%, 0.105%, 0.155% and 0.249%, and that of Inner Mongolia decreases 0.002%, 0.002%, 0.002%, 0.004% and 0.006%. As far as the residential consumption is concerned, the increase in the price of irrigation water reduces the actual consumption level of the residents on one hand, and decreased the demand of agricultural commodity on the other. This is especially true for the six agriculture planting sectors. But the residential consumption of the non-agriculture commodity increases, where the wheat consumption reduces the most—the most is in Ningxia (decreases 0.208%), and the least is in Henan (decreases 0.078%). From these we can see the importance of wheat in the residential consumption in Henan Province. 3) In the case of 15% reduction of irrigation water, the volume of irrigation water is decreased by 9.087×108 m3 in the YRB, accounting for 1.5% of total irrigation water consumption in the YRB. The province with the largest water decrease is Ningxia. The provinces with the least reduction are Inner Mongolia, Henan and Shandong in order, which indicates that these three provinces are less sensitive to the irrigation water price. As to the type of crops, except the other crops sector, the sector with the largest reduction of irrigation water is the wheat sector, while the sectors of vegetable and fruit are two that have slightly decreased of irrigation water. This shows that these two crops are less sensitive to the irrigation water price. 4) System sensitivity analysis (SSA) shows that the results are robust.
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    Estimating the Effect of Vegetation and Precipitation on Runoff and Sediment Using the MMF Model: A Case Study in the Yanhe River Basin
    ZHANG Lia, MIAO Lian-pengb, WEN Zhong-minga
    2015, 30 (3):  446-458.  doi: 10.11849/zrzyxb.2015.03.008
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    In order to investigate the contribution of vegetation to the reduction of runoff and sediment yield of the Yellow River in recent years, the Yanhe River catchment, which has experienced significant vegetation changes in last decade, was chosen as the study area. In this paper, the new version of Morgan-Morgan-Finney (MMF) model (Morgan-Duzant version) was used to simulate the impact of land cover changes on the runoff and sediment yield of the catchment, and the effect of vegetation and rainfall on runoff and sediment yield were estimated through scenario simulations of series of vegetation and precipitation. Then a correlation analysis was carried out to explore the relationships between vegetation variables and the runoff and sediment yield in the catchment. The data used in the present study included Landsat remote sensing images, the hydrologic and meteorological data, and DEM data (25 m× 25 m) of the catchment. The results showed that: 1) the MMF model provided a better prediction of the average annual runoff volume than the average annual sediment production in the Yanhe River catchment. However, when the impact of terraces and soil-retaining dams was incorporated into the MMF model, it also provided a good prediction of sediment production. 2) The relationships between vegetation factors and runoff volume and sediment discharge did not show evident spatial patterns. There was obvious correlation between runoff volume and indirect vegetation variables (such as canopy interception, throughfall eroding force, sediment rate of the slope, et al.), while vegetation cover was more closely related to the sediment discharge. 3) The scenario simulation of 1990, 2000 and 2006 indicated that the vegetation cover of the Yanhe River catchment had been increased greatly in 2006. Compared with 1990 and 2000, the increased vegetation cover reduced the runoff volume by 45.88% and 25.74%, and reduced the sediment discharge by 12.10% and 27.57% in 2006.

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    The Soil Moisture Characteristics under Different Vegetation Types after Extremely Heavy Rainfall on the Hilly-gullied Loess Plateau
    YIN Qiu-long, JIAO Ju-ying, KOU Meng
    2015, 30 (3):  459-469.  doi: 10.11849/zrzyxb.2015.03.009
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    In order to understand the relationship between soil moisture and vegetation after extremely heavy rainfall on the hilly-gullied Loess Plateau, the soil moisture was observed and analyzed under five different vegetation types (Robinia psendoacacia, Caragana intermedia, Artemisia gmelinii, Stipa bungeana and Bothriochloa ischaemun) after a series of heavy rainfall in July 2013. The results show that: 1) Vegetation became the main factor that affected soil moisture after extremely heavy rainfall. 2) The soil moisture under grassland was higher than that under the artificial forests. The soil under Stipa bungeana had the highest soil moisture, soil water storage and available soil water storage, which were 17.8%, 961.2 mm and 691.2 mm, while the soil under 31 years old Robinia psendoacacia had the lowest soil moisture. 3) The infiltration depth of soil under artificial forests was about 300 cm, and about 500 cm under the grassland. It was difficult to recover the moisture in the deep soil under the artificial forest.

