EFFECTS OF STATSGO AND SSURGO AS INPUTS ON SWAT MODEL'S SNOWMELT SIMULATION1

ABSTRACT: Soil data comprise a basic input of SWAT (Soil and Water Assessment Tool) for a watershed application. For watersheds where site specific soil data are unavailable, the two U.S. Department of Agriculture (USDA) soil databases, the State Soil Geographic (STATSGO) and Soil Survey Geographic (SSURGO) databases, may be the best alternatives. Although it has been noted that SWAT models using the STATSGO and SSURGO data may give different simulation results for water, sediment, and agricultural chemical yields, information is scarce on the effects of using these two databases in predicting streamflows that are predominantly generated from melting snow in spring. The objective of this study was to assess the effects of using STATSGO versus SSURGO as an input for the SWAT model's simulation of the streamflows in the upper 45 percent of the Elm River watershed in eastern North Dakota. Designating the model as SWAT‐STATSGO when the STATSGO data were used and SWAT‐SSURGO when the SSURGO data were used, SWAT‐STATSGO and SWAT‐SSURGO were separately calibrated and validated using the observed daily streamflows. The results indicated that SWAT‐SSURGO provided an overall better prediction of the discharges than SWAT‐STATSGO, although both did a good and comparable job of predicting the high streamflows. However, SWAT‐STATSGO predicted the low streamflows more accurately and had a slightly better performance during the validation period. In addition, the discrepancies between the discharges predicted by these two SWAT models tended to be larger at upstream locations than at those farther downstream within the study area.     

OPTIMIZING WELL PLACEMENT IN A COASTAL AQUIFER: OUTER CAPE COD,MASSACHUSETTS1

ABSTRACT: An inverse‐simulation approach is used to determine optimal strategies for developing public water‐supply systems in a shallow, coastal aquifer on the outermost arm of the Cape Cod peninsula in Massachusetts. Typically a forward simulation (or “trial and error”) approach is used to find best pumping strategies, but the chances of finding success with this tact diminish as the number of potential options grows large. Well locations and pumping rates are optimized with respect to: (1) providing sufficient water to areas of water‐quality impairment, (2) minimizing impacts to nearby surface waters, (3) preventing saltwater contamination due to overpumping, and (4) minimizing financial cost of well development. Potential well sites and water‐supply scenarios are separated into “politically‐based” and “resource‐based” categories to gain insight into the degree that pre‐existing political boundaries hinder best management practices. The approach provides a promising tool in transboundary water‐resources settings because it allows stakeholders to find solutions that best meet everyone's goals, as opposed to pursuing options that will create conflict, or are less than optimal.     

Understanding Dispute Resolution Processes for American and Australian Public Wildlands: Towards a Conceptual Framework for Managers

/ The last 20 years have seen the successful application of environmental dispute resolution processes, where people voluntarily negotiate toward mutually acceptable solutions, to many environmental disputes. The effects of contextual influences, such as the number of parties and presence of deadlines, on outcomes are known and frequently described. Less well documented and understood are the interaction processes themselves. This paper draws on two case studies to develop a conceptual framework describing these processes. Disputes associated with management planning for the Bob Marshall Wilderness Complex in the United States and Fitzgerald River National Park in Australia provided the cases. The conceptual framework derived had eight sequential stages: (1) joint definition of problems, (2) uncertainty about what to do, (3) agreement on group procedures, (4) realization of interdependence, (5) enthusiasm about collective possibilities, (6) commitment to working together, (7) consolidation of the group, and (8) implementation of a resolution. The framework provides new insights for managers of public wildlands, especially the need for varying but ongoing managerial involvement in dispute resolution processes. High levels of involvement and influence are essential at the beginning in problem definition and group procedure design and at the end in implementing resolutions. Conversely, agency members must be willing to exert less influence, while still being involved and committed to collective purposes, during the middle stages. Also apparent from the conceptual framework is the importance of developing shared understandings and of allowing sufficient time for understanding to develop, if successful resolution is to be achieved. KEY WORDS: Environmental dispute resolution; Conceptual framework; Public wildlands; Shared understandings; Australia     

