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1.
以佳芦河流域分辨率为0.38 m的航摄影像和5 m的DEM等为信息源,基于ArcGIS平台,获取了流域水土保持措施、土地利用、植被覆盖度、坡度、沟壑烈度等土壤侵蚀影响因子,依据《土壤侵蚀分类分级标准》(SL 190—2007),对各因子进行叠加分析,对水蚀、风蚀区等不同侵蚀类型的土壤侵蚀强度进行了分析评价。结果表明,截至2012年9月,佳芦河流域有水土流失面积1068.89 km 2,占流域面积的94.26%,其中轻度、中度、强烈、极强烈、剧烈侵蚀面积分别为118.69、206.35、126.29、75.08、542.48 km 2;强烈及以上侵蚀面积占到水土流失面积的69.59%,其中强烈和极强烈侵蚀多发生在风蚀区,而剧烈侵蚀主要发生在水蚀区的沟道中。 相似文献
2.
以贵州省猫跳河流域为案例区,运用RUSLE模型对流域1973,1990,2007年土壤侵蚀空间格局进行了模拟。分析了该流域土壤侵蚀动态变化规律,为流域土壤侵蚀的有效防治提供了科学依据。结果表明,(1)流域下游以及上游西部溶蚀丘陵谷地土壤侵蚀较严重,土壤侵蚀量主要来源于强烈、极强烈及剧烈侵蚀区域,旱地和灌草地是流域发生土壤侵蚀的主要用地类型。(2)近30a来,流域土壤侵蚀经历了趋向严重—减轻的变化过程。1973—1990年低强度土壤侵蚀面积在减少,而高强度侵蚀面积在增加。1990—2007年,除了微度侵蚀面积大幅度增加外,其余侵蚀等级面积均在大幅度减少。6°～25°坡度带是发生土壤侵蚀的主要区域,也是水土流失防治及治理的重点区域。 相似文献
3.
基于USLE模型的滇池流域土壤侵蚀时空演变分析 总被引：11，自引：5，他引：6
掌握滇池流域土壤侵蚀的空间分布规律和演变趋势对优化水土保持措施、开展滇池水污染治理和保障流域可持续发展具有重要意义。该文以降雨量、土壤、DEM和遥感影像为数据源,运用RS、GIS技术,结合土壤侵蚀模型计算滇池流域1999—2014年每隔3 a的土壤侵蚀量,分析流域土壤侵蚀强度的时空演变特征。结果表明,无明显侵蚀区域面积在15 a间呈上升趋势,占比从1999年的70%上升为2014年的82%,说明流域土壤侵蚀状况逐渐好转;1999—2014年期间滇池流域土壤侵蚀面积呈逐年下降趋势,1999年侵蚀面积最大,为776 km2,到2014年下降到为468 km2;土壤侵蚀强度等级转移矩阵显示15 a间近75%区域侵蚀强度保持不变,其中以微度侵蚀为主,有18.23%的区域侵蚀强度降低,8.36%的区域强度上升;空间变化上,侵蚀强度降低的区域主要集中于环滇池的入湖河流一带,侵蚀强度上升区域主要为流域东、南、北端海拔较高的山区。该研究有助于分析滇池流域土壤侵蚀在空间上的演变过程,为提出精准的侵蚀防治措施提供决策依据,为流域生态环境保护提供参考。 相似文献
4.
岷江流域土壤侵蚀变化与治理对策研究 总被引：2，自引：0，他引：2
以1995年、2000年遥感土壤侵蚀调查(RS)资料为基础,结合2005年实地调查资料,研究岷江流域土壤侵蚀的演变规律,应用马尔柯夫模型对流域土壤侵蚀的发展趋势进行预测,同时探讨岷江流域水土流失治理分区与对策。结果表明:(1)岷江流域土壤侵蚀现状表现为:侵蚀总面积19 907.7 km2,占幅员面积的43.77%;侵蚀类型以水蚀为主,占侵蚀面积的88.24%;侵蚀等级以中度侵蚀为主,占侵蚀面积的44.07%。与1995年相比,土壤侵蚀面积减少369.6 km2,减少比例为0.81%。计算表明岷江流域2000年土壤侵蚀量为8.94×107t,平均侵蚀模数1 966 t/(km2.a)。(2)应用Markov模型对2005-2025年岷江流域土壤侵蚀面积的预测结果显示:岷江流域土壤侵蚀面积将呈逐年减少趋势。到2025年,土壤侵蚀面积将比2000年减少1 452.87 km2;未来20年内土壤侵蚀量每5 a以3.17×107t的速度减少。(3)岷江流域水土流失治理应在以全流域综合治理为目标,在科学规划基础上,选择优先治理区和重点治理区,以不同类型的治理工程为主要途径,推动岷江流域水土流失的有效治理。 相似文献
5.
