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    Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    LI Chuan-zhe, YU Fu-liang, LIU Jia, YAN Deng-hua, ZHOU Ting
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    Since water allocation scheme in the Heihe River Basin (HRB) between Gansu Province and Inner Mongolia was executed after 2000, water use in the midstream in the HRB was limited by space-time restriction. Therefore, it is important to analyze the land use/cover change and driving force, and the problem of eco-environment. The results were as follows: 1) The land use structure changed greatly in the study area. From 1985 to 2000, farmland, woodland, residential and industrial land increased while grassland, water area and unused land decreased; from 2000 to 2005, farmland, residential and industrial land continued to increase, while the remaining land use types decreased. 2) Since the execution of the water allocation scheme in the HRB, the ecological environment deteriorated more quickly, the main reasons of which may be that the available water decreased and the farmland area increased quickly in such a short period. Grassland, woodland and water area decreased obviously, and the change ratios of grassland, woodland and water area were 2.14%, 7.36% and 3.69%, respectively. 3) From 1985 to 2000, the major patterns of land use change were mutual conversion of farmland and residential and industrial land, mutual conversion of farmland and unused land, the conversions of grassland to farmland; from 2000 to 2005, the major patterns of land use change were the conversions of unused land to farmland, mutual conversion of grassland and farmland. 4) There were obvious spatial differences in land use degree changes, and the greatest change took place in Ganzhou County. 5) The main forces of land use changes in the study area are population growth and economic development. However, the amount of the available water resources of the HRB influenced the land use changes more significantly after 2000.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    XIA Rui, LI Yun-mei, WANG Qiao, Lü Heng, JIN Xin, WANG Yan-fei
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    Taking two SPOT-5 orthophoto images of Beijing-Hangzhou Grand Canal in 2003 as the data source, this paper uses the least square multiple regression to build the model between water quality data and land-use proportion in high flow period and low water period. The result shows that the spatial change of the buffer distance which is the center of the monitoring sections presents obvious responsive relationship with water quality monitoring indexes. In high flow period, the maximum response ranges of DO, CODMn, BOD5, TN and TP are 100 m, 100 m, 300 m, 200 m and 100 m, respectively. But in low water period, the maximum response ranges are 500 m, 200 m, 300 m, 400 m and 200 m. The canal water pollution is influenced by neritic land-use structure. Agricultural effluent, commercial and industrial wastewater, bare land effluent, which are composed by living rubbish and construction refuse, are the important reasons to cause the Beijing-Hangzhou Grand Canal water quality deterioration.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZHANG Jin-ping, QIN Yao-chen
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    In the current situation that is difficult to increase the total arable land area, the relationship between grain yield and the factors of production inputs is important for national food security. Global Moran’s I index of grain yield per hectare in Henan was 0.6921, which indicates a strong spatial autocorrelation. Seen from Moran scatter plot, grain yield per hectare in Henan was the high-high cluster pattern. Moreover, there was significant spatial autocorrelation on the residual of ordinary least squares estimation of grain yield per hectare and the four factors of production inputs did not meet the modeling conditions of the classic linear regression analysis. Geographically weighted regression model can overcome the defects of hypothesis that the coefficients of the independent variables affecting grain yield per hectare are homogeneous in the global model. In addition, it can carry out local parameter estimation. The practice of 108 counties in Henan Province shows that, GWR model reduces spatial autocorrelation of the residual effectively for considering geo-spatial effects, and all test indicators are better than the OLS estimates. Especially,the AICc value of the GWR model decreased by 18.7 compared with the OLS model, and the global spatial autocorrelation of the residual greatly reduced, which are the strong evidence of a more superior performance of GWR over OLS. More importantly, the global models can only obtain the contribution rate of factors in the whole region, however, GWR model gives a more profound and delicate information. Four factors of production inputs have different rules of spatial variation. The impact of irrigation in the OLS and GWR models are both positive. The coefficient estimations of the other three independent