Evaluation Of Ecosystem Service In Southeastern Fujian Based On InVEST Model

The ecosystem service function is the basis for the sustainable development of human society,economy and ecological environment.Quantitative assessment of ecosystem service functions can intuitively understand the importance of ecosystem services,so as to achieve rational allocation of natural resources.The water source of Gulei Petrochemical Base is a national first-level water source protection site with an important geographical location.The InVEST model has been widely used in ecosystem service evaluation to visualize evaluation results.This paper takes the water source of Gulei Petrochemical Base as the research area,based on remote sensing and ArcGIS technology,and uses InVEST model to evaluate the spatial and temporal changes of water conservation,soil conservation,habitat quality and carbon storage function in the study area in 2005,2010 and 2015.Analyze the influencing factors of ecosystems;study the correlation between various service functions;obtain the comprehensive ecosystem service function evaluation index through principal component analysis method,and evaluate the spatial and temporal changes and importance classification of integrated ecosystem service functions;The CA-Markov model predicts the type of land use in 2025 and studies the changes in ecosystem services based on land use change.The following main contents are obtained:(1)Assessment of ecosystem service functionsWater conservation function:The average water production in the third phase of the study area was 2005(417.55mm),2010(495.47 mm),2015(462.98 mm),The average yield of the third phase was quite different.The water use of land use types was:grassland>cultivated land>orchard>woodland.The relationship between water production and precipitation shows a certain regularity and does not present a strict positive correlation.The relationship between the amount of water produced and the potential evapotranspiration reflects a certain regularity and does not exhibit a strict negative correlation.Soil retention function:The total amount of soil retention in the third phase of the study area was 2005(5.4307×10~8),2010(5.5763×10~8),2015(4.7085×10~8).Compared with 2005,the total amount of soil conservation in 2015 decreased(7.222×10~7),and the soil conservation of land use type was:forest land>orchard>grassland>cultivated land,soil retention function and precipitation There was a certain regularity,there was a big difference in the soil holding capacity of different slopes,and the soil retention ability of the medium slope was higher.Habitat diversity function:The average habitat quality index of the third phase of the study area was 2005(0.4691),2010(0.4654),2015(0.4648),The highest average habitat quality index in 2005.The overall average change value was(-0.0043),which was significant.The descending areas are located in the central and eastern parts,and the habitat quality index of land use types is:water area>forest land>garden land>grassland,and human activities have a great impact on habitat quality.Carbon storage function:The average carbon density of the third phase of the study area was 2005(24.99t/hm~2),2010(24.78 t/hm~2),2015(24.62 t/hm~2),The lowest average carbon density in 2015.Different land use types The carbon storage capacity was expressed as:forest land>orchard>grassland>cultivated land.(2)Correlation between ecosystem service functions:synergistic relationships among ecosystem service functions,with the strongest correlation between soil conservation and carbon storage,habitat quality and carbon storage,water conservation and habitats The correlation between qualities was the weakest.(3)The average comprehensive service function index of the third phase was 2005(0.522),2010(0.512),2015(0.505).The importance hierarchy and area statistics of the integrated ecosystem service function were polarized.The general importance level increased by 2762.64 hm~2,and the extremely important area decreased by 4769.01 hm~2.