ASABE Soil Erosion Research Symposium

Upper Watershed Coffee Region

1 - Upland Guanica Bay Watershed Erosion / Run-off Control in the Coffee Growing Regions.

2 - Converting sun coffee to shaded coffee plantations.

3 - The U.S. Fish and Wildlife Service (USFWS) Caribbean field office partnered with the NRCS in providing technical assistance to promote agro- forestry practices.

Over 28 upland farms participated.

Action 1 - Tree Planting for Coffee Shade

Monitoring and Results: Coffee Shade Canopy Development.

Photos courtesy of USFWS and Envirosurvey Inc.

The Río Loco Watershed Project (RLWP) began in 2009 as a multiagency effort to support the US Coral Reef Task Force (USCRTF) Local Action Strategies (LAS) as identified in the Guánica Bay Watershed Management Plan. NRCS work seeks to address LAS at Río Loco related to land based sources of pollution by reducing loss of coral reef cover through the promotion and application of integrated watershed and land use management practices on agricultural lands.

Guánica-Rio Loco Watershed - Implemented Conservation Practices

Lower Watershed Coastal Plains Farmlands.

•Project directly impacted 11 farms at Guánica and 8 in Lajas.

•Private and Public land owned and rented to private farmers and ranchers.

•Farmers are losing land and excess nutrient rich sediment and topsoil is being exported to the Guánica Bay.

•Reservoirs, sedimentation retention and clean water transport.

•Reduced in-stream channel erosion and runoff.

Road cut slope erosion in an actively-cultivated tropical montane setting.

 Plot-, farm-, and watershed-scale effects of coffee cultivation in runoff and sediment production in western Puerto Rico. 

 Sediment Mobilization by Hurricane-Driven Shallow Landsliding in a Wet Subtropical Watershed 

A. Hurricane Maria Precipitation Signature in Puerto Rico:

On the 20th of September 2017, Hurricane María dropped the highest island wide amount of daily precipitation ever recorded in Puerto Rico (records from 1898 onwards) with totals reaching up to 733 mm in 24 hours. Some of the highest rain totals were reported on the East-Central portions of the island, but also included portions of its western regions some of which were contained within the Río Grande de Añasco watershed [Images from Ramos-Scharrón and Arima, 2019].

 Map of slope-failure locations in Puerto Rico after Hurricane María 

 Hurricane Maria Landslide Density 

Hurricane María triggered over 70,000 landslides throughout the island. Landslide hotspots included central and western portions of the island, including portions of the Río Grande de Añasco watershed. Landslides were mapped from high resolution aerial photography as a collaborative project between the Department of Geology at UPR-Mayaguez and the US Geological Survey. 

Landslides triggered by Hurricane María, many of which developed into debris flow, resulted in loss of life and induced significant damage to both private property and infrastructure. [Left top photo by the USGS; all others by S Hughes in Naguabjo (top right), Naranjito (bottom left), and Barranquitas (bottom right)].

C1. Rio Grande de Añasco Sediment Plume

A significant portion of the sediment transported by the Río Grande de Añasco was thought to be generated by surface erosion occurring within farms in the headwater portions of the watershed. A 2014 study funded by UPR-Sea Grant and conducted as a collaborative effort between the Geological and Environmental Remote Sensing Laboratory of UPR-Mayaguez and UT-Austin, confirmed this by suggesting that surfaces devoid of vegetation for the purposes of agriculture, rock quarrying, and construction are responsible for the vast majority of the watershed’s sediment yield. The role of landslides and streambank erosion in producing sediments within this watershed is still unknown but thought to be significant.

Through a combination of remote sensing analyses and in-situ water quality observations, researchers from the GERS-UPR-Mayaguez and UT-Austin were able to establish that the Río Grande de Añasco exerts a major control in the concentration of suspended sediments in the Añasco and Mayaguez Bay during low and moderate streamflow conditions, but that during high streamflow conditions the river’s influence on water quality, and thus marine environments like corals, reaches the coastline of Rincón about 10 km to the north of the river outlet. [Photos by GERS-Lab; maps by Ramos-Scharrón et al. (2014)].

C2. Rio Grande de Añasco Sediment Plume landslide effects.

