Combining CLUE-S and SWAT Models to Forecast Land Use Change and Non-point Source Pollution Impact at a Watershed Scale in Liaoning Province, China

Non-point source(NPS) pollution has become a major source of water pollution. A combination of models would provide the necessary direction and approaches designed to control NPS pollution through land use planning. In this study, NPS pollution load was simulated in urban planning, historic trends and ecological protection land use scenarios based on the Conversion of Land Use and its Effect at Small regional extent(CLUE-S) and Soil and Water Assessment Tool(SWAT) models applied to Hunhe-Taizi River Watershed, Liaoning Province, China. Total nitrogen(TN) and total phosphorus(TP) were chosen as NPS pollution indices. The results of models validation showed that CLUE-S and SWAT models were suitable in the study area. NPS pollution mainly came from dry farmland, paddy, rural and urban areas. The spatial distribution of TN and TP exhibited the same trend in 57 sub-catchments. The TN and TP had the highest NPS pollution load in the western and central plains, which concentrated the urban area and farm land. The NPS pollution load would increase in the urban planning and historic trends scenarios, and would be even higher in the urban planning scenario. However, the NPS pollution load decreased in the ecological protection scenario. The differences observed in the three scenarios indicated that land use had a degree of impact on NPS pollution, which showed that scientific and ecologically sound construction could effectively reduce the NPS pollution load in a watershed. This study provides a scientific method for conducting NPS pollution research at the watershed scale, a scientific basis for non-point source pollution control, and a reference for related policy making.

Integrated Watershed Management and Sedimentation

Environmental development and protection measures such as feasibility studies, land-use planning and soil and water conservation are some of the issues that need to be considered in watersheds management. Apparently, integrated watershed management is emerging as an approach for the sustained development and management of natural resources. The integral enactment of different environmental frameworks, strategies and policies could positively impact watershed- based developmental approaches. Sediment which is brought through water erosion can hamper the proper functioning of waterways as well as the quality of water in dams. Knowhow on soil erosion and the sedimentation process is among the requisites that need to be considered for the control of sedimentation. Other elements like climate, edaphic factors, land management, topography, and land cover, etc. will also determine the sedimentation process. Integrated Watershed Management approach is a worthy approach to manage the ecological, social and economic watershed development challenges in countries like Ethiopia. Thus, this article is intended to assess watershed characteristics that will help to explore the possibilities of reducing sedimentation and its related effects.

Soil and Water Conservation Technology in the Zhifanggou Watershed

Soil and water conservation technology plays an important role in soil and water loss control and the construction of the ecological civilization in vulnerable areas. Here, soil and water conservation technology use over 70 years for the Zhifanggou watershed is summarized and ecological, economic and social backgrounds are determined through consultation with experts and reference to published literature. We found that soil and water conservation technology use includes soil and water conservation engineering technology, soil and water conservation cultivation technology and soil and water conservation biotechnology. Soil and water conservation technology utilization varied with people＇s demands and core problems at different developmental stages of the agricultural eco-economic system. The coupling process of the agricultural eco-economic system at Zhifanggou went through three stages. In stages I and II, soil and water conservation cultivation technology was applied to meet farmers＇ basic life demands. In stage III, all three technologies were applied comprehensively to solve eco-environmental problems and adjust industrial structure. To facilitate regional ecological civilization construction and sustainable development of the ecological economy and society, more emphasis should be given to research and development, implementation of soil and water conservation technology, stand structure improvement, forest grass quality enhancement, biodiversity, ecosystem functional improvement, development of soil and water conservation ecological resources, the coupling of soil and water conservation, and agricultural industry-resource optimization.

