基于GIS的黄河三角洲盐碱地改良分区

黄河三角洲盐碱地面积超过总面积的70％，而盐碱地改良分区是因地制宜，综合治理盐域地的前提，通过综合运用地理信息系统的各种空间数据分析功能，将黄河三角洲土地盐碱化现状分为：非盐碱地，轻度盐碱地，中度盐碱地，重度盐碱地，滩涂5个区，并结合地下水长期观测资料，进行成因分析，建立了黄河三角洲盐碱地改良分区模型，立足土地盐碱化的现状，充分考虑地下水埋深和矿化度，把黄河三角洲盐碱地按改良难易程度分为：易改良区，较难改良区，难改良区，近期不宜作改良区，并针对不同的盐碱地改良区提出了相应的土壤改良对策。     

冀中平原岗、坡、洼地易溶盐的集散

本文讨论了岗、坡、洼地土壤水盐的集散。在坡地的水盐状况下,盐份处于强积盐过程中。岗地一般不发生盐渍化,但在高矿化地下水下,虽为薄膜毛管湿润的水盐动态类型,土壤也可能发生盐渍化。洼地虽然处于易积盐的土壤水份状况下,但由于地下弱矿化水带的存在或形成,槽状洼地和某些碟形洼地却常常没有发生盐渍化。本文还讨论了岗、坡、洼地盐份组成的变化。     

渭干河绿洲不同土地利用类型土壤盐分的变化特征分析

土壤盐分的动态分析与监测,是实现盐渍化土地科学管理与利用的必要前提。运用GIS技术,结合地统计学方法,分析了渭干河绿洲土壤盐渍化的分布格局,探讨了不同土地利用类型下土壤盐分的变化规律。结果表明：土壤盐分离子含量随土层深度增加而减少,CO^2-₃和HCO₃^-变化不明显,整个剖面表现为：Na⁺+K⁺>Ca²⁺>Mg²⁺,SO^2-₄>Cl^->HCO₃^->CO^2-₃,具有中-强变异性,除了HCO₃^-、CO^2-₃和Ca²⁺外,其他盐分离子变异系数随深度增加而减小。不同土地利用类型的土壤含盐量具有显著差异垂向分布,耕地、荒地和草地、林地分别呈现为平均型、表聚型和底聚型盐分剖面,且各类型表层土壤（0～40 cm）含盐量依次为荒地（38.42 g·kg^-1）>草地（16.30 g·kg^-1） > 耕地（5.37 g·kg^-1） > 林地（4.62 g·kg^-1）。渭干河绿洲土壤属于重盐土类型,自然因素（蒸降比和地下水波动等）是土壤盐渍化的形成条件,而人为干扰（土地利用方式、灌排、施肥等）则促进了土壤盐渍化的发展。     

渭-库绿洲地下水对土壤盐渍化和其逆向演替过程的影响

基于遥感数据,结合地下水位观测资料,本文对渭-库绿洲土壤盐渍化与地下水的关系进行了定量研究,并探讨土壤盐渍化的逆向演替过程。研究表明:渭-库绿洲在地下水埋深2.3~2.7 m区间,盐渍地面积占的比例较高,在地下水埋深2.7~3.4 m区间,盐渍地面积占的比例相对较低;渭-库绿洲部分地方地下水位已低于影响地表盐渍化的水位临界值(4.66 m),地下水矿化度低于3 g/L,研究区整体处于有利于土壤盐渍化逆向演替的环境之中;土壤盐渍化的逆向演替过程具有时空特征,由绿洲上部向下部,内部向外部逐步发生逆向演替。     

干旱区土壤盐渍化灾害预警——以渭-库绿洲为例

针对中国西北干旱区普遍存在的土壤盐渍化,以渭干河-库车河绿洲TM影像数据,建立BP神经网络结合Adaboost算法的土壤盐渍化预警度评价模型。首先,根据研究区实际情况设置该模型的4个预警指标（地下水埋深、海拔、盐分指数、归一化干旱指数）,分别提取其连续表面信息,结合BP神经网络作为弱预测器进行预测,将通过不同训练集得到的弱预测器结果结合成强预测器。在利用该模型训练样本时,依据各评价因子对分类结果的贡献率调整其权重,预测的结果能客观反映每个评价因子对该地区土壤盐渍化的贡献程度。结果表明,研究区警情总体情况较严重,绿洲北部内部耕地周围的荒地以及含水量少的区域,盐渍化危险度较高。     

