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961.
Correspondence between spatial patterns in fish assemblages in ohio streams and aquatic ecoregions 总被引:5,自引:0,他引:5
David P. Larsen James M. Omernik Robert M. Hughes Christina M. Rohm Thomas R. Whittier Andrew J. Kinney Alisa L. Gallant Daniel R. Dudley 《Environmental management》1986,10(6):815-828
Land classification systems can be useful for assessing aquatic ecosystems if relationships among them exist. Because the character of an aquatic ecosystem depends to a large extent upon the character of the landscape it drains, spatial patterns in aquatic ecosystems should correspond to patterns in the landscape. To test this hypothesis, the US state of Ohio was divided into four aquatic ecoregions based on an analysis of spatial patterns in the combination of land-surface form, land use, potential natural vegetation, and soil parent material. During the period July–October 1983, fish assemblages were sampled in 46 streams that were representative of the ecoregions, and that had watersheds relatively undisturbed by human activities. Spatial patterns of the fish assemblages were examined relative to the ecoregions; distinct regional differences were identified. The assemblages differed most between the Huron/Erie Lake Plain region and the Western Allegheny Plateau region; assemblages in the Eastern Corn Belt Plains and the Erie/Ontario Lake Plain-Interior Plateau regions were intermediate. This pattern also reflects the gradient in landscape character as one moves from the northwest to the southeast of Ohio. 相似文献
962.
S. F. Shih 《Journal of the American Water Resources Association》1987,23(3):435-442
ABSTRACT: Values of dry biomass of corn, sugarcane, sorghum, rice, taro, millet, cotton, cowpeas, soybeans, and velvet beans as related to the evapotranspiration (ET) were studied. The linear regression model was sufficiently accurate to establish the crop dry biomass and ET relations. A water-use efficiency index (WUE), which is defined as the additional crop dry biomass per unit ET, is used in this study. The WUE were grouped into high, medium, and low categories. The WUE varied from greater than 35 kg ha-1/mm for the high category, between 15 and 35 kg ha-1/mm for the medium category, and less than 15 kg ha-1/mm for the low category. Application of the established model to the Everglades Agricultural Area, Florida, showed that the regional El can be predicted from the known regional crop yields. The crop yield and ET relations could be used as a potential tool to improve water resources planning and management practices for crop production. 相似文献
963.
Marios Sophocleous J. A. McAllister 《Journal of the American Water Resources Association》1987,23(6):997-1010
ABSTRACT: A detailed but simple hydrologic budget for the entire Rattlesnake Creek basin (3,768 km2) in south-central Kansas was developed. With this budget, using minimal daily-weather input data and the soil-plant-water system-analysis methodology, we were able to characterize the spatial distribution of the hydrologic components of the water balance within the basin. A combination of classification and meteorological methods resulted in a basinwide integration methodology. Using this methodology, we found that, in addition to obvious climatic controls, soil, vegetation, and land-use factors also exert considerable influence on the water balance of the area. The available-water capacity (AWC) of soil profiles plays a dominant role in soil-water-deficit development and deep drainage. Vegetation and dryland or irrigated farming particularly affect the evapotranspiration (ET) components, with ET from irrigated corn and alfalfa being two to three times that from wheat. Deep drainage from irrigated wheat fields was found to be significantly higher than that from grassland and dryland wheat; deep drainage from alfalfa is practically nonexistent. We demonstrated how vegetation changes may affect components of the hydrologic cycle. We also showed that different portions of the watershed have different water-balance components and that use of single average values of hydrologic variables in management practices may not be realistic. 相似文献
964.
D. J. Wall D. F. Kibler M. E. Hastings 《Journal of the American Water Resources Association》1987,23(5):919-926
Regional procedures to estimate flood magnitudes for ungaged watersheds typically ignore available site-specific historic flood information such as high water marks and the corresponding flow estimates, otherwise referred to as limited site-specific historic (LSSH) flood data. A procedure to construct flood frequency curves on the basis of LSSH flood observations is presented. Simple inverse variance weighting is employed to systematically combine flood estimates obtained from the LSSH data base with those from a regional procedure to obtain improved estimtes of flood peaks on the ungaged watershed. For the region studied, the variance weighted estimates of flow had a lower logarithmic standard error than either the regional or the LSSH flow estimates, when compared to the estimates determined by three standard distributions for gaged watersheds investigated in the development of the methodology. Use of the simple inverse variance weighting procedure is recommended when “reliable” estimates of LSSH floods for the ungaged site are available. 相似文献
965.
Richard C. Tucker 《Journal of the American Water Resources Association》1972,8(2):257-265
This paper suggests a number of benefits in identifying urban and regional planners as a public in public participation programs of water resources planning studies. A perspective on public participation is presented. Recent trends and developing concepts are identified: emphasis on the need to coordinate urban and regional planning activities with water resources planning, increasing system complexity, the goals and objectives orientation of planning, planning for multi-objectives, the evaluation of a broader range of alternatives, and the consideration of water alternatives as only one set of measures to further society's aspirations. One way to assist in capitalizing on these trends is to seek out participation of those in other planning efforts who are involved in planning but on a different level. Because of their intimate knowledge of an areas history, growth and development, political climate, local perceptions of needs and desires, and major problems and issues they are able to contribute a great deal of insight in making the water resources planning effort more responsive at the local level. The paper describes one of the first major efforts at working-level public-planner contact which was carried out as part of the Susquehanna River Basin Study. A regional survey team comprised of an engineer and an economist from a federal agency and a state water resources planner met informally with planners, city managers, and local planning commissions to discuss issues related to water resources and the growth and development of local areas. This effort while only part of the overall public participation program yielded a number of benefits and if expanded and refined would be a very useful experience in other studies. 相似文献
966.