Integrated Prevention and Control System for Soil Erosion in Typical Black Soil Region of Northeast China

The black soil region of Northeast China is one of the most important food production bases and commodity grain bases in China. However, the continual loss and degradation of precious black soil resources has led to direct threats to national food security and regional sustainable development. Therefore, it is necessary to summarize integrated prevention and control experience of small watersheds in black soil region of Northeast China. Tongshuang small watershed, a typical watershed in rolling hills of typical black soil areas in Northeast China, is selected as the study area. Based on nearly 50 years' experience in prevention and control of soil and water loss, the structures and overall benefits of an integrated prevention and control system for soil and water loss are investigated. Then, the 'three defense lines' tri-dimensional protection system with reasonable allocation of different types of soil and water control measures from the hill top to gully is systematically analyzed. The first line on the top hill can weaken and block uphill runoff and sediment, hold water resources and improve soil property. The second line on the hill can truncate slope length, slow down the runoff velocity and reduce erosion energy. The third line in the gully is mainly composed of waterfall engineering, which can inhibit soil erosion and restore land resources. The 'three defense lines' system is feasible for soil and water loss control of small watersheds in the typical black soil region of Northeast China. Through the application of the in Tongshuang small watershed, There are effective improvements in ecological conditions in Tongshuang small watershed after the application of 'three defense lines' soil and water control system. Moreover, the integrated treatment paradigm for soil and water loss in typical black soil region is compared with that in loess region. The results of this study could offer references and experiences for other small watersheds in typical black soil region of Northeast China.

Effects of Erosion Control Measures on Mountain Floods： A Case Study of the Censhui River South Branch Watershed

To investigate the effects of various erosion control measures on mountain floods, a case study was conducted in Censhui River South Branch Watershed using scenario analysis and soil conservation service （SCS） methods. A distributed hydrological model was developed, and watershed parameters were determined based on satellite imagery, digital terrain models, digital maps and field investigations. Two types of erosion control measures were investigated： the variation of vegetation covers and the change of cultivation techniques. Seven scenarios were considered for the test watershed. The results show： （1） while the de-vegetation results in the increase of peak discharge, the improve of vegetation covers decreases peak discharge at watershed scale; （2） by both improving vegetation cover and enhancing terrace-cultivation technology, the peak discharge is reduced and the peak flow arrival time is delayed; （3） attention should be attached to both early warning system and measures changing the underlying surface and conveyance systems.

Quantitative analysis of morphometry on Ribb and Gumara watersheds: Implications for soil and water conservation

Morphometric analysis is a quantitative measurement and mathematical analysis of landforms.It plays a significant role in understanding the geohydrological characteristics of a drainage basin in relation to the terrain feature and its flow patterns.It also helps to estimate the incidence of infiltration and runoff,and other related hydrological character of a watershed like erosion and sediment transport which has a strong implication for natural resource conservation.This study has attempted to quantify the morphometric characteristics of Guna-Tana watershed for proper implementation of soil and water conservation practices.ASTER (DEM) was used for extracting morphometric parameters.The watershed covers a total area of 3601.5 km2 and it has a basin length of 78.89 km.It has been tried to generate morphometric parameters which account basin drainage network,geometry,drainage texture,and relief characteristics together with hypsometric characteristics.The morphometric analysis of drainage density of the study watershed is 0.49 km/km2 which indicates the basin is highly permeable and result with better underground water storage capacity.Ruggedness number is 0.02 that implies the area is less prone to soil erosion.In addition,it has stream frequency of 0.32 and form factor 0.57 which indicates slightly elongated basin shape.Comparative analysis of its sub watersheds Gumara and Ribb was also undertaken.Therefore,practicing soil and water conservation in the watershed could enhance/strengthen the water storage capacity,prevent sediment loss and related natural resource from the watershed that rehabilitate its productivity.