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    Assessing the Impact of Climate Change on Crop Yield Based on Three-interval Temperature Theory: A Case Study of Maize in Heilongjiang Province (1960-2009)
    WEI Xing, WANG Pin, ZHANG Zhao, CHEN Yi, SONG Xiao, SHUAI Jia-bing, SHI Pei-jun, TAO Fu-lu
    2015, 30 (3):  470-479.  doi: 10.11849/zrzyxb.2015.03.010
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    Average air temperature has been popularly and extensively used to assess the effect of temperature on crop yield. However, it would substantially remove the impacts of the extremes on the yield, consequently resulting in a potential bias on the result. Given this fact, we raised the theory of Three-interval Temperature to characterize the responses of crops to different air temperature conditions: extremely low, normal and extremely high. Heilongjiang Province is a thermal-sensitive region to current climate change and a very important production area of maize. In this study, we constructed statistical models by using the indices of Growing Degree Days (GDD) and precipitation to quantify the influence of climatic variables on maize yield in Heilongjiang Province. We also introduced three temperature indices to compare with the results based on the Three-interval Temperature Theory. The result showed that the heat injury has become a non-neglectable factor that causes the detriment of maize production in Heilongjiang Province while the chilling injury has been moderating since the 1980s. Also, the latter method we raised, denoted as the Three-interval Temperature Theory, had a better performance in the assessment of climate change effects on maize yield, which provided new insights into related studies in other cultivation areas.

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    Study on Thermal Environment Effect of Urban Landscape Pattern: A Case Study on Huadu District, Guangzhou
    HUANG Li-ming, CHEN Jian-fei
    2015, 30 (3):  480-490.  doi: 10.11849/zrzyxb.2015.03.011
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    Huadu experienced economic soaring during 1999-2009. The ever-changing urban landscape pattern impacted the distribution of the thermal environment. The land surface temperature (LST) and land use types in the study area were obtained from Landsat TM/ETM+ remote sensing images. Using the mean-standard deviation method, land surface temperatures were classified and the thermal centroids of low and high temperatures were calculated. And the moving paths of the thermal centroids during 1999-2009 were compared with that of the construction land centroid. Visual landscape metrics, including SHDI, construction land PLAND, FRAC_MN, and DIVISION, were obtained by moving window to analyze their correlations with LST. The results show that: the southern part of Huadu was strongly impacted by human activities. Land use was not the single factor which influenced the distribution of land surface temperature. SHDI and LST were positively correlated, even though the increasing degree of landscape diversity would cause the decrease of the relevance. The correlation between LST and construction land PLAND/DIVISION was stable. The regions with large construction land PLAND or low construction land DIVISION were usually high temperature regions. With the increase of the shape complexity and the area of the construction lands, the correlationship between LST and construction land FRAC_MN become stronger.

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    Spatio-temporal Pattern and Its Driving Factors of Grain Production in Heilongjiang Province
    ZHOU Li-qing, CHENG Ye-qing
    2015, 30 (3):  491-501.  doi: 10.11849/zrzyxb.2015.03.012
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    As one of the most vital grain production areas in China, Heilongjiang Province plays an important role in guaranteeing Chinese's grain security. This paper examines the spatio-temporal pattern and driving factors of grain production in Heilongjiang Province based on the models of ESDA, K-Means Cluster and multi-regression, and the aim is to illuminate the current situation of grain production and provide the scientific basis for promoting the regional ability of guaranteeing national grain security and sustainable development of agriculture inHeilongjiang Province. The results show that the scale of grain production in Heilongjiang Province keeps increasing, and both the seeding area and proportion of soybean experience a wave of “ascent-descent”, while the seeding areas and proportions of corn and rice expand constantly, and they both exceed soybean in 2009 and 2011, respectively. By the end of 2012, the planted acreage of soybean, corn and rice accounted for 17.73%, 45.12% and 26% of the total grain acreages, respectively. Moreover, corn and rice has become the main grain crops in Heilongjiang Province, while the importance of soybean decreased in some way. In addition, the grain production in Heilongjiang Province has certain characteristics of spatial correlation. Of which, the soybean has significant spatial agglomeration, and its Moran's I is 0.6011. Corn takes the second place and shows a weakening trend after 2004, for its Moran's I decreased from 0.6135 in 2004 to 0.48 in 2012. The spatial gathering of rice is the least evident but it began to increase since 2009, and its Moran's I was 0.3709 in 2012. The results also show that the regional types of grain production have a significant spatio-temporal variation and the trend of specialization and regionalization is enhanced. The northern Songnen Plain, Da Hinggan and Xiao Hinggan mountains, as well as the north of Sanjiang Plain have respectively formed the typical areas of soybean, corn and rice. Moreover, multi-regression analysis demonstrates that the agricultural investment, economic environment, technical level and market factor are the main factors that influence the structure and the spatio-temporal variation of grain production in Heilongjiang Province.

