侵蚀产沙模型研究进展和GIS应用

近年来随着地理信息系统 (GIS)技术的发展 ,侵蚀产沙模型与GIS的结合成为必然 ;作者阐述了近年来国际上流行的基于GIS的侵蚀产沙模型 :RUSLE、WEPP、ANSWERS等模型的主要内容、特点及适用范围 ,并对我国以陡坡为代表基于GIS的侵蚀产沙模型进行了介绍和评述 ;提出了目前侵蚀产沙模拟研究中存在的主要问题 ,并对基于GIS的侵蚀产沙模型的研究工作进行了展望。能反映侵蚀产沙时空过程的、基于GIS的分布式侵蚀产沙模型成为研究的重点     

Estimation of Soil Erosion and Sediment Yield Using GIS at Catchment Scale

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.     

不确定性信息下流域土壤侵蚀量计算

根据流域土壤、地形、降雨、植被、管理技术等因素存在的多种不确定性特点,运用盲数来描述和处理通用土壤流失方程USLE中各参数的不确定性,尝试性地提出了不确定性信息下流域土壤侵蚀量计算的新方法。根据这一方法,不仅可以求得研究区域土壤潜在侵蚀量的各种可能取值区间,也可以得到各区间相应的主观可信度。再由盲数均值计算公式,最终得到整个研究区域土壤潜在侵蚀总量。在此基础上,结合区域土壤中氮、磷含量资料,可以计算出吸附态氮、磷的流失量。实例研究表明,运用盲数理论研究流域土壤侵蚀量和吸附态氮、磷流失量,理论上是可行的,计算结果是可信的。     

黄河泥沙来源研究评述

本文在给出泥沙来源的涵义及确定泥沙来源的一些方法的基础上，对黄河泥沙的主要来源区及粗泥沙来源区的研究作了重点评述，简述了有关黄河泥沙来源区侵蚀产沙部位的研究成果及黄河流域水土流失类型及其分布状况。同时，指出了目前黄河泥沙来源研究的一些不足和以后应进一步研究的问题。     

GIS-Aided Modeling of Nonpoint Source Pollution Impacts on Surface and Ground Waters

An application of GIS-aided modeling is done at an area in South Florida. A Geographic Information System (GIS) is interfaced with a nonpoint source pollution model to facilitate data storage, management and display; derivation of model input parameters; and effective presentation of results. parameters, and to visually present results in maps. Results for current conditions and practices show that sediments, nutrients and pesticides are present in surface runoff and ground water. Two alternatives to minimize pollution levels are evaluated, i.e., reduction of fertilizer application to the minimum required for effective agricultural growth and replacement of fertilizers with sewage sludge. In addition, the impact of urbanization of the agricultural area to the pollutant levels is tested. Both alternatives and the urbanization result in overall reduction of pollution.     

白洋淀非点源污染的生态工程技术控制研究

白洋淀是华北地区最大的淡水湖泊,由于它具有丰富的物产和多种生态服务,被誉为“华北明珠”和“华北之肾”。从2003年水质监测结果来看,白洋淀的大部分水域水质为劣Ⅴ类,主要污染物为TP、TN和NH3-N。通过对污染源的实地调查,发现农业非点源污染是造成白洋淀污染的主要原因。由此看来,除继续加强主要工业污染源控制外,如何实施区域环境对非点源污染物的净化能力,是控制淀区污染的主要途径。在分析调查和模拟实验的基础上,提出了包括生态施肥技术、水土保持技术、污水和固体废弃物处理技术、生态缓冲带和湿地生态系统等源头和径流控制措施来控制白洋淀的非点源污染。     

Use of Geographic Information Systems (GIS) in water resources: A review

Increasing public awareness, stricter measures and promulgation of new laws in the area of water resources have made the use of advanced technologies indispensable. Geographic Information Systems (GIS) are an effective tool for storing, managing, and displaying spatial data often encountered in water resources management. The application of GIS in water resources is constantly on the rise. In order to stress the importance of GIS in water resources management, applications related to this area are addressed and evaluated for efficient future research and development. Fundamentals of GIS are summarized and the history of the GIS evolution in water resources is discussed. Current GIS applications are presented including surface hydrologic and groundwater modeling, water supply and sewer system modeling, stormwater and nonpoint source pollution modeling for urban and agricultural areas, and other related applications. Future research and development needs are presented, based on these reviews.     

黄河中游分布式水沙耦合模型研究

针对黄河中游多沙粗沙区的产流产沙特点,在建立逐网格汇流的水文模型的基础上,构建了逐网格汇沙的土壤侵蚀模型,通过水文模型和土壤侵蚀模型有机耦合,实现了泥沙的产生和汇集的分布式计算。由于模型采用逐网格汇流汇沙的方式进行模拟,使得考虑上方来水来沙对产输沙的影响成为可能。根据研究区的特点,模型在土壤侵蚀过程的模拟中,对重力侵蚀的模拟进行了尝试。经黄河中游小理河流域实测资料验证,模型具有一定的计算精度。     