variables, mechanical power per hectare, the fold pure amount of chemical fertilizer per hectare and electricity consumption per hectare, are negative in the OLS model. While positive and negative coefficient estimations co-exist in the GWR model, indicating there is spatial heterogeneity. In high-yield area located in north of the Yellow River, grain yield per hectare is mainly affected positively by mechanical power, irrigation and electricity consumption with greater fertilizer inputs leading to lower yield. High-yield areas along the Huaihe River and in Xinyang are mainly affected positively by the amount of chemical fertilizer and electricity consumption. To increase grain yield per hectare, mechanical power inputs should be strengthened and the efficiency of electricity be improved in the low grain-producing areas in western mountainous and hilly counties. In the most western mountainous counties, the amount of chemical fertilizer should be appropriately increasedly in addition.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZHAI Zhi-wei, SHI Shang-ming, ZHU Huan-lai
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    Geotherm is a clean and renewable energy. With the increasing of traditional energy sources depletion and enhancing of human awareness to environmental protection, the huge heat energy carried by oil and gas production of middle or high water cut oilfield draws much attention. This paper takes Daqing Oilfield in the northern Songliao Basin for example, and divides the geothermal resources into pure underground water and oilfield produced water based on different vectors of geothermal resources in sedimentary basins with oil and gas. By analyzing the formation mechanism of the heat source, investigating current utilization of oilfield production water, the amount of oilfield production water in Daqing oilfield is 3.98×108 m3 every year, equivalent to 56.95×104 t standard coal in using 10 ℃ range of temperature terms, and has huge potential. By comparing the equipment and operating costs between heat pump heating used oilfield production water and traditional boiler heating, 572×104 yuan are saved in 15 years by stable running, and the economic benefits are also considerable, and furthermore, geothermal resource can be reused to heat buildings of oilfield production and living facilities, as well as heat for crude oil gathering and transportation such as clean, environmental and recycling.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZHANG Yi-feng, LIU Chun-la, ZHANG Wei, ZHANG Hong-ye, MU Song-lin, JIA Da-meng, LAN Ting-ting
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    Beijing, the national politic, economic and cultural center, has the formidable synthesis innovation superiority, must make the model in economic system effective and ecosystem stable, constructing the capital eco-economic zone is an inevitable trend of the Beijing mountainous area’s science development. The capital eco-economic zone region scope is Beijing’s seven mountainous area county, its construction must take "two mountains, five rivers, seven groups" as the spatial structure and take "an area, three bases, a platform" as frame goal. As exploring Beijing mountainous area’s environment, economical and social coordinated development way, constructing capital eco-economic zone is the realistic need of optimizing mountainous area’s eco-environment construction, conform to the reforming objective requirement of mountainous area’s development, has vital scientific significance, practical foundation and theoretical basis, should follow "break administration boundary, ecology leadership development" and other principles, spend 10-15 years, construct eco-industrial economic belt (corridor), expand eco-economic zone regional space scope and make the northern China eco-economic growth, to construct it as the Beijing green-rise forerunner area and the national eco-economic model district.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    CHENG Ji-min, CHENG Jie, YANG Xiao-mei
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    The features of biomass and carbon sequestration were studied based on multi-point transect survey and combined with positioning monitoring methods for different type of grasslands from southeast to northwest in the Loess Plateau. The data were obtained for the pre- and post- 11-year fencing. Results showed that carbon density and storage were decreased from southeast to northwest with an exponentially trend among four-type grasslands. In each type of grassland (aboveground living plants, litter/underground of soil root and soil), the characteristics of distribution of carbon density and storage presented a tendency: forest steppe>plateau steppe>hilly steppe>desert steppe. Grassland carbon density and storage, which included living plants, litter, 0-100cm depth of soil root and soil, were 63.38-97.65 t·hm-2 and 230.2877 Tg C for forest steppe, 49.04-68.80 t·hm-2 and 332.3067 Tg C for plateau steppe, 52.33-62.11 t·hm-2 and 484.0555 Tg C for hilly steppe and 11.93-19.62 t·hm-2 and 113.8563 Tg C for desert steppe respectively, after 11-year fencing. The total carbon sequestration of grasslands was 573.10 Tg C after 11-year fencing on the Loess Plateau. Among which, living plant was 42.89 Tg C (7.48% of the total carbon sequestration), litter was 80.40 Tg C (14.03%), living root was 108.66 Tg C (18.96%), and soil was 341.15 Tg C (59.53%). In conclusion, our results demonstrated that grassland fencing can not only restore vegetation and increase biomass, but can also significantly improve grassland carbon sequestration potential.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZHANG Luo-cheng, LI Qing, WU Qing-hua