Effects of soil and water conservation practices on soil physicochemical properties in Gumara watershed, Upper Blue Nile Basin, Ethiopia

Background:Soil erosion is among the foremost causes of declining soil resources in Ethiopia,which in turn affect agricultural productivity.To limit this problem,for the last two decades in Gumara watershed,soil and water conservation measures have been practiced through free labor community mass-mobilization.However,their effect on soil fertility has not been evaluated.This study investigated the impact of implemented soil and water conservation measures on fertility improvement in the Gumara watershed.Both composite and core soil samples were taken from upstream,midstream,and downstream adjacent conserved and non-conserved cultivated and grazing plots.Selected soil fertility indicators were analyzed using standard laboratory procedures.Results:Soil and water conservation practices have resulted in a statistically significantly higher mean values of total nitrogen,exchangeable Na+and Mg2+at p<0.01,and of soil organic carbon and organic matter at p<0.05 in the watershed.The clay content,soil reaction,cation exchange capacity,and exchangeable K+showed nonsignificant,but higher mean values in conserved plots.Furthermore,the effects of conservation practices on soil properties were found more effective in cultivated land uses as compared to that of grazing land uses.This is because conservation treatments had significant effects on organic carbon,total nitrogen,exchangeable Na+and Mg2+in cultivated land uses but only on exchangeable Na+in grazing land uses.The interaction effect of treatments and land uses did not reach a statistically significant result for any of the soil properties considered in this study.Conclusion:Conservation measures have important implications for improving soil fertility in the Gumara watershed.Therefore,proper guidance and follow-up,use of agro-forestry and grass strips,and maintenance are required for the watershed’s sustainability and good soil conditions.

Post-adoption behaviour of farmers towards soil and water conservation technologies of watershed management in India

The Indian Institute of Soil and Water Conservation(IISWC)and its Research Centres have developed many successful model watershed projects in India in the past and implemented many Soil and Water Conservation(SWC)technologies for sustainable watershed management.While many evaluation studies were conducted on these projects in the past,there has been no assessment of the post-adoption status of the SWC technologies over a longer period.It was imperative to appraise the behaviour of the farmers with regard to the continuance or discontinuance of the technologies adopted,diffusion or infusion that took place and technological gaps that occurred in due course of time in the post watershed programme.Therefore,it was realized that the postadoption behaviour of beneficiary farmers who have adopted different soil and water conservation technologies for watershed management projects should be studied in detail.The research study was initiated in 2012 as a core project at Vasad as the lead Centre along with IISWC headquarter Dehradun,and Centres Agra,Bellary,Chandigarh,Datia,Kota&Ooty,with the specific objectives of the study to measure the extent of post-adoption behaviour(continued-adoption,discontinuance,technological gap,diffusion and infusion)of farmers towards the adopted SWC technologies of watershed management.In the present study various indices regarding continued adoption,dis-adoption(discontinuance),technological gap,diffusion,infusion regarding soil and water conservation technologies for watershed management were developed for measurement of post-adoption behaviour of farmers.It was revealed that a little less than three-fourth(73%)of SWC technologies continued to be adopted and more than onefourth(27%)were discontinued by farmers.Out of the total continue adopted SWC technologies by farmers,a little less than onefifth(19%)of technologies continued to be adopted with a technological gap.More than one-fourth(28%)of SWC technologies were also diffused to other farmers’fields in nearby villages and on an average 1.2 technologies were also infused into the farmers'fields from outside by their own efforts in the watersheds developed by the IISWC and its Centres.

山水林田湖草沙系统治理与水土保持高质量发展

[目的]中国水土流失治理已由“全面治理,重点治理”迈向“系统治理,攻坚克难”的新阶段。分析山水林田湖草沙系统治理的内涵、准则及其与水土保持的关系,旨在丰富新时代水土保持理论体系,引领水土保持高质量发展。[方法]在长期理论探索和实践验证的基础上,梳理山水林田湖草沙系统治理理念的发展过程,阐明其内涵、目标与实践准则。[结果]水土流失长期治理实践总结提升形成的以小流域为单元的综合治理技术路线是山水林田湖草沙生命共同体系统思想最朴素的实践体现。小流域综合治理的系统性主要体现为治理对象的系统协调,总体布局的系统统筹,治理措施的系统考量,治理成效的多效益兼顾,实施和管理的多部门协同和多主体参与的共治共享6个方面。水土保持高质量发展实践需要遵循的基于系统治理理念的具体举措包括:利用系统思维理解水土保持高质量发展的内涵和要求,精准诊断山水林田湖草沙系统短板及其控制性要素,构建山水林田湖草沙多层次全方位立体化防控体系,构筑完备的水土保持管理与技术保障体系。[结论]在新的历史时期,应该完整准确理解并全面贯彻落实山水林田湖草沙系统治理的理念,探索整体提升水土保持学术研究水平和治理效能的新路径、新模式、新机制。同时应结合区域或流域实际,对农田、水利、牧业、林业及生产建设活动进行全面综合系统的规划和治理,推动水土保持高质量发展。