以云南洱海流域为研究对象,根据已有的流域DEM、Landsat-5 TM卫星数据和当地降雨、土壤类型等资料,在GIS、Erdas及ArcView软件支持下,应用USLE模型计算了洱海流域1989—2006年土壤侵蚀变化并对其土壤侵蚀特征进行了分析。研究表明:轻度侵蚀由占总面积的13.89%下降到6.47%,中度侵蚀由占总面积的6.49%增至14.04%,微度和极强烈侵蚀小幅增加,强烈和剧烈侵蚀小幅减少;微度、轻度、强烈和剧烈侵蚀多转化为中度侵蚀,面积分别为22.20、123.539、.68和22.91 km2,中度侵蚀多转化为微度侵蚀,极强烈侵蚀多转化为剧烈侵蚀;18年来,土壤侵蚀强度与面积年均变化率以中度侵蚀最大(6.46%),轻度、强烈、剧烈和微度侵蚀年均变化率分别为-2.97%、-0.11%、-0.10%、0.056%,极强烈侵蚀年均变化率最小(0.020%)。 相似文献
6.
安徽省岳西县土壤侵蚀时空演变特征及趋势预测 总被引：1，自引：0，他引：1
利用ArcView 3.3软件,对岳西县1958年、1983年、1992年的土壤侵蚀动态监测图进行屏幕数字化,得到三期土壤侵蚀强度矢量图;利用2004年TM影像,通过目视解译的方法,得到2004年土壤侵蚀强度矢量图。利用Arc-GIS软件,对不同时段土壤侵蚀图进行叠加分析,研究了不同时段不同土壤侵蚀强度面积数量的相互转化及土壤侵蚀程度的变化;运用马尔柯夫模型,预测岳西县土壤侵蚀动态演变趋势。主要结论如下:(1)岳西县土壤侵蚀状况1958-2004年经历了急剧恶化到逐渐恢复的过程。1958-1983年土壤侵蚀不断加剧;1983-1992年土壤侵蚀逐渐恢复;1992-2004年土壤侵蚀进入全面恢复期。(2)相邻时段的土壤侵蚀图叠加结果分析表明,不同时期土壤侵蚀各等级是相互转化的。(3)1958-2004年岳西县土壤侵蚀程度无变化的面积经历了先下降后上升的过程,土壤侵蚀程度等级增加的面积先显著扩大再逐步下降,而土壤侵蚀程度等级下降的面积先减少后增加。(4)马尔柯夫模型预测结果表明,到2016年微度侵蚀土壤面积增加到64 221hm2,中度侵蚀类型面积明显下降;强烈侵蚀与极强烈侵蚀土壤在局部地区有所增加,但这种变化不明显。堆积类型面积呈显著下降趋势,水域面积有所减少。从总体趋势看土壤侵蚀状况向良性循环方向发展。 相似文献
7.
[目的]分析南汀河流域坡面土壤侵蚀的时空分异特征,为流域水土保持和边疆生态环境建设提供科学参考。[方法]基于通用土壤流失方程(USLE),运用RS和GIS技术计算南汀河流域1990,2000及2010年3个时段的土壤侵蚀模数。[结果]3个时段内研究区侵蚀模数呈现先升后降的趋势,年均侵蚀模数从24.75t/(hm2·a)升到30.05t/(hm2·a),然后降为25.87t/(hm2·a)。3个时段内,流域内强烈侵蚀及其以上的侵蚀面积仅占总侵蚀面积的19.94%,但对流域总侵蚀量的贡献高达73.56%。1990—2000年,强烈及强烈以下侵蚀面积减少了1 059.85km2,强烈侵蚀以上的侵蚀面积则增加了112.29km2;2000—2010年,微度侵蚀面积有小幅增加,其余侵蚀等级的侵蚀面积都有所下降。当坡度小于20°时,侵蚀模数随着坡度的增加而增加,坡度超过20°后,侵蚀模数有降低的趋势;从海拔上看,高侵蚀模数区域主要位于海拔500~2 000m范围。[结论]流域内的土壤侵蚀治理已初见成效,但在局部地区,土壤侵蚀仍有加剧现象。 相似文献
8.
