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.

Soil micro-penetration resistance as an index of its infiltration processes during rainfall

Rainfall infiltration is one of the most important driving factors of geological hazards, ecological environment problems, and engineering accidents. Understanding the principle of soil wetting during rainfall infiltration and its influence on soil mechanical properties is crucial for preventing geological hazards. In this study, micro-penetration tests coupled with moisture monitoring were performed to investigate the infiltration process during wetting through the measured change in mechanical characteristics. Results show that penetration resistance increases in the deep layer gradually. With increasing infiltration time,the wetting front keeps moving downward, and its range becomes wider. A slight increase of the penetration resistance in the shallow layer(d ≤ 17.5 mm) is observed. However, the penetration resistance in the middle layer(22.5 mm ≤ d ≤ 32.5 mm) decreases firstly before a slight increase. In the deep layer(d ≥ 37.5 mm), the penetration resistance decreases continuously during infiltration. Based on the measured water content profile during infiltration, it is found that the evolution of soil mechanical characteristics is fully responsible by the infiltration-induced re-distribution of water content along depth. Generally, the penetration resistance decreases exponentially with increasing water content in the soil. When the water content is low, wetting can weaken soil strength significantly, whereas this effect diminishes when the moisture surpasses a certain threshold. The results highlight that the penetration curves and water content profile show close inter-dependency and consistency, which verifies the feasibility of using micro-penetration to investigate rainfall infiltration and wetting process in surface soil layer or laboratory small-scale soil samples. This method enables fast, versatile and high-resolution measurements of infiltration process and moisture distribution in soil.

Effects of ecological soil and water conservation measures on soil erosion control in China’s typical regions:A meta-analysis

[Background]As one of the most serious environmental issues in the world,soil erosion causes water pollution,reservoir siltation,soil productivity decline,thus threatens agricultural systems and even affects global climate.The benefits of ecological soil and water conservation measures(ESWCMs,such as micro basins tillage and contour tillage)are widely understood,including runoff and soil loss reducing to a certain extent when compared with traditional tillage.While few studies have focused on China’s different soil types and erosion characteristics.[Methods]We reviewed literature from Web of Science,Scopus,and China National Knowledge Infrastructure using terms like“Conservation practice”“Contour tillage”“Runoff”“Sediment”“Erosion”and“China”and retained literatures based on criteria such as natural or simulated precipitation,runoff or soil loss data,reported replications and statistics,recorded factors like location and slope,and at least two data pairs per group.Ultimately,49 literatures were selected to quantify the impacts on different ESWCMs and identify the slope and precipitation for the greatest runoff and sediment reduction by calculating the log response ratio(LRR).[Results]The three regions’soil and water conservation benefits varied due to the differences in climate,terrain,and soil properties:1)ESWCMs applied in the black soil region of Northeast China were the most effective in reducing runoff and soil loss(66.65%runoff and 75.83%sediment),followed by those applied in the purple soil region of Southwest China(39.98%runoff and 58.30%sediment)and loess soil region of Northwest China(16.36%runoff and 32.44%sediment).2)Micro basins tillage(MBT)(71.79%runoff and 87.03%sediment)no-tillage with mulch(NTM)(17.30%runoff and 32.51%sediment),collecting soil to form a ridge with no-till(CSNT)(55.78%runoff and 71.36%sediment reduction)were the most efficient soil and water conservation measures in controlling water erosion in the black soil of Northeast China,the loess soil region of Northwest China and the purple soil region of Southwest China,respectively.3)The slope gradients ranged from 0-3°,>3°-5°and>10°-15°(0-3°:97.09%;>3°-5°:74.62%;and>10°-15°:39.41%)caused the largest reduction of runoff in the black soil region of Northeast China,the loess soil region of Northwest China,and the purple soil region of Southwest China.Meanwhile,the effects of sediment reduction were the most obvious,ranging from 0-3°,>10°-15°,and>20°-25°(0-3°:89.32%;>10°-15°:75.94%;and>20°-25°:67.25%).4)The effect of ESWCMs under rainstorms was the most obvious in the black soil region of Northeast China.The effect on runoff reduction under light rain in the purple soil region of Southwest China was the most obvious,but it failed to pass the significance test in sediment reduction.[Conclusions]The results provided optimal conservation tillage measures for three regions,different slopes and different rainfalls,and provided data support for reducing regional soil and water loss in China.

