According to the statistics of cultivated land in Yantai area during the Reform and Opening-up over the past 20 years and with the detailed survey and changing data of land use during the recent live years, this paper...According to the statistics of cultivated land in Yantai area during the Reform and Opening-up over the past 20 years and with the detailed survey and changing data of land use during the recent live years, this paper reveals the basic characteristics of the resource utilization, the basic process of the changes, regional differences, and current direction of cultivated land In addition, this paper makes a preliminary research on the major driving factors and the influence mechanism for the changes in the cultivated land area. and reaches the following conclasions： （1） There was a trend of obvious fluctuant decrease in cultivated laud area during the past 20 years. The changes of cultivated land have undergone the process - slow decrease,steep decrease, slow decrease. And there were three peak periods of cultivated land loss around 1985. 1987-1996 and 1991-1993 respectively （2） The decreased cultivated land was mainly converted into land for industry and mining, residential area. and all kinds of traffic and orchards. The increase of cultivated land mainly came from exploitation and land and arrangement and reclamation of industry and mining land （3） The economic development. population growth and policy are the dominant macro-driving factors for the decrease of cultivated land area in Yantai. The obvious sudden changes during the change process of cultivated land acreage are relevant to the national macro.policies background The rapid decrease of cnltivated land area is synchronous with the overheated economic growth resulting from the direct investment in fixed assets. Spatial distribution of the decrease in cultivated land is congruous with the differences in speed and the scale of economic growth between the different regions of Yantai area. Furthermore. the decrease in cultivated land caused by population increase cannot be ignored.展开更多
Detailed analyses of the monitored data provided by the Yantai Ocean Administration Office between 1989 and 1996 show that, the fluctuation regularities of content of the inorganic phosphorus are as follows: the conte...Detailed analyses of the monitored data provided by the Yantai Ocean Administration Office between 1989 and 1996 show that, the fluctuation regularities of content of the inorganic phosphorus are as follows: the content of inorganic phosphorus fluctuated near the class-1 standard line basically from 1989 to 1993, tended to increase rapidly from 1993, and increased continuously, causing water quality to be deteriorated from the class-2 to class-3 standard by 19%. Causes for increment of the content of inorganic phosphorus are also analyzed. The results show that, the flux of phosphorus entering Yantai nearshore sea area increases at an annual rate of 16.5 percent, in which the increment rates of the phosphorus contained in washing powder and in phosphate fertilizer are 12.9 and 17.5 percent respectively. Both of them kept a positive interrelationship with their fluxes into the sea. In addition, the migration and regeneration mechanism of the phosphorus within the nearshore area also lead to the展开更多
基金Supported by National Natural Science Foundation of China (40101005), Natural Science Foundation of Shandong Province (Q2002E03), and Education Department Foundation of ShandongProvince (J02L01).
文摘According to the statistics of cultivated land in Yantai area during the Reform and Opening-up over the past 20 years and with the detailed survey and changing data of land use during the recent live years, this paper reveals the basic characteristics of the resource utilization, the basic process of the changes, regional differences, and current direction of cultivated land In addition, this paper makes a preliminary research on the major driving factors and the influence mechanism for the changes in the cultivated land area. and reaches the following conclasions： （1） There was a trend of obvious fluctuant decrease in cultivated laud area during the past 20 years. The changes of cultivated land have undergone the process - slow decrease,steep decrease, slow decrease. And there were three peak periods of cultivated land loss around 1985. 1987-1996 and 1991-1993 respectively （2） The decreased cultivated land was mainly converted into land for industry and mining, residential area. and all kinds of traffic and orchards. The increase of cultivated land mainly came from exploitation and land and arrangement and reclamation of industry and mining land （3） The economic development. population growth and policy are the dominant macro-driving factors for the decrease of cultivated land area in Yantai. The obvious sudden changes during the change process of cultivated land acreage are relevant to the national macro.policies background The rapid decrease of cnltivated land area is synchronous with the overheated economic growth resulting from the direct investment in fixed assets. Spatial distribution of the decrease in cultivated land is congruous with the differences in speed and the scale of economic growth between the different regions of Yantai area. Furthermore. the decrease in cultivated land caused by population increase cannot be ignored.
文摘Detailed analyses of the monitored data provided by the Yantai Ocean Administration Office between 1989 and 1996 show that, the fluctuation regularities of content of the inorganic phosphorus are as follows: the content of inorganic phosphorus fluctuated near the class-1 standard line basically from 1989 to 1993, tended to increase rapidly from 1993, and increased continuously, causing water quality to be deteriorated from the class-2 to class-3 standard by 19%. Causes for increment of the content of inorganic phosphorus are also analyzed. The results show that, the flux of phosphorus entering Yantai nearshore sea area increases at an annual rate of 16.5 percent, in which the increment rates of the phosphorus contained in washing powder and in phosphate fertilizer are 12.9 and 17.5 percent respectively. Both of them kept a positive interrelationship with their fluxes into the sea. In addition, the migration and regeneration mechanism of the phosphorus within the nearshore area also lead to the
