基于不同风蚀模型的区域土壤风蚀变化及影响因素研究——以内蒙古自治区为例

基于遥感数据、气象数据等,利用RWEQ模型和风蚀预报模型对内蒙古自治区2000—2017年土壤风蚀进行评估并分析其驱动因素。结果表明：（1） RWEQ模型（R²=0.85,P<0.01）和风蚀预报模型（R²=0.43,P<0.01）的预测值与¹³⁷Cs示踪技术风蚀的值具有较好的相关性,其中RWEQ模型预测精度更好。（2）时间上,RWEQ和风蚀预报模型模拟的结果均表明2000—2017年内蒙古自治区土壤风蚀呈下降的趋势,下降趋势分别为0.73,1.18 t/（hm²·a）,2个模型模拟的土壤风蚀模数在2011年均达到最低值。空间上,2000—2017年,2个模型的模拟结果均表明内蒙古自治区土壤风蚀以微度和轻度侵蚀为主,其中剧烈侵蚀在整个研究区的占比较小（RWEQ 1.79%,风蚀预报模型5.45%）,主要分布于北方风沙区的西南部。趋势上,89.74%（RWEQ）和72.05%（风蚀预报模型）的土壤风蚀模数呈下降趋势,其中显著降低的区域主要分布于北方风沙区的巴丹吉林沙漠和乌兰布和沙漠。（3）大风天数对土壤风蚀具有显著影响,随着大风天数的增多,土壤风蚀呈显著上升趋势,植被覆盖度和降水量的增长在一定程度上可抑制土壤风蚀的进程。     

内蒙古沙尘天气生态环境背景遥感分析

沙尘暴是中国北方地区,特别是沙漠及其临近地区特有的一种自然灾害。据研究,内蒙古中西部地区已成了中国北方主要的沙尘中心和源地。内蒙古地区多属干旱、半干旱气候,生态环境脆弱,由于长期不合理的生产和生活活动,生态环境迅速恶化,水土流失、风蚀沙漠化、盐渍化以及草场退化等问题日益严峻。加之全球气候变化的影响,近年来沙尘天气肆虐该地区,受影响的地区遭到不同程度的危害。利用2000年5～10月份TM假彩色合成影像,解译并获取土地利用现状、植被状况和土壤侵蚀等信息和数据基础上,较全面分析了内蒙古沙尘源地的生态环境背景,并提出了整治对策。     

Effects of desertification on soil and crop growth properties in Horqin sandy cropland of Inner Mongolia, north China

Wind erosion and accumulated sand are recognized as the primary forms of cropland desertification in the arid and semiarid region, Inner Mongolia. However, there is a lack of knowledge on the effects of wind erosion and accumulated sand on soil properties and crop growth properties in this region. A field experiment was conducted from 2001 to 2002 on desertified cropland with gradients of wind erosion and accumulated sand to investigate changes in soil and crop growth properties resulting from desertification in the Horqin sandy land. Results indicated that the soil environment degraded significantly and crop growth and biomass were seriously restrained by wind erosion. In the severely eroded cropland, soil clay, organic matter, total N and P, available N and P, average soil moisture decreased by 59.6%, 71.2%, 67.4%, 31.4%, 64.5%, 38.8% and 51.8%, respectively. Erosion increased soil pH from 8.66 to 8.92; delayed plant life cycle by 6 days, decreased plant height and diameter by 15.5% and 29.1%, and decreased above and below ground biomass and seed yield by 87.3%, 47.9% and 96.5%, respectively. Effects of a little accumulated sand were fewer on soil properties and crop growth and seed yield compared to wind erosion, severe accumulated sand effects on the cropland remain to be studied further. The results of correlation analysis showed that crop biomass and seed production were significantly correlated to organic matter, total N, pH and soil moisture under circumstance of worsened soil environment. In the windy and sandy region in Inner Mongolia, some measures to control cropland erosion should be introduced including construction of windbreak, stubble cultivation, increased organic fertilizer and spring irrigation.     

