Remote Sensing Monitoring Of Wind-preventing And Sand-fixing Effects Of The Coastal Protective Forest In Haitan Island And Its Realization By IDL Programming

Protective forests play an important role in sheltering the regional ecological environment. Wind-preventing and sand-fixing as well as improving micro-climate is significant goal for the construction of protective forest belts in coastal areas. Destructive weather phenomena commonly seen in coastal area such as severe typhoons can be stopped by the protections forests and thus greatly weakened. Therefore, it can be said that protection forests play a positive role in disaster reduction and disaster prevention. Study of wind-preventing and sand-fixing effects of protection forests has vital practical significance in sustainable development and promotion of ecological safety in coastal areas. Field investigation is the traditional method in studying the wind-preventing and sand-fixing effects of protective forests, which is often costly and time-consuming, and the research results are usually in the form of qualitative descriptions. Introduction of the Remote Sensing technology makes it possible to quantitatively study the wind-preventing and sand-fixing effects of protection forests in a large scope. It can also provide scientific and reliable basis for construction and management of protection forests, thus bring us great social, ecological and economic benefits.The present paper took Haitan Island, Fujian Province, China, as study area. Mainly data source used for the study included:one Landsat 5 TM image, one Landsat 7 ETM+image and one Landsat 8 OLI image, which was acquired on Aug 3, 1992, Aug 23,2002, and July 12,2013, respectively. Other data used included:one DEM image with a spatial resolution of 5 meters and the meteorological data of yearly and monthly temperature, air humidity and rainfall between the year of 1980 and 2010, obtained from 10 automatic weather stations located in the study area. A model was built to compute the wind-preventing and sand-fixing effects of protection forests in the study area. With the aid of IDL (Interactive Data Language) programming and secondary development of ENVI, an easy-to-use operational system with friendly user-interface was established, which packaged the computing procedure of wind-preventing and sand-fixing effects. Users can achieve all the functions of the software by just inputting the data. When compared with conventional step-by-step tedious ways of computing of the wind-preventing and sand-fixing effects of the protection forests, the system constructed in present study showed to be more powerful, convenient and efficient, thus has great potential in the future.