共查询到20条相似文献,搜索用时 31 毫秒
1.
Sediment TMDL Development for the Amite River 总被引:1,自引:0,他引:1
The Amite River is recognized as one of the 15 water bodies impaired by sediments in Louisiana, USA. Based on US EPA’s Protocol
sediment TMDL (Total Maximum Daily Load) development is conducted for the Amite River and described in this paper. The TMDL
development consists of four components: (1) development of a new model for cohesive sediment transport, (2) estimation of
sediment loads (sources) due to watershed erosion, (3) river flow computation, and (4) determination of sediment TMDL for
the Amite River. Using the mass conservation principle and Reynolds transport theorem a new 1-D model has been developed for
computation of suspended cohesive sediment transport. Sediment erosion in the Amite River Basin is calculated by combining
the USLE (Universal Soil Loss Equation) model with GIS and the digital elevation model of the Amite River Basin. Digital elevation
data was imported into the GIS which generated inputs for USLE. The calculated average annual rate of soil erosion in the
Amite River Basin is 13.368 tons per ha, producing a nonpoint sediment load of 103 mg/L to the Amite River. The flow computation
is performed using the HEC-RAS software. The computed sediment concentration in the Amite River varies in the range of 3–114 mg/L
and sediment TMDL is 281.219 tons/day. The reduction necessary to support beneficial uses of the river is 55% or 275.946 tons/day.
Results indicate that the combined application of the new 1-D sediment transport model, GIS, USLE model, and HEC-RAS is an
efficient and effective approach to sediment TMDL development. 相似文献
2.
A GIS-based method has been applied for the determination of soil erosion and sediment yield in a small watershed in Mun River
basin, Thailand. The method involves spatial disintegration of the catchment into homogenous grid cells to capture the catchment
heterogeneity. The gross soil erosion in each cell was calculated using Universal Soil Loss Equation (USLE) by carefully determining
its various parameters. The concept of sediment delivery ratio is used to route surface erosion from each of the discritized
cells to the catchment outlet. The process of sediment delivery from grid cells to the catchment outlet is represented by
the topographical characteristics of the cells. The effect of DEM resolution on sediment yield is analyzed using two different
resolutions of DEM. The spatial discretization of the catchment and derivation of the physical parameters related to erosion
in the cell are performed through GIS techniques. 相似文献
3.
基于空间地理信息系统的流域分布式水文泥沙模型为研究流域产流产沙及在河道中的汇流、输移过程提供了,科学有效的手段.针对岷江上游镇江关流域土壤易受降雨侵蚀的问题,采用水沙耦合的流域分布式水文综合模型,对该流域1990年后典型年的径流及泥沙侵蚀输移过程进了数值模拟,并结合镇江关水文站的实测资料对模型进行了验证,计算成果令人满意.分析表明,近年来岷江上游地区的年径流和输沙量均呈现出下降的趋势,且后者下降速率更快,说明泥沙侵蚀输移与径流相比对流域环境变化的反应更为敏感,今后水土保持工作应注重坡面治理. 相似文献
4.
5.
选取乌东德水电站坝区一典型区为试验示范区,以通用土壤流失方程(USLE)为评价模型,运用GIS和RS对各指标因子赋值,对试验区的土壤侵蚀量进行估算与分析。结果表明,试验区平均土壤侵蚀模数为6 088.58t/(km2·a),属于强度侵蚀。试验区中度以下的侵蚀面积占总面积的57.91%,土壤侵蚀量的贡献率仅为8.85%;而91.15%的侵蚀泥沙来自于面积42.09%的强度侵蚀以上的区域,其中,占11.53%的剧烈侵蚀区域贡献了43.83%的侵蚀泥沙。 相似文献
6.
Integration of GIS with USLE in Assessment of Soil Erosion 总被引:8,自引:1,他引:8
A Geographic Information System (GIS) has been integrated with the USLE (Universal Soil Loss Equation) model in identification of rainfall-based erosion and the transport of nonpoint source pollution loads to the Gediz River, which discharges into the Aegean Sea along the western coast of Turkey. The purpose of the study is to identify the gross erosion, sediment loads, and organic N loads within a small region of the Gediz River basin. Similar studies are available in literature, ranging from those that use a simple model such as USLE to others of a more sophisticated nature. The study presented here reflects the difficulties in applying the methodology when the required data on soil properties, land use and vegetation are deficient in both quantity and quality, as the case is with most developing countries. 相似文献
7.
8.
