Integrating water use systems and soil and water conservation measures into a hydrological model of an Iranian Wadi system

Water resources are precious in arid and semi-arid areas such as the Wadis of Iran. To sustainably manage these limited water resources, the residents of the Iranian Wadis have been traditionally using several water use systems(WUSs) which affect natural hydrological processes. In this study, WUSs and soil and water conservation measures(SWCMs) were integrated in a hydrological model of the Halilrood Basin in Iran. The Soil and Water Assessment Tool(SWAT) model was used to simulate the hydrological processes between 1993 and 2009 at daily time scale. To assess the importance of WUSs and SWCMs, we compared a model setup without WUSs and SWCMs(Default model) with a model setup with WUSs and SWCMs(WUS-SWCM model). When compared to the observed daily stream flow, the number of acceptable calibration runs as defined by the performance thresholds(Nash-Sutcliffe efficiency(NSE)≥0.68, –25%≤percent bias(PBIAS)≤25% and ratio of standard deviation(RSR)≤0.56) is 177 for the Default model and 1945 for the WUS-SWCM model. Also, the average Kling–Gupta efficiency(KGE) of acceptable calibration runs for the WUS-SWCM model is higher in both calibration and validation periods. When WUSs and SWCMs are implemented, surface runoff(between 30% and 99%) and water yield(between 0 and 18%) decreased in all sub-basins. Moreover, SWCMs lead to a higher contribution of groundwater flow to the channel and compensate for the extracted water by WUSs from the shallow aquifer. In summary, implementing WUSs and SWCMs in the SWAT model enhances model plausibility significantly.

Benefit measurement of the soil and water conservation for ecological forestry engineering

Data were collected from Three-north Region, Middle and upper reaches region of Yangtze River and Coastal region. By analysis of factors influencing soil erosion, the longitude, latitude, annual precipitation, and the slope degree were selected as regional independent variables and canopy density and stock litter were selected as independent variables, and integral diffusing models were established for evaluation of the benefit of soil and water conservation of forest. By solving the parameters of models using the package of STATISTICA, the Power function between independent variables and dependent variables was set up. The soil conservation amount of forest and economic values were estimated using the contrast method for the ecological forestry engineering of the above three areas.

Effects of Zero Tillage and Residue Retention on Soil Quality in the Mediterranean Region of Northern Syria

Zero-tillage (ZT) and crop residue retention on the soil surface—two components of Conservation Agriculture (CA)—have been identified as promising management practices for sustainable agri- cultural intensification for some time. However, CA technology uptake by farmers in the dry areas of West Asia and North Africa (WANA) has yet to happen large-scale, even though the positive im- pact on yield has been demonstrated repeatedly. To explain the observed consistent increases in crop yield under ZT, a range of soil quality indicators were regularly monitored during 2008 to 2012 in the long-term ZT/CA trials at the headquarters of the International Center for Agricultural Research in the Dry Areas (ICARDA) in northern Syria. Results showed that CA had a positive im- pact on soil fertility. This was measurable by higher soil organic matter (SOM) and microbial bio- mass contents, increased levels of extractable phosphate, sometimes (but not always) higher amounts of larger water-stable soil aggregates, increased soil infiltration capacity and soil water retention. The buildup of SOM and associated carbon (C) sequestration was in the range of 0.29 Mg C/ha/yr, i.e. rather modest. High amounts of surface residues delayed the desiccation of the topsoil during the fallow period, but could not diminish the overall longer-term drying of the topsoil. The observed positive changes in soil quality were little, but nevertheless, in combination with the economic savings that ZT offers, this type of agricultural intensification provides an attractive op- tion for farmers in WANA, from the standpoints of economy and ecological efficiency.

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.

水土保持碳汇内涵与测算方法

水土保持深刻改变着地表覆被和结构、土地利用方式和陆地生态系统结构等,是增强陆地碳汇能力的重要途径。以水土保持林草、工程和耕作措施为切入点,按照“机理阐述—模型构建—分类测算”的总体思路,阐明水土保持碳汇内涵,明确了水土保持碳汇途径,构建水土保持碳汇测算方法,估算全国水土保持碳汇量。结果表明:水土保持具有垂向碳增汇、横向保土固碳(减少侵蚀土壤横向输移导致的碳流失)与减蚀减碳(避免碳排放)的多重功能。2021年,全国现存水土保持措施垂向碳增汇总量为1.54亿t,对陆域碳汇的贡献约43.5%~56.5%,其中林草措施植被和土壤碳汇量超过95%。水土保持保土固碳作用显著,2021年全国水土保持措施保土固碳总量为3 040.86万t,且具有明显的累积效应和长效作用。总体来说,2021年水土保持碳增汇(不包括水土保持林草措施植被碳汇量和土壤碳汇量)和减碳量为5 115万~6 230万t CO_(2),约占到全国现有陆地生态系统碳中和总量的4%~6%,这一部分尚未纳入国家碳汇核算体系,其应是实现“双碳”目标的重要环节。

