ELEMENTS OF A WATER QUALITY INFORMATION SYSTEM FOR THE STATE OF ILLINOIS1

ABSTRACT: A great deal of information can be derived from study of standard stream monitoring data, if these are properly ordered and organized. This information may then be used to make decisions about water quality management. Among critical information items are evaluation of performance to standards, determination of seasonality and time-trends of water quality conditions, and estimation of the effects on water quality to be expected from load reductions or standards modifications. Additional information on the magnitude of individual pollution sources is also critical to water quality management. Each of these items can be derived within the water quality information system which is currently under development for the State of Illinois.     

A PAH fate model for San Francisco Bay

A mass balance model was applied to simulate the long-term fate of PAHs in San Francisco Bay. The model treats the Bay as a single box with interacting water and sediment compartments, and includes loading, volatilization, outflow to the ocean, degradation, and burial in deep sediment. The estimated time required for loss of one-half of the mass in the Bay in the absence of loading ranged from 20 d for naphthalene to 5 yr for benzo(b)fluoranthene. Uncertainty analysis using Monte Carlo simulation indicated a high degree of influence and uncertainty for degradation rates, suggesting that improved estimates of degradation would significantly improve the predictive ability of the model. A comparison of model calculations to literature values suggested that external PAH loading to San Francisco Bay was at or above previous estimates of 3600 kgyr(-1), and that degradation in the Bay was within the range of commonly published estimates for high molecular weight PAHs (4.0 x 10(-5) to 4.0 x 10(-4)d(-1)).     

Analysis of the velocity field in a large rectangular channel with lateral shockwave

In this work the authors describe the main characteristics of the velocity field of hydraulic jumps in a very large channel where lateral shockwaves occur. Experiments were carried out at the Coastal Engineering Laboratory of the Water Engineering and Chemistry Department of the Technical University of Bari (Italy). Extensive flow velocity measurements were investigated in order to have a clearer understanding of both hydraulic jump development and lateral shockwave formation in a very large channel. Eight experiments were performed in a 4m wide rectangular channel; the experiments differed in the inlet Froude number F ₀ and the jump type. Seven tests were carried out with undular jumps and one with a roller jump. The flow velocity and the flow free surface measurements were taken using a two-dimensional Acoustic Doppler Velocimeter (ADV) and an ultrasonic profiler, respectively. The experimental results can be summarized as follow: (i) the formation of well developed lateral shockwaves similar to those of oblique jumps were observed; (ii) the comparison of the experimental and theoretical data shows that the classic shockwave theory is sufficiently confirmed in the analyzed range of Reynolds number, taking into account the experimental errors and the difference between the theoretical and experimental assumptions; (iii) the transversal flow velocity profiles in the recirculating zone show a good agreement with the numerical simulations presented in literature in the case of a separated turbulent boundary layer over a flat plate. This conclusion enables us to confirm the hypothesis that the lateral shockwaves in the channel are the result of a boundary layer which, as observed, forms on the channel sidewalls.     

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.     

CHANGES IN HYDROLOGIC RESPONSE DUE TO STREAM NETWORK EXTENSION VIA LAND DRAINAGE ACTIVITIES1

ABSTRACT: The objective of this work is to determine the effects of extension of a stream network through land drainage activities during the late 1800s on the hydrologic response of a watershed. The Mackinaw River Basin in Central Illinois was chosen as the focus and the pre‐land and post‐land drainage activity hydrologic responses were obtained through convolution of the hill slope and channel responses and compared. The hill slope response was computed using the kinematic wave model and the channel response was determined using the geomorphologic instantaneous unit hydrograph method. Our hypothesis was that the hydrologic response of the basin would exhibit the characteristic effects of settlement (i.e., increases in peak discharges and decreases in times to peak). This, indeed, is what occurred; however, the increase in peak discharges diminishes as scale increases, leaving only the decrease in times to peak. At larger scales, the dispersive effects of the longer hill slope lengths in the pre‐settlement scenario seem to balance the depressive effects of the longer path lengths in the post‐settlement scenario, thus the pre‐settlement and post‐settlement peak discharges are approximately equivalent. At small scales, the dispersion caused by the hill slope is larger in the pre‐settlement case; thus, the post‐settlement peak discharges are greater than the pre‐settlement.     

Individual and collective choice: parallel prospecting and mining in ants

Decision making is of crucial importance in the lives of both animals and humans. How decisions of group members scale up to group decisions is of great interest. Accordingly, we gave homeless ant colonies (n = 67) in three experiments a choice between two nest sites (with small, big or mixed sand grains), each of which had to be excavated to be habitable. Among the colonies that chose only one of the new nest sites, all preferred the ones that could be excavated most easily and quickly. There are interesting parallels between the collective choice of mining sites and the ability of certain ants to select short cuts; both involve positive feedback. However, in this paper, we discuss a mechanism whereby collective co-ordination in the production of social infrastructure can occur in the absence of signalling.     

Photosynthesis and growth responses of pea Pisum sativum L. under heavy metals stress

The present work aimed to study the physiological e ects of cadmium (Cd) and copper (Cu) in pea (Pisum sativum). Pea plants were exposed to increasing doses of cadmium chloride (CdCl2) and copper chloride (CuCl2) for 20 d. The examined parameters, namely root and shoot lengths, the concentration of photosynthetic pigments and the rate of photosynthesis were a ected by the treatments especially with high metals concentrations. The analysis of heavy metals accumulation shows that leaves significantly accumulate cadmium for all the tested concentrations. However, copper was significantly accumulated only with the highest tested dose. This may explain the higher inhibitory e ects of cadmium on photosynthesis and growth in pea plants. These results are valuable for understanding the biological consequences of heavy metals contamination particularly in soils devoted to organic agriculture.     

Is there a role for not‐for‐profit or for‐purpose organizations in supporting governance professionals to engage with climate‐related opportunities and risks?

Climate change in Australia has become a political risk (for political parties) and a physical, transitional, and regulatory risk for businesses. Not‐for‐profits (NFPs) and for‐purpose (FPs) organisations, for example, Climate Alliance Limited, have acted in the absence of national climate risk policy, to support businesses to become better informed to manage their exposure to this risk, and helping them to set their own commitments and pathways to low and net zero carbon businesses. The objective of this article is to demonstrate, through the case study method, how one Australian NFP/FP has influenced the business sector and regulation. Climate Alliance Limited has done this through its interventions of (1) sharing case studies (best practices) on successful transitions to a low carbon business model and linking climate risk to business risk; (2) bringing thought leaders (advocacy) from the Bank of England and UK Prudential Regulator into the Australian finance and business sector; and (3) by offering a program (reward and recognition), showcasing how business leaders have and are adapting to climate risks and capturing business value.