 |
"The Most Excellent Geographic Journal" honored | ||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||
Vol. 25 (2000£©No. 5
Cultivated-land Transition and Land Consolidation and Reclamation in China: Research Progress and Frame
LONG Hualou, LI Xiubin
Abstract: Land use transition is a new integrated approach of land-use and land-cover change (LUCC) study. Land use transition is also one of the major research contents of Global Land Project (GLP), a joint research agenda of the International Geosphere-Biosphere Programme (IGBP) and the International Human Dimensions Programme on Global Environmental Change (IHDP) to improve the understanding of land system dynamics. This paper develops a research frame for cultivated-land transition and land consolidation and reclamation in China, after reviewing the research on land use transition, the theories and models of land-change science, cultivated-land change and land consolidation and reclamation. The frame may include: (1) analyzing the spatial pattern of cultivated-land change in China; (2) understanding the influential factors of cultivated-land transition trajectory; (3) putting forward the theoretical hypothesis on cultivated-land transition; (4) modeling the spatio-temporal changes of cultivated land in China and defining the regional types of cultivated-land transition and the phases where they are in; and (5) providing theoretical and scientific basis for land consolidation and reclamation, an important way to conserve cultivated land in China.
Main Progress and Prospects of Land Resource Ecological Security Research
ZHANG Hongbo, LIU Liming
Abstract£ºEcological security is critical to sustainable development of human society, which includes resource security, biological security, environmental security and etc. And land resource ecological security is an important aspect of resources security. However£¬ the ecological problems of land resource are increasingly serious in such terms as soil erosion, land pollution and desertification, which are threatening regional eco-security and sustainable development. Therefore, the research of land resource ecological security has become the forefront topic in the field of sustainable utilization of land resource. This article interpreted the concept of land resource ecological security firstly, and then summarized the main progress and achievements in land ecological security research, which include the relationship between land resource ecological security and land use/land cover changes, assessment of land resource eco-security and design of land resource eco-security. Finally this article put forward that special attention should be paid to following aspects in the future study of land resource eco-security. Firstly, there is an tendency to integration of the research on mechanism of land resource eco-security, land ecological security assessment and land resource eco-security design. Secondly, study of land eco-security assessment method as well as determination of the threshold of land resource eco-security index should be further discussed. And finally, construction of land use security pattern is still an exploratory work.
Forecast and Countermeasures of the Change of the Cultivated Area of China
by Jia Shaofeng, Zhang Haoxi and Meng Xiangjing
How about the future trends of cultivated area change in China? Figures provided by some materials differ from each other dramatically. In this paper, We discuss the relationship of the decrease of cultivated area with many variables such as total population, urban population, rural population, gross domestic products, primary industry growth, secondary industry growth and tertiary industry growth, et.. It is proved that the decrease of cultivated area is intensively related to population growth and economic development and that the urbanization not only doesn't aggravate the decrease of cultivated area but also do economize on cultivated area. Our forecast is that the cultivated area of China will decrease to 10.741~10.831 million hectares by 2035 when the population peak is reached, which compared to 12. 8 million hedtares in 1985 decrease by 7.8%, and return to 10939~10969 million hectares in 2050 because of the decrease of total population and growth of urbanization level.
TRENDS AND BASIC CAUSES OF THE REGIONAL PATTERN CHANGES IN CHINA'S GRAIN PRODUCTION SINCE 1950'S.
