Modeling military trampling effects on glacial soils in the humid continental climate of southern New York

The purpose of this research is to create a baseline model of soil compaction response to trampling and a methodology to model the effects of trampling on soil. Although trampling studies have been conducted in the past, the analysis of military training in part provides a different perspective and approach. The data showed bulk densities remained relatively constant for a time and then began to increase at an increasing rate for several hundred passes and finally leveled and remained at or below 1.30 g/cm3 through the remainder of the experiment. Mathematical models were created based on empirical data from a trampling experiment using a more standard logistical growth curve as well as curves based on Weibull and gamma cumulative distribution functions (CDFs). The experiment and the resulting models give quantifiable continuous inference on the effects of trampling, as opposed to the existing qualitative assessments. These baseline models will be the foundation for future studies of land management when trampling occurs.     

Distribution of nitrogen species in groundwater aquifers of an industrial area in alluvial Indo-Gangetic Plains—a case study

The groundwater samples collected from the shallow and deep groundwater aquifers of an industrial area of the Kanpur city (Uttar Pradesh, India) were analyzed for the concentration levels and distribution pattern of nitrogenous species, such as nitrate-nitrogen (NO₃-N), nitrite-nitrogen (NO₂-N), ammonical-nitrogen (NH₄-N), organic-nitrogen (Org-N) and total Kjeldahl-nitrogen (TKN) to identify the possible contamination source. Geo-statistical approach was adopted to determine the distribution and extent of the contaminant plume. In the groundwater aquifers NO₃-N, NO₂-N, NH₄-N, TKN, Org-N and Total-N ranged from 0.10 to 64.10, BDL (below detection limit)-6.57, BDL-39.00, 7.84–202.16, 1.39–198.97 and 8.89–219.43 mg l⁻¹, respectively. About 42% and 26% of the groundwater samples of the shallow and deep groundwater aquifers, respectively, exceeded the BIS (Bureau of Indian Standards) guideline value of 10 mg l⁻¹ for NO₃-N and may pose serious health hazards to the people of the area. The results of the study revealed that the groundwater aquifers of the study area are highly contaminated with the nitrate and indicates point source pollution of nitrate in the study area.     

Diffuse source apportionment of the Po river eutrophying load to the Adriatic sea: assessment of Lombardy contribution to Po river nutrient load apportionment by means of an integrated modelling approach

The source apportionment of the annual nutrient load carried by the Po river to the Adriatic sea has been studied.

An integrated modelling approach was applied to the Lombardy plain area, which covers about 34% of the Po river watershed area and accounts for about 50% of the point sources’ loads carried by the river. To extract all the information available from direct instream measurements, two different modelling tools were alternatively used. The source apportionment was investigated considering both dry and wet weather scenarios. In order to quantify the apportionment in dry-weather conditions, the Lombardy portion of the Po river basin was modelled by using the US-EPA QUAL2E model. Such a simulation allowed to assess a significant contribution (about 50% of the total dry-weather load) of a not rain-driven diffuse pollution component (i.e. groundwater, springs, lake emissaries). Moreover, to estimate the rain-driven surface runoff contribution to the instream total load, the Lombardy plain area was also modelled by means of the US-DA SWAT model. SWAT results indicate a runoff contribution to the Po river instream total load of about 10 000 t N yr⁻¹ and 1300 t P yr⁻¹ (i.e. approximately the 10–20% of the total annual Lombardy nutrient load). At the event scale (i.e. the single rainstorm event) the runoff contribution may rise up to 30–80% of the total instream load. Finally, the total annual nitrogen load at the Po basin closure was estimated for the period 1985–2001. Out of a total annual load of 140 000 t N yr⁻¹, Lombardy accounts for 43% (point plus diffuse sources). The rain-driven diffuse sources constitute the 20% of the overall total load, the point sources account for 40%, whereas the remaining 40% is mainly constituted by “dry-weather diffuse sources” (i.e. groundwater, springs, lake emissaries).     

