Table of Content

24 January 2004, Volume 23 Issue 1 Previous Issue    Next Issue

Original Articles

On Establishing The Great Canal Regional Ecological Infrastructure: Strategy and Approaches YU Kongjian, LI Dihua, LI Wei 2004, 23 (1):  1-12.  doi: 10.11820/dlkxjz.2004.01.001 Abstract ( 596 )   PDF (1661KB) ( 1156 )   Save Ecological infrastructure (EI) is the critical natural systems that provide nature’s service to cities and their residents， which is composed of not only the traditionally recognized green systems， but also suburban forests， farm land and natural habitats that are connected as an integral infrastructure. Just like a civic infrastructure that is critical to the sustainable development of a city and a region，so is the ecological infrastructure to the sustainable environment of the region and the city. The construction of the EI must be built across administrative boundaries and must be strategically allocated for the next centuries to come. Therefore， the planning and construction must be taken as long-term strategy at the regional and national scales. The speedy urbanization process， and the enormous landscape change pro-jects such as the water diverting projects from the south to the north， offer great opportunities to the formation of the regional EI. This paper proposes the planning and establishment of a regional ecological infrastructure along the Great Canal to support the sustainability of the east China， meanwhile provides opportunities for local and regional recreation， and protects a historical heritage corridor. Step-by-step approaches are also suggested for the planning and design of the Great Canal ecological infrastructure. References | Related Articles | Metrics

Main engineering measurements and mechanism of blown sand hazard control HAN Zhiwen, WANG Tao, DONG Zhibao, ZHANG Weimin, WANG Xueqin 2004, 23 (1):  13-21.  doi: 10.11820/dlkxjz.2004.01.002 Abstract ( 703 )   PDF (1291KB) ( 875 )   Save Through deeply studying on main engineering measurements and mechanism of blown sand hazard control， the relation between the max wind erosion depth of straw board check sand break and side length of straw board check sand break is theoretically concluded. Using the fluid mechanic theory the different straw height H0 above the ground and relative max space L are computed. We conclude that sand shear velocity in check sand break decreases with the increase of different sand break types and the rate of depth and width H/L， and set up the relation between the rate of leeward wind velocity and upward wind velocity of barriers and distance of leeward of barriers. We also study the effect of blown sand blocking and transporting of different pore rate of nylon net barriers， the aero-rough features of high standing plant and Gobi gravel mulch and chemical sand fixing measure and so on. Through comprehensive review of the studied results， the main problems and tasks facing blown sand engineering are analyzed. The paper points out that close combination of eco-environment control-natural resource development and sustainable development is a way for blown sand control’s development in the future. In the meantime， the theory of study on the combination of blown sand hazard control of eco-environment recover and natural effective development，and technological examples needs to be strengthened. References | Related Articles | Metrics

Treatment Technology of Wastewater Using Constructed Wetland and Its Present Status and Future Prospects in China YU Shaopeng, WANG Haixia, WAN Zhongjuan, SUN Guangyou 2004, 23 (1):  22-29.  doi: 10.11820/dlkxjz.2004.01.003 Abstract ( 859 )   PDF (1160KB) ( 986 )   Save Constructed wetland is an integrated ecosystem ，it has particular mechanism and function on treatment of wastewater. Many countries are paying more attention to it increasingly. Based on the research of all the world , this paper concisely introduces the mechanism and classification of treatment technology of wastewater and analyzes its advantages and deficiencies by the numbers. The advantages of constructed wetland are correspondingly low investment,variety and pertinence of treatment systems , efficient purification capability and especial virescence benefit. The deficiencies are mainly the large-scale land requirement ，more saturation phenomena and limitation with climate than traditional wastewater treatment plants ，but these deficiencies can be hurdled through continuous research. After expatiating the present status of research and application , the paper points out the widely applied prospects of treatment technology of wastewater using constructed wetland in China ，especially in the rural areas and small cities. At last , the author brings forward strategical viewpoint on how to develop it at present. It includes enhancing perception extent ，developing scientific research with focal points and taking ripe technology as chief choice with enough argumentation. References | Related Articles | Metrics

A Case Study on Characteristics and Countermeasures of Environmental Degradation in the Heihe River Basin, Northwestern China QI Shanzhong, WANG Tao, LUO Fang, LUO Wanyin, GUO Jian 2004, 23 (1):  30-37.  doi: 10.11820/dlkxjz.2004.01.004 Abstract ( 684 )   PDF (1289KB) ( 832 )   Save The Heihe River Basin, located in the northwestern China, is an area of typical arid to semiarid features. During the last century, especially the last half century, mankind’s production activities have caused lots of detrimental environmental degradation problems in this basin. Environmental degradation has become a great threat to the whole basin for the future and it requires great effort and resources to ameliorate. Based on investigation and previous studies, the authors found that the main consequences of environmental degradation in Heihe River Basin were water environmental changes, land desertification, soil salinization and vegetation degeneracy, which were mainly resulted from the misuse of water resources by human’s activities. For environmentally and socially sustainable development, there is an urgent need to promote awareness and understanding of the natural, socioeconomic systems at local levels. Understanding the current status and causes of environmental degradation is very important. This paper reveals the important aspects of environmental degradation in Heihe River Basin of northwestern China and suggests possible solutions that may help to ameliorate the situation. References | Related Articles | Metrics