by Lu Qi and Lu Minglun
The traditional grain transportation pattern in China, which is characterized as transporting grain produced in south to north, has been obviously replaced by a new pattern known as 'transporting grain produced in north to south'. The analy sis ba sed on statistical materials shows that this change results from the movement of grain production centers from south to north. The causes which push the product ion centers to north are various, however, the food demand pressure, the technol ogical advance and the economic system reform are the basic ones.ª¤ª¤
UTILIZATION AND DEVELOPMENT OF THE ANCIENT COURSE OF THE YELLOW RIVER
by Zhang Yifeng and Ning Yuanª¤
The ancient Yellow River once took over the course of the Huaihe River in histor ic period. It was formed a closed dune by the impact of the sediment of ancient Yellow River.ª¥ The region of the ancient Yellow River is a developing area with conves land for ms, temperate climate, sandy soil. Sufficient sunshine, dense population and la ck of water resource.ª¥ As a potential agriculture, the ancient course of the Yellow River has many con ditions of green foods production. Exploitation of sufficient land resources and labor force is the fundament of economic development in this region.ª¤ª¤
INDICATOR SYSTEM AND APPRAISAL METHOD OF REGIONAL AGRICULTURE SUSTAINABLE DEVELOPMENT
by Liu Hui
From the basic concept and characteristics of regional agriculture sustainable development, this paper discussed the relationship of supplement each other between regional agriculture sustainable development and territorial system science. On the basis of the four essential objectives for regional agriculture sustainable development, i.e. food security, ecological stable, rural economic development and regional balance, the frame of indicator system for regional agriculture sustainable development was constructed in this paper. In order to evaluate the regional agriculture sustainable development, the general appraisal method was also given out.ª¤ª¥
THE FLUCTUATION AND THE MARKETING MECHANISM OF GRAIN AND COTTON PRODUCTION IN THE NORTH PLAIN OF CHINA
by He Shujin and Jiang Dehua
On basis of field investigation in the North Plain of China and comprehensive an alysis of relevant publications and data, this paper explains the development c haracteristics and fluctuation reasons of grain and cotton production in the Nor th Plain of China, and after studying those effective measures of the marketizat ion of grain and cotton production at home and abroad, also put forward some cou nte rmeasures on transitional mechanism of marketing for stable development of grain and cotton production in this region.ª¤
A RURAL ECONOMY DEVELOPMENT STRATEGY OF THE SHUANGQIAO TOWNSHIP, HUAIYUAN COUNTY, ANHUI PROVINCE
by Zhang Yifeng, Li Zhanshe, and Chen Guanglinª¤
Based on the point of regional development, analysis of natural and social facto rs, and current situation of rural economy, this paper puts forward such an opti mum configuration of water and soil resources for Shuang Qiao township as follow s: first, reinforcing the water conservancy projects on farm land, exploiting un derground water rationally, practicing waterª²saving agriculture; Second, incorp orating planting activities and breeding ones to improve the fertility of soil and acquire a system of good strains, creating produce and products with indige nous features.
AN ANALYSIS ON CHANGES OF THE LAND USE STRUCTURE IN THE SOUTH OF JIANGSU
by Fu Xiaofeng , Zhang Yaocun, and Peng Naizhi
Economic development leads to the changes of the land use structure. Through the study, the characteristics of the changes of the land use structure in the sout h of Jiangsu show that: First of all, the land use for city increases rapidl y since 1980s. The land use for housing and infrastructure is the key reason for the change of the land use structure in city. And the land use for industry has become the second factor for the change of city's land use structure. Secondly, the flourishing of the amount of towns and the increase of the town's land use bring about tremendous changes of landscape in the south of Jiangsu. At present the main factor which leads to the change of the land use in towns is still the increase of the industrial land use. Finally, the increase of the traffic land a nd the decrease of the cultivated land are the main trends of the change of the land use in the south of Jiangsu since 1980s.
