Exploring the Relationship Between Hydrologic Parameters and Nutrient Loads Using Digital Elevation Model and GIS – A Case Study from Sugarcreek Headwaters, Ohio, U.S.A.

Ohio is typical among the Midwestern and Eastern United States with high levels of water pollutants, the main sources being from agriculture. In this study, we used a digital elevation model in conjunction with hydrological indices to determine the role of landscape complexity affecting the spatial and temporal variation in pollutant levels, in one of the most impaired headwater streams in Ohio. More than eighty five percent of the study area is dominated by agriculture. Spatial distribution of slope (S), altitude and wetness index along with other watershed parameters such as flow direction, flow accumulation, stream networks, flow stream orders and erosion index were used within a Geographic Information Systems framework to quantify variation in nitrate and phosphate loads to headwater streams. Stream monitoring data for nutrient loads were used to correlate the observed spatial and temporal patterns with hydrological parameters using multiple linear regressions. Results from the wetness index calculated from a digital elevation model suggested a range of 0.10–16.39, with more than 35% having values less than 4.0. A Revised Universal Soil Loss Equation (RUSLE) predicted soil loss in the range of 0.01–4.0 t/ha/yr. Nitrate nitrogen levels in the study area paralleled precipitation patterns over time, with higher nitrate levels corresponding to high precipitation. Atmospheric deposition through precipitation could explain approximately 35% of total nitrate levels observed in streams. Among the different topographic variables and hydrological indices, results from the step-wise multiple regression suggested the following best predictors, (1) elevation range and upstream flow length for nitrate, (2) flow direction and upstream flow length for ammonia-nitrogen and slope, and (3) elevation range for phosphate levels. Differences in the landscape models observed for nitrate, phosphate and ammonia-nitrogen in the surface waters were attributed partly to differences in the chemical activity and source strengths of the different forms of these nutrients through agricultural management practices. The results identify geomorphologic and landscape characteristics that influence pollutant levels in the study area.     

The influence of grassland management on ground beetles (Carabidae, Coleoptera) in Swiss montane meadows

Effects of grassland management type and intensity on carabid species richness, number of individuals and species composition were studied in the Swiss Prealps. Carabids were censused in 2001 and 2002 in 21 mown and 20 grazed meadows by means of pitfall traps.Mean species richness was significantly higher in mown plots than in grazed plots and species composition was significantly different between these two management types. Additionally, different species characteristic for mown and grazed plots were found. These results suggest that mown meadows and grazed meadows represent two habitat types for carabid beetles.Within both habitats, management intensity was quantified by fertilizing intensity, the number of cuts, cattle density and/or grazing intensity. The relationship between management intensity and the number of individuals and species was positive. Higher fertilizing intensity was the most important factor for higher species richness and had a significant influence on species composition in both habitats. Other variables positively related to the number of individuals, were the number of cuts in mown meadows and grazing intensity and altitude in grazed meadows. Additionally to fertilizing intensity, cattle density was positively related to the number of species in grazed meadows. These results illustrate that in the extensive management systems found in the Swiss Alps and Prealps, even intensively managed meadows can sustain high carabid diversity and abundance.     

Integral use of plants and their residues: the case of cocoyam (<Emphasis Type="Italic">Xanthosoma sagittifolium</Emphasis>) conversion through biorefineries at small scale

During last decades, there has been a growing interest of decreasing the environmental impact generated by humans. This situation has been approached from different perspectives being the integral use of raw materials as one of the best alternatives. It was estimated that 3.7?×?10⁹ tonnes of agricultural residues are produced annually worldwide. Then, the integral use of feedstocks has been studied through the biorefinery concept. A biorefinery can be a promissory option for processing feedstocks in rural zones aiming to boost the techno-economic and social growth. However, many plants produced at small scale in rural zones without high industrial use contribute with residues usually not studied as raw materials for other processes. Cocoyam (Xanthosoma sagittifolium) is a plant grown extensively in tropical regions. Nigeria, China, and Ghana are the main producers with 1.3, 1.18, and 0.9 million tonnes/year, respectively. In Colombia, there are no technified crops, but it is used where it is grown mainly as animal feed. This plant consists of leaves, stem, and a tuber but the use is generally limited to the leaves, discarding the other parts. These discarded parts have great potential (lignocellulose and starch). This work proposes different processing schemes using the parts of the plant to obtain value-added products, and their techno-economic and environmental assessment. The simulation was performed with Aspen Plus and the economic package was used for the economic assessment. For the environmental assessment, Waste Algorithm Reduction of the U.S. EPA was implemented. The obtained results showed that the integral use of plants under a biorefinery scheme allows obtaining better techno-economic and environmental performance and that small-scale biorefineries can be a promissory option for boosting rural zones.     

Macrobenthic invertebrates as bioindicators of trace elements in high-mountain lakes

Environmental Science and Pollution Research - Alpine lakes are extreme ecosystems located in remote areas and populated by few but well-adapted species. Because of their remote location, they are...     

