秦皇岛市土壤侵蚀的特点、原因及保护对策

土壤侵蚀是一种危害严重、分布范围广的生态环境问题,影响人与自然的和谐共存,以及各业生产的可持续发展。通过分析秦皇岛市土壤侵蚀特点、原因,提出综合治理土壤侵蚀的对策和措施,以期为今后该区土壤侵蚀防治与治理提供科学依据。     

秦皇岛沿海地下水脆弱性评价

在介绍地下水脆弱性及其评价方法的基础上，分析了秦皇岛沿海地区地下水脆弱性的影响因素。应用DRASTIC方法与GIS技术耦合的模型，对该区地下水脆弱性进行评价，并进行了脆弱性分区。     

基于ArcGIS的坡度分析

坡度对土壤侵蚀的影响最大,是水土保持工作中首先要考虑的因素之一。用传统方法计算研究区坡度组成和平均坡度的效率低、精度低;而应用ArcGIS软件的空间分析功能对研究区进行坡度分析的效率高、精度高,减少了人为主观因素的影响,为水土保持工作提供一种新技术、新方法。     

秦皇岛市土地利用结构与土壤侵蚀空间格局分析

利用3S技术和景观生态学原理,以小流域为单元对秦皇岛市土地利用结构和土壤侵蚀等级类型进行空间分析,得出了不同土地利用结构所占面积和不同土壤侵蚀类型所占面积及分布小流域,并详细分析了秦皇岛市土壤侵蚀的主要影响因子和不同土地利用结构侵蚀现状。     

基于SWAT模型的湘江株洲段汞面源污染负荷测算

采用SWAT模型模拟了湘江株洲段汞的面源污染负荷,结果表明,SWAT模型可对地表径流量、产流量、土壤侵蚀量进行较好的模拟。研究区汞面源污染负荷总量约为789.7kg/a,其中受污染土壤是面源负荷量的主要来源,占总污染负荷的91.38%。汞面源污染受区域降雨量引起的土壤侵蚀的影响尤其明显。     

滇东北山原土地资源的可持续利用：以会泽县为例

滇东北原区是云南省的区域性贫困区。该区以山地为主，自然条件垂直差异大，土地资源质量较差、管理上存在问题多，本文以会泽县为例，对该区土地资源的持续利用进行了探讨。     

非点源污染模型中土壤侵蚀因子研究进展

非点源污染模型是进行非点源污染模拟研究的重要手段，而土壤侵蚀模型是非点源污染模型的基础，土壤侵蚀因子的研究是土壤侵蚀模型的重要基础。本文对国内外主要土壤侵蚀因子研究的成果进行了概述，并指出在今后相当一段时期内，土壤侵蚀因子的研究仍是土壤侵蚀模型研究的重要工作。     

水源保护区土地利用的时空变化分析——以昆明市松花坝为例

以昆明市松花坝水源保护区为典型区，选取1992年、2001年两期的遥感影像资料对该地区土地利用的时空变化进行了研究。采用监督分类方法对研究区土地利用类型进行分类，发现从1982-2001年林地面积呈明显减少趋势。最后进行驱动力分析，为今后该区的水源地保护提供指导。     

基于RS与GIS的莱州湾南岸滨海湿地景观类型与破碎化分析

应用Landsat--7遥感数据和GIS技术对莱州湾南岸滨海湿地类型、面积和分布现状进行了调查,并对滨海湿地景观特征及景观破碎化程度进行了分析.结果表明,研究区景观类型以盐田、滩涂和养殖池为主,人工湿地面积占整个湿地面积的78.22%.该区主要受人为干扰活动影响,区域景观斑块破碎化程度较高,对研究区湿地产生了严重的影响,因此合理调控人类干扰活动是改善莱州湾南岸滨海湿地环境的根本途径.     

基于地面摄影测量技术的新疆山地草原牲畜采食践踏路迹特征分析

以新疆精河县小海子山地草原为研究对象,运用地面摄影测量的方法获取样区DEM及正射影像。利用ArcGIS 9.1软件对四个样区的基本地形进行分析。结合地形因子,对牲畜采食践踏路迹的形态特征、分布密度、宽度、剖面等因子进行提取和计算,分析牲畜采食践踏路迹的生态作用和土壤侵蚀特征,并进行放牧程度的评价。     

头屯河流域水土流失现状及治理对策

介绍头屯河流域气候、植被、水土资源状况,分析了流域水土流失的现状,提出了水土流失治理对策,总结了水土流失治理措施并提出一些建议。     

山海关区农村生态环境状况及保护对策

从山海关区农村生态环境现状出发,客观分析了农村生态环境存在的水体污染、土壤污染、水土流失等问题,以及影响农村生态环境的主要因素,如污水和垃圾的无组织排放、化肥和农药的不合理使用、基础设施差、监管缺位等,提出应从环保体制、环保意识、基础设施建设、自然资源保护、污染防治、强化监管等方面采取切实可行的措施,保护农村生态环境。     