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    Based on the study of present situation of the Tianmu Lake Basin, a questionnaire including individual information, residential recognition condition of environmental protection and eco-compensation and willingness to pay of residents and tourism was designed. Willingness to payment method, water resource value evaluation and income loss assessment have been chosen to evaluated the standard of ecological compensation. The gross amount of eco-compensation payment is 129240.8 thousand yuan according to WTP method. As to the water resource value evaluation, the result of which is 61904 thousand yuan. Income loss assessment reaches a total eco-compensation amount of 58390 thousand yuan. Comparing with the three results, we think the result of WTP can be regarded as the standard for tourists by introducing ticket price. To carry out ecological compensation, different evaluation systems and special policy must be worked out to protect the enthusiasm of local government and residents for water protection.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZHU Wen-quan, GAO Qing-zhu, DUAN Min-jie, GUO Ya-qi, LI Yue, WAN Yun-fan, BIAN DUO, WEI Lan-ting
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    This study computed the ecological capital over the northwest alpine pastoral area of Tibet (NWT) in 1992, 1995, 2000 and 2006, using the net primary productivity (NPP) and vegetation coverage derived from remote sensing data. The spatial and temporal pattern of ecological capital in the NWT was comprehensively analyzed. The results showed that the ecological capital of alpine grassland ecosystem decreased from southeast to northwest in the NWT. In terms of the composition of ecological capital, climate regulation and water conservation contributed the most part, with a percentage of 45% and 40%, respectively. Organic matter production contributed 11%, soil and fertilization conservation 2%, and nutrient cycling 2%. The ecological capital of alpine grassland ecosystem in the NWT was 61.61 billion yuan in 1992, and rose to 163.72 billion yuan in 2006. The mean ecological capital value per unit area has increased 10.6 thousand yuan/km2 annually from 1992 to 2006. In light of the data inconsistency from different remote sensors and the short time series in remote sensing data, the estimated changing trend in ecological capital may be higher than the actual one, and further investigations should be carried out to validate these results.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    LIU Pu-xing
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    Based on the investigated and selected research plots of 6.8524 hm2 of Populus euphratica which were divided into 566 subplots in 2009 in the middle and lower reaches of the Shule River Basin Oasis, Hexi Corridor, all the trees whose stems are over 2.5 cm in DBH were identified, measured, tagged and mapped by using quaclrat method and every-tree measuring method. The size and age structure and the survival curves were created and the dynamics quantitative estimate was analyzed with field data. The results indicated that the characteristics of the size and age structure of Populus euphratica population were obviously different under different habitats in the middle and lower reaches of the Shule River Basin. In the middle reaches saplings were lack, with a few springwood and old trees, the population of the middle age trees was the biggest, occupying 72.15% of the total; more big trees and less old trees made the age structure present a normal distribution type; the forest stand is young, very dense and tall and the total of Populus euphratica per hectare is 13.45 times that of the lower reaches. In the lower reaches saplings were lack, with few springwood, more middle and old age trees, the population of big and old trees occupied 62.54% of the total, presenting an inverse pyramid type in age structure; the forest stand is older, very sparse, and dwarfish. They are both declining population in the study area. The survival curves of the population conformed to the type of Deevey I, a type of degressive population. The survival ratio was high in the springwood and middle age trees, low in the big and old age trees. The average survival ratio in the middle reaches was higher than that in the lower reaches, the highest in Qiaozi plot of the middle reaches and the lowest in plot of the lower reaches. The result of the dynamics quantitative estimate indicated that the survival amount in springwood and middle age trees of the population showed a negative value, and a plus value in Ⅶ-Ⅺ size class big and old age trees of the population. A general tendency was a dynamics structure relation of declining population. In a word, the trend is that Populus euphratica population, owing to lack of saplings, will be tending to a decline succession in the study area and the rate of succession in the lower reaches will be faster than that in the middle reaches.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    SONG Fu-qiang, LIU Yuan-kai, DU Chun-mei, YANG Feng-shan