Río Grande de Añasco was one of the island-wide landslide hotspots with over 12,400 slope failures (top left maps). When delivered to the stream network (top right photo), sediments produced by landslides have deleterious effects on the island’s water resources. Sediments released by landsliding are believed to represent a key source of the sediment that accumulates in the Río Grande de Añasco’s various water reservoirs such as the Lago Yahuecas, which has been fully filled-in since the early 2000s (bottom left and right images). [Top left map prepared by S Hughes. Bottom left map prepared by C Ramos-Scharrón with data from Hughes et al. (2019).

d. SLIDES-PR is a multi-phase project launched by the Department of Geology UPR-Mayaguez one month after the passing of Hurricane María in 2017. The endeavor benefits from collaborative efforts with the USGS Landslide Hazards Group, USDA-NRCS, UC-Boulder Natural Hazards Center, and the Puerto Rico Junta de Planificación. Some significant products of this project include a Hurricane María landslide inventory of over 70,000 mass wasting sites, a new high-resolution landslide susceptibility map for the island, and a modern landslide guide for residents of Puerto Rico. These products have been used by FEMA to estimate Hurricane María’s landslide-related damages (>$280 million) and by the PR Departamento de Vivienda (Department of Housing) to prepare the $8.2 billion Puerto Rico Mitigation Action Plan (CDBG-MIT) The SLIDES-PR project also trains undergraduate and graduate students at UPR-Mayaguez on issues related to natural hazards. Ongoing efforts of the project include a collaborative investigation with the Caribbean Area NRCS soil survey office, collaborative NSF-funded research with Purdue University, bathymetric surveys, and the installation of a new real-time network of hydrological soil monitoring stations across the island.

Hurricane María landslide maps were used as the basis for the development of an updated landslide susceptibility map for the entire island and a landslide prevention guide for local residents.

Following Hurricane Maria, the University of Puerto Rico – Mayaguez (UPRM) and the City University of New York (CUNY) conducted a flood modeling study. The purpose of the study was to develop a numerical model using the GSSHA model to simulate flooding from extreme weather events, using Hurricane Maria as a case study. The model was calibrated using data from Hurricane Irma and validated with a similar storm in 2007. Storm surge was also included in the model but had a minimal effect on flood depths. The model was used to evaluate the impacts of flooding on critical infrastructure, such as water, electricity, and public schools, in the study area. The study found that the flood's recurrence interval was approximately 200 years, and the flood more severely impacted the water infrastructure than the electrical infrastructure. In the future, researchers aim to use machine learning and neural network techniques to improve the accuracy of rainfall estimates, allowing for rainfall prediction within a 48–72-hour timeframe. The method will allow for better forecasting of the depth and extent of flooding and its potential impact on critical infrastructure.

The GSSHA is a process-based model, developed by the U.S. Army Engineer Research and Development Center (ERDC) Coastal and Hydraulics Laboratory (CHL), and is a multidimensional model that couples overland, surface, and subsurface flow. GSSHA simulates two-dimensional (2D) overland and groundwater flow, one dimension (1D) streamflow, and soil moisture. A feature of GSSHA is the inclusion of spatial and temporal precipitation, allowing the use of NEXRAD precipitation products. It should be mentioned that GSSHA is approved by the Federal Emergency Management Agency (FEMA) for hydrologic modelling [ 66 ]. Some of the hydrological processes and approximations simulated in GSSHA are precipitation distribution, snowfall accumulation and melting, precipitation interception, overland water retention, infiltration, overland flow routing, evapotranspiration, soil moisture in the vadose zone, lateral groundwater flow, stream/ground water interaction, and exfiltration [ 67 ].

Comparison between maximum flooding depth in sub-watershed 1 using the observed USGS data vs. maximum flooding by simulating runoff in the sub-watershed 2 (upstream). Slide images left and right to compare.

A. Presentation of coastal erosion research, education efforts and community engagement.

Ruperto Chaparro-Sea Grant Director, and Dr. Rene Esteves, Marine Extension Director/Research Coordinator, Sea Grant Puerto Rico.