三峡库区万州区段长江水中泥沙量对其水质的影响分析

长江三峡库区的生态环境及水质情况。随着三峡工程建设的不断深入而备受社会各界的瞩目。重庆市万州区地处三峡水库腹心地带。长江自西南向东北横穿万州区全境。过境流程83公里。万州区溪流纵横。水网密布，多数河流直接排入长江。而且在三峡库区大移民进程中有大量的移民集中在万州。在三峡大坝即将合龙之际，研究长江万州流域的水质情况无疑对指导库区的清理工作、生态环境建设等具有重大意义。本文对该地区的水污染源进行了初步考察。同时对万州区段长江流域的水质进行了探索性研究。发现该区水土流失情况较为严重，而且水中的泥沙含量与其COD水平有相关关系。江水中大部分的COD是由泥沙携带的有机物的贡献。     

Determination of Soil Erosion Risk in the Mustafakemalpasa River Basin, Turkey, Using the Revised Universal Soil Loss Equation, Geographic Information System, and Remote Sensing

Sediment transport from steep slopes and agricultural lands into the Uluabat Lake (a RAMSAR site) by the Mustafakemalpasa (MKP) River is a serious problem within the river basin. Predictive erosion models are useful tools for evaluating soil erosion and establishing soil erosion management plans. The Revised Universal Soil Loss Equation (RUSLE) function is a commonly used erosion model for this purpose in Turkey and the rest of the world. This research integrates the RUSLE within a geographic information system environment to investigate the spatial distribution of annual soil loss potential in the MKP River Basin. The rainfall erosivity factor was developed from local annual precipitation data using a modified Fournier index: The topographic factor was developed from a digital elevation model; the K factor was determined from a combination of the soil map and the geological map; and the land cover factor was generated from Landsat-7 Enhanced Thematic Mapper (ETM) images. According to the model, the total soil loss potential of the MKP River Basin from erosion by water was 11,296,063?Mg?year(-1) with an average soil loss of 11.2?Mg?year(-1). The RUSLE produces only local erosion values and cannot be used to estimate the sediment yield for a watershed. To estimate the sediment yield, sediment-delivery ratio equations were used and compared with the sediment-monitoring reports of the Dolluk stream gauging station on the MKP River, which collected data for >41?years (1964-2005). This station observes the overall efficiency of the sediment yield coming from the Orhaneli and Emet Rivers. The measured sediment in the Emet and Orhaneli sub-basins is 1,082,010?Mg?year(-1) and was estimated to be 1,640,947?Mg?year(-1) for the same two sub-basins. The measured sediment yield of the gauge station is 127.6?Mg?km(-2)?year(-1) but was estimated to be 170.2?Mg?km(-2) year(-1). The close match between the sediment amounts estimated using the RUSLE-geographic information system (GIS) combination and the measured values from the Dolluk sediment gauge station shows that the potential soil erosion risk of the MKP River Basin can be estimated correctly and reliably using the RUSLE function generated in a GIS environment.     

水体底泥对污染物的吸附-解吸机理的研究

水体底泥污染已经成为世界范围内的一个重要的环境问题,其污染物主要通过大气沉降、废水排放、雨水淋溶冲刷等进入水体,最后沉积到底泥中并逐渐富集,使底泥受到严重污染。吸附-解吸是底泥污染的重要过程,为了控制水体底泥污染,对底泥对各种污染物的吸附-解吸机理及其影响因素的研究显得极其重要。本文总结了底泥中氮、磷和重金属等的吸附-解吸的影响因素及机理,对今后水体底泥污染方面的研究具有重要意义。     

Index models to evaluate the risk of phosphorus and nitrogen loss at catchment scales

This paper investigates index models as a tool to estimate the risk of N and P source strengths and loss at the catchment scale. The index models assist managers in improving the focus of remediation actions that reduce nutrient delivery to waterbodies. N and P source risk factors (e.g. soil nutrient concentrations) and transport risk factors (e.g. distance-to-streams) are used to determine the overall risk of nutrient loss for a case study in the Tuross River catchment of coastal southeast Australia. In the development of the N index model for Tuross, particulate N was considered important based on the observed event water quality data. In contrast to previous N index models, erosion and contributing distance were therefore included in the Tuross River catchment N index. Event-based water quality monitoring, and soil information, or in data-poor catchments conceptual understanding, are essential to represent catchment-scale processes. The techniques have high applicability in other catchments, and are complementary to other modelling techniques such as process-based semi-distributed modelling. Index models generally provide much more detailed spatial resolution than fully- or semi-distributed conceptual modelling approaches. Semi-distributed models can be used to quantify nutrient loads and provide overall direction to set the broad focus of management. Index models can then be used to refine on-the-ground investigations and investment priorities. In this way semi-distributed models can be combined with index models to provide a set of powerful tools to influence management decisions and outcomes.     