为研究近10年来太湖流域片土壤侵蚀情况,借助2次水利部土壤侵蚀调查数据,统计分析太湖流域片土壤侵蚀现状及其面积在空间上的分布,得出2002-2011年间土壤侵蚀的变化趋势,并利用土壤侵蚀综合指数EI,对流域片的土壤侵蚀情况进行定量评价.结果表明:2011年太湖流域片土壤侵蚀总面积为2.3万km2.其中太湖流域侵蚀面积0.1万km2,东南诸河地区侵蚀面积2.2万km2,侵蚀等级均以轻度侵蚀为主;但太湖流域的轻度侵蚀面积所占比例更大,而东南诸河中度侵蚀及其以上的侵蚀等级面积所占比例更大.2002-2011年间,太湖流域片土壤侵蚀面积整体上呈逐步减小的趋势,共减少1.08万km2,年均减少1 201.24 km2;其中,轻度、中度和强烈侵蚀面积减小,而极强烈侵蚀和剧烈侵蚀面积增加.太湖流域地区EI值远小于东南诸河地区EI值(1.65),表明东南诸河土壤侵蚀总体情况更严重.2002-2011年太湖流域片EI值减小,但少数区域EI值增加明显.建议将其列为重点治理区,进行有针对性的治理. 相似文献
9.
42年来兴国县土壤侵蚀时空变化规律研究 总被引：6，自引：0，他引：6
以江西省兴国县为研究区域,应用遥感和GIS技术,借助6个不同时段的黑白航片、MSS影像和TM数据为信息源,在建立土壤侵蚀解译标志的基础上,对全县3 215 km2范围内的土壤侵蚀进行了监测研究。结果表明,该县从1958—2000年42 a期间,土壤侵蚀的变化分2个阶段。第一阶段是1982年前,全县的侵蚀面积在2 000 km2左右;第二阶段是从80年代初到2000年,该县被列为全国水土流失综合治理重点区,侵蚀面积在18 a间共减少了739 km2,平均每年减少41 km2。将1992与2000年的土壤侵蚀图叠置分析可以看出,该县5个侵蚀等级的面积都有不同程度的降低;在侵蚀等级的转变方面,大约有34%的侵蚀面积,其侵蚀等级发生了改变,其中以改变一个等级的面积为主,大约有66%的侵蚀面积其侵蚀等级未发生变化,说明兴国县的土壤侵蚀已呈现出明显的减弱趋势。 相似文献
10.
<正> 一、南小河沟流域概况 南小河沟流域位于陇东黄土高原沟壑区中部,是泾河支流蒲河左岸的一条支沟,流域面积36.3km~2,共有支毛沟183条,沟道密度1.69km/km~2,主沟长11.8km,平均比降2.8％。流域地貌根据侵蚀形态可划分为塬、坡、沟三种类型,其面积比例分别为56.9％、15.7％、27.4％。 相似文献
11.