PREDICTION OF SEDIMENT REDUCING BENEFIT UNDER DIFFERENT RAINFALL COND ITIONS AND CONTROL DEGREES ON THE LOESS PLATEAU

Based on the distribution of hydrological stations and zoning of types ofsoil erosion, the Loess Plateau (3 10 x 10~3km^2) is divided into 292 erosion units. And taking theerosion modulus > 5000t/km^2 as a criterion, the emphasis control area (149 x 10~3km^2) of the LoessPlateau is demarked, and is divided into 10 control regions. The controllable area and the locationof control measures are conformed. Level terraces are mainly collocated on the 3° ―15° slopes,woodland and grassland are collocated on the > 15° slopes, and the proportion of woodland tograssland is 8: 2 in the forest belt, 5: 5 in the forest steppe belt, and 2: 8 in the steppe belt.The 9000 combinations of soil-water conservation measures in different rainfall conditions areobtained by the permutation and combination method, according to the 9 rainfall frequencies and thecontrollable areas of level terrace, woodland and grassland at 10% of control progress rate. Thequality standards of level terrace, woodland and grassland are ascertained. The evaluation indexesof soil-water conservation benefits of level terrace, woodland and grassland are establishedrespectively in the condition that rainfall index is higher than that of erosive index of slopingfield. Based on the results above, the sediment reducing benefit and soil erosion modulus in thedifferent rainfall conditions and control degrees are analyzed, which could provide adecision-making basis for soil-water loss control on the Loess Plateau.

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.

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.

Effect of mulching with maize straw on water infiltration and soil loss at different initial soil moistures in a rainfall simulation

Mulching and soil water content(SWC) have a significant impact on soil erosion,and this study investigated the effect of straw mulching on water infiltration and soil loss under different initial SWC treatments in a rainfall simulation experiment conducted in northern China.Increasing initial SWC can decrease soil infiltration and increase soil loss.During an 80 mm rainfall event(80 mm·h–1for 60 min),8%,12% and 16% initial SWC treatments decreased cumulative infiltration by8.7%,42.5% and 58.1%,and increased total sediment yield by 44,146 and 315 g,respectively,compared to 4%initial SWC.However,in all the straw mulching treatments,there was no significant difference in stable infiltration rate between the different initial SWC treatments.For all initial SWC treatments,straw mulching of30% or more significantly enhanced water infiltration by over 31% and reduced soil loss by over 49%,compared to the unmulched treatment.Taking into consideration the performance of no-till planters,a maize straw mulching rate of 30% to 60%(1400–3100 kg·hm–2) is recommended for the conservation of water and soil in northern China.

Simulated rainfall in Brazil:An alternative for assesment of soil surface processes and an opportunity for technological development

Rainfall simulators(RS)have been used,above all,to evaluate hydrological processes related to soil water infiltration,surface runoff and soil erosion.They allow repeatability of rain application with different precipitation intensities in field and/or laboratory conditions and should produce events with physical characteristics similar to natural rain.In this manuscript,we carried out a bibliometric and scientometric analysis of studies with simulated rainfall in Brazil to assess the temporal evolution of publications,the main topics addressed and the degree of technological development of the equipment.We searched for the terms“rainfall simulator”OR“simulated rainfall”AND“Brazil”in the Scopus,Web of Science,SciELO and Google Scholar databases.We found 143 articles published in the last 37 years(1985-2022).Our findings indicate that the main research areas covered in papers are soil erosion(57.34%),soil water infiltration(24.47%),nutrient losses(9.8%)and RS development and calibration/assessment(8.39%).In recent years,the number of published papers in international high-impact factor journals has increased.Most of the papers(49.65%)refer to studies carried out by institutions located in the south and southeast regions of Brazil.Moreover,there is a large gap of studies on simulated rainfall in other regions of Brazil,where important biomes such as the Cerrado,Amazon,Caatinga,and their transitions are located.This study informs research priorities on soil erosion under simulated rainfall and provides a bibliographic database that can assist in more detailed future analyses.

