This methodology is developed to assess the Mini/Pico HydroPower potential in a certain area

Initial Steps (Prepare the layer with WGS_1984 and then projected prior to RivEX)

- Create a new layer and define units in meters (from properties)
- Start with the 90m DEM for the area of interest downloaded from http://srtm.csi.cgiar.org/SELECTION/inputCoord.asp
- Merge the DEM tile rasters into one using mosaic (data management) tool
- Insert the administrative boundaries (to extract the area of interest in a later stage)
- Insert inland waters (lakes + reservoirs) 
- Erase the inland water from the administrative boundaries layer (maybe a join/union is necessary prior to that step)
- You should have an area of just land
- Insert the 15s river network from HYDROSHEDS
- Clip the rivers with the layer of just land
- Project the necessary layers. They should be saved in the gdb where rivex will work. Here is the default.gdb

RivEX

- Insert the river layer in RivEX
- As a workspace please insert C:...Documents/ArcGIS
- Follow the established process (not all of them are necessary but it is good to exist because once rivex is closed you have to run the process again..)
	+ Update nodes ID
	+ Create source/mouth nodes
	+ Run Strahler
	+ Run Shreve
	+ Run Upstream lenght
	+ Catchment ID (to node ID)
	+ Downstream lenght
	+ Link type
	+ Identify main channel

	+ Extract Network connectivity (first U/S and D/S and then the upstream segments)

	+ Run regular Sampling/Space points with X km distance 
(in order to method to be able to run, Xkm should be regulated. If 5km is set RivEX cannot proccess areas that are more than 300,000 km^2)
(For areas that are from 300,000 km^2 to 600,000 km^2 used sampling distance 10 km etc etc).

	+ Run transfer network metrics to site (using as site the sampling points)
	+ Find source for site (using as site the sampling points)
	+++ Link sites within a layer (nearest upstream site) (using as site the sampling points)

Optional
	+ Run link samples within Layer (nearest upstream). That will create links between all the sites that have an upstream site providing coordinates. 
	+ Find all sites upstream of a site (creates all the catchment areas)
 	+ Extract network connectivity
 	+ Finds all sites upstream af a site (gives all the nodes attaches to theis respective lines)

Find elevation in sources

 - Extract elevation values to sources (ElevationToSources)
 - Related SourceID (at ElevationToSources layer) with Fnode (from Af_15_line) -> will assign the source nodes to polylines
 - Copy these values in excel and keep only the wanted data. Save as csv and insert in ArcGIS. Export data to make it a shapefile with FID.
 - Join the sources new layer with the elevation extracted layer connected To_Node with sample ID. You can calculate the head for the points that are attached to the sources

Hydrology tools

- Clip the existing DEM with the layer showing only land cover (from initial steps)
- Use Fill to complete the voids 
- Calculate Flow Direction
- Calculate Accumulation
 (Optional) - Use Conditional (cell accumulation value>1000 or 8.6 km2 in the equator)
 (Optional) - Use Stream Link tool using the Conditional raster an an input (get a raster with links and junctions)
 (Optional) - Use Stream Order tool to aqcuire the Strahler river order
 (Optional) - Use Raster to polyline to create a shapefile

Discharge estimation

 - Multiple flow accumulation raster with cell size (here it will be 8558.984054). Outcome in m^2 
 - Use raster calculator to bring the resampled Runoff raster from mm/year to m/sec (here divide with 31556926000)
 - Do the raster calculation in order to obtain the discharge raster in m^3/sec

Elevation to sample points

 - Extract elevation to sample points twice
 - Join the linkage layer two times with the elevation extraction layers. The first time select join From_Node with Sample _ID and the second time To_Node with Sample_ID
 - Create the new field and calculate the potential head by substracting the elevation value from to_node to From_Node
 - Select and Copy all the values in an excell sheet. Here you can keep only the From_node info and the potenial head on them.
 
Power potential estimation

- Connect the discharge layer to that. Get the potential power in these points.
- Calculate the hydropower potential with the hydropower equation P= *g*Q*H*ht*Hg (Here as Q use the 60% of the estimated discharge as 40% is environmental flow)
- Keep the values of P between 100kW and 1000kW
- These points provide the theoritical potential of Mini Hydropower plants in the interested area

Restrictions

- Distance below 1 km from National parks and protected areas
- Distance below 1 km from agricultural facilities
- Distance below 200 m from residential disctricts

End

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Second method applied to Rwanda (optional)

- Find the potential sites (points) acquired from RivEX
- Use Snap pour points tool with these points as feature class input and the accumulation raster
- Use Watershed tool with the Snap pour point raster and flow direction raster as input
- Convert the watersheds into polygons and calculate geometry
- Use the global Runoff Raster and resample it to 0.000833 resolution
- Use zanal statistics to get the raster values assigned to polygons
- Calculate potential discharge using runoff value and area (geometry)
- Overlay (spatial Join) the polygons with the points and assing the potential discharge to the points

- For all the potential sites use zonal statistics with the (resampled) Runoff to find the mean discharge
- For all the potential sites use zonal statistics with elevation to find min-max
- For the sites that they have not upstream site use as head the mean elevation minus min elevation in the polygon
- For the sites that have upstream site use the head calculated (by the elevation difference) and as Q the sum of the discharge

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Notes

srtm_43_13_ProjectRaster
Fill_srtm_431
Extract_Fill2
FlowDir_Extr3
FlowAcc_Flo11
Con_FlowAcc18
SnapPou_Ugan1
Watersh_Flo24
RasterT_Waters14
Uganda_Project
Uganda_Erase_Project
LakesAndReservoirs_Project
af_riv_15s_Clip11_Project
Extract_tif12_Resample_Proje
