| Land had the ability to bear and rear all varieties of abiotic and biotic as one of the objective natural resource.With the rapid development of global economy,the shortage of land resources and deterioration of the ecological environment had become increasingly prominent.The change of land use,effect and driving were the core of the scientists all over the world. Yulin located the typical and central area of the north China ecotone and was the important part in Jin-Shan-Meng "black triangle".Yulin was the new generation enrichment and development zone of coal,petroleum,natural gas,rock salt and other energy mineral resources.So it has a fragily ecological environment and tensely people-land relationship.In this paper,I used the remote sensing image data to obtain Yulin LUCC in1985,1996,2000,and2010.First,I analyzed the Lucc apatio-temoral change and land structure change in study area.Second,I calculated the ecological effect in1996-2010by ecosystem service value.And the ecosystem service value included the supply service, relulation service,support service and cultural service.Finally,I analyzed the natural and human driving factors of landuse and landcover..Through the research,the main conclusions are as follows:(1)The characteristics of landuse changeOn the whole,the different landuse types at different stages was not the same in1985-2010,Yulin.1985-1996-2000-2010,the cultivated area was increasing, decreasing, increasing in the three stages. The cultivated area decreased in1985-2010,and the percent in landuse types areas reduced from39%to36.44%.1985-1996-2000-2010,the forest area was decreasing-increasing-increasing in the three stages. The forest area decreased in1985-2010,and the percent in landuse types areas increased from4.31%to5.55%. the grass area was increasing-decreasing-increasing in the three stages. The grass area percent in1985-2010of landuse types areas increased from41.43%to45.26%. The waterland area was increasing-increasing-decreasing in the three stages. The waterland area percent in1985-2010of landuse types areas decreased from1.14%to0.94%. The construction land area was increasing gradually in the three stages. The unuse land area was decreasing-increasing-decreasing.All in all,the construction land area changed much and it increased by2.62times in1985-2010.The comprehensive landuse dynamic degree in Yulin was0.24%.That indicated the change of landuse was little in a whole.What is more,the district and county landuse change was different in1985-2010.In north six counties,the cultivated and waterland areas decreased,forest,grass,construction,unuse land areas incrseased.While in south six counties,the cultivated,grass,unused land areas decreased,and the forest,waterland,construction land areas increased.The much cultivated decreasing area was in Jingbian county which reduced from1730.19km2to1376.9km2.The much forest increasing area in Dingbian county which increased from166.73km2to369.35km2. The much grass increasing area in Shenmu county and Yuyang district which increased from3499.94km2,2361.7km2to4116.55km2,2945.82km2. The much waterland decreasing area was in Shenmu county which reduced from164.59km2to119.15km2.So the landuse change in north six countied was more fiercely than that in south six counties.(2)Study on the ecological effects of landuse changeThe average of ecosystem service total value increased by14856.34yuan/(hm2· year) in Yulin.And the per area of ecosystem service value in different district and counties were different.The value of cultivated,forest,grass land increased and waterland,unused land decreased.In two basic geomorphologic types,the per area of ecosystem service in loess was bigger than that in wind-sand area.The value in wind-sand area decreased by28.77%,but the value in loess increased by47.99%in the study period.The much value in slope was6°-15°,and increased by37.44×1010yuan from2006to2010.In the district differences,the per area value in north six counties was much than that in south six counties except that the value in Yuyang district decreased.The total value in north six counties was bigger than that in south six counties.While the total value in Dingbian county increased more to4039.12×108yuan.(3)Natural factors on the impact of landuse structure and areaCultivated,foreset,grass,waterland were distributed in the loess hilly semi-arid climate zone,respectively accounted for5.3%,54.68%,50.12%,54.19%.While construction and unuse land were distributed in wind-sand heavy drought climate zone,respectively accounted for75.86%,84.39%. The cultivated and grassland areas were the maximum between1050and1200meters elevation. The forest and waterland areas were the maximum between529and1050meters elevation. The construction and unuseland areas were the maximum between1200and1350meters elevation,respectivelyaccounted for33.84%,31.13%,29.88%,62.18%,33.97%,55.66%.The cultivated land was mainly distributed in the Yan soil and Heilu soil,forest land was mainly distributed in Hong soil and Heilu soil,grass land was mainly distributed in Hong soil,waterland was distributed in Yan soil,Hong soil and Heilu soil,while construction and unuse land were mainly distributed in Hong soil,and respectively accounted for29.7%、38.86%、27.57%、38.78%、29.21%、21.02%、20.32%、22.5%、19.72%、57.52%'77.96%。(4)The human driving mechanism of landuse changeThe most important factors for the north six counties landuse change in Yulin were the change of population quantity,the social economy and agriculture machinery technology development,while The most important factors for the sorth six counties landuse change were the level of city development, social economy and agriculture machinery technology development.The agriculture technology,human income,the level of city development,industrial structure and population made the land demand in north six counties increased greatly.So we must decrease the cultivated and unuse area to increase the construction land area for satisfying people life quanlity and demangding more constrution land to reply social economy development.The population and citizen level made more basic buildings satisfy people demand in south six counties.The characteristic lied in:when I studied the landuse change in1985-2010,Yulin,I also analysed the temporal dynamics of the six north and south counties landuse.Thus,the research was around the south and north differences,which revealed the impact of the landuse change. Second,I analysed the characteristics of the population quantity,economy development,industrial structure,technological level and policy factors as the human driving factors.And it provided more basis for studying on driving mechanism. |
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