A STATISTICAL ANALYSIS ON LAND USE STRUCTURE AND ITS DRIVING FORCES--TAKING YULIN PREFECTURE AS AN EXAMPLE
by Zhang Ming
This paper applies Canonical Correlation Analysis to identify the driving forces of land use structure in 1992 in Yulin Prefecture. Through the Statistical Pack age for Social Science (SPSS) and specific analysis to the results, the contribu tion of each driving force of land use structure can be identified quantitativel y. At the same time, tests were carried out through the canonical correlation c oefficient and redundancy analysis.ª¤
CONDITIONS OF LAND RESOURCES AND CHANGING TREND OF LAND USE IN THE NORTHWEST
by Zhang Hongyeª¤
Based on the analysis on the conditions of land resources, the changing trend in the requirements of land for various purposes, the structure of land use and th e manner of land use is discussed in this paper. The changes in land use are det ermined by both socialª²economic development and conditions of land and water re sources. In this paper, the impacts of the changes in land use on environment an d sustainable agricultural development are also discussed. Policies and measures which can help to achieve the purpose of using land resources effectively are p roposed.ª¤
A STUDY ON THE TEMPORAL VARIATION OF CHINA'S FARMLAND AREA AND GRAIN-CROP SOWN AREA
by Dang Anrong and Yan Shouyong
The temporal variation of China's farmland area and grainª²crop sown area since the year 1949 are studied comprehensively in this paper. Supported by the datab ase of China's national grain production, the author studies the temporal variat ion characteristics of China's farmland area and grainª²crop sown area quantitat ively in two aspects: temporal variation tendency and temporal variation mechanism. Based on the temporal variation regularity obtained above, China's fa rmland area and grainª²crop sown area are predicted by "comprehensive dynamic p rediction method" and "equal dimensional GM(1,1) dynamic prediction method". The prediction result is that China's farmland area will be 94 000 thousand hect ares and China's grain crop sown area will be 108000 thousand hectares by the ye ar 2000.
THE LATEST TENDENCY OF RESEARCH ON LAND COVER CHANGE FROM USGCRP
by Wang Shaoqiang and Chen Yufeng
According to United States Global Change Research Program prepared by the subcom m ittee on Global Change Research of the Committee on Environment and Natural Reso urces Research, this paper simply introducs the goal, content and plan of land ª²cover study in U.S. The USGCRP has advanced our understanding of the key gl obal environmental science issues on the landª²cover changes. To understand the landª²cover changes in the terrestrial ecosystem, the goal of USGCRP is to under stand, predict, assess and respond to the causes and consequences of the landª²c over changes in terrestrial ecosystem resulting from humanª²induced and natural influences, and to provide a stronger scientific basis for the development of en vironment and resources. The USGCRP supports research projects to inventory the current land cover of the Earth and to document the changes; to improve understa nding of the dynamics of landª²cover change; and to document and understand chem ical, physical, and biological processes in the terrestrial and their relationsh ip with Carbon Cycle. For landª²cover research of next ten years, USGCRP will fa ce with some new challenges, such as estimation of time and space of changes in climate and land cover, region analyses of driving force of environment and soci al economy influence on landª²cover changes, comprehensive evaluation for change s in climate, landª²cover, social economy. Because of U. S. leading position on this field, this paper implies basically the international new tendency on land ª²cover change study.ª¤
PROBLEM AND COUNTERMEASURE OF LAND IN THE MODERNIZATION PROCESS OF SOUTHERN JIANGSU PROVINCE
by Liu Yansui and Lu Qi
A systematic analysis on the modern ization and its characteristics in the southern Jiangsu province is made in thi s paper. It is put forward that the development progress from enterprises growª² up to industrialization and urbanization development is the internal power of th e modernization development of southern Jiangsu province, and that the serious q uestions of cultivated land sudden decrease and its quality descending in the pr ocesses of urbanization development will restrict agricultural economy and the w hole regional economy sustainable development, and that the essential approach o f these problems is to understand overall some issue problems. In order to reali ze the objective of the total dynamic equilibrium of cultivated land and provide a well foundation for regional modernization, we must effectually control the t o tal of constructive land as an emphasis and depend on the construction of land u se controlled system.ª¤
ANALYSES OF THE FARMLAND LOSSES IN CHINA: 1986~1995
by Chen Baiming and Li Shishun
This paper contrasts and analyses a dramatic loss of farmland in China during he r postª²reform economic booming period of 1986~1995 from different data sources, and examines the formation of farmland losses. It is found that adjustment of a gricultural structure, nonª²agricultural constructions and natural hazards have played a main role in decreasing the gross quantity of farmland. The findings s uggest the countermeasures of strengthening land use control, etc.ª¥
A STUDY OF RURAL ECONOMY DEVELOPMENT STRATEGY FOR THE HUANGHE MIDDLE REACHES
by Ren Guozhu
The middle reaches of Huanghe River is one of the regions with the worse natural condition, fragile ecological environment and weak rural economical foundation. In this paper, both the advantage including location, resource and restricted c ondition such as ecological condition, science and technology, culture were anal yzed. Meantime, the current state and potential of rural economy development als o were appraised and researched. Further more, the orientation and methods of ru ral economy development of this region in the future were put forward.