休闲农业协同研学旅行课程开发的规划设计研究——以黄河流域休闲农园镶月湖为例

研学旅行能够激发学生学习兴趣,最大化挖掘并发挥其所长。以此为切入点,以黄河流域休闲农园镶月湖为载体,开展理论与实践相结合的研究,探索在黄河流域休闲农业建设中,兼顾文化、生态治理研学课程开发的规划设计方法,以强化学生的水土保持意识,弘扬流域文化,为研学旅行的教育改革服务。

三峡库区水土流失遥感监测及治理研究

三峡库区是长江流域生态环境系统的重要环节,库区生态环境问题备受关注。水土流失是影响三峡库区生态安全、制约库区发挥生态屏障功能的关键环境问题之一。2020—2022年,水利部水土保持监测中心的三峡库区水土流失遥感监测站组织实施了基于遥感技术的三峡库区水土流失动态监测,结合野外考察和数值模拟等手段,对库区土壤侵蚀因子与侵蚀模数进行计算,并对水土流失防治效益进行评价。结果显示:(1)林地和耕地是水土流失发生的主要区域;(2)在相同的土地利用模式下,地形较陡的区域更易发生强度较大的水蚀;(3)2020—2022年,库区水土流失面积呈减少趋势,减少速率约为264 km^(2)/年,水土保持措施面积则以865 km^(2)/年的速率增加,取得较好治理效果。在进一步工作中,可针对性地在坡度较大的水蚀区进行合理的水保措施布设,以进一步提高库区水土流失治理成效。本研究可为三峡库区水土流失治理和水保措施规划以及长江流域生态系统建设提供科学依据。

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。

Impacts of water conservancy and soil conservation measures on annual runoff in the Chaohe River Basin during 1961-2005

Taking the Chaohe River Basin above the Miyun Reservoir in North China as a study area, the characteristics and variation trends of annual runoff and annual precipitation during 1961-2005 were analyzed applying Mann-Kendall test method on the basis of the hydrologic data of the major hydrological station （Xiahui Station） located at the outlet of the drainage basin and the meteorological data of 17 rainfall stations. Human activities including water conservancy projects construction and water diversion as well as implementation of soil and water conservation from 1961 to 2005 were carefully studied using time series contrasting method. The referenced period （1961-1980） that influenced slightly by human activities and the compared period （1981-2005） that influenced significantly by water conservancy and soil conservation measures were identified according to the runoff variation process analysis and abrupt change points detection during 1961-2005 applying double accumulative curve method, mean shift t-test method and Mann-Kendall mutation test technique. Based on the establishment of a rainfall-runoff empirical statistical model, impacts and the runoff-reducing effects of water conservancy and soil conservation measures on runoff reduction were evaluated quantitatively. The major results could be summarized as follows： （1） The annual precipitation in the drainage basin tends to decrease while the runoff has declined markedly since the 1960s, the average annual runoff from 1991 to 2000 was only 90.9% in proportion to that from 1961 to 1970. （2） The annual runoff variations in the drainage basin are significantly related to human activities. （3） During 1981-1990, 1991-2000, 2001-2005 and 1981-2005, the average annual runoff reduction amounts were 1.15×10^8, 0.28×10^8, 1.10×10^8 and 0.79×10^8 m^3 respectively and the average annual runoff-reducing effects were 31.99%, 7.13%, 40.71% and 23.79% accordingly. Runoff-reducing effects by water conservancy and soil conservation measures are more prominent in the low water period.

