dates=[1990 4 27 0 0 0
1990 7 24 0 0 0
1990 10 16 0 0 0
1991 2 4 0 0 0
1991 3 20 0 0 0
1991 4 29 0 0 0
1991 6 18 0 0 0];

[rivers,jd]=getrivers(dates(1,:)-[0 0 1 0 0 0],dates(7,:)+[0 0 1 0 0 0]);
riv=sum(rivers');
riv=riv(:);

ti=zeros(1,7);
for ii=1:7,
ti(ii)=tind(jd,dates(ii,:));
end
vol=cumsum(riv)*3600*24;
diff(vol(ti))