Farmers’ Perceptions of Land Degradation and Their Investments in Land Management: A Case Study in the Central Rift Valley of Ethiopia

To combat land degradation in the Central Rift Valley (CRV) of Ethiopia, farmers are of crucial importance. If farmers perceive land degradation as a problem, the chance that they invest in land management measures will be enhanced. This study presents farmers’ perceptions of land degradation and their investments in land management, and to what extent the latter are influenced by these perceptions. Water erosion and fertility depletion are taken as main indicators of land degradation, and the results show that farmers perceive an increase in both indicators over the last decade. They are aware of it and consider it as a problem. Nevertheless, farmers’ investments to control water erosion and soil fertility depletion are very limited in the CRV. Results also show that farmers’ awareness of both water erosion and soil fertility decline as a problem is not significantly associated with their investments in land management. Hence, even farmers who perceive land degradation on their fields and are concerned about its increase over the last decade do not significantly invest more in water erosion and soil fertility control measures than farmers who do not perceive these phenomena. Further research is needed to assess which other factors might influence farmers’ investments in land management, especially factors related to socioeconomic characteristics of farm households and plot characteristics which were not addressed by this study.     

The influence of use-related,environmental, and managerial factors on soil loss from recreational trails

Recreational uses of unsurfaced trails inevitably result in their degradation, with the type and extent of resource impact influenced by factors such as soil texture, topography, climate, trail design and maintenance, and type and amount of use. Of particular concern, the loss of soil through erosion is generally considered a significant and irreversible form of trail impact. This research investigated the influence of several use-related, environmental, and managerial factors on soil loss on recreational trails and roads at Big South Fork National River and Recreation Area, a unit of the U.S. National Park Service. Regression modeling revealed that trail position, trail slope alignment angle, grade, water drainage, and type of use are significant determinants of soil loss. The introduction of individual and groups of variables into a series of regression models provides improved understanding and insights regarding the relative influence of these variables, informing the selection of more effective trail management actions. Study results suggest that trail erosion can be minimized by avoiding “fall-line” alignments, steep grades, and valley-bottom alignments near streams, installing and maintaining adequate densities of tread drainage features, applying gravel to harden treads, and reducing horse and all-terrain vehicle use or restricting them to more resistant routes.     

浅谈新疆风电场水土保持措施配置——以新疆华电小草湖风电场二场一期工程为例

风能作为一种清洁无污染的可再生能源,已经被广泛运用到电力事业的发展中来。近年来,新疆的风力发电发展迅速,风电场建设过程中不可避免地会对土壤及植被造成一定的破坏,人为地加剧了水土流失。概述了风电项目水土流失特点,以新疆华电小草湖风电场工程为例,结合项目区具体特点,分区设置防治措施。通过工程措施、植物措施与临时措施的有机结合,有效地防止水土流失。     

Effect of Human Activities on Overall Trend of Sedimentation in the Lower Yellow River,China

The Yellow River has been intensively affected by human activities, particularly in the past 50 years, including soil–water conservation in the upper and middle drainage basin, flood protection in the lower reaches, and flow regulation and water diversion in the whole drainage basin. All these changes may impact sedimentation process of the lower Yellow River in different ways. Assessing these impacts comprehensively is important for more effective environmental management of the drainage basin. Based on the data of annual river flow, sediment load, and channel sedimentation in the lower Yellow River between 1950 and 1997, the purpose of this paper is to analyze the overall trend of channel sedimentation rate at a time scale of 50 years, and its formative cause. It was found in this study that erosion control measures and water diversion have counteractive impacts on sedimentation rate in the lower Yellow River. Although both annual river flow and sediment decreased, there was no change in channel sedimentation rate. A regression analysis indicated that the sedimentation in the lower Yellow River decreased with the sediment input to the lower Yellow River but increased with the river flow input. In the past 30–40 years, the basin-wide practice of erosion and sediment control measures resulted in a decline in sediment supply to the Yellow River; at the same time, the human development of water resources that required river flow regulation and water diversion caused great reduction in river flow. The former may reduce the sedimentation in the lower Yellow River, but the reduction of river flow increased the sedimentation. When their effects counterbalanced each other, the overall trend of channel sedimentation in the lower Yellow River remained unchanged. This fact may help us to better understand the positive and negative effects of human activities in the Yellow River basin and to pay more attention to the negative effect of the development of water resources. The results of this study demonstrate that, if the overuse of river water cannot be controlled, the reduction of channel sedimentation in the lower Yellow River cannot be realized through the practice of erosion and sediment control measures.