Scientific evaluation of the tropical rainforests resources in Africa using field investigation and satellite data

这项研究的重点是对非洲热带雨林区，特别是扎伊尔河流域进行实地调查，以便建立一个科学的生态气候学数据库，用于分析热带雨林生态系统和气候参数(降雨量、温度、植被覆盖等)的季节、年际和长期变化。在这里指出我们对这个热带雨林区和周围稀树草原林地和草原地区的分析的主要新发现：1.温度资料存在显著的2-5年的振荡，与南方涛动指数(SOI)，因此ENSO2.正相关。在温度、湿度和降雨量中记录了一种无所不在的准年代际振荡(QDO)，其周期与太阳活动(太阳黑子数)相匹配。3.在扎伊尔的所有站点都观察到了持续变暖的趋势，1960年至1990年期间平均上升了0.5%至1.5%ﾟC：这比在同一个30年期间观察到的全球变暖的数值还要高。4.对于所分析的每个点，都有强烈的干旱趋势，表现为降雨量的大幅减少和旱季的延长(有些站的旱季长达3个月)。5.这些长期趋势(变暖和变干)的大小表明，这些现象是区域性的，并植根于当地生态气候条件的变化中。这些变化与当地人的生活方式和生活环境的变化(轮垦、林火、柴火等)之间的显著关系。已被突出显示。

This research was performed focusing on field investigations over the tropical rainforest region in Africa, especially the Zaire River Basin, so as to create a scientific ecoclimatological database for the analysis of the seasonal, inter-annual and long-term changes in both the rainforest ecosystem and the climatological parameters (rainfall, temperature, vegatation cover, etc.) over this region.Suffices to point here the main new findings from our analyzes over this tropical rainforest region and the surrounding savanna woodland and grassland areas : 1. The existence of a remarkable 2-to 5-year oscillation in the temperature data, with strong positive correlationship with the Southern Oscillation Index (SOI), and therefore the ENSO.2. An omnipresent quasi-decadal oscillation (QDO) in the temperature, humidity and rainfalls records, with a periodicity matching that of the solar activity (sunspot numbers). 3. A persistent warming trend observed at all the stations in Zaire, with a mean increase of 0.5 to 1.5ﾟC over the 1960-90 period : this is more than the values observed for the global warming on the same 30-year period. 4. For every analyzed point, a strong desiccation trend, manifested by a strong decrease in rainfalls as well as the lengthening of the dry season (up to 3 months at some stations). 5. The magnitude of these long term trends (warming and desiccation) suggests that these phenomena are regional and imbedded in the change in the local ecoclimatological conditions. The remarkable relationship between these changes and the local people's lifestyle and alteration of the environment for their living (shifting cultivation, bushfire, fuel wood, etc.) has been highlighted.