Deep soil water infiltration and its dynamic variation in the shifting sandy land of typical deserts in China

Soil moisture is the key resource constraint in arid ecosystems, and has been a focus of research on restoration. However, quantitative studies on the contribution of rainfall to deep soil rainfall infiltration are lacking. In this study, we used the YWB-01 Deep Soil Infiltration Water Recorder which had been invented by ourselves to measure the quantity of rain infiltration into deep soil, 150 cm below ground, in four locations in China: Mu Us Sandy Land and Ulan Buh, Tengger, and Badan Jilin deserts over a 2-year period. We found:(1) Deep soil rainfall infiltration decreased progressively from east to west and from semiarid to arid areas, with two locations completely lacking rainfall infiltration. Heavy rain was important to deep soil infiltration in shifting sandy land of arid and semiarid areas.(2) Seasonal variation of infiltration was correlated with rainfall, with a time lag that was less apparent in areas with more rainfall.(3) For single intense rainfall events, infiltration maximums occurred 40–55 h after the rainfall, during which the infiltration rates increased rapidly before reaching a peak, and then decreased slowly. Continuous infiltration could last about 150 h. Rainfall infiltration was determined by the combined action of intensity, quantity and duration. Rainfall with low intensity, long duration, and large quantity was most favorable for deep soil infiltration. Our results can be used in water resource assessments and protection during eco-restoration in the arid and semiarid areas in China.

建立科学评价体系促进水土保持措施的可持续发展

为促进水土保持措施的可持续发展,分析了当前水土保持工作的局限性,重点关注管理不足、监测体系不完善以及科研与技术创新滞后等问题。针对这些挑战,建议建立综合评价指标体系,优化数据收集与监测手段,并选择适当的评价方法,以科学评估水土保持措施的实际效果及其长期影响,促进水土保持的科学决策。通过构建多维度评价指标体系和实施综合数据监测,为有效开展水土保持工作提供指导,从而促进生态环境改善与可持续发展,确保在应对日益严峻的水土流失问题时,实现资源的高效利用与生态平衡的维护。

黄土塬区不同土地利用方式土壤水分对次降雨的响应特征

[目的]探究土壤水分对次降雨响应过程,揭示该地区不同土地利用方式的土壤水分特征,进而为缺水地区降水利用和农业水资源合理配置提供观测依据。[方法]对2021年黄土塬区苜蓿草地、休闲地、高产农田(正常施肥)和低产农田(长期不施肥)4种土地利用方式的土壤水分进行了定位监测,并分析其对大于30 mm的3次降雨事件响应过程。[结果]随着降雨量的增加,苜蓿草地、休闲地、高产农田和低产农田的降雨入渗和水分再分布深度也呈增大趋势,最大水分入渗深度分别为300,500,500,500 cm。不同土地利用方式土壤含水量具有明显的季节特征,月均土壤含水量呈现先增大后减小的趋势,最小值分别出现在8月、1月、1月和6月,最大值均在10月。雨季后,土壤水分仍处于再分布过程,12月底苜蓿草地、休闲地、高产农田和低产农田水分再分布深度分别达到400,700,800,700 cm;土壤储水量变化滞后于降雨量,9—10月土壤储水量变化最强烈,苜蓿地、休闲地、高产农田和低产农田土壤储水量增幅分别为390.6,197.5,299.8,157.4 mm。[结论]4种土地利用方式中,亏缺严重的苜蓿草地土壤水分对降雨的响应最为敏感,最大响应深度可达400 cm,土壤储水量变化幅度也最大,水分再分布过程导致其变化滞后于降水量。

