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Study On Sustainable Land Use In Urban Agriculture

Posted on:2005-10-07Degree:DoctorType:Dissertation
Country:ChinaCandidate:S M GuoFull Text:PDF
GTID:1116360122988942Subject:Crop Cultivation and Farming System
Abstract/Summary:PDF Full Text Request
This study run through the basic idea of Ecoregional approach methodology and systematic design by integrating agronomy, ecology, environmental economics, resource economics and maths. The study methods included macro- and micro-analysis, qualitative and quantitative analysis, theoretical and case study, statistical analysis and model simulation and so on. Resources shortage and environmental pollution casued by intensive agriculture were examined for a specific suburban area Shunyi District Beijingissues were systematically analyzed including landuse changes, landuse driving force, water-limited yield simulation with WOFOST model, ecological , environmental and economical analysis of landuse, as well as optimizing pattern of landuse with RCSADSS model. The results were as following:1. In 2002, the agro-landuse is still primary type of landuse and arable land occupied 43% of total agro-landuse of Shunyi District. There is lesser proportion in horticulture and forestry landuse, indicating a large potential for forestry development. In contrast, a high percentage of 22.4% of land was occupied by residential and industrial plants, indicating sharp increase in industrial and urban construction.The roads and idle land kept a stable rate of 7% and 6% separately .Considering limit of land resources, land use in Shunyi District should be followed a connotation way.Compared to the area of cereal, cash crop and vegetable in Shunyi District with that of China, the proportion of cereal and cash crop area was at lower level, whereas the proportion of vegetable area is far more than that of whole China, indicating the characteristic of dominance situation of horticulture landuse in suburb of big city life Breijing.In the past decade from 1992 to 2002, the evident changes of land use had taken place. .Three stages can be distinguished in term of change velocity: slow stage (1992-1996), steady stage (1996-1999) and rapid stage (1999-2002). The obvious features were marked by a sharp decrease of arable lands together with an increase trend for other landuse.2. 95% of water-used by agriculture come from groundwater, and it occupied 80% of total water consumption(2001).Water shortage is becoming the major obstacle of sustainable agricultural development and the key is raise efficiency of wateruse.The results of WOFOST model simulation showed that the yield of winter wheat was 2323 kg/hm2 under the rainfeed conditions, 5946kg/hm2 with irrigation, while the potential yield is 8485kg/hm2 with the abundance supply of light, temperature, water and fertilizer. The dramatic gap of yields was caused by limits of water supply. In the coming years, water will be the first restraint factor to realizing yield potential of winter wheat in Shunyi District,3. The ecological function is being payed more and more attention compare with the economic function of urban agriculture .The overuse of fertilizer and castoff corned from animal excretion have been the big problems of environmental. The study of ecological service value of landuse indicated that the change of ecological service value come from the sharp decreasing of arable land area and increasing of other landuse type with less ecological service value. As a consequence, the ecological service value of lands of Shunyi decreased by 1.25 million yuan RMB during the period of 1993 to 1998 and increased by 11.47 million yuan RMB sine 1998 to 2002. Now, the major factors influencing the land ecologic service value were area of arable, horticulture and forests lands. Results of calibration of indicate that the ecologically accepted fertilizer dosage of Shunyi District in 2002was 328.27 kg/hmz while the actual one was 1034kg/hm2.Such a result was derived base on the externality and rules of marginal cost Applying contingent valuation method of environmental economics, survey on the willingness to pay for harnessing water pollution caused by the waste water discharged by big farm was conducted. The result suggest residents' awareness of environment protection and health pro...
Keywords/Search Tags:sustainabile land use, environmental-economics, driving force, structure optimization.
PDF Full Text Request
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