Numerical Simulation of Different Irrigation Scheduling on Oasis in Northwest China GAO Yanhong, CHEN Yuchun, LV Shihua 2004, 23 (1):  38-50.  doi: 10.11820/dlkxjz.2004.01.005 Abstract ( 466 )   PDF (1873KB) ( 696 )   Save The variation of energy and water exchange between land surface and atmosphere, the influence on atmospheric temperature and humidity at 2m height, soil moisture at four layers (10cm, 30cm, 60cm, 100cm)， and surface/underground runoff under different irrigation schedule from 20 July to 30 July, 2002 were analyzed on oasis in arid region of NW China and simulated using the non-hydrostatic atmospheric mesoscale model MM5, in which the land surface process parameterization (OSU LSM) was involved and soil layers, vegetable layer, hydrological process and snow were included. The horizontal resolution was selected as 1km. We knew from “Numerical simulation of Oasis’ Environmental influence under different quantity irrigation in arid regions of Northwest China” that 500m3/hm2/10d is a proper volume for later dekad of July,2002. We determinate the best irrigation schedule based on the method of keeping soil moisture steady. The results showed that: firstly, soil volumetric water content fell down gradually when irrigating 50m3/hm2/d every two days or every several days. Soil moisture could not keep in a stable range, and could not provide steady water supply for the plant growth. So this irrigation schedule is not a proper one for later dekad of July in oasis. Secondly, the surface runoff of irrigation schedule is smallest when irrigating ten days evenly and the quantity is 50m3/hm2 every day. Soil moisture variation of it is smallest also among the following three schedules: irrigating ten days, and 50m3/hm2, every day; 100m3/hm2/d, every two days; and 250m3/hm2/d, every five days. So the first schedule is the best scheduling according to the irrigation schedule determination method from soil moisture maintenance. But it is difficult to realize because of a series of problems such as equipment and labors. Then, the most similar schedule can be adapted in real life. In one word, the shorter the interval between irrigations under the given irrigation quantity crops need every time, the better. So the irrigation water can be transformed to soil moisture as soon as possible to supply crops on it, not to flow down along the slope of topography as surface runoff. So we’d better irrigate as the best irrigation schedule so as to hold the limited water resources. References | Related Articles | Metrics

An Overview On The Study Of Biogeochemical Cycle For Rare Earth Elements (REEs) JI Hongbing, WANG Lijun, DONG Yunshe, WANG Shijie, LUO Jianmei, SUN Yuanyuan 2004, 23 (1):  51-61.  doi: 10.11820/dlkxjz.2004.01.006 Abstract ( 736 )   PDF (1359KB) ( 963 )   Save This paper is a general summary for rare earth elements (REEs) applications in agriculture, the characteristics of their distribution, transport and fate in soils, waters and plants, and concise prospects to the future development in this field. Along with the increase of REEs in the environment, it has caused the concern on our society for the influence on ecological environment and mankind’s health. The solid speciation of REEs in soil horizons is an important parameter to its environmental effects and biological utilizations. However at present the sequential extraction experiment results on the speciation of REEs are varied in different regions and soil profiles, and it is chiefly to be related with environmental conditions, such as the mineral compositions of parent rocks and climate, etc. REE distribution in waters is affected by the environmental parameters (pH and organic matter) and water chemistry processes, the REE contents are also influenced by mankind’s activity. REE distribution in plants is usually identical with that in soils. Under different dressing methods, REE distribution in each organ of plants is closely related with the dressing position after short-term. At present the REEs location and speciation in plants are understood clearly, while the hyper-accumulation mechanism researches for REEs in plants are in doom. References | Related Articles | Metrics