暴雨条件下水土保持措施对坡面产流产沙的影响

[目的]探究暴雨条件下水土保持措施对坡面产流产沙的影响,可对科学制定高效的水土流失防治措施提供依据。[方法]依托北京密云区石匣小流域水土保持科技示范园的7个径流小区,选取了2010—2021年20场自然暴雨观测数据,运用统计和相关分析等方法探讨了不同水土保持措施对产流产沙和面源污染的影响,并分析了降雨、土壤、植被因子与产流产沙之间的相关性。[结果](1)在2010—2021年研究区年降雨总量相对平缓,但年降雨频率有所增加、暴雨发生次数呈现出上升趋势。(2)在20次暴雨条件样本中,荆条的减流率和减沙率分别为94.13%和99.76%,减流减沙效益优于刺槐+侧柏+鱼鳞坑、玉米+梯田等其他组合。荆条、刺槐+侧柏+鱼鳞坑对面源污染的防治效果较好,污染指标显著低于平均水平。(3)降雨因子、植被因子与径流泥沙的相关性分析显示,平均雨强、I30、I60与径流量呈显著正相关,相关系数分别为0.54,0.73,0.7;平均雨强、I60与泥沙量呈显著正相关,相关系数分别为0.58,0.5;植物盖度与径流量、泥沙量明显负相关,相关系数分别为-0.51,-0.58。[结论]综合考虑暴雨条件下的径流泥沙数据,我们认为在保障经济效益的前提下,推荐该地区采用荆条作为优先水土保持措施。

公路建设生态环境保护及水土保持措施

生态环境建设已成为国家发展的重要战略。现代化背景下,随着国民经济迅速发展,民生问题愈发受到重视与关注,公路建设工程数量不断增加。而公路建设的过程,会对周围生态环境造成一定的影响与破坏,甚至加剧水土流失,这对生态环境保护与水土保持工作实践落实带来较大挑战。为进一步提升生态环境质量,缓解水土流失现象,维持生态平衡,本文分析公路建设对生态环境及水土保持的危害,并探讨相关实践措施,以期促进美丽中国建设进一步实现。

Dynamic study of infiltration rate for soils with varying degrees of degradation by water erosion

Ultisols,widely distributed in tropical and subtropical areas of south China,are suffering from serious water erosion,however,slope hydrological process for Ultisols under different erosional degradation levels in field condition has been scarcely investigated.Field rainfall simulation at two rainfall intensities (120 and 60 mm/h) were performed on pre-wetted Ultisols with four erosion degrees (non,moderate,severe and very-severe),and the hydrological processes of these soils were determined.The variation of soil infiltration was contributed by the interaction of erosion degree and rainfall intensity (p < 0.05).In most cases,time to incipient runoff,the decay coefficient,steady state infiltration rate,and their variability were larger at the high rainfall intensity,accelerating by the increasing erosion severity.Despite rainfall intensity,the infiltration process of Ultisols was also significantly influenced by mean weight diameter of aggregates at the field moisture content,soil organic carbon and particle size distribution (R2 > 30%,p < 0.05).The temporal erodibility of surface soil and soil detachment rate were significantly and negatively correlated with infiltration rate (r <-0.32,p < 0.05),but less significant correlation was observed between sediment concentration and infiltration rate for most soils,especially at the high rainfall intensity.The variation of surface texture and soil compactness generated by erosion degradation was the intrinsic predominant factors for the change of infiltration process of Ultisols.The obtained results will facilitate the understanding of hydrological process for degraded lands,and provide useful knowledge in managing crop irrigation and soil erosion.

