| Green Food comes from good ecological environment.The ecological and environmental quality of the producing area is the most basic factor of impacting on the green food quality.The good or bad environmental quality of the producing area makes the development of green food suffer from restriction.Therefore,it is of great significance for protecting the environment quality of the producing area,improving the product quality and protecting the ecological environment to investigate,monitor and evaluate the environmental quality of the producing area.The paper selects Fangshan District of Beijing City as the typical area to evaluate the environmental quality of the green food production base of Fangshan District on the basis of air, water,soil and other environmental information and tries to find a general method to evaluate the environmental quality of the green food production base of similar places.Furthermore,the paper does the spatial analysis of soil environmental factors(the fertility and heavy metal in soil), thereby showing the space distribution and development trend of each element.The following conclusion is put forward:(1) In accordance with the principle of the largest membership,the soil nutrient level of every country is Grade I fine level,Da Anshan,Hebei,Nanjiao,Puwa and other places have the best environmental quality with an average membership degree of more than 0.9.But Liuli River is the lowest level of membership because of the loss of organic matter,nitrogen and other matters (the membership degree is only 0.6486).(2) In accordance with the principle of the largest membership,the soil heavy matels of every country are in grade I clean level.Changyang,Da Anshan,Doudian and other places have the best environmental quality with an average membership degree of more than 0.97.But Hebei,Yanshan,Shidu and Xiayunling are lowest level of membership because of the exceed of the concentrations of Cu,Cr,Cd,Hg and other elements.(3) Soil nutrients and heavy metals from Fangshan District are used by the fuzzy comprehensive evaluation,22 township of Fangshan District are in grade I clean level.The whole soil conditions is good,Da Anshan,Puwa,Nanjiao and shijiaying are the best(the membership degree is more than 0.85).But Hebei,Yanshan,Liangxiang,Xia Yunling, Changyang are not better than other regions because of the individual elements in the overweight or lack of soil nutrients.(4) In accordance with the principle of the largest membership,Water environmental Quality from Fangshan District belongs to I clean levels,but clean-up standards such as Liangxiang,Han Cunhe district are falling,perhaps because of water environmental quality reduction caused by serious petrochemical pollution.(5) The results of this study show that the application of the AHP-fuzzy comprehensive evaluation method is able to overcome preferably the unscientific polarization in the environmental quality,and solve effectively the problems brought by the fuzzy border in the evaluation criteria and the monitoring errors.So the results may reflect objectively the environmental quality state of Fangshan District.(6) The paper puts the data and its spatial location together to establish the attribution database depending on the GIS technology and deals with the data of fertility elements in soil bv Kriging interpolation.The results of interpolation shows that agrotypc and character are the main effect element,Alkaline nitrogen,the nitrogen content from the mountains to the plains region shows decreasing trends;potassium concentrion is low in Shidu area,Puwa,Liangxiang,and other places,crop absorption,the soil removed from the resulting potassium concentration of mountain soil K The lower soil type differences lead to the mother of agricultural soil available phosphorus content was significantly higher than that available phosphorus in the plain areas of the leading causes of mountain organic matter content than in the plain areas,in addition to the impact of the end of organic fertilizers,straw may also promote the improvement.(7) The paper puts the data and its spatial location together to establish the attribution database depending on the GIS technology and deals with the data of heavy matels contamination elements in soil by Kriging interpolation.The results of interpolation shows that Cu concentration has higher copper content in district from Shidu,Puwa,Hebei and Qinglonghu,but the southern region such as the Liulihe low content,probably caused by the soil type,climate and other factors. Cr metal content from district of Yanshan,Zhoukoudian,Chengguan,Shilou,was high,and generally higher than that of its value in the context of values,heavy metals Hg,As in the central (Yanshan area) was significantly higher than that in surrounding areas,the impact of the high value end of the main factors in the region,Petrochemical and the surrounding region may also caused enterprises increased their content.(8) The paper also realizes the visualization interface by using VB program,thereby making ihe search,addition,inquiry and the generation of report forms easier and the work procedure simpler and work efficiency higher. |
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