Simulation of Runoff and Suspended Sediment Transport Rate in a Basin with Multiple Watersheds 总被引:1,自引:1,他引:0
Accurate runoff and suspended sediment transport rate models are critical for watershed management. In this study, a physiographic
soil erosion–deposition (PSED) model is used in conjunction with GIS, to simulate the runoff and sediment transport process
during storm events in a multi-watershed basin. This PSED model is verified using three typhoon events and 33 storm events
in Cho-Shui River Basin, located in central Taiwan. Cho-Shui River Basin has 11 sub-watersheds displaying a variety of hydrologic
and physiographic conditions as well as high concentrations of suspended sediment in river flow and a steep average channel
bed slope of 2%. The results show the capability, applicability, and accuracy of the PSED model for multi-watershed basins. 相似文献
9.
Estimation of Soil Erosion for a Himalayan Watershed Using GIS Technique 总被引:12,自引:0,他引:12
The fragile ecosystem of the Himalayas has been an increasing cause of concern to environmentalists and water resources planners. The steep slopes in the Himalayas along with depletedforest cover, as well as high seismicity have been major factors in soil erosion and sedimentation in river reaches. Prediction ofsoil erosion is a necessity if adequate provision is to be madein the design of conservation structures to offset the ill effects of sedimentation during their lifetime.In the present study, two different soil erosion models, i.e. theMorgan model and Universal Soil Loss Equation (USLE) model, have been used to estimate soil erosion from a Himalayan watershed.Parameters required for both models were generated using remotesensing and ancillary data in GIS mode. The soil erosion estimated by Morgan model is in the order of 2200 t km-2 yr-1 and is within the limits reported for this region.The soil erosion estimated by USLE gives a higher rate. Therefore, for the present study the Morgan model gives, for area located in hilly terrain, fairly good results. 相似文献
10.
Estimation of Sediment Yield and Areas of Soil Erosion and Deposition for Watershed Prioritization using GIS and Remote Sensing 总被引:5,自引:2,他引:3
A Geographical Information System (GIS) based method is proposed and demonstrated for the identification of sediment source and sink areas and the prediction of sediment yield from watersheds. Data from the Haharo sub-catchment having an area of 565 km2 in the Upper Damodar Valley in Jharkhand State in India was taken up for the present study due to availability of gauged data at multiple locations within watershed area. The watershed was discretized into hydrologically homogeneous grid cells to capture the watershed heterogeneity. The cells thus formed were then differentiated into cells of overland flow regions and cells of channel flow regions based on the magnitude of their flow accumulation areas. The gross soil erosion in each cell was calculated using the Universal Soil Loss Equation (USLE). The parameters of the USLE were evaluated using digital elevation model, soil and landuse information on cell basis. The concept of transport limited sediment delivery (TLSD) was formulated and used in ArcGIS for generating the transport capacity maps. An empirical relation is proposed and demonstrated for its usefulness for computation of land vegetation dependent transport capacity factor used in TLSD approach by linking it with normalized difference vegetation index (NDVI) derived from satellite data. Using these maps, the gross soil erosion was routed to the watershed outlet using hydrological drainage paths, for derivation of transport capacity limited sediment outflow maps. These maps depict the amount of sediment rate from a particular grid in spatial domain and the pixel value of the outlet grid indicates the sediment yield at the outlet of the watershed. Up on testing, the proposed method simulated the annual sediment yield with less than ±40% error. 相似文献
11.
应用输沙量推演流域侵蚀量的方法探讨 总被引:3,自引:0,他引:3
鉴于至今还没有一个有效获取流域侵蚀产沙量的方法,在分析悬移质泥沙与侵蚀泥沙之间的数量与粒配关系的基础上,阐述了应用输沙量推演流域侵蚀量在理论上的可能性,但却存在着难点,且主要表现在水文站数量不足与区域分布不均、流域内的生态环境复杂与区域差异大、水文站输沙量观测记录起始时间不同步、及新技术应用存在时空条件的局限性。结合与侵蚀产沙和泥沙输移比相关的定性与定量指标,提出了应用输沙量推演流域侵蚀量的方法,即"层次类剔法",来计算与评估流域侵蚀量和泥沙输移比,具体的操作过程是首先制作一幅流域地貌类型地块图,然后是逐类型、逐类型地块的侵蚀量计算和沟道流域泥沙输移比的判断,最终获取流域不同地块的侵蚀强度和流域泥沙输移比。本研究结果可为水土流失监测点的选择提供科学依据,同时对解决流域的泥沙问题也有重要的启迪作用。 相似文献
12.