Gary D. Tasker Scott A. Hodge C. Shane. Barks 《Journal of the American Water Resources Association》1996,32(1):163-170
ABSTRACT: Five methods of developing regional regression models to estimate flood characteristics at ungaged sites in Arkansas are examined. The methods differ in the manner in which the State is divided into subregions. Each successive method (A to E) is computationally more complex than the previous method. Method A makes no subdivision. Methods B and C define two and four geographic subregions, respectively. Method D uses cluster/discriminant analysis to define subregions on the basis of similarities in watershed characteristics. Method E, the new region of influence method, defines a unique subregion for each ungaged site. Split-sample results indicate that, in terms of root-mean-square error, method E (38 percent error) is best. Methods C and D (42 and 41 percent error) were in a virtual tie for second, and methods B (44 percent error) and A (49 percent error) were fourth and fifth best. 相似文献
967.
Anne B. Hoos 《Journal of the American Water Resources Association》1996,32(4):855-863
ABSTRACT: Urban water-quality managers need load estimates of storm-runoff pollutants to design effective remedial programs. Estimates are commonly made using published models calibrated to large regions of the country. This paper presents statistical methods, termed model-adjustment procedures (MAPs), which use a combination of local data and published regional models to improve estimates of urban-runoff quality. Each MAP is a form of regression analysis that uses a local data base as a calibration data set to adjust the regional model, in effect increasing the size of the local data base without additional, expensive data collection. The adjusted regional model can then be used to estimate storm-runoff quality at unmonitored sites and storms in the locality. The four MAPs presented in this study are (1) single-factor regression against the regional model prediction, Pu; (2) least-squares regression against Pu; (3) least-squares regression against Pu and additional local variables; and (4) weighted combination of Pu and a local-regression prediction. Identification of the statistically most valid method among these four depends upon characteristics of the local data base. A MAP-selection scheme based on statistical analysis of the calibration data set is presented and tested. 相似文献
968.
为衡量能源消耗控制指标对我国区域能源安全管理的影响,以区域能源安全为研究对象,探索在能源消耗弹性控制下区域能源安全状态的动态变化规律。通过分析影响区域能源安全的影响因素,根据国家、行业和地方标准对指标的标准化赋值,构建了由反映能源安全驱动力、能源安全压力、能源安全状态、能源安全响应和能源安全响应的17个指标组成的DPSIR指标体系;基于选取样本指标的交互特征,在充分考虑能源消耗弹性控制的前提下,构造了融合模糊积分方法和数据包络分析方法的FI-DEA模型,并利用该模型对我国10个典型区域2012—2014年能源安全状况进行了动态评价。结果表明,在能源消耗弹性控制下,采用FI-DEA模型进行区域能源安全动态评价结果是符合实效的,2013—2014年,河北等地的能源安全管理有效性凸显,其能源安全动态评价值为0.96,比上年同期显著改善;而重庆等地的能源安全管理有效性较弱,其能源安全动态评价值为0.683 2,出现明显下滑。 相似文献
969.
随着城市化和工业化水平的逐渐提高,河南省的空气污染问题也日益严重.利用嵌套网格空气质量模式(NAQPMS),数值模拟了2013年7月-2014年6月年河南省大气细颗粒物及其前体物(NO2、SO2、PM10、PM2.5)的地面浓度,并量化了其主要来源.结果表明:模式能够较好地再现污染物的时空演化特征.整体来讲,河南省PM2.5的高值区集中在中部和北部地区,呈现冬季高、夏季低的特点.在线源解析模拟发现,河南省不同地区PM2.5的来源有所不同,中西部地区主要来自于本地,而在东部和北部地市,来自周边省份的区域输送更为显著,其贡献达到40%~50%,且在PM2.5浓度的高值区更为明显.就行业贡献而言,居民源、工业源和机动车排放是河南省PM2.5浓度的主要来源,其浓度贡献分别为23.7 μg·m-3(贡献比例24%,下同)、20.6 μg·m-3(21%)和21.3 μg·m-3(22%),电厂、农牧业和地面扬尘的浓度贡献分别为7.0 μg·m-3(7%)、8.7 μg·m-3(9%)和17.8 μg·m-3(18%).受居民源影响最大的地区是河南中东部和北部地市,其贡献达到PM2.5浓度的27%、27%和25%.工业源影响最大的地区集中在太行山南部地市,其浓度贡献为26.4 μg·m-3(24%),在其他地市的贡献为17%~23%.机动车对河南东部影响最为显著,其浓度贡献为22.9 μg·m-3(24%).电厂和农畜牧业对全省PM2.5的贡献分布比较均匀,分别为6%~9%和8%~10%.分析不同浓度下的PM2.5来源,发现工业源和扬尘贡献随PM2.5浓度增加逐渐降低,而居民源和机动车排放的贡献则有所增加,在PM2.5浓度高于100 μg·m-3期间,达到22%和20%. 相似文献
970.
自“十一五”实行总量减排以来,国家和地方均投入了大量资金,用于治理工程的建设,减排效果显著.如何在保证经济社会发展的前提下,实现COD等污染的进一步减排,也是一个丞待研究的课题.然而在各类污染物产排量因经济社会发展而急剧增加的背景下,想要彻底解决环境污染问题,仅依靠工程减排措施恐难以为继.以2014年-2030年济南市COD减排优化研究为例,探讨了未来总量减排的发展方向,并在此基础上,提出未来总量减排的建议. 相似文献