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    Pinus koraiensis is a rare and endangered tree species and is also growing typically symbiotic plant dependent on ectomycorrhizal fungi. In this paper, the forest of Pinus koraiensis at Xiao Hinggan Mountain was taken as a destined area for study, and ectomycorrhizal fungal resources and diversity under the forest of P.koraiensis was also investigated, and components of the culturing medium for Suillus grevillei (Kl. ) Sing. was optimized as well, using response surface experiments. First of all, 21 species under 8 genera of 5 families were identified under the Korean pine forest at Xiao Hinggan Mountain, where the ectomycorrhizal macro-fungal resources are rich, with dominating species of Suillus grevillei, Amanita vaginata and Russula mustelina, and the Pinus koraiensis as an ectomycorrhiza host plant. Based on MMN medium, through response surface analysis we confirmed that components of the optimal medium for culturing Suillus grevillei are KH2PO4 0.3 g, peptone 16 g, glucose 12 g, CaCl2 0.05 g, MgSO4·7H2O 0.15 g, malt extract 3.0 g, FeCl3 (1% solution) 1.2 ml, NaCl 0.025 g, (NH4)2HPO4 0.25 g, vitamin B1 trace 0.005 g, agar 20 g, and added water to 1000 ml. The optimized medium would provide basis for large-scale Suillus grevillei production in the future.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZHAO Bin, SUN Long, HU Hai-qing, SUN Zhi-hu
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    For the aim of understanding the relationships between the soil microbial biomass and nutrient content after fire in Larix gmelinii forest in Da Hinggan Mountains of China, detailed field investigations were conducted in burned area with different fire intensities (serious, medium and low fire intensity). To find the impact factors of microbial biomass,we measured soil microbial biomass carbon (Cmic), nitrogen (Nmic) and soil nutrient of different fire intensities with a fumigation-extraction method after burned three years. The results showed that the Cmic in serious burned site was significantly higher than in the medium, low and unburned sites. Though the Nmic has no significant effect in different treatments, yet it was the biggest in serious burned site. Mean soil Cmic in serious burned site was different significantly with medium, low and unburned sites. The mean Cmic of serious, medium, low and unburned sites was 692.8, 499.9, 428.8 and 498.7 mg·kg-1, and the mean Nmic was 70.6, 55.2, 50.9 and 54.1 mg·kg-1, respectively. The content of soil organic carbon and total N in serious burned area was 82.6 g·kg-1 and 4.9 g·kg-1 respectively, which was higher than in the unburned area significantly and presented an ascending trend with the increase of fire intensity. The content of soil total phosphorus increased significantly, but it has no significant difference among different fire intensities. Soil available phosphorus content increased in light burned area significantly, which was 29.9 mg·kg-1, but a decrease occurred with the increase of fire intensities. Soil moisture content, pH and soil organic carbon influenced the Cmic and Nmic significantly, the soil microbial biomass was positively correlated to the soil moisture content, pH and soil organic carbon.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    SHI Jun, CUI Lin-li, TIAN Zhan, YU Qing-ping
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    Based on the mean daily temperature data from 446 meteorological stations during 1961-2007 and those from RegCM3 model during 2010-2039, the impact of temperature change on heating and cooling energy consumption of residential buildings in East China were studied by the method of degree-days with 10 ℃ and 22 ℃ as the baseline temperature of heating degree-days and cooling degree-days. The results indicate that from 1961 to 2007, heating degree-days and the sum of heating degree-days and cooling degree-days decreased basically in the whole East China, with more decrease in the northern part and less decrease in the southern part of East China, and cooling degree-days increased in most part of East China, with more increase in the Yangtze Delta region, the eastern part of Zhejiang and the coastal areas of Fujian. During the period from 2010 to 2039, heating degree-days will decrease continuously in the whole East China, with more decrease in the northern part and less decrease in the southeastern part of East China, and