The Study on the Potential Natural Vegetation and Future Prospect LIU Huamin, WU Shaohong, ZHENG Du, YANG Qinye 2004, 23 (1):  62-70.  doi: 10.11820/dlkxjz.2004.01.007 Abstract ( 718 )   PDF (1119KB) ( 666 )   Save Global change has received more and more attention for decades. Understanding how terrestrial ecosystems would respond to global change is necessary for ensuring the earth suitable for human existence and sustainable development in future climate. The study of vegetation-environment relationship is the basis for the study of global change and terrestrial ecosystems. But the nature vegetation all over the earth has been destroyed or modified by the humankind for thousands of human activities, and present vegetation is the result of long-term interaction between vegetation and site factors including man-made impacts. The devastation of the nature vegetation covers up the relationship between vegetation and environment. The studies of vegetation-environment relationship based on the actual or existing vegetation can not reflect the real relation between vegetation and environment. How to construct the potential natural vegetation reflecting the environmental deciding factors is starting points for the research on vegetation-environment relationship. In this paper, the author briefly reviews the concept of the potential natural vegetation, summarizes the different time-spatial scales of the studies, and concludes the main characteristics of the two developing stages: (1) the traditional qualitative research based on the experience; (2) the quantitative research based on the predictive models. The following tendencies in relation to the studies on potential natural vegetation in China are pointed out: Establishment of the predictive vegetation models which will have China's own distinguishing features, simulation and prediction of the potential natural vegetation in China using these models at different time-spatial scales; replacement of the simple climate predictor by comprehensive environmental variable as the independent variable in the predictive model. At last the studies of the potential natural vegetation coupling with GCMs are emphasized. References | Related Articles | Metrics

Land Use/Land Cover Change and Driving Forces in the Region of Upper Reaches of the Dadu River BAI Wanqi, YAN Jianzhong, ZHANG Yili 2004, 23 (1):  71-78.  doi: 10.11820/dlkxjz.2004.01.008 Abstract ( 480 )   PDF (1001KB) ( 910 )   Save Based on remote sensing imageries of 1967，1987 and 2000， and a digital elevation model with a scale of 1∶250000， the land use/ land cover change and driving forces in an area of 18665 km2 in the region of upper reaches of the Dadu river are examined. The results show that the dominant land type in research area changed from forest land to grassland between 1967 and 2000. This was mainly decrease of 319774 hm2 and its proportion to total area dropped from 30.92% to 13.78%. Landscape pattern analysis finds out that forest patches had an increasing regularity with fragmentation process，which indicates that the decreased forest was an outcome of a planed cutting by state-owned forestry enterprises， rather than of blind cutting by local people. This point has been approved by historical documents. Therefore， it is concluded that governmental policies played a dominant role in land use/land cover change of this region. For analyzing various bio-physical and socio-economic driving forces， the method of Logistic stepwise regression is applied in our study. Through spatial analysis， the most significant drivers and their relative importance for cultivated land， forest land， grassland， water area， built-up land and unused land are founded out from such factors as terrain， elevation， roads， water system， urban and rural residential areas. References | Related Articles | Metrics

Sustainable land use: literature review and research progress DAI Erfu, WU Shaohong 2004, 23 (1):  79-88.  doi: 10.11820/dlkxjz.2004.01.009 Abstract ( 747 )   PDF (1178KB) ( 925 )   Save The concept of Sustainable Land Use (SLU) was firstly proposed at the first international symposium on sustainable land use that was held by Indian Council of Agricuiltural Research（ICAR）， United States Department of Agriculture （USDA） and United States Rodale Institute at New Delhi on 1990. From then on， extensive research works has been performed internationally by many scholars and research societies， covering all aspects that related to sustainable land use. This paper aims at reviewing literature on sustainable land use research， expounding research progress， and lastly advising future research directions. Firstly， concept and connotation on SUL was identified，which can be expressed as land use structure and land use approach that can fulfill improving human demand， reserve and improve human living standard， to be harmonious and effective on land use structure， ecologically suitable， economically viable and socially acceptable. Secondly， research scope and objectives on SLU were also illustrated. The fundamental objectives on SUL study is to investigate land use dynamics， to forecast future changing directions， as well as to analyze driving factors to these changes and lastly to select suitable decisions on sustainable land use strategy at different scales. So， research focuses on investigating land changing process， and formulating regionally or globally integrated models. On international research progress， three aspects on SUL study are summarized and discussed， which includes systematic analysis， assessment and integrated research models on SUL. Following conclusions can be drawn through literature review and research progress investigation: ① SUL study must be performed under extensively international cooperation and multi-discipline scholars. ② On modeling approach to mechanism and progress analysis on SUL， multi-space and hyper-time models should be fulfilled based on scientific and perfect theory base. ③ SUL modeling approach should be performed on mechanism analysis and process analysis. ④ On quantitative approach， there are so many factors， especially those related to social， economic and cultural issues，being too difficult to be quantified， which prevents penetrating analysis on SUL study. ⑤ The difficulty on data acquiring as well as data quantify has always been obstacles for SUL. ⑥ How to cover all aspects and factors that related to physical， social and ecological perspective， and how to express temporal process on these aspects and factors， still needs to be further studied. After catalog and comment on Chinese research proceedings on SUL， unfortunately， it can be found that gap still exists on Chinese study status comparing to that international. Such disparity are major: ① Theory investigation is major based upon traditional land use analysis， but not on structure， function and evolving process investigation directly related to SUL. ② On SUL assessment， much effort is focused on land suitability extension， and not giving prominence to SUSTAINABILITY and TEMPORAL， which are the core of SUL. ③ Statistical methods are widely used on driving mechanism study to SUL， while mechanism-based and process-based analyzing approach has not been performed. ④ Abroad model for SUL study are implemented in Chinese study， our own models that suitable to China has not be reported. Even though， many peculiar work has also been done on special areas， just like SUL study to Pearl River Delta， Yangtze River Delta， Three Gorge Area， North-East Plain in China， Loess Plateau， Tibet Plateau and so on. These works also serve as study samples to international SUL research. On Chinese research direction in the future， we basically think that focus should be attended on fundamental theory， application theory and special study cases to SUL. References | Related Articles | Metrics

