Monitoring On The Protection Benefits Of Coastal Protective Forests Construction Based On Remote Sensing

The monitoring and evaluation of coastal shelterbelt protection effective is an important foundation for coastal shelterbelt forest resource management and reform. In this paper, the research object is the monitoring and evaluation of effectiveness of coastal protection forest construction. The paper use1988 and 2003 remote sensing data, combined with ancillary data, through field surveys, index selection, data analysis, modeling, and method validation to analyze the effectiveness channge of the regional water and soil conservation before and after the coastal shelterbelt construction from different functions. And on this basis, the coastal protection forest protection model was constructed to reflect the comprehensive benefit of coastal forest protected construction. Building model of human interference through the remote sensing index to reflect the impact of human afforestation. From two aspects of comprehensive protection and impact of human disturbance to analyze and verify the good benefit of the coastal shelterbelt protected construction and achieve the space-based, specific and quantitative of protected effectiveness of coastal protection forest. It provide an important basis and technical support for reasonable coastal shelter forest management, transformation and planning. The main conclusions are as follows:(1) Referenced to land use classification system of ministry of land resources and combined with the regional situation, the land use classification systems of Zhuangpu county was determined:class one was divided into the land, water, residential areas, woodland, sand and unused land, forest land was further divided into casuarina, slash pine, acacia economic forest and other types of woodland.(2) Based on the analysis approach such as OIF index, correlation coefficient and standard deviation, selected the best band and combined with the basis for field determination of spectral data, using hierarchical classification to extract land use thematic information by the appropriate threshold spectrum to those reflectance difference for the larger land-use type, while using supervised classification to those dfficult to distinguish and human-computer interaction for visual interpretation in local area. Classification result was the 1988 land use classification accuracy of 91.08% in 2003, the land use classification accuracy of 90.63%, in1988, the forest type classification accuracy of 85.49% in 2003, the forest type classification accuracy of 87.94%. using field validation to verify 2008 land use and forest types, the overall classification accuracy of 89.41%.(3) Using the data related to ground support and according to Chinese USLE soil erosion model, it implemented the dynamic monitoring of soil erosion of Zhangpu in 1988,2003 and 2008 and reflected the analysis of soil and water conservation the protection benefit of coastal protection forest. The results showed that in 1988 the incidence of soil erosion in the area of up to 21.86 hm2·a, the maximum intensity was only moderate erosion erosion and the area was only 0.03% of total area.(4) Through the land use change, landscape pattern channges and channges in vegetation cover, comprehensive qualitative analysis of regional protection fixing benefits was achieved. The results showed that the coastal shelterbelt played the role of sand-fixing better, desertified area of the region continueis decreasing, the overall conversion to farmland and forest land and vegetation cover was increased.(5) It was the first time to build the model of monitoring the benefits of coastal protection forest based on emote sensing technology, the regression correlation coefficient was 0.909 and the overall accuracy was 77.82%.Dynamic monitoring of desertification of the 7 seaside villages and towns in Zhangpu county showed that non-desertified area increased from 43.51% in 1988 to 80.30%, while mild, moderate or sandy area were reduced from 41.71% and 14.78% to 18.44% and 1.27% respectively.(6) The paper used 1988 and 2003 image data to build the interference index model based on afforestation of the impact of human disturbance and made interference index map. By used the township as a unit to analysze the correlation of positive effective of impact of human disturbance of coastal protection forest and soil erosion, vegetation cover and sand-fixing effectiveness. The results showed that it had a good correlation of the overall value of the index of human disturbance and soil erosion, vegetation cover and sand-fixing positive efficiency.(7) The paper selected soil erosion modulus, vegetation cover, bare sand area ratio, forest productivity, gross domestic product (GDP) as the assessment factors of comprehensive protection benefits of coastal protection forest and used the integrated index, the results show that:the protective effect of Zhangpu county level and above in a better ratio of 50.48% in 1988 and then reached 72.59% in 2003.(8) Through the binomial equations of interference index value and the overall efficiency index value own and soil erosion and combined with mean and standard deviation of this two indicators, integrated to determine the threshold value of interference index which reflected the positive effects of coastal protection forest protection in Zhangpu county was 1.5812 and the overall efficiency index ratio was 0.89575.And then according to the threshold set the two index, the project information of Zhangpu county index map which reflected the positive effect of the coastal protection forest protection was extracted. The results showed that overlapping area between them was 149327 hm2, accounting for 79.1436%, with high consistency. Finally the paper analysis and verify the good benefit of the construction of coastal shelterbelt protection from two aspects of comprehensive protection and Impact of human disturbance.