“双碳”目标下水土保持碳汇计量、监测与评估的思考

开展水土保持碳汇计量、监测与评估是服务我国“碳达峰、碳中和”战略的重要举措之一,可为未来的水土保持措施实施和政策制定提供理论支撑。笔者以“碳达峰、碳中和”战略背景下碳汇相关政策与研究为基础,指出我国水土保持碳汇发展方向,阐明水土保持碳汇计量的概念、应用及评估认证体系。水土保持碳汇计量监测是“双碳”战略、水保规划、内生动力的重要实现手段,也是碳交易、生态富民和投入机制的主要应用场景。加强水土保持碳汇评估、分类管理和认证体系的建设,健全碳汇调查监测技术方法,能够推进水土保持碳汇的精确评估,为碳中和目标提供理论和技术支撑。新时期应全面推行水土保持碳汇计量监测体系建设,提升水土保持碳汇开发方法,建立水土保持碳增汇考核指标,持续挖掘水土保持碳汇增长的潜力,加强碳汇水土保持措施多元化发展,拓宽水土保持碳汇投资渠道,完善水土保持碳汇交易保障机制,推动水土保持碳汇参与碳市场交易。

黑土区坡耕地水土保持耕作措施对土壤理化性状的影响

为探寻黑土区坡耕地不同水土保持耕作措施对土壤理化性状的影响机理,开展了田间小区试验。设置横坡耕作(TP)、垄向区田(RF)、深松(SF)、横坡耕作+垄向区田(TP-R)、横坡耕作+深松(TP-S)、垄向区田+深松(RF-S)3种水土保持耕作措施及3种组合耕作措施,并以常规顺坡耕作(CK)为对照,分析了土壤孔隙度、土壤机械组成、水稳性土壤团聚体稳定性、土壤养分含量等指标,并采用TOPSIS模型对不同水土保持耕作措施进行了综合评价,筛选了土壤稳定性强且蓄水保肥效果良好的水土保持耕作措施。结果表明:在玉米的全生育期内,深松、垄向区田、横坡耕作均能提高土壤体积含水率。TP-S处理体积含水率最大,0~40 cm土层平均体积含水率较CK处理增加29.47%;RF-S处理平均孔隙度最大,TP-S处理次之,平均孔隙度较CK处理分别增大10.68%、9.25%;TP-S处理能够显著提高土壤稳定性,其中平均质量直径(MWD)、几何平均直径(GMD)和大团聚体含量(R0.25)较CK处理分别增加12.30%、19.57%、13.97%;TP-S处理能够改善土壤机械组成,TP-S处理粗砂粒、粉粒、黏粒含量较CK处理增加15.40%、26.89%、1.90%,细砂粒含量较CK处理降低31.56%;TP-S处理IN(无机态氮)、AP(有效磷)、AK(速效钾)含量最高,较CK处理IN、AP、AK含量分别增加42.81%~55.32%、39.69%~40.68%、20.41%~25.45%。由TOPSIS模型综合评价结果可知,TP-S处理贴合度最高,土壤结构更稳定,且蓄水保肥效果更好,为适宜该地区的水土保持耕作措施。

“23·7”京津冀地区暴雨洪水与土壤侵蚀调查——以河北省邢台市临城县为例

[目的]开展“23·7”(20230729—0801)京津冀地区暴雨洪水过程及水土保持调查工作,分析小流域的暴雨洪水过程以及暴雨所造成的土壤侵蚀状况,为水土保持决策提供科学支撑。[方法]采用野外调查的方法对河北省临城县皇迷东沟和梁家庄西沟开展洪痕测量调查并计算洪峰流量模数,分析暴雨洪水对小流域造成的侵蚀危害。[结果]①该次降雨持续时间长、雨强大。梁家庄西沟和皇迷东沟流域累计雨量分别达到1008.5和613.6 mm。②按洪痕法调查推算了洪峰流量,皇迷东沟、梁家庄西沟小流域洪峰流量模数为10.80和36.07 m^(3)/(s·km^(2))。坡度和水土保持措施是影响洪峰流量的主要因素。较大的坡度会使洪峰流量变大,而完善的水土保持措施可以起到有效的削峰作用。③调查小流域位于泜河流域上游,是该次暴雨中心和洪水的主要产流区,小流域洪峰流量模数大于下游水文站洪峰流量模数。④梁家庄西沟的侵蚀情况比皇迷东沟严重,主要原因是皇迷东沟的果园、梯田和谷坊的面积比例大于梁家庄西沟,皇迷东沟的平均坡度小于梁家庄西沟且梁家庄雨量站的降雨量峰值持续时间更长。[结论]良好的水土保持措施可以有效减少洪峰流量以及侵蚀现象的发生。实施水土保持措施是必要且有效的。应该进一步完善梯田、台地谷坊的建设。