cooling degree-days will increase continuously in the whole East China, with more increase in the southern part and less increase in the northern part and coastal areas. The sum of heating degree-days and cooling degree-days will decrease in the northern part and increase in the southern part of East China during 2010-2039. In the past 47 years, the decrease of heating degree-days was much more than the increase of cooling degree-days in East China, so temperature change on the whole was favorable to the decrease of energy consumption of residential buildings. In the future 30 years, the decrease of heating degree-days was close to the increase of cooling degree-days in East China, so the impact of temperature change on energy consumption of residential buildings will be little.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    DONG Bin, CHEN Li-ping, QIAN Guo-ying
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    In the paper, two periods (2000 and 2006) of TM remote sensing images with similar temporal phase were selected as the basic data sources, and supervised classification and expert classification were carried on the forest resources classification and the confirmation, finally, analytic hierarchy process and fuzzy mathematics analysis were used to study the ecological suitability of forest resources synthetic evaluation model in the Yellow River Basin of Shandong Province. The results indicated that the forest resources are distributed unevenly: The forest coverage of Jinan, Tai’an and Laiwu was over 30%, however, the forest coverage of other seven cities was only 15%. In the aspect of the forest resources ecological suitability, Tai’an was the best, Jinan and Laiwu were good, while Zibo, Binzhou, Heze, Dongying and Dezhou were just so-so, Jining and Liaocheng were the worst. During the six years period, Tai’an changed from good to excellent, Jinan and Laiwu got the high remarks, and however, Jinan tended to develop well while Laiwu tended to go to the contrary direction. Although Zibo, Binzhou, Heze, Dongying and Dezhou did not get the good standard, but their development trends seemed to be better. In addition, the ecological suitability of forest resources of Jining and Liaocheng was not good enough.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    YANG Qi-yong, YANG Jing-song, LI Xiao-ming, LI Dong-shun
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    In this paper we present a case study of Yucheng City, which is a representative district of salt-affected soil under amelioration in northwest Shandong Province. Using Delphi approach and grey correlative degree method, the evaluation factors were chosen. The comprehensive evaluation model of soil suitability was established when weights of these factors were determined by AHP method. The geospatial techniques included Inverse Distance Weighting (IDW), Radial Basis Function (RBF) and Ordinary Kriging (OK). On the basis of Root-Mean-Squared-Error, the IDW was found to be the most successful one, and it was used to estimate the Index of Soil Suitability (ISS) of sampling sites. The contour map of the soil suitability was drawn after determining the ranks of ISS by scatter diagram. The results showed that the soil suitability of cultivated land in Yucheng City is good in general. The area of the first and the second grades is 27.24% of the total area. The area of the third and the fourth grades is 45.48%, and that of the fifth and the sixth grades is 27.28% of the total area. Distribution of cultivated land soil suitability grades was affected by topography when the terrain varies from the highlands to the low-lying depressions, and Yellow River irrigation has an effect on soil suitability grades. This study explored the technical methods of the soil suitability evaluation in the saline soil improvement district, and this study contributes significantly to the improvement of saline soil cultivated land resources, sustainable use and soil quality improvement.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    QI Rui, GENG Yong, ZHU Qing-hua
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    Water resource serves as an important basis for regional economic development and social stability. Hence it is necessary for us to seek an appropriate method to evaluate the overall efficiency of regional water resource so as to make a reasonable water protection strategy. Based upon water footprint theories, this paper presents an innovative evaluation method on water resources. We raised an indicator system for assessing water footprint structure, benefit, ecological security and its stability. A case study on Dalian city is conducted in order to test its rationality and applicability. Our research results show that this method is feasible and reasonable.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    YU Zheng-jun, REN Zhi-yuan, ZHANG Hui, LU Jin-rong, LI Jing