Ecological modeling for water quality management of Kwangyang Bay, Korea

This study estimated the appropriate pollutant load reduction from point sources in Kwangyang Bay, Korea, using an eco-hydrodynamic model. The total chemical oxygen demand (COD), nitrogen (TN), and phosphorus (TP) loads from rivers and ditches that provide input to the bay were approximately 2.8x10(4), 2.5x10(4), and 5.9x10(2) kg day-1, respectively. Wastewater discharge from industrial complexes was the greatest contributor to pollutant loads in the inner part of the bay. COD values in the inner part of the bay were greater than 3.0 mg l-1, and exceeded Korean seawater quality grade III limits. A residual current was simulated, using a hydrodynamic model, to have a slightly complicated pattern in the inner part of the bay, ranging from 0.001 to 8 cm s-1. In the outer part of the bay, the simulated current flowed out to the South Sea with a southward flow at a maximum of 15 cm s-1. The results of the ecological model simulation of COD levels showed high concentrations, exceeding 4 mg l-1, in the southwest of the Myodo, an area of wastewater discharge, and lower levels, approaching less than 1 mg l-1, closer to the outer part of the bay. Engineering countermeasures to reduce the organic and inorganic material loads from point sources by more than 45% were required to keep the COD levels below 2 mg l-1.     

城市第三产业发展对环境的污染影响

本文通过对城市第三产业污水、废气、噪声污染的特点、规律及对策论述，为科学、有效解决城市第三产业污染问题提供了一定实践经验。     

Modelling asymmetrically distributed circular data using the wrapped skew-normal distribution

We consider problems of inference for the wrapped skew-normal distribution on the circle. A centered parametrization of the distribution is introduced, and simulation used to compare the performance of method of moments and maximum likelihood estimation for its parameters. Maximum likelihood estimation is shown, in general, to be superior. The operating characteristics of two moment based tests, for wrapped normal and wrapped half-normal parent populations, respectively, are also explored. The former test is easy to apply, maintains the nominal significance level well and is generally highly powerful. The latter test does not hold the nominal significance level so well, although it is very powerful against negatively skew alternatives. Likelihood based tests for the two distributions are also discussed. A real data set from the ornithological literature is used to illustrate the application of the developed methodology and its extension to finite mixture modelling. Received: September 2003/ Revised: April 2005     

Replace the NOAEL and LOAEL with the BMDL01 and BMDL10

Although benchmark-dose methodology has existed for more than 20 years, benchmark doses (BMDs) still have not fully supplanted the no-observed-adverse-effect level (NOAEL) and lowest-observed-adverse-effect level (LOAEL) as points of departure from the experimental dose–response range for setting acceptable exposure levels of toxic substances. Among the issues involved in replacing the NOAEL (LOAEL) with a BMD are (1) which added risk level(s) above background risk should be targeted as benchmark responses (BMRs), (2) whether to apply the BMD methodology to both carcinogenic and noncarcinogenic toxic effects, and (3) how to model continuous health effects that aren’t observed in a natural risk-based context like dichotomous health effects. This paper addresses these issues and recommends specific BMDs to replace the NOAEL and LOAEL.

A note on non-parametric and semi-parametric modeling of wildfire hazard in Los Angeles County, California

This paper explores the use of, and problems that arise in, kernel smoothing and parametric estimation of the relationships between wildfire incidence and various meteorological variables. Such relationships may be treated as components in separable point process models for wildfire activity. The resulting models can be used for comparative purposes in order to assess the predictive performance of the Burning Index.

Multi-parameter renewal processes and simulation of forest fires

The concept of the renewal property is extended to processes indexed by a multidimensional time parameter. The definition given includes not only partial sum processes, but also Poisson processes and many other point processes whose jump points are not totally ordered. Various properties of renewal processes are discussed. Renewal processes are proposed as a basis for modelling the spread of a forest fire under a prevailing wind.

A traffic safety evaluation of California's traffic violator school citation dismissal policy

Introduction

This study evaluated California's traffic violator school (TVS) citation dismissal policy.

Method

This study identified and compared two large samples of drivers either completing a TVS (N = 210,015) or convicted of a traffic citation (N = 168,563).

Results

Prior to adjudication, the TVS group had characteristics (e.g., lower prior conviction rate and smaller proportion of males) that were predictive of a lower subsequent crash risk. However, the TVS group exhibited significantly more crashes than did the convicted group in the subsequent one-year period. The difference (4.83%) increased to 10% after adjusting for the more favorable characteristics of the TVS group. The TVS group also had a higher adjusted subsequent crash rate at each prior driver record entry level, reflecting a loss in the general and specific deterrence of the non-conviction masked status of TVS dismissed citations. It was reported that the TVS dismissal policy results in approximately 12,300 additional crashes annually with economic costs of approximately $398,000,000.

Conclusions

The avoidance of licensing actions resulting from the dismissal policy assists in explaining why the driving public is exposed to an increased crash risk. A number of recommendations are offered to reduce the negative traffic safety impact of the TVS citation dismissal policy.