Tetrahymena pyriformis cultures were maintained when transferred serially in solutions containing 105 to 107Klebsiella pneumoniae cells.ml?1, bacterial numbers that were observed to persist in the presence of protozoa. The number of cells of one strain of K. pneumoniae surviving predation in solution was essentially the same in the absence of an alternative prey as in the presence of a second K. pneumoniae strain. Toxins deleterious to protozoa did not appear as the animal consumed the bacteria. T. pyriformis reduced the abundance of Escherichia coli from about 108 to 106.ml?1. but the latter number persisted for 15 days; however, in solutions containing chloramphenicol, the abundance of E. coli fell to 590 cells. ml?1 in 15 days. In solutions containing the antibiotic, T. pyriformis reduced the Rhizobium sp. population from more than 106 to less than 103 cells in 10 days and K. pneumoniae from more than 108.ml?1 to zero in 18 days. An appreciable decline in abundance of these bacteria did not occur in the antibiotic-amended liquid free of protozoa. T. pyriformis did not greatly reduce Rhizobium sp. numbers when both were added to irradiated soil, but the predator caused the bacterial population to decline from 4 × 108 to fewer than 105.g?1 in 16 days in chloramphenicol-treated soil. Colpoda sp. inoculated with Rhizobium sp. into soil sterilized by autoclaving only reduced the prey abundance from 109 to 108.g?1, but the protozoan caused the bacterial population to fall to about 100.g?1 in 15 days in the presence of the antibiotic. The population of Rhizobium sp. added to nonsterile soil dropped from in excess of 108 to 6 × 106.g?1 in 29 days. but it declined to 550. g?1 in the same period when chloramphenicol was also introduced. It is concluded that the ability of these bacteria to maintain themselves in solution and in soil is governed by their capacity to reproduce and replace the cells consumed by predation. 相似文献
12.
Hang T. Nguyen C.-H. Kang C.-J. Ma Kum-Chan Choi Jin Seog Kim Joung Hae Lee Ki-Hyun Kim 《Water, air, and soil pollution》2009,196(1-4):225-243
The ionic composition of total suspended particulate (TSP) and fine (PM2.5) fractions was investigated from an 1,100 site in the middle of Mt. Halla in Jeju Island, Korea from March to November 2006. The sum concentrations of cation and anion species in TSP fraction were 205 ± 170 and 183 ± 164 neq m?3, respectively, while those for PM2.5 as 118 ± 129 and 88.5 ± 89.3 neq m?3, respectively. In TSP, the concentration of the major ions changed in the order of SO4 2? > NH4 + > Ca2+ > Na+ > NO3 ? > Mg2+ > K+ > Cl?, while its PM2.5 counterpart as NH4 + > SO4 2? > Ca2+ > NO3 ? > Na+ > Mg2+ > K+ > Cl?. Inspection of the temporal variabilities of ionic components indicated that most ions peaked in spring or fall months. The back trajectory analysis showed that the atmospheric composition of the major ionic species was affected fairly sensitively by long-range transport from China under the favorable meteorological conditions. In contrast, the lowest ionic concentration levels were seen most abundantly, when air masses passed from South Sea. Hence, the analysis of ionic concentration data suggests that their distributions are controlled by the combined effects of various source processes including the most prominent Chinese origin and the meteorological condition favorable for such transport. 相似文献
13.
An integrated model was developed to simulate the temporal change and spatial variation of temperature and spatial distribution of TM (total mass) and MC (moisture content) of the final compost for composting process of sewage sludge. The model included biodegradation kinetics of organic matter and balance equations of energy and mass. First-order assumption was applied to describe the biodegradation process with correction functions of temperature, oxygen, MC, and FAS (free air space). The transfer process was considered in balance equations of energy and mass. A finite difference method was used to solve the model. Two trials of 0.21 m3 were run to estimate parameters and evaluate the simulation. The model could predict TM and VS (volatile solid) of the final compost well, temporal trend of oxygen concentration and water removal, and also a good fitting of the temporal and spatial change of temperature. Hrx (reaction enthalpy of biodegradable volatile solid) and ηBVS (mass fraction of biodegradable volatile solid) were considered the most sensitive parameters based on the sensitivity analysis. Future research was suggested to focus on reasonable humidity assumption, measuring accurate value of thermodynamics and kinetics parameters of sewage sludge, and simulating the composting process with different aeration modes and turning of the pile. 相似文献
14.
pH对磷钾铝石形成的影响 总被引：3，自引：1，他引：2
Effects of column temperature and flow rate on separation of organic acids were studied by determining nine low-molecular-weight organic acids on reversed-phase C18 column using high performace liquid chromatography(HPLC) with a wavelength of UV(ultraviolet)214 nm and a mobile phase of 18 mmol L^-1 KH2PO4 buffer solution (pH2.1).The thermal stabiltiy of organic acids was determined by comparing the recoveries of organic acids in different temperature treatments.The relationships between column temperature,flow rate or solvent pH and retention time were analyzed.At low solvent pH,separatioin efficiency of organic acids was increased by raising the flow rate of the solvent because of lowering the retention time or organic acids.High column temperature was unfavorable for the separation of organic acids.The separating effect can be enhanced through reducing column temperature in organic acid determination due to increasing retention time.High thermal stability of organic acids with low concentrations was observed at temperature of 40℃-45℃,Sensitivity and separation effect of organic acid determination by HPLC were clearly improved by a combination of raising flow rate and lowering column temperature at low solvent pH. 相似文献
15.
