1.
Understanding land use influence to coastal
ecosystems in the Rio Grande de Manati Watershed
MÓNICAA. FLORES HERNÁNDEZ & ROSA SÁEZ URIBE
University of Puerto Rico, Río Piedras Campus
Department of Environmental Sciences
http://www.fideicomiso.org/slideshow-esp.html

2.
Research Problem
 The economic shift and the population growth have provoke significant
changes in watersheds that have altered its water and sediment
dynamics (Crk, Uriarte, Corsi, & Flynn, 2009; Hosonuma et al., 2012; Macedo et
al., 2012).
 Sediment discharge being one of the modified parameters.
 An increase in sediment inputs could result in degradation of coastal
ecosystem (Fabricius, 2005).
 Decreasing sunlight and oxygen availability.
 Total burial of an ecosystem.
 Understanding sediment dynamics in a
watershed is important to attend the
problem at its source and to implement
more integrated management practices.
Milliman and Farnsworth (2013)

3.
Goals and Objectives
Main Goal:
 Study sediment dynamics along the Río Grande de Manatí
watershed to infer how the land use is influencing riverine inputs to
coastal ecosystems.
Objectives:
 Relate the land use in the watershed to the sediment inputs in the river .
 Analyze river contribution to the coastal zone trough suspended sediment.
 Establish a relationship between suspended sediment concentration,
turbidity and sunlight attenuation in the coast.
 Outreach for students of public schools through workshops.

4.
Methodology
Land use:
 A land use map will be constructed using remote sensing techniques
focusing primarily on sources of sediment production and transport
(bare lands, roads, urban areas) and areas of sediment catchment
(forest, pastures).
 Remote sensing and Soil & Water Assessment Tool (SWAT) modeling
will be used.
 This model will be calibrated with different values of topography,
rainfall, temperature, land use, soil type and other parameters
belonging to the climate and topographic conditions of the Río
Grande de Manatí watershed.

5.
Methodology
Sediment sampling:
 Suspended sediment samples will be obtained in three (3)
sites along the Río Grande de Manatí River:
 Samples will be tested for turbidity, filtered, dried and
weighted in the lab to determine total suspended solids
(TSS).
 Turbidimeters will be left in each site to collect data
continuously for the period of study.
 Data will be downloaded biweekly.

6.
USGS 50038100
USGS 50035000

7.
Outfall influence to the coast:
 Reflectance and radiance measurements of the outfall
influence throughout the period of study will be obtained using
satellites images from NOAA AVHRR and Orbview-2 Sea WiFS.
 In situ measurements coincident with clear-sky satellite overpasses
will be made 6 times during the sample period to correlate with
satellite information.
 This data will be incorporated to SWAT.
Methodology

8.
Activities and Timetable
2016 J F M A M J J A S O N D
Suspended sediment
sampling (river) X X X X X X X X X X
Suspended sediment
sampling (coast) X X X
Sediment sample processing X X X X X X X X X X
Data analysis X X X
SWAT Training X X
Land use map generation
with SWAT X X X X
Annual report X
2017 J F M A M J J A S O N D
Suspended sediment
sampling (river)
X X X X X X X X X X
Suspended sediment
sampling (coast)
X X X
Sediment sample
processing
X X X X X X X X X X
Data analysis X X X
Workshop preparation X X
Workshops at public
schools
X X
Final report X

9.
Potential Benefits
 With this research, we will be able to understand sediment
generation and transport along the watershed.
 Our findings could translate in recommendations for better and
more integrated management practices and strategies to control
sediment inputs to the coastal zone.
 With a better understanding and a better management of the
sediment inputs along the watershed, both coastal and riverine
ecosystems could be properly tended.

10.
Budget Summary
COST ITEM UPR fund pairing
Personnel $6,000
$18,000
Co-PI’s summer stipend
Stipend for two (3) undergraduate
students .
$39,400 in Co-PI’s salary for 2 years
$12,000 in stipend for 2
undergraduate students for 2 years
Travel $300 Workshops in schools 0
Equipment $12,000
$1,100
$2,400
Two turbidimeters (Eureka Water
Probes)
Portables Turbidimeters (Hatch
2100)
Boat rental (6 trips)
$6,000 1 turbidimeter
$4,903 1 Portable flowmeter
Expendable
Supplies and
Equipment
$1,500
$1,690
Transportation to sample sites (46
trips)
Water quality equipment and
educational material for workshops
Indirect costs 48% of Direct Costs, current UPR
rate.