SUITABILITY ASSESSMENT ON THE WASTE LAND RESOURCES OF CHINA'S MINING AREAS
by Su Guangquan, He Shujin, and Guo Huanchengª¤
It is urgent in the time of high speed development of China's mining industry to research the issue of waste land reclamation of China's mining areas b ecause of the severe damage of China's land resources in mining areas and low re clamation ratio (about 10%) of its waste lands. To launch in the whole country t he suitability assessment of the waste land reclamation of China's mining areas can serve as a realª²time guide for relevant researches because of its basic fun ction in the research of the waste land reclamation of China's mining areas. Acc ording to this function, the thesis divides the waste land resources of China's mining areas into 25 subª²categories of 5 categories on the basis of field investigation and utilization of certain principles. Every type of 25 sub ª²categories is assessed on their suitability for the waste land reclamation, an d corresponding ways for the exploitation and utilization of China's waste land resources are also put forward. These detailed methods can in an efficient way s erve as a scientific assessment tool for the evaluation of China's waste land re clamation, so as to improve the efficiency of China's waste land reclamation and utilization, and to provide an efficacious reference for relevant policy making .
STUDIES ON THE MOVEMENT OF FARMLAND GRAVITY AND ANALYSES OF ITS DRIVING FORCES IN INNER MONGOLIA, CHINA
by Bao Yuhai, Wulantuya, Xiangbao, and Zhao Xiaoli
In this paper, the history of land reclamation in Inner Mongolia, China, was re viewed briefly and the farmland gravity and the population gravity, in the rural areas of the whole region in years between 1949~1996, were calculated with the statistics data from Inner Mongolia in recent 50 years. On the basis of this , it came to the conclusion that both the farmland gravity in Inner Mongolia and the population gravity in the rural areas have been moving toward northeast. Th e paper also analyzed simply the driving forces of movement of the farmland grav ity and proposed several suggestions.
CHANGES OF POVERTY RELIEF POLICIES AND THEIR IMPLEMENTATION EFFECT IN CHINA
by Liu Huiª¤
Poverty is a serious challenge facing the world today. Since the opening and re form, China's economy has developed very quickly. At the same time, the number of poor people decreased from 250 million in 1978 to 58 million in 1996. Howeve r, poverty is still a prominent problem in the development of China. Since 1949 , the Chinese government has promulgated a series of different poverty relief po licies in different times. So, this paper reviewed the changes of poverty reli ef policies and stressed on analyzing the Chinese government's explorative pover ty relief policies, such as provide work as a form of relief, poverty relief by science & technology, siteª²fixed poverty relief by organization, regional c ooperation, resettlement of poor farmers, etc. Further more, the paper analyzed thei r implementation effects on solving basic survival problems: decreasing the size of the poverty-stricken population, promoting local economic development and im proving environment. It also discussed the causes of the different effects of po verty relief in different regions in the past few years, and pointed out some pr o blems in the implementation of poverty relief policies at present, such as empha sizing largeª²scale poverty relief measures while neglecting birth control, exc essive investment and scale in resettlement plan, etc. At last, the paper evaluated th e latest poverty relief polices defined by the central government and the local provinces.
