| Currently, Land utilization/Cover Changes (LUCC) and regional ecological effects assessment were hot issues of global environmental change research. In this article we selected the Fen River watershed as study area and study the 2000-2010 land use dynamic change here by using the GIS, RS techniques, land use change index model, the dynamic degree model, the degree of exponential change models, Markov transfer matrix method and the grid overlay with the remote sensing images based on Landsat TM, SPOT-NDVI data, weather data and vegetation soil data and so on, and then calculated the value and substance of NPP, fixing carbon and releasing oxygen, water and soil conservation, water conservation by the method of CASA model of solar energy utilization, the US General Soil Erosion Equation (USLE), storage capacity model. This study reveals that the characteristics of land use in study area during 10 years, and the ecological environment effect were evaluated by preliminary test and evaluation, to develop the regional land use change and promoting the regional economic and social development. The study provide a certain theoretical basis and data to support industrial and agricultural development and ecological environment construction. The results are as follows:(1) The number of structural features of the Fen River Basin 2000-2010 land use is that the proportion of the total area of arable land is the largest area; but in the past 10 years, Area of it has a decreasing trend, Area of the other land use types show an increasing trend. The increase trend of construction land is very significant and the urban and suburban areas is spreading outward. Degree of land use change was negative indicate that the area was in a period of adjustment or recession on the whole. In aspects of the dynamic transfer, on the east and west sides of the river basin the transfer of land use types mainly feature is the transference of forest and grassland; In the Jinzhong basin, Linfen Basin and Yuncheng Basin the transfer of land use types mainly feature is the transference of construction land. The relative rate of change Land utilization in the study area are significant differences and have a dramatic changes, and the area of of each land use type changes unstably. The highest and lowest rate of change in arable land is jiaokou county and fushan county; The highest and lowest rate of change inwoodland is wanrong county and houma county; The highest and lowest rate of change in grassland is fushan county and xiaoyi county; The highest and lowest rate of change in construction land is fushan county and gu county;(2) In the view of landscape pattern index, farmland landscape accounted for about half of the tile types, Water landscape throughout the tile type is very rare; The patch density index has an upward trend on the overall,The fragmentation degree of the landscape increase; The results of mean patch fractal dimension show that the arable landscape becomes increasingly uneven with a complicated development trend, while other sites shapes tend to be simplified and regularized; The results of the index of cohesion indicates that physical connectivity between farmland, woodland and grassland lower, The results of landscape diversity index show a more balanced distribution of landscape patches during the study period.(3) In the 2000-2010, the value of ecological effects in The Fen River Basin has a large differences in the spatial and temporal distribution. We make estimates mainly from the NPP Value, Value oxygen release carbon sequestration, soil and water conservation Value, Value of Water Conservation; The total value of NPP in 2000-2010 increased from 12.74 million yuan to 15.07 million yuan, NPP Value of each unit area of land use types Were all improved. In the spatial distribution, the area with higher value basicly located in Linfen Basin, Yuncheng Basin which is in the Fen River basin and downstream areas, the area with lower value basicly located in urban construction land intensive areas and mine gathering area. The statistics of county showed that NPP highest and lowest values were Wanrong and Jiexiu. The value of fixing carbon and releasing oxygen in 2000-2010, on the Fen River Basin, increase from 46.66 million to 55.19 million. Its spatial distribution and spatial distribution of NPP is similar. Maximum and minimum values of the county statistics is consistent with the NPP county distribution. Various types of soil and water conservation value Land utilization volume has improved in 2000-2010, among them, the water Conservation value of forest is highest and the grass have the fasted growth. From the point of view of spatial distribution, Water and soil conservation value higher areas basically distributed in the hilly-gully loess plateau of the middle and lower reaches of fenhe river basin on both sides, Vegetation is abundant, thus soil and water conservation quantity is larger. The total value of soil and water conservation is shouyangCounty, with the largest change in the past 10 years and an increase of 17.682 billion yuan. The total volume of water conservation between 2000-2010 is rising from 30.9697 million in 2000 to 33.3793 million yuan in 2010.The total volume of water conservation in different land use types is also large differences in the contribution rate. Its contribution rate descending sort is woodland, farmland, grassland, other types of land use (water, land for construction).(4) Ecological effects of the total volume of the Fen River Basin Rose from 15.374 billion in 2000 to 23.23 billion in 2010, Ecological effects of the value per unit area counties are rising. Some counties located east and west sides of the Fen River Basin, eco-environmental effects Value increased substantially because of the implementation of the Returning Farmland to Forest policy in recent years. Different types of ecological effects Land utilization are not the same Value, The contribution rate for the total Value of ecological services of woodland is highest, followed by grassland, arable land, other land.(5) The change of the ecological effect not only affected by the ecological environment such as the influence of hydrothermal conditions and NDVI changes, but also affected by human activities such as land use change. The mainly reasons include the powerful implementation of returning farmland to forest policy and the rapid expansion of urban construction land and so on. In the region of rich vegetation coverage,the type of land use changing mostly distributed in the area of the stability and forest land, grass land with frequent transfer of areas changing. Due to less factors of human activity disturbance, the net production capacity and carbon oxygen release ability of the land use type of the stable changing areas is more effective. High amount of soil conservation areas are mainly distributed in valley hills on either side of the mountain area, this area is greatly influenced by human activities on the vegetation area and transfer of the highest rates of woodland and grassland. Water conservation value of high regional distribution mainly distributed in northeast, and both sides of the vegetation cover of rich areas. Low value area of the distribution mainly distributed in north and south on both sides of the plain where these areas are less affected by human activities. Also,in the stability of the land use of changing area and construction land.The innovation points in this paper:(1)In this paper, we estimate human activities on land use change impacts with the mothed of residual analysis, both calculation results are very consistent, from the impact of human activities on the forest land, grassland space and the space of the transfer of forest land, grass land, so the method is feasible. Then,combined with the feature of the ecological environment change and the ecological effect assessment in the study area, we can preliminarily concluded that the reason why the ecological effect of land use change in temporal and spatial variation. (2) To make the results more accurate, we improved the land use change dynamic model, according to the actual situation of the study area. (3) Calculate the time scale ecological effects and analyzed it with data in consecutive years, So that time and space scales can maintain a high accuracy. |
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