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    Regional development is a course of accumulation based on many factors, which is directly related to resources utilization and conversion. And material possession production and accumulation embody the outcome of regional development. Thus, focusing on material possession, regional development can be evaluated from resources and perspective of resources conversion. The material-based development index model was established based on the infrastructural level, transportation accessibility and economic development level in this paper. By using GIS technology and mathematics statistics methods, this paper then calculated the material-based development of each county of Guanzhong-Tianshui Economic Zone in 2006, 2007, 2008, and systematically evaluated the material-based development of the Economic Zone. The result showed that: 1)Except several counties, the material-based development index of Guanzhong-Tianshui Economic Zone showed a rising trend, but the growth rate is not great. Growth rate of only seven counties exceeded 4%. The fastest-growing areas are not the areas under the jurisdiction of the cities, but are the counties with material-based development index being in the moderate level. 2)The center of material accumulation index of the Economic Zone is in Liquan County of Xianyang in 2006, 2007 and 2008 with little change in geographic location. 3)The material-based development index of Guanzhong is generally higher than that of Shangluo and Tianshui, showing a narrow east-west trend.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    HUANG Xiao-lan, CHEN Jian-yao, ZHOU Shi-ning, XIE Li-chun, JIANG Hua-bo, DONG Lin-yao
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    Cultured-independent molecular analyzing technology was used to construct 16S rRNA gene library and gene sequences of microbial groups for groundwater samples collected at Zhuhai Campus of Sun Yat-sen University and Tangjiawan Town. Microbiological groups were compared to identify the adaption and possible evolution due to urbanization by using the campus as a background. The Proteobacterium, Candidate division OPx and uncultured archaeon(uncultured Crenarchaeote and Euryarchaeote)were found predominant in the recharge, middle and discharge zones of the campus, while none of the uncultured archaeon and Candidate division OPx were found in Tangjiawan. Although microorganism in the groundwater evolves in response to the change from a background with little anthropogenic influence to a urbanized town, linkages of microbial groups between two sites were detected by the genetic neighbor-joining tree, indicating its evolution under a changed environment.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    LI Zong-li, LI Yuan-yuan, WANG Zhong-gen, HAO Xiu-ping, LIU Xiao-jie
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    The remarkable growth in China’s population and economy over the past several decades has come to realize at a tremendous cost to the country’s environment, particularly around water. China’s water resources are over-allocated, inefficiently used, and grossly polluted by domestic and industrial wastes, to the point that vast stretches of rivers are dead and dying, lakes are cesspools of waste, groundwater aquifers are over-pumped and unsustainably consumed, and direct adverse impacts on both human and ecosystem health are widespread and growing. For addressing these crippling water problems, a new strategy of Interconnected River System Network (IRSN) is put forward, which is of great necessity for improving the capacity of water resources allocation, sustaining river’s heath and enhancing flood and drought control. However, up to now both the theory and technology of IRSN have still been a blank, far from the practices. Based on the further requirement of national water security and the improvement of the ecological civilization, with the new idea of human-water harmony and water resources livelihood, this paper presents a concept of IRSN, which can be defined as a river system network formed by constructing the hydraulic connection of water bodies of rivers, lakes and wetlands with various kinds of water projects, characterized by proper diversion and drainage,reasonable storage and discharge, adjustment of low and high runoff, complementary water multisource, controllable capacity, and the river system network appears to be complex, systematic, dynamic, temporal and spatial. Then the general thoughts of IRSN is proposed on the basis of the river system connection goal, the study of the IRSN can be carried out at four steps: 1) mechanism analysis, the theoretical basis of the whole study; 2) system identification and assessment, the analysis of the current status of IRSN in the researched region/basin, and the construction of Safety Evaluation Model with the complete indicators; 3) IRSN project plan, the make-out of the programmers with the requirement and problems of the society, and choosing the optimal decision from the solutions set; and 4) river system optimization and adjustment, the river system network will be reevaluated with the information of the monitoring system, and adjusted according to the principle of realizing the goal of sustainable development. According to the general thought of IRSN, some key problems worth specially concerning in the study are discussed, including different scales of IRSN, the process of river network connection, the pattern matching, the function of IRSN and the control methods.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    WANG Zhong-gen, LI Zong-li, LIU Chang-ming, LI Yuan-yuan, LIU Xiao-jie, HAO Xiu-ping