FAMILY MODELS USED IN OPTIMAL ALLOCATION OF REGIONAL LAND USE
by Liu Yansui
The optimal allocation of land use not only include the macroscopic optimization of the structural pattern of quantity and space, but also include the reasonabl e matching of productive factors in microcosmic scale. Thus, it is a multiª²obje ctive and hierarchic sustainability process of fitted measure. Taking Yueqin cit y as an example, the new method to study the optimal allocation of land use in c ounty region using family model is put forward in this paper. The family model are co mposed of three patterns, namely, spatial zone, structural optimization and micr ocosmic design model according to the internal relation of optimal allocation ob jectives of land use, which can give play to itself single action and synth etic advantage to coordinate relation between quantity and space, macroscopic an d microcosmic in the light of their identity and complementary in the allocation and measure. Therefore it has wide application prospect.ª¥ Although there are different visual angles among three models, they own common c enter to seek for the topgallant structural effects of land use. Their combinati ve way is to build harmonious mechanism between the suitable expansion of nonª²a gricultural constructive land and efficient preservation of cultivated land and microcosmic stimulant mechanism of intensive use of various lands. Its essence i s that the optimal combination of two powers, expanding out of constructive land in town and the regulative constraint of basic farm, will be put into together.The optimal allocation of land use is a unity between land productivity organiza tion and land productionª²relation coordination. Therefore, its tasks are not on ly to promote regional industrial structure upgrade and optimal layout by carryi ng out the plan of optimal allocation of land use, but also to actuate the reasonable matching of microcosmic productive factors in land use depends on th e progress of science and technique and the perfection of market mechanism. ª¤
EVALUATION AND PROPOSE OF EXPLOITATION OF RESERVED CULTIVATED LAND IN THE NORTHERN CHINA
by Cai Yumei and Guo Huancheng
The exploitation of the reserved cultivated land in Northern China plays an impo rtant role in relaxing the tension between people and land, and in balancing gro ss cultivated land, but the question of ecological environment is also serious, especially in interlace zones of agriculture and stockbreeding. The paper analyz es spaceª²time characteristics of the reserved cultivated land exploitation in Northern China in the whole, and the data of typical investigation region is als o used, which come from TM satellite image processing (1¡Ã10000) of America done by Agriculture Ministry. Then, the countermeasure and propose is put forward o n the basis of synthetic evaluation.ª¤
STUDY ON THE METHODS OF LAND USE DYNAMIC CHANGE RESEARCH
by Wang Xiulan and Bao Yuhai
From the respect of the meaning and the researching contents of land use and cov er change, the methods for land use change were analyzed. Further, the methods o f establishing land use dynamic change model were mainly introduced. These models include land resources quantity change model, land resources environmental qua lity change model, land use degree change model, land use change regional divers ity model, land use spatial change model and land requirement forecasting model.
A STUDY ON CULTIVATION TECHNIQUES OF INCREASING PRODUCTION IN WHEAT GROWN AFTER DRY RICE HARVESTS
by Zhang Yifeng, Wang Dasheng, and Liu Yong
Wheat grown after the rice harvest is very difficult to sow in time, because rice is harvested too late. In addition, the soil after rice harvests is harden ed and impervious, not good in functions of physics and chemistry, so the produc tion of wheat grown after rice harvests is low and unstable. To change the situa tion, we advance a test of replacement of rice by dry rice. The result displays that wheat grown after dry rice harvest has increased by 100 kg, because dry ric e ripens 10 day earlier than wheat grown after rice and the function of soil can be regulated in physics and chemistry features.
Theoretical study and practical exploration on the shift of rural surplus labour
by SUN Fenghua
This paper employs the viewpoints of philosophy, geography, demography and devel opmental economics. It not only analyses and evaluates the theories of shift of rural surplus labour both in China and abroad, but also induces and summarizes e xperiential moulds of shift of rural surplus labour. Its purpose is to provide s cientific theoretical bases and practial experiences to solve the problem of shi ft of rural surplus labour in China.ª¤
Evaluation indexes and methods of soil quality concerning red soil degradation
by SUN Bo and ZHAO Qiguo
Being important for evaluation of soil degradation, monitoring and assessment of soil quality is a sound basis for updating the designs of sustained soil manage ment system. But now there is a lack of uniform indexes for evaluating soil qual ity changes, and the methods to integrate the main soil properties with soil man agement practice are also meager for the same purpose. In this paper, principles of selecting indexes for red soil quality evaluation are put forward firstly. A nd then an index system applicable to evaluating dynamic changes in red soil qua lity is approached from chemical, physical and biological aspects. Indexes used to conduct research on evaluation of red soil quality in hilly region of South China are reviewed. Besides, the methods from land assessment are chos en for evaluation of red soil quality, and some new methods for soil quality as sessment in the world are outlined, too.
