Risk Assessment Of Sandstorm Disaster-pregnant Environment In Ordos

Sandstorm is one of the most serious ecological problems and is paid widely attention in the whole world. The generation of the sandstorm has brought critical mischief and threatens not only to the balance of the environment,but also to people's life and property. So risk assessment of Sandstorm disaster is the Precondition and foundation to implement various measures to control sandstorm disaster scientifically and effectively.The case study was carried out in Ordos, in which sandstorm happened frequently. In this thesis, took 20-m resolution Landsat Thematic Mapper(TM) images(in 2000, in 2007) of Ordos region and the climate data from 1990 to 2007 as the data foundation, used integrated approaches of principle of wind erosion and remote sensing, GIS, Excel and SPSS. According to the natural and personal reasons for sandstorm disasters, the indicators and models are selected to assess the risk of disaster-pregnant environment of sandstorm disasters in Ordos. On the base of that, this study finds out the grade criteria of the assessing index and risk index and discusses effective methods theoretically and technically. This paper concludes some meaningful conclusions as follow:1. Sandstorm of Ordos has distinct reducing trend: The frequency of sandstorm has a reducing tendency from 1990 to 2007. It reduces 0.98 every year.2. From 2000, the government carried out Return field to forest and grass, Forbid grazing policy. Therefore, these policies slow down the process of land diffusion effectively. In Ordos, the wind erosion areas become 75322.1797hm2 smaller from 2000 to 2007.3. In this study, the author discovered risk index sequence of the eight town of Ordos according to risk assessment on the sandstorm disaster-pregnant environment. That is,in 2000,HangJinQi > WuShenQi > ETuogeQanQi > ETuoGeQi > DaLaTeQi > EJinHoLuoQi >DongSheng > ZhunGar; in 2007, HangJinQi > ETuogeQanQi > WuShenQi> DaLaTeQi > ETuoGeQi > DongSheng> ZhunGar >EJinHoLuoQi; The result from these two assessments proves that the serious desertification places has the highest risk index of sandstorm disaster-pregnant environment.4. The key to prevent sandstorm in Ordos is fix sandy. Fixing sandy will combine with the risk grade, each area has own methods to solve.