Land degradation,economic growth and structural change: evidences from Italy

The present study investigates the relationship between land degradation and the evolution of the productive structure in Italy during the last 50 years (1960–2010). The objectives of the study are twofold: (i) to present and discuss an original analysis of the income–environment relationship in an economic-convergent and environmental–divergent country and (ii) to evaluate the impact of the (changing) productive structure and selected socio-demographic characteristics on the level of land vulnerability. The econometric analysis indicates that the relationship between GDP and land degradation across Italian provinces is completely reverted once we move from a cross-sectional analysis to panel estimates. While economic and environmental disparities between provinces go in the same direction, with richer provinces having lower levels of LD, over time the growth process increases LD with the economic structure acting as a significant variable.     

Toxicity persistence in runoff and soil from experimental soybean plots following insecticide applications

Persistence of toxicity in runoff water and soil was investigated in experimental soybean plots subjected to successive runoff events following pesticide application. Runoff events were produced by irrigation using a sprinkler system. The pesticides applied were cypermethrin and endosulfan, which are widely used in soy production in Argentina. Toxicity tests were performed on two abundant components of the regional fauna, the amphipod Hyalella curvispina and the fish Cnesterodon decemmaculatus. Runoffs from two pesticide applications were assayed at different stages of the growing season: an early application when the soil was almost bare and a late one close to harvest, when the ground was covered by vegetation and just before soy leaves fell. Toxicity to H. curvispina in runoff ceased almost one month after the early application of the two pesticides, while it persisted for over three months after the late application. Soil toxicity to H. curvispina and runoff toxicity to C. decemmaculatus followed the same pattern. Higher temperatures and solar radiation are likely to have enhanced insecticide degradation after the early application. Lower temperatures and solar radiation in combination with increased organic matter from litter probably contributed to the longer persistence of toxicity recorded after the late application, as compared with the early application. Cypermethrin caused no mortality to C. decemmaculatus after the early application, while endosulfan toxicity persisted for almost four months after the late one.     

The New England Air Quality Forecasting Pilot Program: Development of an Evaluation Protocol and Performance Benchmark

Abstract

The National Oceanic and Atmospheric Administration recently sponsored the New England Forecasting Pilot Program to serve as a “test bed” for chemical forecasting by providing all of the elements of a National Air Quality Forecasting System, including the development and implementation of an evaluation protocol. This Pilot Program enlisted three regional-scale air quality models, serving as prototypes, to forecast ozone (O₃) concentrations across the northeastern United States during the summer of 2002. A suite of statistical metrics was identified as part of the protocol that facilitated evaluation of both discrete forecasts (observed versus modeled concentrations) and categorical forecasts (observed versus modeled exceedances/nonexceedances) for both the maximum 1-hr (125 ppb) and 8-hr (85 ppb) forecasts produced by each of the models. Implementation of the evaluation protocol took place during a 25-day period (August 5–29), utilizing hourly O₃ concentration data obtained from over 450 monitors from the U.S. Environment Protection Agency’s Air Quality System network.     

Assessment of potentially harmful elements pollution in the Calore River basin (Southern Italy)

The geographical distribution of concentration values for harmful elements was determined in the Campania region, Italy. The study area consists of the drainage basin of the River Calore, a tributary of the river Volturno, the largest Southern Italian river. The results provide reliable analytical data allowing a quantitative assessment of the trace element pollution threat to the ecosystem and human health. Altogether 562 stream sediment samples were collected at a sampling density of 1 site per 5 km². All samples were air-dried, sieved to <100 mesh fraction and analyzed for 37 elements after an aqua regia extraction by a combination of ICP-AES and ICP-MS. In addition to elemental analysis, gamma-ray spectrometry data were collected (a total of 562 measurements) using a hand-held Scintrex GRS-500 spectrometer. Statistical analyses were performed to show the single-element distribution and the distribution of elemental association factor scores resulting from R-mode factor analyses. Maps showing element distributions were made using GeoDAS and ArcGIS software. Our study showed that, despite evidence from concentrations of many elements for enrichment over natural background values, the spatial distribution of major and trace elements in Calore River basin is determined mostly by geogenic factors. The southwestern area of the basin highlighted an enrichment of many elements potentially harmful for human health and other living organisms (Al, Fe, K, Na, As, Cd, La, Pb, Th, Tl, U); however, these anomalies are due to the presence of pyroclastic and alkaline volcanic lithologies. Even where sedimentary lithologies occur, many harmful elements (Co, Cr, Mn, Ni) showed high concentration levels due to natural origins. Conversely, a strong heavy metal contamination (Pb, Zn, Cu, Sb, Ag, Au, Hg), due to an anthropogenic contribution, is highlighted in many areas characterized by the presence of road junctions, urban settlements and industrial areas. The enrichment factor of these elements is 3–4 times higher than the background values. The southwestern area of the basin is characterized by a moderate/high degree of contamination, just where the two busiest roads of the area run and the highest concentration of industries occurs.     

Water sharing agreements sustainable to reduced flows

By signing a water sharing agreement (WSA), countries agree to release an amount of river water in exchange for a negotiated compensation. We examine the vulnerability of such agreements to reduced water flows. Among all WSAs that are acceptable to riparian countries, we find out the one which is self-enforced under the most severe drought scenarios. The so-called upstream incremental WSA assigns to each country its marginal contribution to its followers in the river. Its mirror image, the downstream incremental WSA, is not sustainable to reduced flow at the source. Self-enforcement problems can be solved by setting water releases and compensations contingent to water flow. We apply our analysis to the Aral Sea Basin. We compute the upstream incremental compensations for the Bishkek agreement and asses its vulnerability with historical flows.