A study on change types of cultivated land resource in Guangdong Province
by SUN Xianguo, CAO Kangª²lin, and WANG Peng
The lower possession per capita of cultivated land resource is one of the import ant problems in Guangdong Province for all time and the trends of decrease will continue with further development of economy. In this paper, the spatial and tem poral characteristics of the change of cultivated land resources were analysed u sing the statistics from 1949 to 1990, and 4 types were separated according to t he grading of the cultivated land area and the cultivated land area per capital by yearly average variation. Type ¢ñ is the regions of most serious decrease in cultivated area including Shenzhen, Zhuhai, Guangzhou, Dongguan and Zhongshan. T ype ¢ò is those of more serious decrease in cultivated area, including Foshan, J iangmen, Huizhou, Shantou, Chaozhou, Jieyang and Shanwei. Type ¢ó is those of sl ight decrease in cultivated area, including Yunfu, Zhaoqing, Maoming, Shaoguan, Yangjiang, Qingyuan, Heyuan and Meizhou. Type ¢ô is those of no decrease in cult ivated area, including Zhanjiang. The characteristics of the spatial distribution of those regions are linked to e conomic development and population growth. Regions of type ¢ñ and ¢ò are located at the core area, around the beaches of the Pearl River Mouth, while regions of types ¢ó and ¢ô located at the Eastern, Western and Northern of the province wh ere economy is developing and population growth is slow.
The Research on the Comparison between Arrangement Migration and Development Migration --The Arrangement of Chinese Reservoir Migration
by ZHU Meirong
Since China was established, the arrangement of Chinese reservoir migration has experienced a changed process from the arrangement migration to development mig ration. Analyzing, comparing and researching the essential difference of these t wo kinds of migration will help realize and grasp the basic laws of reservoir de velopment migration under the socialist market economic conditions. We can follo w laws, approach subjects and promote the development of reservoir development m igration.ª¤
Change of Land Degradation in South China and Impacts of Human Activities
by LU Jinfa
Three pilot areas are chosen for study on temporal change of land degradation i n South China. Based on criteria for land degradation assessment an interpretati on of land use, vegetation, surface material and erosion morphology is made by using aerial photos of two periods, and with the help of GIS an assessment of la nd degradation is carried out by using Fuzzy model. Comparison of land degrada tion maps between 1950's and 1980's shows that changes of land degradation are different from one area to another because of differences of human activities. In the mountain area slightly affected by human activity very slightly degraded land markedly increases due to soil conservation and the remained degraded land tends to decrease from 1950's to 1980's. The reverse situation happens in the ar ea heavily affected by human activity and morphologically characterized by lower undulating hills. Development of land degradation there manifests itself as dra stic reduction of nonª²degraded land and severely and very severely degraded lan d as well as increases of slightly and moderately degraded land. In the low moun tain and hill area moderately affected by human activity some increase of modera tely degraded land is observed at the expense of marked decrease of nonª²degrade d land. It is proved that the changes of land degradation are mainly attribute d to reclamation of land and depletion of vegetation led by adverse human activi ties. In South China most severe land degradation has taken place neither in the moun tain area slightly affected by human activity nor in the area heavily affected b y human activity and morphologically characterized by lower undulating hills but in the low mountain and hill area moderately affected by human activity.