Einstein推移质公式的改进研究

很多学者对Ｅｉｎｓｔｅｉｎ推移公式建立过程中的冲刷概率，泥沙无因次单步运行蹁和泥沙交换时间等方面进行了深入研究与改进，并得到了改进后的推移质输沙率公式。     

Estimation of Potential Soil Erosion for River Perkerra Catchment in Kenya

River Perkerra catchment with an area of 1207 km² is drained by River Perkerra, which is one of the rivers flowing into Lake Baringo whose drainage area is 6820 km². The lake is in a semi-arid area of Kenya. Its depth has reduced from 8 m in 1972 to 2.5 m in 2003 due to siltation resulting from high erosion rates in the catchment. The entire catchment is characterised by very steep slopes on the hillsides and gentle slopes in the middle and lower reaches where the surface is bare with very little undergrowth. Interventions to control soil erosion in this fragile ecosystem have been limited partly because of lack of data on erosion and its spatial distribution. In the present study, Universal Soil Loss Equation (USLE) was used in conjunction with GIS Arc/Info and Integrated Land and Water Information Systems (ILWIS) to estimate potential soil loss from River Perkerra catchment. Various physical parameters of the equation were derived by analysing spatial data and processing Landsat TM satellite imagery of the catchment. The estimated potential soil erosion from the catchment was 1.73 million tonnes/year while the sediment yield at the catchment outlet was found to be 1.47 million tonnes/year. The sediment delivery ratio derived using an empirical equation was 0.83. This figure indicates that a higher proportion of sediments generated in the catchment is delivered at the outlet. The use of GIS enabled the results of erosion potential to be mapped back onto the catchment. This is useful in identifying priority areas that require urgent management interventions in controlling soil erosion.     

GIS在开发建设项目水土流失预测中的应用探索

本项研究应用GIS系统的空间数据分析管理功能和二次开发功能,在对预测因子定量分析、分类提取信息的基础上建立了GIS水土流失预测系统,为开发建设项目水土流失预测提供一种新的方法。     

泥沙输移比尺度依存及分形特征

泥沙输移比是连接流域地面侵蚀与河道输沙的纽带,是反映流域侵蚀产沙及输移能力的指标,对正确评价水土保持减沙效益与生态建设宏观决策有重要意义。本文基于对国内外泥沙输移比研究的系统梳理,探讨了流域泥沙输移比的尺度依存及分形特征。分析认为：泥沙输移比在其内涵中深刻体现了对尺度的标定;国内外不同区域内流域泥沙输移比具有尺度依存性,并有严格的尺度域;泥沙输移比可以由分形维数来定量描述,即由1km2左右的典型流域单元的泥沙输移比值和流域的分形维数来建立尺度上推或下推的测算模型。本研究结果明确了泥沙输移比研究不能割裂“尺度性”这一学术认知,并为泥沙输移比尺度效应及转换研究提供了新的思路。     

Simulation Modeling of Runoff,Groundwater Flow and Sediment Transport into Kastoria Lake,Greece

Kastoria Lake is located in northwestern Greece. The whole basin of the lake is about 253 km². For the computation of the surface water volume inflowing into the lake from the main streams of the sub-basins located around Kastoria Lake, a rainfall-runoff sub-model is used. A quasi-three-dimensional simulation model of the Kastoria basin aquifer is also realized, in order to estimate the groundwater contribution to the volumetric budget of the lake and the whole basin as well. For the computation of sediment load inflowing into the lake from the main streams of the sub-basins, the rainfall-runoff sub-model is combinedwith a soil erosion sub-model and a sediment transport sub-model for streams. A GIS was developed in the hydrologic basin with all data needed for parameter identification and model application. The data base was enriched by a series of on site measurements of water discharge made in all main streams for one whole hydrologic year. By means of the resulting mathematical sediment model, those sub-basins, which deliver most sediment load to the lake, are identified. On the basis of this identification, a series of control measures, for the reduction of sediment inflowing into the lake, at certain places of the above mentioned sub-basins is proposed.     

应用输沙量推演流域侵蚀量的方法探讨

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。     

鸭河口水库入库面源污染负荷预测研究

利用鸭河口水库汇流区有关土壤侵蚀基础研究资料 ,考虑预测年汇水区内植被覆盖因子和侵蚀控制因子的变化 ,运用通用土壤流失方程和可浸出污染物负荷估算公式 ,分别对土壤流失面源污染负荷和农田施肥氮磷污染负荷进行了计算 ,对鸭河口水库水资源保护及富营养化防治具有重要意义。     

长江上游输沙量阶段性变化和原因分析

通过对长江上游干流和主要支流年输沙量变化特征、降雨条件、20世纪90年代土地利用和水库拦沙变化过程的对比分析研究,揭示出三峡水库蓄水运用前长江上游年输沙量存在1~2个突变点,具有显著的阶段性变化现象。其中嘉陵江流域年输沙量在1985年以后和1994年以后显著减少,水库拦沙是主要原因;岷江流域年输沙量在1967年以后和1994年以后显著减少,降雨变化比水库拦沙的贡献大;乌江和整个上游年输沙量在1985年以后和1992年以后显著减少,也主要与水库拦沙有关。20世纪最后十年间的土地利用变化对上游侵蚀输沙影响不显著。     

水土流失与农业非点源污染

水土流失既是一种非点源污染形式,同时又是其它非点源污染物流失的载体。其它非点源污染物通过流失的土壤颗粒的携带作用进入水体,造成水体污染。水土流失是引起农业非点源污染的一个重要原因,控制水土流失是减少农业非点源污染的必要途径。