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流域非点源分布式模型AnnAGNPS参数的不确定性研究 总被引:1,自引:0,他引:1
流域非点源分布式模型的不确定性研究成为目前的热点问题之一。本研究以宁波市章溪河流域为研究区,通过GIS软件AreView和AnnAGNPS模型,集成利用莫里斯分类筛选法,选取临界源面积、SCS曲线系数、水土保持因子、饱和导水率、氮磷吸收率、施肥量等6个因子进行敏感性分析。模拟结果表明,土壤饱和导水率、水土保持因子和径流曲线CN值对模型输出结果影响较大;水土保持因子对泥沙、总磷和总有机碳负荷的模拟结果影响最大,均呈显著负效应;径流曲线CN值对总氮负荷计算结果影响最大,呈显著正效应。 相似文献
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以西枝江流域为研究对象,结合GIS技术,建立了AnnAGNPS模型数据库,对流域内非点源污染主要影响因素的特征以及非点源污染的时空分布特征进行了分析。结果表明:流域内降雨侵蚀力、径流深、土壤侵蚀和沉积负荷的年际问变化很大,降雨侵蚀力月问分布极不均匀,季节变化十分明显,后三者的变化趋势都与平均降水量表现出较好的对应关系,但是又并不完全一致;流域内的径流深空间分布极不均匀,而土壤侵蚀、沉积负荷空间变化相对不是十分明显,三者都有沿河道向两边逐渐递减的趋势,在人口密集地区及河塘密集地区,径流相对其他区域比较大。本文为西枝江流域的非点源污染模拟研究提供了基础数据平台,也为该模型在整个东江流域的合理应用奠定了科学基础。 相似文献
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海河流域农用化肥施用量比较大,高于全国平均水平。但是由于水资源严重缺乏,且降雨量有逐年减少的趋势,加之人类活动的影响,产生农田径流的几率极低,通常情况下,土壤中未被作物吸收利用的氮磷不会随地表径流进入水体。在发生暴雨的情况下,土壤中的氮磷则有可能随地表径流和土壤侵蚀进入附近河道,污染地表水。另一方面,海河流域的降雨80%集中在6—9月的汛期,大雨促使土壤硝态氮向土壤剖面深层迁移,存在污染地下水的威胁,但污染程度如何,需要进一步研究确定。总之,海河流域种植业非点源污染有可能集中爆发在有暴雨的汛期,具有显著的突发性特征。 相似文献
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构建增江流域非点源污染数据库,包括DEM、土地利用,土壤类型,气象数据等,应用分布式流域水文模型SWAT(Soil andWater Assessment Tool,swat 2009版)对增江流域的非点源污染进行模拟。模型运行阶段为2000-2003年,分别应用2000-2001年和2002-2003年的实测月均流量及硝酸盐氮监测数据对模型的参数率定和验证,采用决定系数R2和Nash-Suttcliffe系数对模拟结果进行评定。其中水文模拟的R2均>0.9,Nash-Suttcliffe模型效率系数均>0.8;硝酸盐氮模拟的R2均>0.7,Nash-Suttcliffe模型效率系数均>0.6,表明SWAT模型在增江流域具有较好的适用性。 相似文献
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在设计工作中,计算暴雨径流可采用多种方法,通常的推理法是在给定具有一定频率的暴雨强度-历时关系和所研究流域的汇流时间的情况下来确定最大流量。流量过程线法是在提供径流随时间的变化过程,以及进一步迭加各子流域的径流时是优越的。然而,采用这些方法都要求较多的附加资料,特别是暴雨分布的详细资料。本文介绍一种概化的流量过程线法,目的在于对峰值和径流时间分配这两个因素进行工程性预 相似文献
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成都市径流污染的概念性模型 总被引:7,自引:0,他引:7
概念性模型是根据城市径流形成过程及对水体影响变化的物理机理建立的一套数学模型,模型及参数均有明确的物理意义。本文用概念性模型求出了成都市街道地表物的累积量,降雨径流污染负荷量,并模拟了污染物对受纳水体的影响。 相似文献
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Malchus B. Baker Arnett C. Mace 《Journal of the American Water Resources Association》1976,12(4):719-730
ABSTRACT Spring runoff from two forested watersheds in northern Minnesota is a function of annual snowfall, soil water recharge, and water supply rates. A drainage basin with a clay soil and a hardwood overstory had greater snowmelt and water supply rates than another drainage basin with a sandy soil and conifer overstory. The average soil water recharge rate for the clay soil was 28 percent less than for the sandy soil. The lower recharge rate of the clay soil resulted in spring runoff which averaged 40 percent of water supplied during the three year study while an average of two percent was produced on the sandy soil. Soil frost which affected soil water recharge varied between soil types and was influenced by amount of soil water storage and snow cover. 相似文献
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Estimating runoff phosphorus losses from calcareous soils in the Minnesota River basin 总被引:4,自引:0,他引:4
Bioavailable phosphorus (BAP) in stormwater runoff is a key issue for control of eutrophication in agriculturally impacted watersheds. Laboratory experiments were conducted in soil runoff boxes to determine BAP content in simulated storm runoff in 10 (mostly) calcareous soils from the Minnesota River basin in southern Minnesota. The soluble reactive phosphorus (SRP) portion of the runoff BAP was significantly correlated with soil Mehlich-III P, Olsen P, and water-extractable P (all r2 > 0.90 and p < 0.001). A linear relationship (r2 = 0.88, p < 0.001) also was obtained between SRP in runoff and the phosphorus saturation index based on sorptivity (PSIs) calculated with sorptivity as a measure of the inherent soil P sorption capacity. Runoff levels of BAP estimated with iron oxide-impregnated paper were predicted well by various soil test P methods and the PSI, of the soils, but correlation coefficients between these variables and runoff BAP were generally lower than those for runoff SRP. Using these relationships and critical BAP levels for stream eutrophication, we found corresponding critical levels of soil Mehlich-III P and Olsen P (which should not be exceeded) to be 65 to 85 and 40 to 55 mg kg(-1), respectively. 相似文献
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Berry ED Woodbury BL Nienaber JA Eigenberg RA Thurston JA Wells JE 《Journal of environmental quality》2007,36(6):1873-1882
