| As an important part of global and regional change,the research of land cover changes mainly involves three aspects: the process of land cover changes(What),the factors that driving the land cover changes(Which),and the interaction between land cover changes and the factors(How).Since the industrial revolution,the land use change caused by human activities has become an important factor affecting the land cover change,and it is more and more concerned by the academic and government departments.Population structure as the human production and living activities important characterization,the change can be directly reflects the human activities on land use/cover is the mode of action,strength,breadth and depth,as well as the decision-making behavior change.And then,it reflect the land cover change impact and process.Therefore,it is necessary to reveal the interaction between population structure and land cover change,so as to provide a reference for the adjustment of human activities and regulate land use.Accounts for nearly 40% of the global land area,area of our country land is about 53%,and still showed further expansion trend in arid and semiarid regions,to precipitation and climate change rate,the vegetation is sparse and relative to a single community,ecological environment fragile and response to global change and human activities in more sensitive and intense etc.as the main characteristics.The in the middle reaches of the Heihe River Basin area of Zhangye City as an example,select the 2001-2013,Zhangye City,the population structure of urban-rural structure,industrial structure,occupational structure,sex structure index change data,and the land cover is the correlation analysis of the dynamic changes and the coordinated development degree analysis,the population structure in arid regions of land cover influence relationship and draw preliminary conclusions are as follows:1)In 2001-2013 years,the total coverage area of Zhangye city remained stable.In general,the land cover is dominated by grassland and forest land,the two is still the largest twovegetation types,but the proportion of grassland area is decreasing year by year,while the proportion of forest land area is increasing year by year.2)In 2001-2013,cultivated land area of Zhangye City,the summer crop area,harvest crop area,economic crop area,grain crop area and total sown area accounts for than to maintain the overall growth trend,multiple cropping index also fluctuated upward trend,indicating that local expanded cultivation phenomena obviously,residents increase harvest will strongly active,also resulted in Zhangye City,the land utilization in continuous improvement.3)In 2001-2013,The total population quantity and rural population the number of overall of Zhangye city showed decreasing trend,but urban population as a whole presented slow growth trend,reveal the Zhangye city population outward migration is obvious,especially the emigration of rural population,which a considerable part of the relocation of the rural population feedback to the local urban population,making the urban population increased slowly.Also rises from the rural labor force,but engaged in agriculture(production)labor population has decreased and the secondary and tertiary industry population increased,rising number of urban workers,indicating that the number of the first industry to the second and third industry shifted,namely rural population transfer to the urban population.Research shows that the change of population structure respectively and land use / cover change showing a different relationship,reaction with population structure in different part of land use / cover change effects or responses vary.4)First,in addition to woodland and grassland,the population and rural population and all land cover of Zhangye City was negative or weak correlation exists between types,especially there is a very significant negative correlation and harvest crops,economic crops,grain crop acreage,total planting area,total population and the multiple cropping index and rural population and cultivated land area are also found highly significant negative correlation,display while reducing the total population and rural population,but the farmer's income will remain strong and expanded cultivation phenomenon is still significant.In addition,urban population,urban workers number and area of cultivated land,harvest crops,grain crop acreage between showed a highly significant positive correlation,and with an area of woodland and grassland presented significantly negative correlation,indicating that the Zhangye city urbanization not blind to occupy agricultural land,at the same time,the urban population are increased with the increase in demand for food consumption,resulting in the increase of cultivated land,also indirectly led to the cultivated land occupied by the large amount of woodland and grassland.Finally,rural number of households and grassland,woodland and summer crops,in addition to other cover was extremely significant positive correlation betweentypes,indicating that the family unit of human activities(or demand)over individual activities /demand of land use / vegetation cover effect is more significant.5)From the point of view of industrial structure,Zhangye City,the first industry number and the grassland and woodland area change has little correlation,and summer crop area change significant negative correlation,and several other cover types showed highly significant negative correlation.Two or three the correlation between the number of industry and land cover change has not reached a significant level.From the point of view of occupational structure,agriculture and forestry,animal husbandry and fishery population changes with the crop acreage showed highly significant negative correlation,and the multiple cropping index showed significant negative correlation;and industry,construction industry,transportation industry and commercial food service industry changes in the number and acreage of crops increases now extremely significant positive correlation;number of commercial food service industry also and the area of grassland and forestland changes showed significant negative correlation.In addition,the changes of labor force in rural areas showed a significant positive correlation with the planting area,and negatively correlated with the area of grassland and forest land.Above is further illustrated in Zhangye City while engaged in agriculture,forestry,animal husbandry and fishery number in reducing,but to promote income,expand farming phenomenon is still significant,the land utilization rate is increased;also show at the same time,industry,construction industry,transportation industry and the number of commercial food service industry increased to supplement in agriculture,forestry,animal husbandry and fishery staff turnover,etc..6)In 2001-2003,the Land Cover comprehensive index of Zhangye City had a rapid decline,after 2003,land cover comprehensive index increased slightly each year,especially in 2011 appeared an obvious rise,to 2013 reached a relatively high level,but still did not reach the level of 2001.A preliminary analysis on the effect of the land utilization rate of main causes of violent changes in 2001-2003 of Zhangye City,should be that Zhangye city suffered 50 years of rare low temperature freezing in 2002-2003,in addition,in 2003 Zhangye city by SARS,earthquake,and on the implementation of the 2000 and 2002 Heihe water unified dispatch and water-saving society construction pilot program of the effect may also be one of the reasons,with the adjustment of industrial structure and adapt quickly,and in 2003 the implementation of the "people's Republic of China Rural Land Contract Law" and other relevant laws and regulations,especially after 2010 the production base construction rapid development,utilization rate gradually to the recovery and stability of integrated land.7)In 2001-2013,the population structure and land cover of Zhangye is the coordination degree of the overall trend is the first decreased and then increased,experience the primary coordination phase(2001),non coordination stage(2003-2010)and advanced stage of coordination(2002 and 2011 to 2013.In 2001-2013,the population structure and land cover of Zhangye City is the coordinated development of the overall trend is first decreased and then increased,has experienced: on the verge of imbalance decline stage(2001)-barely coordinated development stage(2002)-serious imbalance in the recession phase(2003),moderate disorders in the recession phase(2004-2007)-mild disorders recession(2008-2009)-on the verge of disorders in the recession phase(2010)-the intermediate coordinated development stage(2011-2013).The results show that the relationship between population structure and land cover has experienced a long period of time after the run in,gradually tend to be coordinated or stable,and gradually to the direction of good coordination.8)From the prediction results,in the next few years,the population structure and land cover of Zhangye city is still in the stage of advanced coordination,coordinated development degree in intermediate coordinated development stage and well coordinated development stage between fluctuations in the state,that in do not consider climate change,natural disasters and other conditions,Zhangye City,the population structure and land cover is in the next few years will still be in relatively harmonious and stable development stage.The above conclusions,some of the existing knowledge is consistent,but there are a considerable part of the existing cognitive,is bound to Zhangye's industrial restructuring,urbanization and other policies to develop and adjust to provide reference. |
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