Ecosystem Service Values Measurement And Spatial-temporal Differentiation Of Green Space Landscape Absorbing Haze In Beijing-Tianjin-Hebei Urban Agglomeration

As one of China's three core urban agglomerations,the Beijing-Tianjin-Hebei urban agglomeration has been accelerating with the pace of urbanization,and environmental pollution,especially air pollution,has continued to increase,making this region one of the most heavily polluted areas in China..In the context of national ecological civilization construction and the coordinated development of Beijing,Tianjin,and Hebei,the exploration and solution of smog pollution has gradually become a hot topic in the region at home and abroad.From the perspective of landscape ecology,the prevention and control of smog not only needs to control the"source"landscape that increases the source of smog pollution,but also requires reasonable planning and layout to suppress the spread of smog and a"sink"for purification and absorption of smog.landscape.A large number of studies based on"landscape pattern-ecosystem service value"have shown that urban green space landscape has a great effect on the purification and absorption of haze,and the change of its landscape pattern also has a significant impact on the realization of the ecological service function of absorbing haze.Therefore,according to the research on the ecological service value of the green space ecosystem in the Beijing-Tianjin-Hebei urban agglomeration and the spatial and temporal changes of the landscape pattern of the green space,the reasonable planning and layout of the ecological space in the area,and the better realization of the ecological service functions in the purification of haze Is of great significance.This paper selects the Beijing-Tianjin-Hebei urban agglomeration as the research area,and uses the four land use data of 2000,2005,2010,and 2015 to extract four types of green land landscape types in the study area:forest land,cultivated land,grassland,and garden land;using Fragstats software from Spatial-temporal differentiation of greenland landscape patterns at two scales:type and landscape.At the same time,based on the principle of absorption of the three components of SO₂,NO_x and particulate pollutants by various types of vegetation,and the relevant policies for the management of smog in the region,the value of the amount of haze components absorbed by greenbelt types consistent with the actual conditions of Beijing-Tianjin-Hebei region was calculated.Using ArcGIS software to analyze the changes in the level of haze absorbing haze service value of greenland landscapes,and based on the principle of spatial autocorrelation to analyze the temporal and spatial clustering characteristics of haze absorbing value.It will provide relevant reference for the decision-makers of Beijing-Tianjin-Hebei urban agglomeration to plan and lay out the green space,make better use of the ecological service function of purifying the smog and haze of the green space ecosystem,and alleviate the smog pollution in the Beijing-Tianjin-Hebei area.research shows:?1?From 2000 to 2015,the overall area of the green space landscape in the Beijing-Tianjin-Hebei urban agglomeration was in a state of decline,and the overall composition ratio in 15 years showed regular characteristics of cultivated land>forest land>grassland>garden land.It accounts for more than 50%of the entire green space landscape,but the proportion is decreasing.From the perspective of changes in the overall pattern of the green space landscape,from 2000 to 2015,NP,PD,LSI,and ED continued to grow,especially during 2005-2010.The growth rate was relatively large,and it became"slow"throughout the period.Growth-rapid growth-decline";MP,LPI,AWMPFD,and CONTAG showed a trend of gradual reduction in addition to the entire period,and the declines decreased by 7.5%,8%,0.43%,and 2%,of which MP and The reduction in LPI is relatively large.The trends of SHDI and SHEI are the same,with an increase of 2.3%.From the perspective of the changes in the spatial pattern of the green space of each landscape type,during the period 2000-2015,the overall decline in MP and LPI of the grassland landscape was the largest,and LSI and AWMSI also showed a decreasing trend,indicating that the grassland landscape was affected by human factors.Larger,showing a gradually broken state;At the same time,the edge effect is more obvious,and the ecological service function is gradually weakening;the overall increase in NP and PD of the forest landscape is small,and CA,MP and LPI are all greatly improved At the same time,with the decrease of AWMSI year by year,LSI has a large downward trend,which indicates that under the influence of more positive human factors,the ecological service function of the landscape has been improved to a certain extent.?2?From the perspective of the changes in the value of haze-absorbing ecological services,the total value of haze-absorbing haze in the green space landscape of the Beijing-Tianjin-Hebei urban agglomeration in 2015 was 31,662.91×10⁸ yuan,an increase of0.95 percentage points compared to 2000.Inverted"N"change characteristics of"decline-significant increase-decline";from the perspective of the ecological service value of the single type of haze absorbed by the landscape type,the overall characteristics of dust retention>NO_x absorption>SO₂ absorption are shown;The contribution of haze absorption value is generally forest land>arable land>grassland>garden land.?3?There is a large difference in the spatial and temporal distribution of the amount of haze value.The high-value areas are mainly distributed in the central area of Beijing,Tianjin,and Hebei,and have a tendency to converge with time.The low-value areas are mostly located in urban centers and the Bohai Rim,and they have a tendency to spread to the next high-value areas over time.The spatial and temporal clustering space of the haze value has significant autocorrelation,and the agglomeration tends to gradually increase.The overall number of L-L clusters and H-H clusters is relatively large,and both are gradually increasing;H-H clusters are mainly distributed in the northeast of Beijing,Tianjin,and Hebei,and L-L clusters are mainly distributed in central Beijing's central urban area and the Bohai Rim region.?4?In the planning of greenland landscape prevention and control of haze,we should continue to strengthen the layout of the forestland landscape ecological network and improve the connectivity of the forestland landscape pattern in the northern region;strengthen the construction of the greenland ecological corridor in the southeast,especially in urban built-up areas The construction of the ecological buffer zone in the surrounding zone will change the current situation of the distribution of high-value areas where the value of absorbing haze is too concentrated;rationally control the expansion of the boundary of urban construction land,strengthen the protection of cultivated land landscape,and prevent the surrounding effects of urban construction land from strengthening,leading to cultivated land landscape over fragmentation.