Methods

This page lists an EVOLVING collection of methods to obtain ecohydrological data:

1. Using global datasets that can be used for data-poor regions (admittedly with some degree of error)

2. Scientific/technical methods to measure ecological, biogeochemical and hydrological parameters ( a partial list)

3. Ecohydrological monitoring toolkits for use by schools and citizen science organizations.

4. Making data useable and sharable - standardized collection, formatting, storage and management.

1. ClimateWizard: climate (temperature, precipitation, evapotranspiration) hindcasts (1920 --) and predictions (2100) by 16 widely used General Circulation Models (also known as Global Climate Models of GCMs) downscaled to a 50 km grid resolution for any part of the world. Data is available as maps, bar graphs (anomalies) and line graphs (time series). One can either choose a country and zoom on, or upload a shapefile of a desired area.

Climatewizard is a good data source for obtaining both the regional climate variation (such as greater rainfall in mountain areas in Tanzania) as well as possible projections. Note that while temperature predictions are straightforward, being based on an energy budget of incoming radiation, atmospheric heat storage (greenhouse gases) and land reflectivity. rainfall predictions are far, FAR more complex, with very little agreement being shown between the major models.

2. Worldclim

3. MODIS 16 ET: annual/monthly potential and actual evapotranspiration for much of the world at a 1 km resolution. Data available as geotiff raster image that can be displayed in GIS. Need cropping to required area using GIS, as tiffs are for the whole world and are huge data files ( > 500 Mb). Values divided by 10 for expressing in mm/year or mm/month.

The MODIS 16 site has 8-day, monthly and annual ET datasets, available as GeoTIFFs, that can be opened in GIS and classified and displayed, am attaching a map for the nile basin countries with ET shown in 5 ranges. 

the site has several options for data:

1. ftp://ftp.ntsg.umt.edu/pub/MODIS/NTSG_Products/MOD16/MOD16A3.105_MERRAGMAO/Geotiff/

has geotiffs for the whole world, these are massive files, and need to be cropped. Not the most useful

2. ftp://ftp.ntsg.umt.edu/pub/MODIS/NTSG_Products/MOD16/MOD16A3.105_MERRAGMAO/Y2014/

is far better, as data packets are smaller. each packet is for a certain region of the world, and the world has been divided into tiles in a grid named by horizontal and vertical. See following image., for instance, Jos (Nigeria) may fall in h18v7 or h18v8.  One needs a hdf viewer to see this data, and that can be downloaded free.

4. Land use change (2000 - current year)

   - Forest cover change - https://earthenginepartners.appspot.com/science-2013-global-forest

   - Surface water body area change

5. Landsat data - for land cover classification - http://world.time.com/timelapse/

6. Topographic map - ASTER 30 DEM (Digital Elevation Model) providing a map of the Earth's land surface at a 30 m resolution.

7. Phenology -PhenoCam network: BASED at the University of New Hampshire, this site gets images from phenology cameras spread across ecosystems in many parts of the (developed) world, as well as image processing such as Green Chromatic Coordinate, an index of primary productivity at a site, and how that varies with season. https://phenocam.sr.unh.edu/webcam/gallery/

1. Hydrology - measurement of streamflow ( float method, weir method for smnall streams, mechanical current meter, water level and flow based ratings curve to get discharge from water level, then more expensive methods include Acoustic Doppler velocity). Groundwater wells offer a look into water table dynamics.

2. Stable Isotopes - infer water sources used by plants like rainwater or groundwater, water use efficiency

3. Plant water and nutrient relations - sap flow, stomatal conductance, leaf water potential, water stress, niutrient allocation and translocation, decomposition and productivity. Lysimeters for measuring evapotranspiration across different grassland and wetland plant communities.

4. PIT tags for fish movement - track fish movements amongst different habitats and seasonal hydrology. effect of exotic fish on native communities

5. Water quality

Using Arduino/Seeeduino microprocessor boards and allied sensors, power sources, data storage and transmission circuits available from a variety of vendors such as Seeeduino, Atlas Scientific, Adafriut and Sparkfun, to name a few. These are especially useful in places where budget is a constraint. Furthermore, these open source systems are much easier to repair, because they are modular items, that can be repaired or replaced individually, unlike a professional sensor. However, making and maintaining them does require some degree of knowledge of electronics and programming, unlike professional sensors that are easier to install ( though not always).

Watch a video where Roman Evarist explains the construction of an automated water level logger in use in Tanzania.

If budget is not an issue, robust networks can be created by using a variety of professional sensors ( Campbell Scientific, Odyssey, Stevens, LiCor, HOBOs, etc) , and dataloggers. To transmit data, radio modems and cellular modems can be used. A network of sensors can be setup using Loggernet. Sensors and catalogers are powered by solar panels, battery banks and charge controllers. Systems are usually rugged and require minimal maintenance,; they however are 4-6 times the cost of open source systems. 

1. Hydrological monitoring

2. Biomonitoring of water quality and  stream ecosystems based on aquatic macroinvertebrates

See link below