A. S. Manucharov Z. N. Tyugay V. G. Vityazev T. N. Pochatkova G. V. Kharitonova 《Moscow University Soil Science Bulletin》2011,66(3):93-99
It was revealed that the influence of soluble salts on the hydrophysical properties of clayed minerals depends on the nature
of minerals, the properties and state of salt (in solution or sorbing), and the region of fundamental hydrophysical characteristics
(FHCH). The treatment of clayed minerals by NaCl, MgCl2, Ca(CH3COO)2, and ZnCl2 solutions increased their water-retention in the range NaCl > MgCl2 > Ca(CH3COO)2 ≈ ZnCl2. Pb(CH3COO)2 decreased the water-retaining ability of clayed minerals in all the FHCH range. A differential characteristic of the action
MgCl2, Ca(CH3COO)2, and ZnCl2 on smectite is decrease of capillary water deduction. 相似文献
16.
利用玻璃微电极技术测定了扬稻6号(籼稻)幼苗根尖细胞在吸收不同NO3-浓度(0.01、0.02、0.1、0.2、0.5、1.0和2.0.mmol/L)过程中膜电位的变化。结果表明,1)水稻根系吸收NO3-引起膜的去极化,去极化到一定程度后出现复极化;有小部分水稻根表现为超极化。在0.01～1.0.mmol/L范围内,去极化大小随外界NO3-浓度的增加而增加,且差异显著(P0.05)。0.01.mmol/L.NO3-产生较小的去极化,平均为3.8.mV;0.5.mmol/L.NO3-产生了最大去极化,平均为40.2.mV;当外界NO3-浓度大于1.0.mmol/L时膜电位去极化大小呈下降趋势。根系吸收不同浓度的NO3-而使膜电位去极化的进程符合Michaelis-Menten动力学。2)复极化有部分复极化和完全复极化两种。超极化也有两种:一种是膜电位先超极化,后缓慢复极化;另一种是先出现一个小的去极化,然后是较大幅度的超极化。3)运输蛋白抑制剂PGO抑制了根系吸收NO3-而产生的膜电位的响应。4)对于经CaSO4溶液预培养的水稻来说,C2+主要引起膜电位超极化。 相似文献
17.
《Applied soil ecology》2007,35(2):390-403
A plan was developed to apply biosolid to soil of the former lake Texcoco to fertilize the pioneer vegetation. Because, no information exists about how differences in electrolytic conductivity (EC) might affect mineralization of biosolid and dynamics of C and N in soil, 20 soil samples forming a gradient in EC ranging from 22 to 150 dS m−1 were characterized, amended with 500 mg biosolid C kg−1 dry soil and incubated aerobically at 22 ± 2 °C while production of CO2, concentrations of ammonium (NH4+), nitrite (NO2−), and nitrate (NO3−), and NH3 volatilization were monitored at 22 ± 2 °C for 70 days. Soil characteristics showed large variations with maximum values often >10-times larger than minimum values. The production of CO2 in the unamended soil ranged from 25 to 159 mg CO2-C kg−1 day−1 and NH3 volatilization from 0 to 189 μg NH3-N kg−1 day−1. Application of biosolid increased production of CO2 significantly 1.4-fold and volatilization of NH3 11.5-fold. The EC explained most of the variation in production of CO2, while particle size distribution explained most of the variation in volatilization of NH3. The concentration of NH4+ in the biosolid-amended soil decreased sharply in the first 14 days, with the EC explaining most of the variation found, and remained constant thereafter with a small increase at day 70. Significant increases in the concentration of NO3− were generally found in soil with EC < 64 dS m−1. The EC explained most of the variation in production of CO2, and dynamics of NH4+ and NO3− while clay positively and sand content negatively affected NH3 volatilization. It was found that increases in EC inhibited C and N mineralization in soil of the former lake Texcoco. 相似文献
18.
