April L. James

A reference data set of hillslope rainfall-runoff response, Panola Mountain Research Watershed, United States

Although many hillslope hydrologic investigations have been conducted in different climate, topographic, and geologic settings, subsurface stormflow remains a poorly characterized runoff process. Few, if any, of the existing data sets from these hillslope investigations are available for use by the scientific community for model development and validation or conceptualization of subsurface stormflow. We present a high-resolution spatial and temporal rainfall-runoff data set generated from the Panola Mountain Research Watershed trenched experimental hillslope. The data set includes surface and subsurface (bedrock surface) topographic information and time series of lateral subsurface flow at the trench, rainfall, and subsurface moisture content (distributed soil moisture content and groundwater levels) from January to June 2002.

Practicing the science of sustainability: the challenges of transdisciplinarity in a developing world context

Questions related to how we practice sustainability science remain salient in the face of the failure to achieve broad-scale sustainability objectives. Transdisciplinarity is an essential part of sustainability science. Transdisciplinary conceptual scholarship has been more prevalent than empirical scholarship or applications, especially in developing world contexts. In a single case study of a multiyear project addressing water security issues in HaMakuya, South Africa, we used a framework for assessing transdisciplinary objectives to facilitate more systematic learning for those who practice sustainability science. We found that defining the problem and assembling our team were easier than the co-creation of solution-oriented knowledge and the reintegration and application of this new knowledge. Our singular case study speaks to the potential challenges related to building relationships and co-creating knowledge in an epistemologically diverse setting. Other case studies appear to have negotiated these issues in developing country contexts, and this leaves room further investigation for how to practice transdisciplinarity under these conditions.

Moving SWAT model calibration and uncertainty analysis to an enterprise Hadoop-based cloud

With enhanced availability of high spatial resolution data, hydrologic models such as the Soil and Water Assessment Tool (SWAT) are increasingly used to investigate effects of management activities and climate change on water availability and quality. The advantages come at a price of greater computational demand and run time. This becomes challenging to model calibration and uncertainty analysis as these routines involve a large number of model runs. For efficient modelling, a cloud-based Calibration and Uncertainty analysis Tool for SWAT (CUT-SWAT) was implemented using Hadoop, an open source cloud platform, and the Generalized Likelihood Uncertainty Estimation method. Test results on an enterprise cloud showed that CUT-SWAT can significantly speedup the calibration and uncertainty analysis processes with a speedup of 21.7-26.6 depending on model complexity and provides a flexible and fault-tolerant model execution environment (it can gracefully and automatically handle partial failure), thus would be an ideal method to solve computational demand problems in hydrological modelling. CUT-SWAT is the first Hadoop-based calibration tool for SWAT.CUT-SWAT significantly reduced the calibration and uncertainty analysis time.CUT-SWAT is easy to scale up by adding more computers.CUT-SWAT provides a fault-tolerant model execution environment.

Hydrologic Impacts of Municipal Wastewater Irrigation to a Temperate Forest Watershed.

Land application of municipal wastewater to managed forests is an important treatment and water reuse technology used globally, but the hydrological processes of these systems are not well characterized for temperate areas with annual rainfall of 1200 mm or greater. This study evaluated the impact of municipal wastewater irrigation to the local water balance at a 3000-ha land application facility where secondary-treated wastewater is land applied to a mixed hardwood-pine forest over 900 ha. Stable isotopes of hydrogen (H) and oxygen (O), chloride concentrations, and specific conductance were used in combination with hydrometric measurements to estimate the wastewater composition in groundwater, surface water, and at the watershed outlet during dry and wet seasonal periods and during one large rainfall event. Wastewater and water bodies receiving irrigation were found to have significantly higher δH, δO, specific conductance, and chloride concentrations. Using these tracers, a two-component, three-end member geochemical mixing model estimated mean wastewater compositions in the surficial aquifer receiving irrigation from 47 to 73%. Surface water onsite was found to reflect the high wastewater composition in groundwater. Land-applied wastewater contributed an estimated 24% of total streamflow, with the highest wastewater compositions in surface water observed during major storm events and at low-flow conditions. Groundwater and surface water within the watershed were found to have proportionally higher wastewater compositions than expected based on the proportion of irrigation to rainfall received by these areas.

