| Fresh water resource scarcity is a global problem, Beijing as one of the world's serious water shortage cities, the per capita water resource is less than 300m, which is 4% of the world average value, and this makes Beijing a serious wat er deficient area. Miyun Reservoir is currently the only surface water source in Beijing, supplying more than 50% of Beijing urban surface water resource. In order to protect the water quality, quantity, and surrounding environment of Miyun Reservoir, national and Beijing, Hebei governments did a lot of work about water saving irrigation, pollution control, water and soil conservation in Miyun Reservoir watershed during the last few years, which made great achievements in vegetation restoration and reconstruction, but also led to a significant change of land use / cover and landscape pattern. For this reason, on the basis of available information of Miyun Reservoir watershed, based on the TM and MSS remote sensing satellite images, using remote sensing and GIS technology, we established 4 spatial information database of land use in the Miyun Reservoir watershed in 1978, 1988, 1998 and 2008 to analysis land use/cover change. We established CA, Markov composite model to simulate and predict land use changes to further more explore the driving mechanism and to forecast future land use pattern. We combined the qualitative analysis and quantitative calculation: compare the simulation results and the actual situation, apply DCCA model to analysis the impact of policy factors to land use change, reveal the land use change process and mechanism under the human activities effect, which can help land managers analysis land use trend under different macro-policy, to support rational land use planning and decision-making support. At the same time, in order to study the forest landscape structure and function, diagnosis the health status of forest landscape, balance regional development, protect the fragile ecological environment, and make scientific and reasonable ecological compensation standards, in this paper we zoned different priority areas of forest landscape restoration based on the livelihood improvement and different priority areas of forest protection based on ecological benefits, in order to provide scientific basis for adjusting social and economic development strategies and forest landscape restoration and improvement.The main results of this study are as follows:1. The farmland, grassland, water area and unused land have decreased, while the forest land, urban and rural, mining, residential areas have increased during 1978-2008. The farmland, forest land, and grassland were the main land use types in this watershed, but their proportion changed from 1978 to 2008. The forest land increased 4 891.75km2 from 1978 to 2008, and grassland degradation is also one of remarkable characteristics of spatial change of land use in Miyun Reservoir watershed, may be due to the mass degenerative high coverage grassland, medium and low coverage grassland tended to increase in some time period, in general the area of grassland greatly reduced, while quality of the grassland declined too; there was 1 350.04km2 farmland reduced during 1978-2008.2. As to the transfer situation of land use types in Miyun reservoir watershed, it mainly shown as the change among nonirrigated farmland, forest land, shrub land, high coverage grassland, moderate coverage grassland and low coverage grassland. The nonirrigated farmland reduced 1 858.67km2 during 1978-2008, and mainly changed to forest land, shrub land and high coverage grassland, the increased area of nonirrigated farmland is 521.04km2, which mainly from high coverage grassland. The increased area of forest land is 4 893.55km2, which mainly from nonirrigated farmland and open forest land. The shrub land reduced 752.65km2 during 1978-2008, and mainly changed to forest land, high coverage grassland and moderate coverage grassland, the increased area of shrub land is 1 689.21km2, which mainly from nonirrigated farmland, open forest land and high coverage grassland. The open forest land reduced 3 816.31km2 during 1978-2008, and mainly changed to forest land and shrub land, the increased area of open forest land is 383.81km2, which mainly from nonirrigated farmland, shrub land and high coverage grassland. The high coverage grassland reduced 1 394.31km2 during 1978-2008, and mainly changed to forest land and shrub land, the increased area of high coverage grassland is 769.82km2, which mainly from nonirrigated farmland and low coverage grassland. The moderate coverage grassland reduced 274.41km2 during 1978-2008, and mainly changed to nonirrigated farmland, forest land and high coverage grassland, the increased area of moderate coverage grassland is 540.45km2, which mainly from nonirrigated farmland and high coverage