水土保持碳汇项目管理信息系统的开发探索

水土保持碳汇项目信息化管理可以为水土保持碳汇项目开发提供科学规范的技术手段。分析了水土保持碳汇项目管理信息系统开发的主要挑战、建设目标及总体框架,以福建省长汀县罗地河小流域综合治理水土保持碳汇开发为研究对象,探索水土保持碳汇项目开发的全过程信息化体系建设,总结了系统在罗地河小流域综合治理过程中的应用情况以及存在的不足,并提出相关建议,以期为提升水土保持碳汇项目管理水平提供借鉴参考。

南方红壤侵蚀流域不同情景措施的减沙效应模拟

为揭示南方红壤侵蚀流域不同情景措施的减沙效应,实现区域可持续发展,采用SWAT(soil and water assessment tool)模型模拟方法,以南方典型花岗岩红壤侵蚀流域——福建长汀朱溪流域为研究区域,在模拟该流域产流产沙状况的基础上,通过不同水土保持措施和不同土地利用方式调整的情景设置,量化分析不同情景措施对该流域的减沙效应。结果表明,SWAT模型的模拟效果能达到模型要求的精度,2013—2017年朱溪流域年均径流量和年均泥沙量分别为4.793×10^(7)m^(3)和1.037×10^(7)kg。乔灌草混交和全坡面种草措施能有效提高植被覆盖度,减沙效果优越;不同土地利用方式下模拟得到朱溪流域单位面积年均减沙率为3.49%。以上研究结果可为红壤侵蚀流域泥沙阻控的生态恢复措施提供决策参考。

泰州市姜堰区淤溪小流域综合治理效果分析

通过实地调查、测量和地面观测等多元化方法,对淤溪小流域综合治理项目的防治责任范围、工程措施、林草措施、耕作措施、区域水质等情况进行全过程监测,充分掌握建设过程中水土流失情况和对周围环境的影响,并对监测数据进行整理计算分析,通过全过程精细化监测和数据精准处理,科学评估淤溪小流域综合治理成效。

夏县红沙河片区生态清洁小流域综合治理

红沙河片区存在河源区保护力度弱、沟道水系连通状况差、水资源和土地资源利用率低、农村基础设施差等问题。通过在预防保护区进行封禁治理,综合治理区布置坡改梯工程、保土耕作、林草工程、泉水利用工程等水保工程,同步推进面源污染防治、人居环境整治和文旅工程建设,生态修复区对赤峪河、吴家峪沟进行沟槽整治、边坡治理、岸边绿化等措施,将片区建设成为生态旅游型生态清洁小流域,可完善区内农业灌溉设施,提高了区内泉水利用率、土地生产力及沟道行洪能力,可有力促进当地特色产业、特色旅游业的发展,实现山青、水净、村美、民富的目标。工程建设亦可为同类工程建设提供借鉴和参考。

仁义河生态清洁小流域建设工程

灵石县仁义河生态清洁小流域建设,是山西省水土保持重点项目之一。项目区总面积40.764 km^(2),涉及2个乡镇的9个行政村,水土流失严重,治理程度较低。针对项目建设目标和水土保持现状,提出了以提高植被覆盖率和防洪排水为主要建设内容的工程设计,在指导生态清洁小流域建设的同时,也可为同类地区水土保持生态建设提供参考借鉴。