An Analysis on the Changing Trends and Affecting Factors of Foodgrain and Oilseed Production in Tibet Autonomous Region
by NNIMA Tashi
The changing trends in foodgrain and oilseed production, and the affecting factors of that trends are analyzed in this paper. It is shown that the per unit yield is the predominant driving force of foodgrain and oilseed production in Tibet. Sustainable increase of the per unit yield of foodg rain and oilseed production, and following countermeasures should be adopted: ap plication of improved crop varieties, promotion of the cultivation system, impro vement of the low yield land and buildingª²up of the capacity for irrigation sy stem for cultivated land.ª¤
Evaluation on Grades of Subsistent Resources for Sustainable Agricultural Development in Hunan Province
by LI Hui
Based on the analysis of the farmland resources, water resources, coordination b etween water and farmland, climate resources, creature resources, and the qualit y of biological environment etc. The author has studied the characteristics of t he subsisent resources in every county of Hunnan Province, and has probed into t heir grades, types and regions. The basic conclusions are as follows: the subsis tent resources of the mountainous areas in the east, south and west of the provi nce are superior to those in the hillª²basin areas and the plain of the Dongting Lake area, the subsistent resources in the county of lowª²grade population dens ity are superior to those in the county of highª²grad population density. As a r esult, this article probes into advantage and defect of subsistent resources in every county of Hunnan Province, in order to decide resources potency of sustain able development in agriculture.ª¤
Spatial Modeling of Land Use and Its Effects in China
by CHEN Youqi, Peter H. Verburg, and XU Bin
This paper introduces the main principles and structure of the GIS model (CL UE[CD#*2]CH, Conversion of land use and its effects in China) to analyze the lan d use change. Through GIS modeling, this paper reveals the factors that determin e the distribution of the different land use types, and special emphasis is put to cultivated land. Correlation and regression analysis are used to identify the most important explanatory variables from a large set of candidate determining factors. We found that the distribution of land use in China is best described b y a combination of different biophysical and socioª²economic factors. Furthermor e, both scale and type of the studied region can have a very important effect on the correctness of the model. The result shows that the distribution of cultiva ted land is strongly correlated with the distribution of population, especially with the distribution of agricultural population. This relation shows the rural character of China, where population and agriculture are strongly clustered. Oth er important factors explaining the distribution of cultivated land are the suit ability of the soil for irrigated rice cultivation, elevation, temperature, and s ome hydrological conditions. This means that cultivated land is also strongly re lated to the suitability of the soil for agriculture. In the spatial aspect, thi s model reveals that the conversion of cultivated land in China will mainly happ en in the transition area between the eastern farming region and the west husban dry region, because of the land suitability and ecological reasons. The main res ults of the CLUE[CD#*2]CH model can be judged as reasonable and applied to the p olicyª²making related land use/land cover change.
The Interacting Models and Mechanisms of Soil Nitrogen with Rainfall and Runoff
by ZHANG Xingª²chang and SHAO Mingª²an
Soil N loss by erosion on slope land is affected by soil mineral N los s mainly by runoff and organic N loss mostly by sediment. The process of soil ni trogen loss by erosion is restricted by interaction of soil nitrogen with rainfa ll and runoff. The interacting process of soil N with rainfall is divided into t wo stages: under rainfall conditions, soil N releasing process from soil to rain drops and soil N (mostly nitrite N) infiltrating process from top soil to deep soil in soil profile. Meanwhile, interacting process model of soil N with runoff is divided into three types, i.e. the mixed depth model of interacting pr ocess of soil N with runoff, the releasing and transporting model of soil N from topsoil to runoff and from upper slope to down slope, and process model of soil N loss by erosion. Based on analysis on interaction of soil with rainfall and r unoff on slope land, the interacting models and mechanisms of soil nitrogen with rainfall and runoff are discussed to provide research methods and thoughts for further study on soil N loss by erosion.ª¤
The Discussion of Motive Forces and Measures to Sustainable Rural Economics of Western Plain of Shandong Province --A Typical Case Study of Dongchangfu County
by WANG Yunª²cai and GUO Huanª²cheng
Dongchangfu County is a county with the characteristics of Liaocheng and agricul ture area of north china and Huanghuaihai region. It has large population and l ess developed economic, particularly rural economic is backward. With the devel opment of 50 years in the past it had formed four characteristics of PRED system . Firstly, gross population is large scale and increasing rapidly, but lessª²edu cated. Secondly, natural resources such as mineral, water and energy are scare, land resources are main natural resources but are poor and less productive. Th irdly, natural disasters such as drought, flood, saltization and alkalization ha d been better prevented from, but some of them still did great damages to people ; fourthly, with the rapid growth of economic, capital and technology inputs are less sufficient, it consumes large resources with large waste.\; The study on motive forces of sustainable rural economics is the research of mai n promoting forces and the restricted factors which hamper the economics growth during the year of 1980 to 1996, when the development of it was the fastest in the past, the aim of it is to foster the growth pole of sustainable rural econom ic and take the measures to it correspondingly.