干旱区典型绿洲土地利用／覆被变化及其对土壤盐渍化的效应研究-以新疆沙雅县为例

本研究选用了1989年、1998年以及2009年Landsat TM／ETM＋影像,利用3S技术,深入剖析了盐渍地的分布与变化状况,结合研究区20年水盐动态变化,分析了盐渍土土壤的含水量、含盐量、pH值、TDS以及7大化学成分的分布现状,并基于土地利用／覆被变化的研究,研究了土地利用／覆被变化与土壤盐渍化效应的影响。分析结果表明：①20年间,研究区土地利用／覆被类型有很大的变化,综合土地利用动态度仅为0．476％,中轻度盐渍地和重度盐渍地恶化速率呈现先增加后减少的趋势,盐渍化进程有所遏制,但依然无法扭转逐步恶化的趋势。②研究区土壤呈碱性,土壤盐渍化的危害主要是NaCl,其次是MgCl2以及Na2SO4;各采样点不同深度的含水量大小存在明显差异,但变化趋势基本相似,其中表层土壤的含水量与其他深度土层含水量的区别显著;不同深度的土层,盐渍土的类型也有着较大的差异性。③20年间,耕地转化为中轻度盐渍地和重度盐渍地的面积分别占原耕地面积的3．484％和0．418％,水体、沙漠、其他与中轻度盐渍地、重度盐渍地的相互转化均非常微弱,中轻度盐渍地与重度盐渍地之间的相互转化频繁。     

GEO-Environmental Suitability Evaluation of Land for Urban Construction Based on A Back-Propagation Neural Network and GIS: A Case Study of Hangzhou

Evaluating the geo-environmental suitability of land for urban construction is an important step in the analysis of urban land use potential. Using geo-environmental factors and the land use status of Hangzhou, China, a back-propagation (BP) neural network model for the evaluation of the geo-environmental suitability of land for urban construction was established with a geographic information system (GIS) and techniques of grid, geospatial, and BP neural network analysis. Four factor groups, comprising nine separate subfactors of geo-environmental features, were selected for the model: geomorphic type, slope, site soil type, stratum steadiness, Holocene saturated soft soil depth, groundwater abundance, groundwater salinization, geologic hazard type, and geologic hazard degree. With the support of the model, the geo-environmental suitability of Hangzhou land for urban construction was divided into four suitability zones: zone I, suitable for super high-rise and high-rise buildings; zone II, suitable for multi-story buildings; zone III, suitable for low-rise buildings; and zone IV, not suitable for buildings. The results showed that a BP neural network can capture the complex non-linear relationships between the evaluation factors and the suitability level, and these results will support scientific decision-making for urban-construction land planning, management, and rational land use in Hangzhou.     

Present situation and tendency of saline-alkali soil in west Jilin Province

Saline-alkali soil is a kind of degraded soil, in which the content of dissolvable elements is supernormal. The soil structure, physical and chemical qualities have degenerated due to impact of both natural and human factors. Soil salinization in temperate semi-humid area includes grassland salinization, cropland salinization and partially, wetland salinization. In the 40 years, from the late 1950s to late 1990s, the saline-alkali soil in temperate semi-humid area expanded, and aggravated to c…     

Present situation and tendency of saline-alkali soil in west Jilin Province

Taking west Jilin Province as an example, this paper put forward the assessment index of salinization, and based on it, the authors present the distribution characteristics of saline-alkali soil in the 1980s and the 1990s in west Jilin and analyze its physical and chemical properties in detail. The developing tendency of salinization was also inferred by comparing the saline-alkali soil of the 1980s with that of the 1990s. Finally, the natural and human factors leading to salinization are analyzed.     

