I looked into this and found Sublimation from a seasonal snowpack at a continental, mid-latitude apline site by Eran Hood, Mark Williams, and Don Cline go into great detail on this subject.
Martinelli (1960) reports that sublimation is
responsible for only 1-2% of summer snowpack ablation in snowfields between 3500-3800 m in the Rocky
(West and ...
Physicalgeography.net and the Colorado State basic hydraulic page have a good explanation of Horton's Laws.
The first thing that needs to be done in analysing a drainage basin is to classify the stream segments in a basin according to Strahler's method. For each stream order tabulate:
the number of segments
the average length of the segments
the average ...
The rational method is especially usefull for small areas. For larger catchments it is less accurate. Then you should use a rainfall-runoff model but that is only possible when you have sufficient data. A more simple method is the use of runoff coefficients. Maybe something like the SCS method.
Spreadsheets work well for this.
You have 12×12 observations so use 144+1 = 145 as the number of observations for calculating your probabilities.
Put your discharge data in a column and sort from highest to lowest. Put a column of Rankings next to it and number from 1 up to your maximum (1 to 144). Put a column next to that and calculate your probability ...
This is a broad question, the best way to compare the models is to go through the manuals and compare the process algorithms to see how the various hydrologic processes are handled. There are other considerations as well, including:
what environment/watershed are you modelling? How large, how urbanized, what type of soils/environment/precipitation vs ...
I'll preface by saying I have no hands-on experience with either model; however, HSPF has always seemed cumbersome whereas SWAT seems more user friendly. Again, just my read of the software without any practical experience. But, until that person comes along to answer you're question, here's my two cents:
The best way to answer this questions is to sit down ...
A typical ratio calculated to quantify this type of response, especially at larger scales (such as for land use changes) is the runoff ratio:
$$R = Q/ P$$
where $R$ is the runoff ratio [mm/mm or dimensionless], $Q$ is the annual flow volume [mm], and $P$ is the annual precipitation [mm]. The runoff ratio is usually calculated for a given data period (...