基于土壤粒度和大风日数的风蚀风险预报

为寻求一种较为简便、广泛适用的土壤潜在风蚀风险评价方法体系,选取内蒙古中西部的吉兰太戈壁、乌兰布和半固定沙地、毛乌素沙地、武川农田和希拉穆仁草原5种典型风蚀试验区,基于数字图像技术,获取地表不可蚀颗粒含量,结合地区大风日数资料,建立土壤潜在风蚀风险指数方程,并进行实地验证。结果表明:吉兰太戈壁、灌丛地表已经处于粗化过程后期,抗风蚀能力较强,平均抗风蚀指数分别为91.40%和81.40%。由于灌丛群落的存在,乌兰布和沙漠半固定沙地土壤颗粒空间分布差异明显,导致土壤抗风蚀能力呈现不同程度的差异。毛乌素沙地风成沙物质颗粒较细,抗风蚀指数仅为13.40%,极易起沙。应用土壤潜在风蚀风险方程实地表征所得结果与实际情况吻合,与人类活动关系最为密切的农田、草原土壤潜在风蚀风险最高。研究结果可实现科学、有效地预测地表潜在风蚀风险,为干旱、半干旱地区风蚀荒漠化监测提供理论依据和技术支撑。     

柳河地区土壤侵蚀定量分析

<正> 一、柳河地区土壤侵蚀模式 柳河地区位于北纬42°10′～43°00′,东经120°30′～122°30′,地处辽西与内蒙交界,面积7000多km~2,是全国水土保持重点区之一。从全国侵蚀分区看,柳河地区属风蚀、水蚀过渡区、春季风蚀严重,夏季水蚀严重;北部风蚀严重,南部水蚀严重,时空各异。 为了推算全区的土壤侵蚀量,我们首先建立风蚀、水蚀过渡区的侵蚀类型模式及不同类型条件下的侵蚀强度模式。设总侵蚀量为E,则 E=E水+E风 (1) 柳河地区是风蚀、水蚀的过渡类型区,过渡类型是典型的模糊数学问题,因此我们采用模糊集合即建立隶属度的方法来求土壤侵蚀类型模式。 在柳河地区的每一个地理位置上,设水蚀与风蚀的模糊集分别为U水、U风,与其相应的隶属函数为P水、P风。则有 P水+P风=1 (2) 由上式可见,只要确定P风即可求出P水。这里因缺少风蚀的定位观测资料,只得用经验推理法来求P风。分析影响风蚀隶属度的主导因素,得到隶属函数:     

1986-2013年黄河宁蒙河段风蚀模数与风沙入河量估算

为缓解宁(宁夏)蒙(内蒙古)河段的淤积问题,需要对该河段风蚀灾害和风沙入黄量的时空变化进行研究。该文选取综合风蚀模拟系统(integrated wind-erosion modeling system,IWEMS)和修订版风蚀方程(revised wind erosion equation,RWEQ)对1986-2013年黄河宁蒙河段风蚀模数进行了估算,并结合风沙输移方程,对不同河段的风沙入黄量进行了计算。发现宁蒙河段的风蚀灾害主要发生在乌兰布和沙漠、库布奇沙漠和河东沙地等沙漠区域。自1986年以来河东沙地的风蚀模数逐渐降低,而乌兰布和沙漠的风蚀模数则逐渐凸显,成为宁蒙河段风蚀最严重的区域。1986-2013年间,整个宁蒙河段受风蚀灾害的面积逐渐减小,平均风蚀模数迅速下降,线性拟合函数斜率高达-182.81。风沙入黄量结果显示,石嘴山—巴彦高勒段的年均风沙入黄量最大,高达9.31×106 t/a;下河沿—青铜峡段最小,其值仅为7.6×105 t/a。另外,除石嘴山—巴彦高勒段之外,其余河段风沙入黄量并未呈现出明显的减小趋势。通过对宁蒙河段气象和土地利用数据的分析,发现宁蒙河段的风蚀模数的变化主要受气候条件的影响。该研究结果可为解决黄河淤积问题、完善黄河沿岸风沙防护体系提供参考。     

