insolation duration

基本解释

That is to say, everyday the insolation-duration on slope decreases or it is invariable when the grade of slope increases.
在任意时段（如月、季、年等）内，坡面的可照时间也总是随坡度的增加而减少或保持不变。
According to the formula to calculate the everyday insolation-duration, it is possible that the everyday insolation-duration on slope is equal to zero.
根据坡面日出日没时角配置关系及其变化规律，坡面的可照时间可根据不同的情况用一组具体的计算公式表示。
Due to local terrain factors such as slope, aspect and terrain inter-shielding, the insolation duration over rugged terrain is different from over horizontal surface.
由于坡度、坡向和地形之间相互遮蔽等局地地形因子的影响，实际起伏地形下的日照时间与水平面上的日照时间有一定差异。