在华北土石山区潮关西沟流域天然森林植被调查的基础上,对森林植被群落种间联结和生态位进行研究。结果表明:种间正联结关系非常显著的有柞栎和蒙椴、柞栎和迎红杜鹃、蒙椴和山杨、蒙椴和白蜡、山杨和白蜡、春榆和北京丁香、春榆和大花溲疏、臭椿和山杏、臭檀和栾树、臭檀和大花溲疏、锐齿鼠李和孩儿拳头、小叶鼠李和酸枣。另外,依据种间联结关系,划分了4个生态种组。分析了主要乔灌木的生态位宽度,乔木树种蒙椴、柞栎、春榆和灌木树种荆条、小叶朴和酸枣的生态位宽度均较大。比较了不同种对的生态位重叠指数,乔木不同种对中,山杏和北京丁香、柞栎和白蜡、蒙椴和春榆具有较大的生态位重叠,灌木不同种对组合中,荆条和酸枣、绣线菊和迎红杜鹃、荆条和小叶朴、蚂蚱腿子和迎红杜鹃的生态位重叠较大。 相似文献
19.
通过样地法对小浪底水库库区山地生态系统不同群落间的Shannon-Wiener指数(H′)、Simpson指数(D1)、Margalef物种丰富度(D2)、种间相遇概率(P)和Pielou均匀度指数(Jsw)等多样性指数进行研究,利用统计方法分析不同群落的物种多样性指数与其所处环境的关系。结果表明:1)物种多样性指数和丰富度指数与群落类型有密切关系,同一类型的群落中,多样性指数随演替时间表现出复杂的关系;2)土壤含水量对H′、P、Jsw、D1等呈极显著的正相关性,土壤厚度与H′、D1、P呈显著正相关性;多样性指数与坡度无相关性;土壤有机质、速效氮、速效磷等养分指标与多样性指数H′、D1有显著的正相关;3)多样性指数H′与乔木、灌木群落生物量表现为正相关关系,草本群落与D1相关性不显著;4)乔木林群落的恢复时间与Jsw、H′呈正相关关系,其余多样性指数(P、D1、D2)与恢复时间关系不显著(P>0.05);恢复时间每增加10a,群落物种数平均增加约6种;5)物种多样性指数H′与灌木的盖度和高度呈极显著正相关性;有些单优群落随高度增加和盖度提高,多样性指数反而表现出降低;6)草本植物群落的高度和盖度与物种丰富度指数D2与呈显著的负相关关系,与H′相关性不显著。 相似文献
20.
This work is referred to the characterization of the environmental hydrochemistry in the broader Sapes area – Thrace region, on the basis of physico-chemical properties of surface and groundwaters occurring in the volcanosedimentary formations of this area, where gold mining activities are planned to operate. Volcanic rocks are considerably altered where they are in contact with hydrothermal solutions. Aquifers are formed within these formations. Surface and ground waters are strongly metalliferous and their hydrochemical facies present similar but complex water types. Certain characteristic chemical types are the following: Ca-Mg-HCO3-SO4, Ca-Mg-SO4-HCO3. Ca-SO4, Ca-Mg-SO4. Ca-Na-Cl-HCO3, Na-Cl. A small majority of the water samples present the following order of anion dominance HCO3 ? > SO4 2? > Cl?. Calcium is the dominant cation. Bicarbonates and sulfate ions are the dominant anions. The order of dominance for the heavy metals in surface and ground waters is as follows: Fe > Mn > Zn > Ni > Cu. The saturation index of waters regarding minerals is low. Computer simulation indicates that calcite and dolomite are common minerals in all water samples which are saturated in respect to quartz and argillaceous-siliceous minerals. The most pronounced property of waters is their acidic character. The high metal concentrations are related to water with low pH. Sulfide minerals control the low pH values of waters which is an important control factor for the evolution of the water chemical composition. The abundance of sulfates is attributed to the dissolution of the minerals pyrite (FeS2) and alunite (KAl3(SO4)2(OH)6. The water–mineral interactions are responsible for the chemical composition of waters. Water quality problems can be successfully handled by the use factor analysis. 17 chemical parameters can be substituted by five factors which successfully represent the hydrochemical processes as well as their geographic distribution. Volcanic rocks in the study area have the potential to produce acid drainage. 相似文献