黄河上游宁夏-内蒙古段跃移沙粒起动风速的空间分布

黄河上游宁夏-内蒙古段穿越河东沙地、乌兰布和沙漠和库布奇沙漠,大量风沙被吹入黄河,因此,迫切需要揭示宁夏-内蒙古河段沙粒起动风速的空间分布规律,从而为该区域的风沙防治工作提供理论依据。首先,应用归一化植被指数（normalized different vegetation index,NDVI）数据集计算该河段地表植被盖度、植被迎风面积指数与粗糙度。而后,通过植被迎风面积指数计算摩阻起动风速的影响函数,研究河段摩阻起动风速的空间分布。利用实测数据检验摩阻起动风速的计算方法,表明摩阻起动风速的计算方法误差较小。研究表明,研究区内风速廓线均呈对数函数的分布规律,并利用风速廓线方程计算了研究区不同下垫面（10 m高度）处的起动风速,进而得到跃移沙粒起动风速的空间分布。结果显示研究区风蚀风险最大的几个区域大多临近黄河。最后,根据当年最大NDVI值与下一年风季（3月至5月）NDVI平均值之间的关系,提出利用当年最大NDVI值对下一年风季起动风速的预测方法,该研究为黄河宁夏-内蒙古段的风蚀预报提供理论支撑。     

内蒙古砒砂岩地区风蚀、水蚀及重力侵蚀交互作用研究

内蒙古砒砂岩地区是黄河重要的粗沙来源区 ,具有水蚀、风蚀及重力侵蚀交互的特点。利用 3个试验流域1983～ 1997年的天然观测资料 ,分析得到了砒砂岩侵蚀交互作用的时空分布规律 ;通过对砒砂岩的理化性质及侵蚀产沙特性的分析表明 ,砒砂岩的产流和产沙能力均高于当地的黄土和风沙土。建立了砒砂岩地区的水蚀模型 ,并对水力侵蚀过程进行了模拟     

阴山北部耕作土壤表土颗粒分析模型探讨

在内蒙古自治区阴山北部农牧交错带耕地表土33组颗粒分析实验数据基础上,运用M atlab软件对VanGenuchten等模型进行模拟求参,并得到能较为精确地表征当地土壤颗分曲线的数学模型,以期为全面综合分析阴山北部农牧交错带风蚀沙化地表土壤的抗风蚀能力有所帮助。     

内蒙古砒砂岩地区水土流失规律研究

内蒙古砒砂岩地区是黄河重要的粗沙来源区,该地区具有水蚀、风蚀及重力侵蚀交互的特点。利用三个试验流域1983～1997年的天然观测资料,分析得到了砒砂岩侵蚀交互作用的时空分布规律;通过对砒砂岩的理化及侵蚀产沙特性的分析表明,砒砂岩的产流和产沙能力均高于当地的黄土和风沙土。本研究建立了砒砂岩地区的水蚀模型,并对水力侵蚀过程进行了模拟。     

中国土壤风蚀灾害发生的范围

从大尺度讨论土壤风蚀灾害,认为风蚀是侵蚀因子（风力、可蚀表面等）和抑制因子（植被、水分等）斗争的结果,风蚀灾害发生在侵蚀风和干燥无覆被土壤共同出现的时段,所以说气候决定风蚀灾害的范围。依据李世奎等的《中国农业气候区划》诊断各个农业气候区发生风蚀灾害的时间和强度,农业土壤和非农业土壤采用的方法相似,但指标体系不同,确定了中国土壤风蚀灾害发生的范围。结果表明中国土壤风蚀灾害主要发生在温带,范围涉及国土面积60.9%的广大地区,其中,东部季风农业气候大区和青藏高寒农业气候大区,土壤风蚀灾害以农业土壤为主;西北干旱农业气候大区,农业和非农业土壤均遭受风蚀灾害,而且风蚀程度也大于其他气候大区。     

Effect of grazing on wind driven carbon and nitrogen ratios in the grasslands of Inner Mongolia

Wind erosion and dust storms are common phenomena in the semi-arid Xilingele grassland (Inner Mongolia) and contribute considerably to matter balances. Dust emission and dust deposition affect particles of the silt and clay fraction and the organic matter predominantly, the carriers for nutrients in soils. Based on wind erosion measurements in spring 2005 and 2006 the organic carbon and total nitrogen contents of dust were analyzed to determine the contribution of wind erosion processes on C- and N-ratios to the grasslands.     

