Question

谁可以帮我分析一下这个英语句子的成分啊 provided that，used for分别修饰的是什么

This indicates that there is indeed a connection between event scaling and quantile scaling provided that peak discharges used for quantile based analysis are selected from nested watersheds on a rainfall-runoff event basis than selecting only one peak discharge event per year per streamflow gauging site.
还有，are selected 前面的主语应该是什么啊
后面的than我觉得可以翻译为而不是....那么这是什么词组用法，还是说前面进行了省略？
谢谢

Answer 1

这是一个长难句，现来分析一下：
This是主语：
indicates是谓语；

that there is indeed a connection between event scaling and quantile scaling
是宾语从句；
provided that在这里是连接词，意思是“假如，如果“，类似于if。
are selected的主语是peak discharges，

used for 是peak discharges的定语。
这里的than可以翻译成 是...而不是...。