省沽油中硒含量及其测定方法研究

采用消化液硝酸／高氯酸消解法、硝酸-硫酸消解法和微波消解方法消化省沽油，用原子吸收分光光度法测定硒（Se）含量。比较了3种消解方法在测定省沽油中的硒含量。发现微波消解法测定野生省沽油（干菜）中Se含量准确性好、时间段效率高、对环境污染少、操作简单。     

在线衍生化吹扫捕集-气相色谱/质谱分析水中的五氯酚

建立了通过乙酸酐衍生化-吹扫捕集-气相色谱／质谱分析水中五氯酚的新方法，探讨了吹扫时间、样品池温度、离子强度以及衍生化试剂的加入量等条件对捕集效果的影响。结果表明：采用吹扫时间25min、样品池温度60℃、离子强度20％氯化钠以及衍生化试剂的量200μl等条件对水中的五氯酚有较好的捕集效果，用于水中五氯酚的测定，结果满意。     

军用浸渍活性炭中银含量测定方法——火焰原子吸收分光光度法

本研究建立了一种用空气-乙炔火焰原子吸收分光光度法测定浸渍活性炭中银含量的分析方法，对酸介质浓度、共存元素的干扰进行了探讨，在0—1．0ml沪范围内，银含量与吸光度呈线性关系，相关系数为0．9999。对09型浸渍活性炭标准物质进行测定，测定结果的相对标准偏差为0．191％（n=10），加标回收率为97．5％-101．4％。     

Increase in Hair Lead, but not Blood Lead Content of Occupationally-Exposed Workers

This study attempted to investigate whether increased hair lead concentrations due to environmental exposure are accompanied by parallel increases in blood lead concentrations. A sample set consisting of both occupationally-exposed individuals and persons from the general population was investigated. The lead content of scalp and pubic hair from the general population (n=189), traffic police personnel (n=27) and battery workers (n=22) were analysed. The hair samples were taken from the nape of the neck by cutting 23 cm closest to the scalp and cleaned using a washing procedure developed in our laboratory. The effectiveness of the washing procedure was partly determined by examining the scanning electron micrographs of the hair samples. Venous samples of blood were taken from each volunteer's arm.The traffic police and battery plant operators sampled had significantly higher average scalp hair and pubic hair lead levels than the non occupationally-exposed general population. No significant differences were found between the blood lead values of these workers and the general population. Compared to the general population both occupationally-exposed groups had significantly more symptoms of lead toxicity.Lead particles were still observed on the hair shafts after the washing procedure. The amount of such lead contamination was difficult to quantify, the problem being further exacerbated by the difference in hair texture of the persons sampled. This exogenous contamination therefore detracts from the usefulness of hair as an indicator of lead exposure.     

Testes mass in megachiropteran bats varies in accordance with sperm competition theory

Sperm competition is a widespread phenomenon influencing a range of characters, including investment in gonadal tissue. Conspecific proximity is one factor which can influence the risk of sperm competition and hence testicular investment, and decreased confidence of paternity may be one cost of group living. Aspects of female biology may also influence spermatogenic investment and sperm morphology. This study examines the associations between relative testes mass and roost-group size across 17 species of Megachiroptera. Associations between breeding season duration and investment in spermatogenesis are also examined, as are associations between female reproductive tract dimensions and testes mass and dimensions of spermatozoa across all bats. Relative testes mass was significantly positively associated with roost-group size at a species level and after appropriate phylogenetic control (pairwise comparisons and comparison of independent contrasts). There were no significant relationships between breeding season duration and relative testes mass. Across all bats, neither testes mass nor sperm length were significantly related to dimensions of the female tract. The results are discussed in the context of sperm competition. Received: 7 January 1998 / Accepted after revision: 8 August 1998