A couple of points:
The medal is a Military Service General Medal. This award was instituted in 1847, retrospectively covering actions in the Revolutionary and Napoleonic Wars and had to be applied for, in writing, by the proposed recipient. This means the recipient had to still be alive in 1847 (though he was allowed to die before the medal was actually issued, in which case it was still issued but went to his next of kin
). This also means the list of awards is actually a very, very small subset of the personnel who fought the wars. Many of the rank and file still alive in 1847 probably never even heard of it. See:
http://en.wikipedia.org/wiki/Military_General_Service_MedalOne of the best sources I've found for information on the Peninsular Army is Oman "Wellington's Army" (digital copy available online at Internet Archive,
http://www.archive.org/details/wellingtonsarmy100oman ) which has in its appendices a complete listing of the British Army in 1809 with stations plus a year by year tracking of the organisation of Wellington's army through the campaign. Also see p198 for systems of promotion. Napier's history of the war is also on Internet Archive (though he has been criticised for his biased attitudes towards some aspects of the campaign) along with many other histories and memoirs. Most of Oman's definitive history is too recent to be out of copyright and digitised, but has been reprinted recently.
When an army is retreating, rivers and ridges form natural defensive positions, thus during the Allied advance into the south of France in 1814 a number of the battles involved forcing river crossings, hence the names of the battles.
Sue