Wen-Chieh Chou 《Water Resources Management》2010,24(10):2075-2090
Computer simulation models are becoming increasingly popular in predicting soil loss for various land use and management practices. A GIS-based system, GeoUSLE, was developed in this study for soil loss prediction and sediment yield estimation in the watershed scale. The Universal Soil Loss Equation (USLE) and watershed analysis models are incorporated in the system. The required watershed information and USLE factors are derived from digital elevation models (DEMs) and remote sensing data. The GIS-based system can flexibly delineate drainage networks and watersheds and rapidly query the sediment yield at any point or watershed outlet via the point-and-click interface. The study presents an example application of the system to an agricultural reservoir watershed in central Taiwan. The estimated result shows that the developed system scales up USLE applications from the slope to the watershed, which can be used to assess the erosion hot spots in a watershed for the management decision making. 相似文献
13.
Finite Element Method and GIS Based Distributed Model for Soil Erosion and Sediment Yield in a Watershed 总被引:1,自引:1,他引:0
The objective of this study is to develop a soil erosion and sediment yield model based on the kinematic wave approximation
using the finite element method, remote sensing and geographical information system (GIS) for calculating the soil erosion
and sediment yield in a watershed. Detachment of soil particles by overland flow occurs when the shear stress at the surface
overcomes the gravitational forces and cohesive forces on the particles. Deposition occurs when the sediment load is greater
than the transport capacity. Beasley et al.’s (Trans ASAE 23:938–944, 1980) transport equations for laminar and turbulent flow conditions are used to calculate the transport capacity. The model is
capable of handling distributed information about land use, slope, soil and Manning’s roughness. The model is applied to the
Catsop watershed in the Netherlands and the Harsul watershed in India. Remotely sensed data has been used to extract land
use/land cover map of the Harsul watershed, and other thematic maps are generated using the GIS. The simulated results for
both calibration and validation events are compared with the observed data for the watersheds and found to be reasonable.
Statistical evaluation of model performance has been carried out. Further, a sensitivity analysis has also been carried out
to study the effect of variation in model parameter values on computed volume of sediment, peak sediment and the time to peak
sediment. Sensitivity analysis has also been carried out for grid size variation and time step variation of the Catsop watershed.
The proposed model is useful in predicting the hydrographs and sedigraphs in the agricultural watersheds. 相似文献
14.
In the present study the SHETRAN river basin modelling system was used in conjunction with Geographic Information System (GIS) to estimate potential erosion and deposition rates within the catchment and the concentrations of sediment in a flow at the catchment outlet on the example of the 114.31 km2 mountainous torrential Lukovska River catchment in Serbia. The streams in the Lukovska River catchment are short, steep and often produce hazardous torrential floods as a consequence of strong rainfall of short duration. The soil erosion and sediment discharge were analysed in view of the catchment response to physical characteristics of the catchment. Considering that the most of total annual sediment discharge in watersheds of torrential character is achieved during storm events, the SHETRAN modelling system was calibrated on the example of a storm event in 1986 and validated for three other storm events in 1974, 1976 and 1979. The simulated results of discharges and sediment concentrations at the catchment outlet for both calibration and validation events were compared with the observed data and found to be reasonable. The changes of erosion and deposition rates within the catchment and in the course of time were estimated for the calibration event in 1986. The simulated erosion rates were within the range of 1 to 10.5 t/ha and corresponded to the observed rates of erosion in Europe during extreme rain events. The presented methodology is useful in identifying the erosion vulnerable regions in a catchment where erosion control measures should be implemented. 相似文献
15.
16.
将栅格新安江模型与改进通用土壤侵蚀方程进行耦合,建立基于栅格尺度的水沙模拟模型,以淮河上游息县水文站以上为研究区域,基于研究流域DEM数据、土地利用数据、土壤数据以及息县站2000年-2010年水文数据,模拟了淮河上游2000年-2010年输沙过程。并基于构建的水沙模型,结合流域2020年和2030年土地利用远景规划数据设定两种土地利用模式情景,定量分析了不同土地利用模式情景对流域土壤侵蚀的影响。研究结果表明:基于栅格新安江模型的水沙耦合模型在淮河上游具有较好的模拟精度,模拟的输沙量相对误差小于15%,确定性系数0.6以上,满足泥沙模拟精度要求;林地用地面积增加5%,流域土壤侵蚀量减少8.78%,城镇用地面积增加8%,流域土壤侵蚀量减少12.73%。研究成果可为淮河水土保持治理和规划提供参考。 相似文献
17.