水土保持植物措施碳汇研究综述

开展水土保持碳汇研究,分析水土保持植物措施的碳汇效应,可为全面提升水土保持碳汇能力、制定固碳增汇政策措施、科学推进水土流失综合治理工作、推动高质量发展和实现“双碳”目标提供科学依据。论述了水土保持植物措施的碳汇意义、碳汇功能内涵和机理、碳汇量的计算方法,并通过总结和分析国内外相关文献,深入分析水土保持植物措施对生态系统固碳功能、植被固碳和土壤碳库的影响,提出了以固碳增汇为目标的水土保持植物措施配置方案。

1986-2018年黄土丘陵区典型小流域不同水文年水沙变化

[目的]探讨黄土丘陵区罗玉沟典型小流域水沙变化趋势以及不同水文年径流输沙对水土流失治理的响应差异,量化降水和人类活动对流域水沙影响的相对贡献,以期为黄土丘陵第三副区流域水土流失治理和水资源管理提供参考。[方法]基于罗玉沟流域1986—2018年的降雨、径流、输沙等数据,采用Mann-Kendall检验法、累积距平法及双累积曲线法分析流域水沙变化趋势及驱动因素。[结果]1986—2018年罗玉沟流域河流由常流河转变为季节性河流,干河日数显著上升(p<0.01),2000年以来干河日数多在300 d以上;同期,罗玉沟流域径流输沙显著下降(p<0.05),与基准期1986—1993年相比,1994—2007年减水减沙率分别为61.9%,44.3%,2008—2018年径流输沙分别减少67.5%,76.4%;在2008—2018年平水年和枯水年间罗玉沟流域输沙模数分别为(1 080.0±107.5) t/km^(2),(167.8±111.4) t/km^(2),而在暴雨频发丰水年,输沙模数仍接近4 000 t/km^(2);流域产流产沙能力降低,水沙关系发生改变,相同径流条件下输沙量减少,即流域径流含沙量水平降低,开始变清;相比降雨变化而言,人类活动是流域水沙变化的主导因素,1994—2007年人类活动对减水减沙的贡献率分别为83.3%和79.5%,而2008—2018年人类活动的贡献率分别为91.8%,94.4%,表明流域水沙变化受人类活动影响越来越大,其中,坡改梯及退耕还林还草工程是主要影响因素。[结论]因沟道治理工程建设不足,罗玉沟流域在丰水年因沟道重力侵蚀导致流域输沙仍然剧烈,因此,需要加强沟道治理进一步减少流域水土流失。

农业水利灌溉模式与高效节水措施探讨

农业是国家发展的基石,而发展农业选择科学的水利灌溉模式以及高效的节水技术,才能保证农业水利灌溉的效率和质量,提高农业综合生产力,促进我国农业经济的发展。对此,本文分析了农业水利灌溉事业的建设情况,列举了几种常见的农业灌溉模式,深入探讨了农业水利灌溉中存在的问题和不足,并提出了节水技术措施和解决办法。

水土保持方案编制现状分析与讨论

为贯彻落实《水利部印发贯彻落实〈关于加强新时代水土保持工作的意见〉实施方案》,根据2022年水土保持方案质量抽查情况和2023年1月发布的《生产建设项目水土保持方案管理办法》(以下简称《管理办法》)要求,2023年7月水利部制定了针对不同区域、不同行业水土流失特点的《生产建设项目水土保持方案审查要点》(以下简称《审查要点》)。为更好地理解与把握新颁布的《审查要点》和《管理办法》,针对当前水土保持方案中存在的变更率过高、前期工作不扎实、水土保持内容缺失、响应法规标准要求不够等问题进行了剖析,并就项目的完整性、前期工作的重要性、对主体工程的理解程度、水土保持措施布设的科学性及其他相关内容的相符性方面,对方案编制内容进行了重点分析,在此基础上对《审查要点》的条款要求进行了系统解读,明确了水土保持方案内容审查的红线要求,为规范水土保持方案编制与审查提出了解决方案。

大型山地光伏电站施工期水土保持关键技术浅析

随着科技进步以及对新能源的需求,越来越多的光伏电站在太阳能资源丰富的山地地区建造。在建设过程中对周边环境产生的影响不可避免,往往会引发水土流失问题。本文以云南临沧市某大型山地光伏电站项目为例,通过对其水土流失现状及危害的分析,并以水土保持措施在该项目中的应用情况,对大型山地光伏电站施工期的水土保持关键技术进行浅析。

农田灌溉调度过程中存在的问题及优化措施

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