The Comment on Research of Western Intra-urban Residential Relocation Models ZHANG Wenzhong, LIU Wang 2004, 23 (1):  89-95.  doi: 10.11820/dlkxjz.2004.01.010 Abstract ( 571 )   PDF (837KB) ( 679 )   Save Urban inhabitants’ housing choice behavior affects urban residential spatial structure. Further more, urban inhabitants’ housing choice behavior is relevant to segregation on residential spatial structure, race discrimination, residential mobility and suburbanization. So many scholars pay more attention to housing choice behavior. This paper mainly introduces the theory frame of housing choice behavior research and methodology and important models Housing market and inhabitant’s social attributes influence residential location decision process and relocation choice behaviors. Housing’ location is fixed and housing is expensive and everlasting. So present stock and developing trend of housing market determine household’s residential location decision process and household’s relocation choice behavior. Inhabitants’ social attributes include income, profession, age, education degree, household structure, race and religion. Inhabitant’s location process exhibits some regular spatial preferences because of age, household scale, income and workplace. There has been a sharp dichotomy between micro-level and macro-level analyses in past research. Under assumption of utility maximum, micro-level research mainly focuses on mechanism of consumer housing choice behavior. On the contrary, macro-level research mainly focuses on equilibrium of housing market, the relationship between mobility probability, population, income and present housing condition. This paper mainly introduces main residential location decision process and relocation choice behavior models and authors make some comments on them. References | Related Articles | Metrics

Analysis of the Coordination of Ecological Economy in Urban-Suburb District Based on Ecological Footprint Model WANG Shuhua, ZHANG Yifeng,MAO Hanying 2004, 23 (1):  96-104.  doi: 10.11820/dlkxjz.2004.01.011 Abstract ( 542 )   PDF (1260KB) ( 720 )   Save By taking an urban-suburb district, Xinle city, as an example, this paper applies the ecological footprint indicator to value the coordination state of the regional ecological economy. After research, we can draw a series of conclusions as follows: (1) The supply and need shows an uneven character, ecological deficit is serious, and the coordination state in Xinle city is not optimistic; (2) The structure of supply-need shows an obvious dissymmetry ; (3) The natural resources usage of this city is higher than that of whole country and that of the eastern area. Finally, the authors analyze the reasons of ecological deficit and the feasible measures to reduce it. On the base of above analyses, this paper uses the results of ecological footprint and the formula of development capability to calculate the diversity index and the development capability. Through the calculation, we can draw a conclusion that the diversity index of Xinle county is 0.8996 and the development capability of the ecological economy system is 1.2918, and the research example have a higher development capability. The most important approach to improving the development capability is increase the diversity of ecological footpring. References | Related Articles | Metrics

Effect of Water Stress on Dry-matter Partition and Yield Constitution of Winter Wheat YU Li, YU Qiang, LUO Yi, LIU Minghua 2004, 23 (1):  105-112.  doi: 10.11820/dlkxjz.2004.01.012 Abstract ( 622 )   PDF (973KB) ( 596 )   Save Dry-matter accumulation, partition and yield of winter wheat by different irrigation or water stress in different development stages was analyzed. The proportion of stem was low and the proportion of spike was high under the fitting water condition, there were 24% of stem and 56% of spike. But on the condition of water stress, the proportion of stem became higher and the proportion of spike was lower. On condition of water shortage, the proportions of stem and spike were 36% and 43% respectively, and on the redundant water condition, the proportions were 37% and 48%. The contribution from stem to yield was 0.308 g/stem under the fitting water condition; on the condition of water shortage the contribution from sheaths to yield was highest in treatments, was 0.18 g/stem. The relationship between yield and evapotranspiation indicated that the highest theoretical yield was 6240 kg/hm2 in Yucheng under present fertilizer and management level. The evapotranspiration at highest yield was 473 mm; and the evapotranspiration was 403 mm when water use efficiency was highest. Groundwater was an important water resource in this area. Amount of water supplied by groundwater to wheat from jointing to maturity stages was 22% of total water consumption of winter wheat. References | Related Articles | Metrics