Determining the survival of zoonotic pathogens in livestock manure and runoff is critical for understanding the environmental and public health risks associated with these wastes. The occurrence and persistence of the bacterial pathogens Escherichia coli O157:H7 and Campylobacter spp. in a passive beef cattle feedlot runoff control-vegetative treatment system were examined over a 26-mo period. Incidence of the protozoans Cryptosporidium spp. and Giardia spp. was also assessed. The control system utilizes a shallow basin to collect liquid runoff and accumulate eroded solids from the pen surfaces; when an adequate liquid volume is attained, the liquid is discharged from the basin onto a 4.5-ha vegetative treatment area (VTA) of bromegrass which is harvested as hay. Basin discharge transported E. coli O157, Campylobacter spp., and generic E. coli into the VTA soil, but without additional discharge from the basin, the pathogen prevalences decreased over time. Similarly, the VTA soil concentrations of generic E. coli initially decreased rapidly, but lower residual populations persisted. Isolation of Cryptosporidium oocysts and Giardia cysts from VTA samples was infrequent, indicating differences in sedimentation and/or transport in comparison to bacteria. Isolation of generic E. coli from freshly cut hay from VTA regions that received basin discharge (12 of 30 vs. 1 of 30 control samples) provided evidence for the risk of contamination; however, neither E. coli O157 or Campylobacter spp. were recovered from the hay following baling. This work indicates that the runoff control system is effective for reducing environmental risk by containing and removing pathogens from feedlot runoff. 相似文献
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Keith Willett David M. Mitchell H. L. Goodwin Baxter Vieux Jennie S. Popp 《Journal of Environmental Planning and Management》2006,49(2):181-207
The Illinois River Basin in eastern Oklahoma and northwest Arkansas is an example of a region where significant growth in poultry production has been accompanied by water quality problems. The primary concern in the basin is the problem of phosphorus in runoff that is associated with application of litter to crops. Existing data suggest that there has been a continuing decline in the quality of water in the Illinois River, and discussions have focused on developing and implementing a phosphorus standard. The specific objectives of this study are to estimate the reduction in poultry production necessary to achieve the reduction in phosphorus runoff under a set of phosphorus constraints, including soil test phosphorus, and to estimate the opportunity costs of reducing poultry production in the basin under each phosphorus constraint on the economic activity in the watershed. A mathematical programming model that incorporates poultry production and cropping decisions is developed. The parameters for the model are identified and then it is solved to provide a base solution. Model solutions are then developed for the different policy target levels of phosphorus. The model structure is modified to account for the presence of soil test phosphorus levels and the corresponding limits on soil test phosphorus throughout the basin. This formulation includes current soil test phosphorus throughout the basin. All of the applications assume that the only disposal option for poultry litter is land application within the basin. An economic impact assessment of the effects of phosphorus limitations in the basin is also conducted for Arkansas counties only, Oklahoma counties only, and all five affected counties combined. 相似文献
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J. M. Hill V. P. Singh H. Aminian 《Journal of the American Water Resources Association》1987,23(1):21-27
ABSTRACT: A computerized geographic information system (GIS) was created in support of data requirements by a hydrologic model designed to predict the runoff hydrograph from ungaged basins. Some geomorphologic characteristics (i.e., channel lengths) were manually measured from topographic maps, while other parameters such as drainage area and number of channels of a specified order, land use, and soil type were digitized and manipulated through use of the GIS. The model required the generation of an integrated Soil Conservation Service (SCS) curve number for the entire basin. To this end, soil associations and land use (generated from analysis of Landsat satellite data) were merged in the GIS to acquire a map representing SCS runoff curve numbers. The volume of runoff obtained from the Watershed Hydrology Simulation (WAHS) Model using this map was compared to the volume computed by hydrograph separation and found to be accurate within 19 percent error. To quantify the effect of changing land use on basin hydrology, the GIS was used to vary percentages from the drainage area from forest to bare soil. By changing the basin runoff curve numbers, significant changes in peak discharge were noted; however, the time to peak discharge remained essentially independent of change in area of land use. The GIS capability eliminated many of the more traditional manual phases of data input arid manipulation, thereby allowing researchers to concentrate on the development and calibration of the model and the interpretation of presumably more accurate results. 相似文献