用气象数据估算固定和半固定沙地的起沙速率

Taibus County, Inner Mongolia, China, lies in a farming-pastoral ecotone, where severe wind erosion and various aeolian sand hazards are prevalent and fixed and semi-fixed sand dunes occur frequently. This study was conducted to investigate the relationships between sand transportation rate and wind speed for the fixed and semi-fixed sand dunes based on field measurements. The annual quantity of soil erosion by wind was estimated using meteorological wind data. The results indicated that the sand transportation rate in Taibus County in 2000 was 57.38 kg cm-1 year-1 for the semi-fixed dunes and 4.56 kg cm-1 year-1 for the fixed dunes. The total duration of erosive winds covered 12.5% of the time of the year, and spring posed the highest potential of sand transportation. Wind with low speed (≤17 m s-1) and high frequency plays a dominant role in sand transportation, while strong wind (≥17 m s-1) with low frequency significantly enhanced the sand transportation. Erosive wind speed, directions, and frequency were three crucial dynamic factors influencing sand hazards in the farming-pastoral ecotone. The dominant factors intensifying sand and dust storms in Taibus County might be related to the favorable wind condition in combination with the durable drought, which led to land desertification and vegetation degradation.     

半干旱草原潜在土壤风力侵蚀空间格局研究

中国绝大多数的干旱半干旱地区遭受着严重的风力侵蚀。风蚀可导致土壤流失、肥力下降,最终导致土地荒漠化。半干旱草原区的荒漠化问题日益突出,由此带来的沙尘暴等灾害天气增多,给人们的生产生活带来诸多不便。从影响土壤风力侵蚀的风速、干燥度、植被盖度、地形起伏度、土壤可蚀性以及放牧压力6个方面出发,借助GIS技术,通过主成分分析研究半干旱草原区达茂旗土壤风力侵蚀的空间分布格局。结果表明:达茂旗潜在土壤风力侵蚀指数由南向北呈高—低—高趋势。达茂旗北部地区土壤风蚀主要受风速、干燥度和植被指数影响;中部地区风力侵蚀主要受地形起伏度的影响,地形起伏对风的消减作用增强,使得风力降低,加之该地区土壤可蚀性和干燥度相对较低,风力侵蚀指数低;南部土壤风力侵蚀主要受放牧压力影响,春季正是牧草返青季节,植被盖度低,且牲畜密度相对较大,放牧对草场的压力大,土壤风力侵蚀严重。风力侵蚀各影响因子的时空异质性是导致半干旱草原风力侵蚀空间异质性的主要原因。干旱草原风力侵蚀空间异质性的主要影响因素是风速、干燥度和植被指数,其次受地形和土壤可蚀性的影响,而放牧压力是半干旱草原区土壤风力侵蚀的主要人为因素之一。     

Estimation of Sand Transportation Rate for Fixed and Semi- Fixed Dunes Using Meteorological Wind Data

Taibus County, Inner Mongolia, China, lies in a farming-pastoral ecotone, where severe wind erosion and various aeolian sand hazards are prevalent and fixed and semi-fixed sand dunes occur frequently. This study was conducted to investigate the relationships between sand transportation rate and wind speed for the fixed and semi-fixed sand dunes based on field measurements. The annual quantity of soil erosion by wind was estimated using meteorological wind data. The results indicated that the sand transportation rate in Taibus County in 2000 was 57.38 kg cm-1 year-1 for the semi-fixed dunes and 4.56 kg cm-1 year-1 for the fixed dunes. The total duration of erosive winds covered 12.5% of the time of the year, and spring posed the highest potential of sand transportation. Wind with low speed (≤ 17 m s-1) and high frequency plays a dominant role in sand transportation, while strong wind (≥ 17 m s-1) with low frequency significantly enhanced the sand transportation. Erosive wind speed, directions, and frequency were three crucial dynamic factors influencing sand hazards in the farming-pastoral ecotone. The dominant factors intensifying sand and dust storms in Taibus County might be related to the favorable wind condition in combination with the durable drought, which led to land desertification and vegetation degradation.     

基于多因子层次覆盖模型的潜在土壤侵蚀等级评价——以内蒙古林西县为例

以内蒙古林西县作为研究案例,采用降雨侵蚀力、主要地形体、土壤可蚀性、植被盖度及水土保持措施等参数,利用TM影像、DEM、土壤类型图、土地利用类型图等地理辅助数据与地面实测土壤理化性质及多年降水数据,在GIS与RS技术支持下,对5个单因子作用下研究区潜在水土流失风险进行评价.并基于多因子层次覆盖评价模型,对复合因子及多因子综合作用下研究区潜在水土流失状况进行评价.结果表明:地形、土壤与植被盖度3个因子对土壤侵蚀的贡献量较大,土地利用方式与降雨强度对土壤侵蚀的贡献量较小.5个因子综合作用的结果是:林西县有近77%的土地面积面临强度及强度以上水土流失的危险.其中轻度及微度水土流失面积占总土地面积的比例较小,二者共占总土地面积比例14.8%,主要分布在林西县西北部的中高山坡度较低地区;强度水土流失占22.8%,主要发生在北部的中山区及中部的河谷平川区;极强度水土流失占43.8%,主要发生在中部及南部低山丘陵区;剧烈水土流失面积占10.8%,集中分布在北部中山高坡区.     