新疆铁干里克绿洲水文过程对土壤盐渍化的影响

在对塔里木河下游绿洲地表灌溉水和地下水水质特征及土壤盐分实测分析的基础上,探讨了地表水、地下水过程及其对土壤盐渍化的影响。结果显示：塔里木河下游绿洲灌区地表水矿化度与土壤表层0～50cm盐分含量呈显著正相关,与50～100cm土层含盐量相关性不显著;地下水埋深与土壤盐分含量密切相关,0～50cm表层土壤盐分含量随地下水埋深的增加而下降,其中0～20cm下降幅度最大。当地下水埋深较浅时,绿洲内土壤含盐量高,呈T型分布,盐分表聚性强,土壤盐分含量随土壤深度的增加呈下降趋势;当地下水埋深较深时,绿洲内土壤盐份呈菱形分布,中层土壤盐分高,且地下水矿化度和土壤盐分分布转折点均为6.0m。据此推断,6m是地下水盐分积聚和表层土壤盐分积累停止的临界地下水埋深。     

为生态建设服务的吉林省西部景观类型研究*

在GIS技术支持下,依据有关原则,对吉林省西部景观类型进行了划分;选取地形和地貌、人类对景观的利用水平以及沙碱化程度三个指标对景观类型进行了稳定性评价。在此基础上,结合景观生态学的有关理论,采用类型重要值、嵌块体密度和平均内缘比率分析了吉林省西部各小区(东部区,中部区和西部区)内不同稳定类型的景观空间结构,提出了重建不稳定类型应以西部区为重点并要注意其内部结构的协调性、防止亚稳定类型向不稳定类型过渡也应以西部为重点、东部区的景观生态建设应注意增加其异质性等建议。     

干旱区耕地质量等级评价及土壤养分与盐渍化的分析研究 ——以民勤绿洲为例

为整体掌握民勤绿洲耕地质量、土壤养分以及盐渍化状况等,充分利用县域耕地资源,分析研究民勤绿洲耕地质量等级划分及其耕地土壤养分和盐渍化现状,为及时准确掌握绿洲耕地地力状况提供科学依据,同时为绿洲耕地土壤养分、盐渍化障碍提供改良措施。基于农业农村部《耕地质量调查监测与评价办法》(农业部2016年第2号)和《耕地质量等级》国家标准(GB/T33469-2016)的相关要求,构建民勤绿洲县域评价体系,通过综合运用空间分析、模糊数学、层次分析和综合指数等方法,对民勤绿洲耕地质量等级进行综合评价。结果表明:(1)民勤绿洲耕地质量平均等级为3.26等;分布有一至七等级地,八、九、十等级地没有分布;以三、四等级地为民勤绿洲耕地的主要等级分布,面积占比分别为31.63%、28.27%。泉山区中部和坝区灌溉农业区多分布一、二等级地。湖区灌溉区多分布三、四等地。在绿洲边缘带较多分布五、六、七等地。(2)民勤绿洲耕地土壤有机质平均含量在10.00~15.00 g·kg^-1之间,全氮平均含量在0.50~1.00 g·kg^-1之间,总体处于较低水平。有效磷和速效钾总体处于中等水平。昌宁区、泉山区与坝区交界东北部以及湖区镇(昌宁镇、东湖镇、南湖镇、泉山镇、西渠镇)耕地土壤养分平均含量较均低。(3)民勤绿洲盐渍化耕地的面积为32240.36 hm²,占民勤绿洲耕地总面积的30.09%;主要以轻度盐渍化为主。轻度盐渍化多分布在湖区红沙岗镇、红沙梁镇、西渠镇等镇;中度盐渍化分布在昌宁镇以及环河区沿风沙线一带。其评价结果对民勤绿洲耕地资源的科学管理和可持续利用以及绿洲农业的发展具有重要意义。     