东北黑土区小流域综合治理模式研究

选取适宜的小流域综合治理模式是保障小流域地区治理与发展的重要举措,有助于提高治理的针对性和治理效益。本文根据东北黑土区自然地理条件和农业生产方式,本着归纳共同性、区分差异性的原则,将东北黑土区划分为漫川漫岗型、丘陵沟壑型、风沙型、中低山地型和平原型5种小流域治理类型区。并在全面调查研究、科学系统划定东北黑土区小流域治理类型区基础上,坚持分区治理、分类施策,通过总结东北黑土区典型小流域综合治理成效,分析提出适合东北黑土区小流域综合治理的模式,以期为管理实践及科学指导推进东北黑土区小流域综合防治、合理利用黑土地提供参考。

西南小流域洪峰流量估算

[目的]准确预测小流域的洪峰流量,为小流域水文应用和水保措施设计提供支撑。[方法]利用重庆万州刘家沟小流域2013—2021年共215次降雨事件数据,采用皮尔逊相关分析的方法,分析了重庆小流域次暴雨洪峰流量与降雨参数和径流参数的相关关系,进而采用线性回归和非线性回归方法,根据降雨径流资料估算了洪峰流量。[结果]研究建立了适用于西南小流域的洪峰流量公式,使用172场降雨事件数据进行参数率定,其模型有效系数为0.85;使用43场降雨事件对模型进行验证,相应的模型有效系数为0.82,结果表明新公式在研究区是可以接受的。[结论]研究建立的洪峰流量公式,能够较好地预测研究流域的洪峰流量,新建公式将为重庆乃至中国西南小流域进行水土保持措施的决策、水土保持工程设施设计和土壤侵蚀评价等提供一定技术基础。

越城区坡塘小流域水土流失治理及施工技术应用

绍兴市越城区坡塘小流域存在水土流失问题。通过分析该区域的综合生态治理项目,评估水土流失、生态退化和生产条件等制约因素对当地生态环境稳定及区域可持续发展的影响,采用了土地封育、水土保持和生态恢复等多元化治理策略,以期优化生态环境,减缓水土流失,增强区域水源涵养能力。通过实地调研与数据分析,精准实施上述水土流失治理措施。结果表明,综合治理能有效改善小流域生态,增强农业生产能力,推动区域共同富裕,促进人与自然和谐共生。

广州市从化区生态清洁小流域划分及建设模式研究

生态清洁小流域的建设对河湖生态环境的保护与涵养、生态环境的恢复、科学开展国土绿化、建设宜居宜业的美丽乡村等方面都有着十分重要的意义。该研究以广东省广州市从化区为研究区域,基于DEM数据,通过ArcGIS技术将境内水源保护区、农业发展区、生态旅游区、城镇宜居区等划分为85条生态清洁小流域,划定为水源保护型、绿色发展型、和谐宜居型和生态旅游型4种类型,并探索其适宜的小流域建设模式,可为后续生态清洁小流域规划设计提供参考。

基于小型水利水保工程的小流域水土保持优化设计

针对小流域水土流失的加重,研究提出基于小型水利水保工程对其进行优化设计。通过水利水保工程、经果林、改梯田措施等,改进优化小流域。结果表明,水土流失面积治理程度为88.46%,项目产生的直接经济效益559.85万元,农民人均纯收入增加565元。研究表明,优化后小流域的保水保土能力增强,水土流失得到明显控制,可为安龙县社会经济发展提供生态保障。

小流域综合治理工程水土保持措施研究

为解决小流域水土流失及生态环境破坏问题,以某小流域综合治理工程为例,通过实地调查和资料收集,总结了该小流域水土流失的原因和特点,分析了水土保持措施在案例工程中的应用,包括前期调查、中期管控、效果评估、后期监测等方面,并提出了小流域综合治理工程水土保持措施的应用要点,以期提高小流域综合治理工程的效果,促进水土保持和生态环境保护。