I'm not sure if whether should answer your question in English because it seems that you gave yourself a Japanese name, am I right? Anyway here is my explanation: "上升" and "下降" mean "goes up" or "goes down". These two words, I think, describe abstract things to indicate a trend. For example, "这条曲线在这里上升"="this curve goes up here" "增加" and "减少" mean "increase" or "decrease".These two words, in most circumstances,describe a change in number such as "我的工资增加了" =“my salary increases this year”. Actually for me, a native chinese guy, can not tell the difference between them accurately because Chinese is not a language so accurate as English, which means, a single chinese word may have different meanings in different situations and most similar words are interchangeable if slight bias in meaning is acceptable. It is really a tough question and I think you should not remember much rules but just read more and get used to some common use.Here are more examples: 中国的人口正在增加: the population of China is increasing. 海平面在过去的几年里一直在上升：the sea level has been rising in the past few years 股票价格一直在上升：the stock price is increasing; yeah, a tough one because it contradicts with my explanation above. So, let off the rules and just feel the language~ actually in chinese we always use"上涨"to describe increase in price. I think those is enough~

上升和下降 一般用于可以用线性图表达的数据，如股票， 增加和减少 一般用于可以用柱状图表达的数据，如年龄，人口等

Good question！上升是向上的感觉，形容气体，液体都是往上面来的感觉，比如，我感觉水往上升，可以形容抽象事物，但经常表现数据，比如，我们中国的GDP直线上升，增加意思是面积上的扩大，量的扩大，就是比以前更多了，比如以前你有3万块钱，现在你有5万块，就是在增加