grassland. The low coverage grassland reduced 613.28km2 during 1978-2008, and mainly changed to forest land and high coverage grassland.3. The fragmentation degree of irrigated farmland, beach land and forest land reduced from 1978 to 2008, the total edge of open forest land and river trench gradually decreased, which indicating that their shape becoming more and more regular and simple, strong disturbed by human activities. From the whole developing trend of landscape pattern we can see that the trend of patch number, patch density and mean patch area shows the landscape of Beijing part tend to be integrated, while the Hebei part tend to fragmentation, and the increase in the landscape fragmentation degree of Hebei part after 1988 has led to the increasing of landscape fragmentation of Miyun Reservoir watershed. Both the landscape diversity index and landscape evenness index of Beijing and Hebei part gradually decreased, and the decreasing speed in Beijing part was faster than Hebei. ?4. The decreasing speed of nonirrigated farmland, open forest land and high coverage grassland in Hebei part during 1988-1998 is higher than 1978-1988, while the increasing speed of forest land, shrub land and moderate coverage grassland is higher than 1978-1988. The increasing speed of forest land, open forest land and moderate coverage grassland in Hebei part during 1998-2008 is higher than 1988-1998, while the decreasing speed of nonirrigated farmland, shrub land and high coverage grassland is higher than 1988-1998. The decreasing speed of open forest land and high coverage grassland in Beijing part during 1988-1998 is higher than 1978-1988, while the increasing speed of forest land and shrub land is higher than 1978-1988. The simulation results of land use situation in 2008 in Beijing part mainly show that the simulation result of open forest land is larger than actual result, while the nonirrigated farmland and shrub land are smaller than actual result. This implied the policy disturbance exacerbated the increase of forest land and the decrease of farmland and grassland in 1988-1998, but the policy disturbance intensity decreased during 1998-2008. The results of DCCA analysis show that human activities guided and regulated by national ecological construction projects is the main driving force of land use change in Miyun Reservoir watershed, it is also the direct driving force of large increased area of forest.5. Compared the simulated result in 2020 to the actual situation in 2008 we can see that farmland and grassland continued to show a decreasing trend, forest land, water area and construction area has increased compared with 2008. Overall, the land use change trend during 2008-2020 is similar to the trend of the last 3 time period, but the change speed reduced significantly.6. The zoning of different priority areas of forest landscape restoration based on the livelihood improvement and different priority areas of forest protection based on ecological benefits showed that: the 1st area of socio-economic development potential areas is mainly distributed in Chicheng County, Fengning County and Miyun County, the 2nd area is mainly distributed in Miyun County, Yanqing County and Luanping County, the 3rd area is mainly distributed in Chicheng County, Fengning County, Huairou County, Yanqing County, Luanping County and Xinglong County, the 4th area is mainly distributed in Chicheng County and Fengning County; there are 7 villages belong to the 1st area of forest landscape restoration, and most of them located in Chicheng County, there are 377 villages belong to the 2nd area of forest landscape restoration, and most of them located in Chicheng, Fengning and Guyuan counties, there are 606 villages belong to the 3rd area of forest landscape restoration, and most of them located in Chicheng and Miyun counties, there are 116 villages belong to the 4th area of forest landscape restoration, and most of them located in Huairou, Miyun and Yanqing counties; there are large areas of the 1st and the 2nd areas of forest system carbon sequestration function area, which are 441 928.95 hm2 and 318 505.95hm2 respectively, about 46.40% and 33.44% of the total area, and the 5th area has the smallest area, which is about 3.17% of the total area; there are large areas of the 2nd and the 3rd areas of forest system water conservation function area, which are 55.45% and 28.28% of the total area respectively, and the 5th area has the smallest area, which is about 2.34% of the total area; also there are large areas of the 2nd and the 3rd areas of forest ecosystem function area, which are 542 812.69hm2 and 256 413.25hm2 respectively, about 55.45% and 28.28% of the total area, and the 5th area has the smallest area, which is about 0.30% of the total area.
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