应用遥感技术调查内蒙古土壤侵蚀现状成果概要

内蒙古自治区是我国北方地区土壤侵蚀严重的省区之一。研究和查清全区土壤侵蚀现状,是水土保持一项重要的基础工作。本文简要地介绍了应用遥感技术调查内蒙古土壤侵蚀现状所取得的成果:全区土壤侵蚀面积为115万多平方公里。其中,水蚀面积占23.6％,风蚀面积占64.6％,冻融侵蚀面积占11.8％;Ⅱ级以上三种类型的侵蚀面积占74.05％。文章阐明了各类各级土壤侵蚀的分布特征,按流域和行政区对区内的土壤侵蚀进行了评价,提出了土壤侵蚀区划及防治区划成果。     

不同地表状况对土壤风蚀的影响——以内蒙古太仆寺旗为例

通过对采取不同耕作措施和不同留茬方式的农田土壤进行野外风沙观测.观测结果表明,人为因素对农田土壤风蚀影响非常大,不同地表状况的土壤风蚀特征存在显著差异.留茬地因为表面残茬的存在显著增加了土壤表面粗糙度,从而使得其风蚀强度较小;而秋翻地人为扰动较大,表面覆盖度较小,其风蚀强度在所研究的土壤中为最大.因此,对于内蒙古太仆寺旗农田土壤风蚀较严重区域,应该采取留茬措施以减少人为扰动,增加覆盖度以提高土壤表面粗糙度,从而有效地减少土壤风蚀.     

植被盖度和残茬高度对保护性耕作农田防风蚀效果的影响

为定量评价植被盖度、残茬高度对保护性耕作农田的防风蚀效果,以空气动力学粗糙度和抗风蚀效率为评价指标,利用移动式风蚀风洞对内蒙古武川县保护性耕作农田和对照秋翻地进行了原位测试。结果表明,随植被盖度和残茬高度的增加,空气动力学粗糙度和抗风蚀效率均增加,抑制风蚀效果加强;在30 cm残茬高度、50%植被盖度下保护性耕作农田的平均抗风蚀效率可达80.55%,具备了很好的防风蚀效果。因此,要有效防治农田土壤风蚀,保护性耕作农田应具有50%以上的植被盖度和30 cm以上的留茬高度。     

Formalizing expert judgements in land degradation assessment: a case study for Ethiopia

Expert judgements are potentially a valuable source of information in land degradation assessment, especially in areas where data paucity impedes the use of quantitative models. However, expert opinions are also much disputed because they are not tested for consistency, abstain from formal documentation, while their quantitative interpretation is inherently unidentifiable. This paper evaluates and formalizes the use of expert judgements to conduct a nationwide water erosion hazard assessment in Ethiopia. We, therefore, test the experts' judgement for consistency, its correlation with quantitative measurements on soil loss and its reproducibility. The study uses an Ethiopian and an international dataset for which experts gave qualitative judgements on water erosion hazard, for well‐described sites under different types of land uses. Experts show a high consistency in their judgements on land degradation, but a comparison with quantitative soil losses from runoff plots reveals that boundaries of middle classes vary widely between experts, while they tend to overestimate soil loss. Reproducing expert opinions with an ordered logit model shows a reasonable accuracy in predicting presence or absence of erosion, yet the model is less precise in distinguishing between higher erosion classes. In 58 per cent of the cases, the model gives a similar classification as the experts, in 19 per cent the model estimates higher and, more seriously, in 23 per cent a lower erosion class. Mapping the model results for Ethiopia demonstrates a high erosion hazard for land under annual crop cultivation, while erosion under perennial crops, rangeland and forest is absent or moderate. The likelihood of the model to select the correct hazard class for rangeland is relatively high but medium to low probabilities prevail for erosion classes of other land uses. The model needs a further justification to give adequate results for arid areas. Copyright © 2003 John Wiley & Sons, Ltd.