It is my own case. It is describing the drop of 2 oz Pocket Water Purifiers in Non Stop flights during the 72 Hours of a water hazard.
Assumption for the exercise is water trcuking is disabled during the flood and airport are congested. You can imagine the drops of water purifiers in a non stop flights (mainly micolights, UAVs, small aircrafts, balloons...) like a banquet to cater a community of 20, 000 people or more (if it is 20,000 people to rescue during the aftermath, like banquet, I have assess that number of water purifiers would be let us say 20000 + 25% of the initial drops. A total of 25,000 (2 Oz Pocket water Purifiers would be drop over the flood prone area as an alternative answer to airport congestion, road blocks due to flood and secondary community water supply sources contaminated. So, the strategy would be to deliver the 2 oz Pocket water purifiers from the sky, for instance by using unmanned aircrfats (UAVs)

List of Partners:
The HelpDesk partners include but are not limited to the following: Asian Disaster Preparedness Centre | AGRHYMET | Australian Bureau of Meteorology | Cap-Net/UNDP | Czech Hydrometeorological Institute | EUROAQUAE | Deltares | Global Water Partnership | Hamburg University of Technology | International Association of Hydraulic Research | International Association of Hydrological Sciences | Japan Ministry of Land, Infrastructure Transport and Tourism | Korean Institute of Construction Technology | Nile Basin Capacity Building Network | PROHIMET | RAMSAR | Regional Centre on Urban Water Management | The International Centre for Water Hazard and Risk Management | Stockholm International Water Institute | Swiss Federal Office for the Environment | UN/ISDR | UNESCO-IHE | University of Dundee | University of Idaho | University of Nice Sophia Antipolis | UNOSAT

Truly, it would work if the flood risk is only the rise of water, which relevant and not all these multihazards i.e. including loss of lives, livelyhood and properties. As suggested by past water hazards and authors, there is a huge component of flood risk influenced by water poisoning, households looting, water trucking disabled and so on.
How do the hydrograph helps? Well it is helping to predict the flood arrival times, which accompany the river peaks of discharges.
Lots of studies of previous contexts of flood showed that urbanism and the impervious surfaces were the main driver of flood (as well as excessive tree cuts/clearing). For instance, East of USA used to be a wheat field area and the peak of water discharge during rain cycle was smooth (with little amplitude). After, urbanism there is a huge increase of floods and peaks of water discharges are sharp. So, the only way to cut these peaks were to use water reservoirs. The purpose of the hydrograph was similar of dam discharges, when used in Phillipines to prevent uncontrolled dam discharges -analogous to river discharges- Hydrograph wouldhelp to predict the water elevation in the river and not associate multihazards.

My view point the Technical distinction is easy. Don't mix them. It is not sytematic. For instance, there are several authors that wrote on the subject. The WMO/GWP and IFR helpDesk as a concept to describe it. However concept is just 90% of the build up for a project. I let you consult the definiton given in the flood Program booklet (hard copy or downloaded one). As I felt it is much more about flood due to the river congestion caused by the sediments carried by the flood flows that leave the river stream to abandon the river channels and go to the flood plains (if there is one).Another, side of the flood definition are given by best authors. I found the wetting front of Joseph Holden (geographer) very relevant to explain the limit of the water penetration in the flood plains (and how drainage could occur) and also, the nature and structure of the soil is influencing the water penetration (for more details about it there is a literature from J. A. Allan. (Hydrologist). The hydrograph records river discharge peaks for dam release and/or to prevent river flooding. But floods occur with the impervious surfaces due to urbanism and excess of trees clearing. Of course the environmental dimension is added with global warming and gives more sceneries and drama to the flood pictures. For a good drain control or implementing an hydrograph network, I think one needs to take into consideration the dual aspects of water hazards. And also, the water may also be contaminated with various hazards. As WMO and WHO said most disasters follow the aftermath of the flood with the water (or food) poisoning and most hazards have a flood components.

The tool is good. As I felt, it was addressing the real issue of climate change and flooding. However, my concern is to know numbers of organizations, which are willing to use them. I suppose, lots of them, hopefully.

Another concern is: "how do you frame them and it is a relevant, if as I read newspapers various risks: mistakes were done in the duration time for the melting of Polar snow ice sheet and long time delay for temperature increases, also, the UN did not sign the approval document at COP15, noneless the UNGFCCC nearly consensus was setting in people minds that changes were irreversible".

In additon, it does not change so much, lobbying groups are producing they own outputs and influencing political decisions. What the world need is more incentives, communication and anticipation. It is good to know that platform like SIWI/WMO flood division are not useless, striving and participating in these changes by better understanding links between climate change and floods. Also, technically societies should be ready to answer to when, where, how...these thing could happen and prevent them.

The tool help to understand forces or globalization and climate change, understand may not be enough but transforming with tools, actions, mitigations and adaptation strategies in the uniqueness of the world.