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Infiltration models are based on physical characteristics of the soil and initial soil moisture. For a given soil it is based on the initial soil moisture distribution. A computer simulation model for flood runoff systems (FH-Model) was used to analyze 39 sets of rainfall-runoff data on four small watersheds ranging in size from 17 to 342 square kilometers located in the Yamaska River basin in Quebec. From these analyses, parameters and coefficients have been determined for a water loss (infiltration) equation. A method for determining the loss parameters, using a nonlinear least square curve fitting technique, is presented. Expressions were made to relate the loss parameters to antecedent precipitation. The equations were tested on 11 storm rainfall and runoff events on a watershed located in the same region and close agreements were found. 相似文献
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Miller JJ Handerek BP Beasley BW Olson EC Yanke LJ Larney FJ McAllister TA Olson BM Selinger LB Chanasyk DS Hasselback P 《Journal of environmental quality》2004,33(3):1088-1097
Southern Alberta, which has a cold climate dominated by strong chinook winds, has the highest density of feedlot cattle in Canada. However, the quantity and quality of runoff from beef cattle (Bos taurus) feedlots in this unique region has not been investigated. Our objectives were to compare runoff quantity (1998-2002) with catch-basin design criteria; determine concentrations of selected inorganic chemical parameters (1998-2000) in runoff in relation to water quality guidelines and the potential implications of irrigating adjacent crop-land; and determine if total heterotrophs, total coliforms, and Escherichia coli (1998-2000) persisted in the catch-basin water and soil. Runoff (< 0.1 to 42.5 mm) for a 24-h duration that included maximum peak discharge was less than the recommended design criteria of 90 mm based on runoff from 24 h of rainfall with a 30-yr return period. We found that curve numbers between 52 and 96 (mode of 90) were required to match the USDA Natural Resources Conservation Service predicted runoff and actual runoff volumes. Total P posed the greatest threat to water quality guidelines, and K posed the greatest threat for exceeding crop fertilizer requirements if catch-basin effluent was used as irrigation water. Water in the catch basin had continually high populations of E. coli throughout the study, with values ranging between log10 2 and log10 8 100 mL(-1). In contrast, soil in the catch basin generally had low populations of E. coli that were < log10 2 g(-1) wet wt., but at times higher populations between log10 2 and log10 6 g(-1) wet wt. were also found. 相似文献
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Jan A. Derecki Lieutenant Alan J. Potok 《Journal of the American Water Resources Association》1979,15(5):1418-1429
ABSTRACT: The feasibility of simulating monthly runoff for southeast Michigan, which comprises four major river basins, was evaluated with the Streamflow Synthesis and Reservoir Regulation watershed model. The evaluation covered a 13-year period (1961–73), which encompassed a complete runoff cycle. Results indicate it is feasible to simulate monthly runoff volumes on a regional scale with a single equivalent watershed by using daily precipitation and temperature data. Simulation of regional flows appears particularly attractive for the Great Lakes basin, since the basin consists of many relatively small watersheds. This method also appears promising for development of monthly runoff forecasts by employing average monthly meteorological data distributed on a daily basis. Tests of six-month runoff forecasts show relatively small deterioration with time and offer considerable improvement over climatology. 相似文献
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J. J. McDonnell Ian F Owens M. K. Stewart 《Journal of the American Water Resources Association》1991,27(4):679-685
ABSTRACT: Soil water potentials, slope throughflow, runoff chemistry, and isotopic composition were monitored in a 97 m2 zero-order basin within the Maimai 8 watershed on the South Island of New Zealand, for a natural rain storm and two artificial water applications. Contrary to results previously reported for other portions of the Maimai catchment, much of the runoff occurred as a shallow subsurface organic layer flow. For the 47 mm natural rain event, pre-storm soil matric potential ranged from ?60 to ?150 cm H2O. No saturation was produced within the profile, and the majority of storm runoff emanated from flow within the organic horizon perched on the mineral soil surface. Hillslope applications corroborated this interpretation by showing >90 percent new water flushing with negligible mineral soil moisture response. Although the mechanisms cited in the text are not representative of the entire catchment, the study demonstrates: (1) the value of a combined physical-chemical-isotopic approach in quantifying slope processes, and (2) the heterogeneous nature and diversity of slope runoff pathways in a relatively homogeneous catchment. 相似文献