Land Use Change In Dali City

It had the most direct influence on physical environment induced by human activities,land use/cover change(LUCC)became the core area of global environment change and sustainable development research since 1990s.As a major strategic decision to protect high-quality cultivated land in the dam area and urban spatial expansion in Yunnan Province,the implementation of the“construction land uphill”strategy had profound influence on land use development in Dali City.This article analyzed land use changes in Dali from 2009 to 2016 of construction land expansion and arable land occupation under strategy hill town based on land use change survey in 2009 and 2016,slope,statistical bulletins,annals of statistics and land-use planning of Dali city with GIS technology,field surveying,quantitative analysis and qualitative analysis method,which intended to providing experiences for sustainable land utilization,the further implementation of hill town strategy and construction of the new urbanization in Dali.Results showed that:(1)Land use structures in Dali City showed:(1)Land resources was highly exploited in Dali City,and cultivated land and construction land were the main landscape types.(2)The land reclamation rate is greater than the average level of Yunnan province,though the total cultivated land amount was really limited in Dali City which had a relatively large proportion in paddy field,and land resources are increasingly inadequate in Dali City.(2)The overall analysis of change of land use in Dali shows that:(1)All types of construction land continues to grow rapidly,and the fact that construction land is taking up agricultural and other land is a prominent feature during the study.(2)Among all land types,the area of urban land,paddy fields,dry land,forest land,land for traffic and water conservation and irrigated land changes the most,while the area of other land changes less.(3)The area of agricultural land transferred to construction land reached 2692.50 hm~2,accounting for 88.23%of the total amount of construction land converted,of which the area of cultivated land converted to construction land reached 1605.71 hm~2,accounting for 59.64%of the total agricultural land converted to construction land.(4)The area of other land converted to construction land reached 381.44 hm~2,which has been mainly converted into urban land and land for traffic and water conservation with an area of 267.66 hm~2 and 73.45hm~2 respectively,totaling 341.11 hm~2 and accounting for 89.43%of other land converted to construction land.(5)In the change of agricultural land,apart from the transfer of agricultural land to other land,there is also conversion within agricultural land as well including the conversion from dry land to irrigated land and from paddy fields,dry land and woodland to other agricultural land.(3)Analysis of the slope change of various places in Dali showed that all kinds of construction land had moved“uphill”to a certain extent.The area of different types of construction land at different slope gradients had increased.The area of construction land at 0°~6°and above 6°increased by 1417.83 hm~2 and 1654.11 hm~2respectively,and the proportion of construction land area at 0°~6°decreased from73.17%to 67.55%with the net decrease reaching 5.62%.There has been an increase in land with over 6°slope gradient.The analysis of the“uphill”land for urban,industrial and mining and the occupation of arable land shows that urban land mainly occupies agricultural land at below 25°and other land at 0°~15°.The occupation of cultivated land is mainly concentrated in paddy fields and dry land at below 25°,totaling 914.71 hm~2.The expansion of industrial and mining land mainly occupies agricultural land and other land at over 6°.The occupation of cultivated land is mainly concentrated on dry land at 6°~25°,totaling 11.92 hm~2.(4)Analysis of driving factors behind land use change showed that land use change in Dali City is mainly driven by factors in policy,economy,population growth and transportation.The analysis of the effect of land use change in Dali shows that the implementation of the“construction land uphill”strategy has alleviated the occupation of cultivated land by construction land,promoted the transformation from dry land to irrigated land,and taken an initial step in implementing the policy of“Two Protections and Two Developments”in Dali.These are positive effects.However,there are also negative effects such as the increase in arable land at below6°occupied by new construction land,the destruction of ecology because of development and utilization of steep slopes at above 25°as well as the“construction land uphill”strategy,occupation of lots of forest land and natural reserves.(5)Given the results of land use change analysis,the main problems in land use in Dali City are:(1)The resources of arable land continue to decrease,and the pressure on arable land protection in the dam area is high.(2)The scale of construction land has expanded rapidly,and the development of urbanization has lagged behind.(3)The level of effective use of construction land needs to be further improved.(4)Tasks of ecological construction and environmental protection are arduous.(6)In response to the above problems,the author proposes countermeasures for sustainable land use in Dali City:(1)Reasonably delineate the“three lines”of Dali City(red line of permanent basic farmland,red line of ecological protection,boundary line of urban development),and vigorously optimize the development pattern of national land.(2)Strictly control the loss of high-quality arable land in the dam area and improve the quality of arable land.(3)Strengthen the space control of construction land,optimize the urban and structure of rural land use,and continuously improve the effective utilization of construction land.(4)Strengthen the environmental protection of the land with the protection of the Cangshan Mountain and the Erhai Lake as the core,and realize the sustainable economic and social development of the city.