In line with the National Sea Grant College Program’s focus areas, Puerto Rico program has identified the following priority needs as the most important ones for our region:

• Inventory and population studies of important coastal species and biological resources (e.g., fish, coral reef, seagrasses, mangroves, microbes)
• Studies that promote habitat restoration and reforestation (e.g., salt ponds, coral reefs, mangroves, wetlands, hydrographic basins)
• Impacts of climate change (e.g., sea level rise, flooding, increases in rainfall, storms and hurricanes, seawater temperature, erosion, species migration) on coastal areas
• Habitat connectivity and utilization (e.g., adjacent ecosystems, land-use planning)
• Development of environmental indicators and environmental/biological standards for public health (e.g., water quality, nutrients, sediments)
• Establishing the resilience capacity or limit of adaptive change of local communities frequently visited by tourists and resource users and their ability to adapt to climate change
• Assessment of the socio-economic impact of commercially and recreationally important marine organisms on local communities.
• Studies on the impacts of invasive/exotic species and pathogens (e.g., natural stressors, lionfish, microbes)
• Establishing baselines of commercial and recreational marine organisms (e.g., fish, conch) to obtain reliable estimates of size and catch trends
• Habitat mapping and identification of critical areas (e.g., spawning aggregation sites, coral reefs)
• Physical models that link watershed and coastal processes in order to address and test a wide variety of issues (climate change, habitat migration, management of ecosystems, hazards, and anthropogenic influences).

Historical data and photos from 1930 clearly demonstrate the changes along the coast. Erosion issues on the coast have always occurred due to natural processes. However, impacts have been aggravated by excessive legal and illegal development on the coast, and the recurrence of extreme weather events occurring as an effect of climate change.

The Department of Civil Engineering and Surveying was established dreaming on investing in education to support the social and economic development of Puerto Rico.  During this time, extraordinary accomplishments have been the outcome of all the efforts this Institution has returned to our society.  We proudly have developed for over a century with areas of expertise in Structures, Construction, Transportation, Geotechnical, Environmental and Water Resources and Surveying and Topography. We also focus on applying best practices to provide sustainable, resilient and safe civil built and natural infrastructure to our community. You are welcome to visit our department web page ( https://www.uprm.edu/inci/  ).

At present time, we offer six academic programs:  two undergraduate programs (BS in Civil Engineering (1913) and BS in Surveying and Topography(1978)), and four graduate programs (three masters programs with thesis, project or course options, and a Ph.D.).  The graduate programs focus on options in Environmental, Structures, Transportation, Geotechnical, and Construction. The Civil Engineering and the Surveying and Topography Programs are accredited by ABET. Our graduate program persistently attracts graduate students from Puerto Rico and abroad.  The master’s program was created in 1966.  The Ph.D. program began in 1993.

Overall, our Department has grown to:  educate our students, develop the research needed to create new knowledge, provide the necessary technology to lead the sustainable and effective urban development, provide the sensitivity to protect and restore the environment, and educate the most capable labor force to lead the socio-economic development in Puerto Rico and elsewhere. Our faculty, administrative personnel, students, and partners are committed to excellence by facing the new challenges of the profession and forming the most competitive professionals, citizens, and human beings to serve our people and resolve civil engineering and surveying problems.

The UPRM Coastal Resilience Center (CRC) sponsored by the Department of Homeland Security (DHS)  conducts research and education to help the community by transferring state of practice knowledge to stakeholders (students, faculty, professionals, first responders, and workforce) through formal (curriculum, internships, student projects, undergraduate research) and professional (workshops, seminars, lectures, short courses, webinars) learning experiences ( https://www.uprm.edu/inci/crc-2-mod/  ). It will serve as a vehicle to engage the community as a whole to understand and learn its members’ roles and responsibilities in providing resilient infrastructure. The project helps the community understand better various stages in coastal infrastructure hazard prevention, preparedness, mitigation, response, recovery, and adapt. It  focuses on understanding the natural phenomenology, the engineering methodologies to address the level of risk the infrastructure is exposed to, the engineering methodologies and technology to analyze and predict the level of resistance and vulnerability the infrastructure and community is exposed to, the sustainable and resilient alternatives available at the state of the practice or state of the art to cope with risks and vulnerabilities. The project motivates students and faculty to students and  professionals into homeland security careers and practice.