山体效应及其对山地垂直带分布影响的比较研究

Mass elevation effect (MEE) not only has an important impact on regional climate, but also has an important role in controlling the mountane ecological-geographical patterns. But there is no regional comparative study of MEE, and the previously established MEE models have low explanation abilities. In order to reveal the regional differences of MEE, six mountains with obvious MEE are chosen as target areas in this proposal, which are the Tibetan Plateau, the Andes, the Alps, the Rocky Mts., the Scandinavia and the mountains in New Zealand. Using the MODIS、TRMM、GHCN、DEM and the data of treeline and snowline, this proposal will research on the following questions: 1) Quantitative analysis of MEE from the aspects of heating effect and dehumidifying effect. Using the air temperature difference in and outer of the mountain, continentality and aridity as indices, this proposal will study the characters and mechanism of MEE on the basis of estimating the air temperature of the mountains (using geographical weighted regression method) and correcting the TRMM monthly precipitation data (using step by step correction or optimal interpolation method). 2) Factor analysis of MEE. The proposal will identify the formation factors of MEE based on the comprehensive analysis and comparison of the MEE in different regions；3) The implication of MEE. By comparing the effects of MEE on treelines and snowlines in different regions, this proposal try to disclose the mechanism of interactions between the mountain ecology patterns and MEE; 4) The digital MEE model. We will construct the regional MEE models with high explanation ability, and analyze the implication of MEE for the distribution of mountain altitudinal belt. The purpose of this proposal is to reveal the style, the intensity and the range of the implication of the non-zonal factor such as the MEE for mountain ecological-geographical patterns, and to further promote the development of the quantitative MEE study. Moreover this proposal will enhance the research of the basic theory of the physical geography.

山体效应对区域气候和山区生态-地理格局具有重要的影响。但目前没有进行区域性对比研究，导致对山体效应差异性认识不足，以基面高度为第一要素建立的山体效应模型的解释能力有待提高。通过山体效应及其影响的区域对比研究可以进一步提高山体效应定量化及其数值模拟的精度，把山体效应研究推向新高度。本项目选择青藏高原、安第斯山、落基山、阿尔卑斯山、斯堪的那维亚和新西兰山地等6个代表性山地，利用MODIS、TRMM、GHCN、DEM和全球林线、雪线等垂直带谱数据，在气温估算和TRMM降水数据订正的基础上，以山体内外气温差、降水大陆度和干燥度等为指标，从增温和减湿两个方面定量分析和比较研究山体效应的区域差异性及其形成因子的构成；比较分析不同区域山体效应对林线、雪线等垂直带的影响，从而建立高精度山体效应数字模型，揭示山体效应这一非地带性要素对山地生态-地理格局的作用方式、强度和范围。

山体效应对区域气候和山区生态-地理格局具有重要的影响。近年来，在山体效应定量化及其对垂直带的影响研究方面取得了很大的进步，并提出了基面高度是山体效应形成的第一要素，但以基面高度为山体效应代用因子的山体效应模型精度不高，亟需通过全球性主要山地山体效应的对比研究，进一步寻找和细化山体效应形成的区域影响要素，构建高精度的山体效应数字模型。本项目选择青藏高原、安第斯山、落基山、阿尔卑斯山4个代表性山地，基于MODIS地表温度、CHIRPS降水数据、GHCN数据、DEM和全球林线、雪线等垂直带谱数据，利用半球视域算法中的太阳辐射量算法计算了各个山地的太阳辐射，利用GWR方法估算了各个山地的气温，并利用逐步插值法等对4个研究区的CHIRPS 降水数据订正；在此基础上，同海拔高度上的气温差、林线高度差，太阳辐射差等为指标，比较研究上述4个山地的山体效应并探讨其区域差异性的影响因素。研究结果表明：（1）各个山地等温线高度、太阳辐射与林线的分布规律均沿着山体边缘向内部逐渐升高：阿尔卑斯山最热月与最冷月内部与边缘地区的太阳辐射量分别相差180-210 kWh/m2、10-20 kWh/m2，最热月10℃等温线和最冷月0℃等温线在山体内部与外部的高差都为500-1000m，内部林线比外部高250-850m；青藏高原最冷月与最热月内部与外部地区的太阳辐射量相差20-85Kwh/m2、30-95Kwh/m2；山体内外气温差约在10-15℃、2-10℃左右，林线高度内部比外部高500-1000m；安第斯山最冷月与最热月的太阳辐射内部比边缘地区分别高20-110kwh/m2、35-85Kwh/m2，最热月10℃等温线内部比外部高1000-2000 m，内部林线比边缘地区高2000-3000 m。（2）安第斯山和青藏高原的山体效应最为显著且前者高于后者，落基山和阿尔卑斯山的山体效应相对较小，山体的规模对山体效应具有重要的影响。本项研究进一步揭示了山体效应的区域差异性及其对山地生态-地理格局的作用方式、强度和范围，推动山体效应定量化的发展。