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。

横断山区典型流域次降水事件水沙特征分析

横断山区干热河谷高温低湿,植被稀疏,水土流失现象较为严重,是金沙江、澜沧江和怒江等大江大河泥沙的主要源区。干热河谷地区水土流失多由次强降水事件造成,因此在该区域基于次降水事件尺度开展水沙特征研究,对于评价降雨和下垫面对流域产流产沙的相对贡献、指导未来水土保持实践具有重要意义。基于金沙江一级支流龙川江流域小黄瓜园水文站1966—2018年实测水沙数据,运用Mann-Kendall方法划分基准期和变化期,并基于2期次降水事件,对比分析降雨等级相同、暴雨覆盖面积比例等级相同、降雨量和降雨空间分布相似等3种情况下,2期水沙特征及变化原因。结果表明:1)小黄瓜园1966—2018年径流量和输沙量呈现明显下降趋势,其中2008年为突变年份;2)水土保持措施主导下的下垫面变化是变化期径流输沙减少的主要原因。长期以来龙川江流域实施的水土保持工程有效地改变下垫面的情况,减流减沙效果明显。应进一步加强横断山区等地形复杂地区次降水事件尺度水沙变化研究,更好地指导水土保持优化配置与管理。

三维土工网边坡防护水土保持能力研究

路基边坡防护工程可减轻降雨对坡面土体的侵蚀作用,为深入研究坡面防护材料水土保持能力的定量表征方法,通过室内人工降雨边坡侵蚀模型试验,分析不同降雨强度和不同三维土工网防护下路基边坡的降雨侵蚀规律,提出三维土工网水土保持能力的试验测定方法及相关系数计算公式。研究结果表明:三维土工网防护边坡泥沙流失干质量明显小于相同条件下不设防边坡泥沙流失干质量,土工网防护在减少边坡侵蚀量的同时,有利于边坡侵蚀进程的快速稳定,但土工网的水土保持能力随雨强增大急剧下降。泥沙流失速度随着降雨的持续而逐渐减小,后期趋于收敛稳定,侵蚀历程采用指数函数拟合具有较好的相关性。建议设防边坡的试验降雨时间不少于70 min,不设防的边坡试验降雨时间不小于100 min。水土保持能力系数随雨强的增大呈对数函数关系减小,雨强超过100 mm/h时水土保持能力系数实测值与对数函数拟合值差异较大,建议在测定材料水土保持能力系数时雨强取20~100 mm/h,可取50 mm/h作为标准试验雨强。泡面类三维土工网水土保持能力显著优于普通三维土工网,而双泡面的三维土工网优于单泡面三维土工网。试验条件下凹凸泡面三维土工网的水土保持能力系数主要分布在1.71~3.03,建议50 mm/h雨强三维土工网水土保持能力系数不应小于1.5。

大别山区不同水土保持措施配置模式的效益评价

[目的]为揭示大别山区不同水土保持措施的减流减沙效益,优化大别山区水土保持措施的配置模式。[方法]基于黄冈市石桥铺、红安县、英山县和团风县4个站点径流小区的侵蚀观测数据,对比分析不同水土保持措施配置模式下的水土保持效益。[结果](1)正常农耕种植无明显水保效益,梯田+耕作配置模式下水保效益得到提高,均取得正向的水保效益,其中石坎梯田+花生油菜综合效益最好,土壤侵蚀削减率达到55%;(2)生物措施结合工程措施的配置模式有着良好的水保效益,但其减流减沙效益存在差异,如石坎梯田+板栗的减沙效益要优于减流效益;(3)香根草、香根草等高绿篱是研究中水保效益最优异的措施,香根草等高绿篱的综合效益达到70%。[结论]香根草、香根草等高绿篱适宜在黄冈市和大别山区进行推广,同时多种措施结合的配置模式相较单一措施更具有优势。研究结果可为湖北省大别山区水保措施的优化配置提供参考。