FLOW CHARACTERIZATION IN THE SANTEE CAVE SYSTEM IN THE CHAPEL BRANCH CREEK WATERSHED, UPPER COASTAL PLAIN OF SOUTH CAROLINA, USA

Karst watersheds possess both diffuse and conduit flow and varying degrees of connectivity between surface and groundwater over spatial scales that result in complex hydrology and contaminant transport processes. The flow regime and surface- groundwater connection must be properly identified and characterized to improve management in karst watersheds with impaired water bodies, such as the Chapel Branch Creek (CBC), South Carolina watershed, which has a long-term sampling station presently listed on an EPA 303(d) list for phosphorous, pH, and nitrogen. Water from the carbonate limestone aquifer of the Santee Cave system and spring seeps in the CBC watershed were monitored to characterize dominant flow type and surface-groundwater connection by measuring dissolved calcium and magnesium, total suspended solids, volatile suspended solids, alkalinity, pH, specific conductance, and stable isotopes (d 18 O, d 2 H). These measurements indicated that the conduit flow to Santee Cave spring was recharged predominantly from diffuse flow, with a slow response of surface water infiltration to the conduit. Qualitative dye traces and stage elevation at Santee Cave spring and the adjacent Lake Marion (equal to the elevation of the flooded portion of CBC) also indicated a relation between fluctuating base level of the CBC reservoir-like embayment and elevation of the Santee Limestone karst aquifer at the spring. Methods described herein to characterize the flow type and surface-groundwater connection in the Santee Cave system can be applied not only to watershed management in the Chapel Branch Creek watershed, but also to the greater region where this carbonate limestone aquifer exists.

Organizational Structures and Data Use in Volunteer Monitoring Organizations (VMOs)

Complex environmental problems call for unique solutions to monitoring efforts alongside developing a more environmentally literate citizenry. Community-based monitoring (CBM) through the use of volunteer monitoring organizations helps to provide a part of the solution, particularly when CBM groups work with research scientists or government managers. This study of volunteer monitoring organizations (VMOs) active in 2009 in the United States was conducted via survey in order to better understand the organizational structure, data collection procedures and data use of water-quality monitoring by volunteers, focusing on North Carolina. Organizational structures and origins of monitoring groups are discussed and reveal a wide variety of types and history of programs. Data collection procedures including required training and quality assurance were explored and discussed through the survey. Many groups require training of a varied type, but fewer complete quality assurance plans. Multiple types of volunteer monitoring data uses were indicated, including management and research. This study suggests a lack of structure at the state level may hinder the usefulness of data collected for purposes other than local information and environmental education. Cooperation between research scientists and VMOs may aid organizations in publishing more of their data and developing a quality assurance plan.

Visual analytics of high-frequency lake monitoring data

In recognizing the cumulative effects of multiple stressors on altering aquatic ecosystem function, scientists have become increasingly interested in capturing high-frequency response variables using a variety of sensors. This practice has led to a demand for novel ways to visualize and analyze the wealth of data in order to meet policy and management goals. Time series data collected as part of these monitoring activities are not easily analyzed with traditional methods. In this paper, a visual analytics system is described that leverages humans’ innate capability for pattern recognition and feature detection. High-frequency monitoring of weather and water conditions in Lake Nipissing, a large, shallow, inland lake in northeastern Ontario, Canada, is used as a case study. These visualizations are presented as Web-based tools to facilitate community-based participatory research among scientists, government agencies, and community stakeholders. These analytics techniques contribute to collaborative research endeavors and to the understanding of the response of lake conditions to environmental change.

Comparison of five snow water equivalent estimation methods across categories

Dorset Environmental Science Centre, Ontario Ministry of Environment and Climate Change, 1026 Bellwood Acres Rd., Dorset P0A 1E0 Ontario, Canada Department of Geography, Nipissing University, 100 College Drive, Box 5002, North Bay P1B 8L7 Ontario, Canada Surface Water Monitoring Centre, Ontario Ministry of Natural Resources and Forestry, 300 Water Street, Peterborough K9J 8M5 Ontario, Canada Correspondence Huaxia Yao, Dorset Environmental Science Centre, Ontario Ministry of Environment and Climate Change, 1026 Bellwood Acres Rd., Dorset P0A 1E0, Ontario, Canada. Email: huaxia.yao@ontario.ca

Visual analytics and remote sensing imagery to support community-based research for precision agriculture in emerging areas

Abstract Agriculture in northern Ontario, Canada, has not yet reached the level of development of the southern regions of the province. In spite of the increasing desirability of the former region for agricultural expansion, northern agricultural producers – as well as other producers in “emerging” areas – have less access to information and decision support services relative to more established agricultural regions. At the same time, geographic information systems (GIS) are now being integrated into precision agriculture to assess field variability, to ensure optimal use of information, to maximize output, and to increase efficiency. To address this trend, a community-based research initiative based on an interactive web-based information visualization and GIS decision support system has been deployed with the aim of providing northern Ontario producers with access to the data they need to make the best possible decisions concerning their crops. This system employs citizen science and community-based participatory research to build a mutually beneficial partnership between agricultural producers, researchers, and other community stakeholders.