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    Resource Research Method
    Application of WWFWater Risk Assessment Tools in China —A Case Study in the Yangtze River Basin
    WEI Na, QIU Ya-qin, GAN Hong, LU Qiong, LIU Jia-jia, GAN Yong-de, WANG Chun-yan, LIU Niu
    2015, 30 (3):  502-512.  doi: 10.11849/zrzyxb.2015.03.013
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    According to the current situations of water resources, water environment, water resources management and information statistics in China, the paper readjusts the evaluation index system of water risk for river basin based on the evaluation index system of water risk presented by WWF and DEG, and makes it more suitable for the national condition of China. The indexes are graded by five-grade and five-score scale. Also, the weights and calculation methods of some indexes are adjusted. The weighted comprehensive index summation process is adopted to calculate the integrated evaluation score of basins. The comprehensive evaluation is conducted in the Yangtze River Basin and its seven secondary subareas. The results show that the risk scores of the Yangtze River Basin and its subareas in 2010 are between 1.1 and 1.8, and the risk grade is class Ⅱ, which means it is a low risk area. There are some differences among the scores of the secondary subareas. The scores of the Taihu Lake water system and the Hanjiang River are relatively high. The score of the Jialing River is the lowest. The contribution rates of the three categories of indexes to the water risk are different. The physical risk has a relatively higher influence on the water risk, its contribution rate being 45%-60%; the second one is the regulatory risk, and the contribution rate is 21%-32%; the reputational risk has a lower influence and the contribution rate is lower than 25%. Finally, the future research directions in the field of water risk evaluation are proposed based on the existing problems in the course of China water risk evaluation.
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    Influence of Different Sea Surface Dynamical Roughness Parameterization Method on Wind Energy Resource Assessment in Offshore Area
    ZHOU Rong-wei, HE Xiao-feng
    2015, 30 (3):  513-522.  doi: 10.11849/zrzyxb.2015.03.014
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    Regional distribution of wind energy resource at useful height was achieved by numerical simulation method. The results of wind speed simulation were influenced by dynamical characteristics of sea surface. WRF model was used to simulate in different sea surface dynamical roughness parameterization schemes to disclose the influence of different scheme on wind energy resource assessment in offshore and coastal area and evaluate the applicability of each scheme. Three schemes were used to simulate the wind field with WRF model in Hangzhou Bay: constant value of 0.0001 (P_0), scheme of WRF model with constant coefficient in parameterization formula (P_WRF), and scheme of Yelland and Taylor using different coefficients for different wind speeds (P_YT). The following conclusions were drawn by comparison between the simulation results and the observation data: 1) the simulation results of P_WRF and P_YT schemes were better than that of scheme P_0, and the result of P_YT scheme was more in agreement with the observation data than that of P_WRF scheme. 2) During the sea wind, the improvement was more obvious in P_YT scheme. 3) When the observational wind speed was less than 8 m/s, the relative errors of simulated wind speed in three schemes all decreased with the increase of wind speed, and the result of P_YT scheme was the best, and that of P_0 scheme was the worst. While the relative errors of all three schemes increased with the increase of wind speed when the wind speed was greater than 8 m/s, and the relative error of P_YT scheme was the greatest, while that of constant value was the least. 4) The difference between three schemes was obvious in coastal and offshore area, while in the area where was far from the coastline, the difference was less. In coastal and offshore area, the average wind speed was overestimated with about 0.5 m/s by P_WRF scheme than by P_YT scheme, while the average wind power density was overestimated with about 50 W/m2.
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    Comprehensive Discussions
    Review of Food Loss and Waste Research and Its Prospects
    GAO Li-wei, CHENG Sheng-kui, CAO Xiao-chang, ZHANG Dan, LIU Xiao-jie, QIN Qi, LIU Yao, WANG Ling-en
    2015, 30 (3):  523-536.  doi: 10.11849/zrzyxb.2015.03.015
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    There is growing global concern over food loss and waste and its impacts on resources and environmental issues, and curbing food loss and food waste is becoming another way to ensure food security. However, knowledge of food loss and waste is entirely inadequate worldwide. Here, based on a great amount of literatures and documents at home and abroad, we gave a whole review of research progress on food loss and waste on global scale and found that there is still a long way to go to reduce food loss and waste globally, however, there has been considerable researches. Firstly, it was lack of standardized theoretical framework that includes the definition of food loss and food waste, the demarcation of study segments and the research methods, which caused the difficulty to compare the previous findings. Secondly, there were few researches focusing on economic underdeveloped countries and regions, and the researches about countries in economic transformation mainly concentrated in the 70-80s of the 20th century, so there were less researches about current situation of these countries, especially food loss in postharvest segments. So it was urgent to strengthen case studies of the countries and regions above. Thirdly, reducing food waste by changing consumer behavior was also an important aspect to be strengthened, which can provide policy makers with effective interventions to curbing food waste in consumer segments. In the end, this research gave a prospect that the reduce of food loss and waste will be of great importance in the future and called for cutting down food loss and waste by different ways.

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