Soil Erosion Assessment in a Hilly Catchment of North Eastern India Using USLE, GIS and Remote Sensing 总被引:9,自引:1,他引:8
In the present study, soil erosion assessment of Dikrong river basin of Arunachal Pradesh (India) was carried out. The river
basin was divided into 200 × 200 m grid cells. The Arc Info 7.2 GIS software and RS (ERDAS IMAGINE 8.4 image processing software)
provided spatial input data and the USLE was used to predict the spatial distribution of the average annual soil loss on grid
basis. The average rainfall erositivity factor (R) for Dikrong river basin was found to be 1,894.6 MJ mm ha−1 h−1 year−1. The soil erodibility factor (K) with a magnitude of 0.055 t ha h ha−1 MJ−1 mm−1 is the highest, with 0.039 t ha h ha−1 MJ−1 mm−1 is the least for the watershed. The highest and lowest value of slope length factor (LS) is 53.5 and 5.39 respectively for the watershed. The highest and lowest values of crop management factor (C) were found out to be 0.004 and 1.0 respectively for the watershed. The highest and lowest value of conservation factor (P) were found to be 1 and 0.28 respectively for the watershed. The average annual soil loss of the Dikrong river basin is 51 t
ha−1 year−1. About 25.61% of the watershed area is found out to be under slight erosion class. Areas covered by moderate, high, very
high, severe and very severe erosion potential zones are 26.51%, 17.87%, 13.74%, 2.39% and 13.88% respectively. Therefore,
these areas need immediate attention from soil conservation point of view. 相似文献
18.
Identification of critical erosion prone areas in the small agricultural watershed using USLE,GIS and remote sensing 总被引:10,自引:1,他引:9
In the present study, Karso watershed of Hazaribagh, Jharkhand State, India was divided into 200 × 200 grid cells and average
annual sediment yields were estimated for each grid cell of the watershed to identify the critical erosion prone areas of
watershed for prioritization purpose. Average annual sediment yield data on grid basis was estimated using Universal Soil
Loss Equation (USLE). In general, a major limitation in the use of hydrological models has been their inability to handle
the large amounts of input data that describe the heterogeneity of the natural system. Remote sensing (RS) technology provides
the vital spatial and temporal information on some of these parameters. A recent and emerging technology represented by Geographic
Information System (GIS) was used as the tool to generate, manipulate and spatially organize disparate data for sediment yield
modeling. Thus, the Arc Info 7.2 GIS software and RS (ERDAS IMAGINE 8.4 image processing software) provided spatial input
data to the erosion model, while the USLE was used to predict the spatial distribution of the sediment yield on grid basis.
The deviation of estimated sediment yield from the observed values in the range of 1.37 to 13.85 percent indicates accurate
estimation of sediment yield from the watershed. 相似文献
19.
Abstract Previous research on runoff show flow and sediment movement in rivers, and river bed variations are usually separated. This paper, from the point of view of the basin as a whole system, presents an integrated approach by combining runoff simulation with numerical model of sediment transport in rivers to simulate the whole processes of hydrological variables and flow-caused bed variations from the very upper part of the basin to the river mouth. To accomplish this purpose, BTOPMC, a rainfall-runoff model, and NUSTM-1D, a well-developed numerical model for sediment transport and river bed variations, are selected to form a combined model. The application of the proposed model to the lower Yellow River shows that it can properly simulate rainfall-caused runoff, the change of suspended sediment concentration along the river, and river bed variation. 相似文献
20.
基于径流侵蚀功率的流域次暴雨输沙模型研究——以岔巴沟流域为例 总被引:4,自引:0,他引:4
流域次暴雨侵蚀产沙模型研究是国内外土壤侵蚀研究的重点领域之一。提出了基于径流深和洪峰流量模数两个流域次暴雨洪水特征参数的径流侵蚀功率的概念;利用岔巴沟曹坪水文站1959至1990年间历年实测的次暴雨洪水径流泥沙资料,系统研究了该流域次暴雨径流侵蚀功率与流域输沙模数之间的相关关系,建立和验证了基于径流侵蚀功率的岔巴沟流域次暴雨输沙模型。结果表明,岔巴沟流域次暴雨径流侵蚀功率与流域输沙模数之间具有极显著的幂函数相关关系;模型验证期的次暴雨输沙模数模拟值与实测值之间具有较好的一致性。 相似文献