基于辐射干燥度的黄土高原潜在植被分析-analysis of potential vegetation in loess plateau based on radiation dryness.docx

function relationship between sunshine hours ( S ) And the Global Solar Radiation ( Q ) of the Loess Plateau region more accurate.⑶ Loess Plateau region net radiation contours reflect the energy gradient of thisarea better, Budyko radiation drying index contours reflect the of dry-wet gradient of Loess Plateau region better.⑷ The results show that, in addition to the simulation results of the smaller areaof warm moist deciduous broad-leaved forest category, cold temperature dry mountain grassland category, the cold temperature moist mountain meadow type are not very good, the area coincidence rate of the other 14 categories with larger area has reached above 60 percent, in which of eight categories has reached above 80 percent, to achieve a better simulation results on the whole and more accurately reflect the natural zone regularity of vegetation characteristics as the representatives.⑸ This study use a lot of methods of GIS, it not only can provide analysisfunctions of geographic data with large space scope and high spatial resolution, in particular the GIS data processing of digital elevation model (DEM) data, and produce the most basic terrain parameters such as elevation, gradient, aspect, but also can produce other useful terrain parameters as many as 17 hydrological and ecological simulation , making large-scale vegetation distribution simulation possible in the mountainous areas with complex conditions.Key words: Loess Plateau; Global solar radiation; Net radiation; climatological calculation method；Budyk’s classification system ; Potential vegetation modeling;V独创性声明本人声明所呈交的论文是我个人在导师的指导下进行的研究工作 及取得的研究成果。尽我所知，除了文中特别加以标注和致谢的地方 外，论文中不包括其他人已经发表或撰写过的研究成果，也不包括为 获得西北师范大学或其他教育机构的学位或证书而使用过的材料。与 我一同工作的同志对本研究所做的任何贡献均已在论文中作了明确 的说明并表示了谢意。签名：日期： 关于论文使用授权的说明本人完全了解西北师范大学有关保留、使用学位论文的规定，即： 学校有权保留送交论文的复印件，允许论文被查阅和借阅；学校可以 公布论文的全部或部分内容，可以采用影印、缩印或其他复制手段保 存论文。（必威体育官网网址的论文在解密后应遵守此规定）签名：导师签名：日期： I1. 引言1.1 选题背景和意义 1.1.1 选题背景 近年来，以“全球变暖”为突出标志的全球环境问题己经引起了各国政府、 科学家及社会各界的极大关注。人类的活