Impacts of Irrigation on Soil Environment by Lifting ª¤ up Water from the Yellow River in Ningxia
by YU Jiangª²ping, WEN Yunª²chao, ª¤ WANG Yiª²ming, and SONG Naiª²ping
In this study, soil survey was conducted at Hecaogou village of Tongxin County, which is located at the area of Ningxia irrigated by lifting up water from the Y ellow River. On the basis of soil survey, irrigationª²induced changes in soil sa linity, soil texture, nutrient and trace element content and their impacts on so il sandification, salinization and soil environmental quality were analyzed and discussed. The results indicate that: (1) Irrigation can obviously reduce the sa lt content of surface soil, but there is a trend for salt to gather at the depth of 50~90 cm and soil salization is likely to emerge again if irrigation were ce ased or irrigation water were reduced; (2) The sandification is mitigated, with a decreasing in sand fraction and an increasing in clay fraction; (3) Irrigation may slightly increase the nutrient content, with the organic matter content and the total P increased more than others, while increase of Copper, Chromium, Zin c, Nickel and Cadmium content will partly decrease the soil environment quality and the soil F leaching is a challenge for reducing F poisoning in this area.
Impacts of Irrigation on Soil Environment by Lifting ª¤ up Water from the Yellow River in Ningxia
by YU Jiangª²ping, WEN Yunª²chao, WANG Yiª²ming, and SONG Naiª²ping
In this study, soil survey was conducted at Hecaogou village of Tongxin County, which is located at the area of Ningxia irrigated by lifting up water from the Y ellow River. On the basis of soil survey, irrigationª²induced changes in soil sa linity, soil texture, nutrient and trace element content and their impacts on so il sandification, salinization and soil environmental quality were analyzed and discussed. The results indicate that: (1) Irrigation can obviously reduce the sa lt content of surface soil, but there is a trend for salt to gather at the depth of 50~90 cm and soil salization is likely to emerge again if irrigation were ce ased or irrigation water were reduced; (2) The sandification is mitigated, with a decreasing in sand fraction and an increasing in clay fraction; (3) Irrigation may slightly increase the nutrient content, with the organic matter content and the total P increased more than others, while increase of Copper, Chromium, Zin c, Nickel and Cadmium content will partly decrease the soil environment quality and the soil F leaching is a challenge for reducing F poisoning in this area.
The Relationship between the Ecology Background of ª¤ Reclaiming the West and the Outª²ofª²poverty
by ZHANG Yiª²feng, WANG Youª²feng, CHENG Zhiª²gang,and ZHOU Liª¬
Agriculture is the main department of the west of China, and the basic way to fe ed the people. But the agriculture level of the west is fairly laggard. Lack of the apparatus and machinery has become a big problem to this region. The e cology environment of the West is so poor that the habitat gets too little produ ction to sustain their life. How to meliorate this situation is an important top ic of the development of the west. Analysing the agriculture condition of th e west and the main reason for the low level of agriculture, we can draw the con clusion that the bad ecoª²environment is the most important reason for the laggi ng of the west. So the ecoª²environmental protection and rehabilitation should b e taken as a core issue and a pressing task. Several strategies about how to im prove the ecoª²environment are suggested in this paper, including inhibit defore sting and reclaiming, change some used land to forestry and meadow and build the preservative forestry for the water source. by these means the west of China wi ll get not only the ecoª²environment production but also the economy and society production. The fulfilment of these strategies needs lots of related laws a nd regulations. And it is necessary for the government to pay more attention to the agricultural development of the West and the ecoª²environment protection.
| hotprint | abstract | researcher | news | institution | About us | Chinese |
|
|
|
All rights reserved.
Friday, January 12, 2007
|