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    Climate change and human activities affected water supply and water management, and brought a lot of water issues, such as drought, flood, water shortage, deterioration of water environment, etc. In order to fundamentally increase water resources allocation ability, improve ecological environment quality, and enhance the capacity to withstand flood and drought disasters, in China, a new national strategic plan on the constructing river system network was put forward. We have called this plan as IRSN (Interconnected River System Network) plan. To grasp the strategic thinking of IRSN, this paper, based on the basic concept of river, lake, and water system, discussed the hydrological characteristics of rivers and lakes, and analyzed the role of rivers and lakes in the river system network, and pointed out that the river is the main component and lake is the "connector ", "converter" and "storage device" of constructing river system network, and reservoir can be seen as an artificial lake. How to keep the river water mobility and continuity and play the role of lake water storage capacity and ecological benefits as wetland, are the keys to IRSN plan. This paper presents four basic water cycle issues that should be concerned in the implementation process of IRSN plan. First is about water balance. As the structure and characteristics of the natural water system were changed by engineering measures (such as water diversion project, construction of dams, reservoirs, etc. ), the original water balance must be broken. We need to re-examine the new relationship of water balance of the changed river water system. Second is energy balance. The connection of rivers and lakes should be done according to the conversion law of water, the potential energy and kinetic energy, and as far as possible using water bodies own energy to maintain water mobility. Third is about water resources renewability. Just improve river mobility to enhance water resources renewability in river water network. This is the most basic goal of IRSN plan. Fourth is about water cycle scale. As for different water cycle scales, the water connectivity rules are different. So, IRSN plan has the characteristics of multi-temporal and multi-spatial scales.As IRSN plan is an important new plan on water management in China, the related theoretical researches have lagged behind the practices. The purpose of this study is to promote the establishment of theoretical system on IRSN plan. The results of this paper will lay the theoretical basis of hydrology for implementation of the IRSN strategic plan.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Lü Xiao, HUANG Xian-jin, ZHONG Tai-yang, ZHAO Yun-tai
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    For the purpose of keeping abreast the development of farmland fragmentation analysis in China, this paper gives a comprehensive description of the research on farmland fragmentation by using the summary and comparison analysis approaches. The analysis is organized from three aspects flowed as the definition of farmland fragmentation, the main fields concerned by farmland fragmentation and the measurement method. The main features about the research of farmland fragmentation go as follows. Firstly, the connotation of farmland fragmentation is clear and has been widely recognized, but the measurement method for the degree of fragmentation still needs further study. Secondly, the farmland fragmentation research in China mainly focuses on the causes and the effects on agricultural production. Among them, the research on negative effects of agricultural production is most sufficient. Furthermore, the relationship between farmland fragmentation and land consolidation attracted more attention. The research on the relationship between farmland fragmentation and land transfer is quite inadequate. The last but not the least, the study on land fragmentation mainly uses economic research methods, such as production function and regression analysis. Geographical spatial analysis method and the method of landscape ecology have not been used in the research. Besides, some suggestions on further studies of decoupling are put forward in this paper. These suggestions include giving more concern on comparative study of different areas based on different economic and social background; strengthening the study on relationship between farmland fragmentation and comprehensive regulation of rural land; in order to expand the research angle and research content, trying to combine the discipline of geography with landscape ecology, especially using the methods of RS and GIS in farmland fragmentation.