民勤绿洲不同土地利用类型下土壤水盐的空间分布特征分析

以石羊河流域下游——民勤绿洲为研究区域，通过野外采样、实地调查和实验分析，对不同土地利用类型下（耕地、林地、草地、湿地、盐碱地、撂荒地和荒漠）土壤的水盐特征进行研究，结果表明研究区土壤含水率整体偏低，范围为5.35%~20.58%，土壤含盐量的平均值为47.02 g·kg^-1，盐渍化程度严重。土壤含水率和含盐量表现为中等变异性，说明其易受到气候、地形、水文地质以及人为活动的影响。不同土地利用类型下土壤水盐的垂直分布差异显著，土壤含水率在垂直方向上的变化特征较为复杂，但含盐量在垂直方向上主要表现为“表聚型”和“振荡型”。民勤绿洲各土层土壤水盐的水平分布均呈条带状分布,土壤含水率整体表现出西高东低，南高北低，而土壤含盐量则表现出相反的趋势。     

乾安县土地利用变化及其生态效应

Based on GIS and statistical methods, with the help of searching historical literatures andcalculating the landscape indices, the land use changes of Qian'an County in both spatial and temporalaspects from 1945 to 1996 has been analyzed in this paper. And the driving forces of land use changesand their ecological effects are discussed too. The main findings of this study are as follows:(1)Landuse changed greatly in Qian'an during 1945-1996, characterized by a decrease in grassland, wetlandand water bodies,and an increase in cultivated land, saline-alkali land, and the land for housing andother construction purposes. Grassland decreased by 175,828.66 ha, and cultivated land increased by     

Land use change and its ecological effect in Qian'an County of Jilin Province

Based on GIS and statistical methods, with the help of searching historical literatures and calculating the landscape indices, the land use changes of Qian'an County in both spatial and temporal aspects from 1945 to 1996 has been analyzed in this paper. And the driving forces of land use changes and their ecological effects are discussed too. The main findings of this study are as follows: (1) Land use changed greatly in Qian'an during 1945-1996, characterized by a decrease in grassland, wetland and water bodies, and an increase in cultivated land, saline-alkali land, and the land for housing and other construction purposes. Grassland decreased by 175,828.66 ha, and cultivated land increased by 102,137.23 ha over the half century. Accordingly, the main landscape type changed from a steppe landscape to a managed agricultural ecosystem. (2) Results of correlation analysis show that the land use change in the study area was mainly driven by the socioeconomic factors.　(3) The ecological effects of land use change in the area are characterized by serious salinization, degression of soil fertility and the weakening of landscape suitability.     

基于土地覆被和水文过程变化的松嫩平原典型区域土地盐渍化成因分析（英文）

Causes of land salinization were determined via land cover and hydrological process change detection in a typical part of Songnen Plain.The area of saline land increased from4627 km2 in 1980 to 5416 km2 in 2000,and then decreased to 5198 km~2 in 2015.The transformation between saline land and other land covers happened mainly before 2000,and saline land had transformation relationship mainly with cropland,grassland,and water body.From 1979 to 2007,groundwater depth fluctuated to increase and was mainly deeper than3.3 m.Spatially,the area of the region where groundwater depth was deeper than 3.3 m increased from 46.7%in 1980 to 84%in 2000,while the area of the region almost occupied the whole region after 2000.Precipitation and evaporation changed little,while runoff decreased substantially.Shallow groundwater,change of cropland,grassland,and water body induced from human activities and decrease of runoff and increase of irrigation and water transfer from outer basin were the main reasons for land salinization before 2000.After 2000,groundwater with relatively great depth could not exert great influence on land salinization.Protection of grassland and wetland prevented the increase of the area of saline land.     

北疆农区土壤盐渍化遥感监测及其时空特征分析

基于MODIS数据,利用归一化植被指数和盐分指数的二维特征空间关系建立土壤盐渍化遥感监测模型,对北疆农区2000年以来的土壤盐渍化状况及其空间动态变化进行了监测分析,并探讨了典型区土壤盐渍化的主要驱动因素。结果表明：① 土壤盐渍化遥感监测指数可以从宏观上定量刻画北疆农区的土壤含盐量;② 北疆农区土壤盐渍化空间特征呈现出总体上逆转、局部严重发展的态势;③ 土壤盐渍化等级在不同时间段的发展或逆转的方向主要由中度向重度及重度向盐土间的相互转化,其中重度盐渍化农用地的转化幅度最大;④ 不同土壤盐渍化等级中盐土的形成与农区降水量和干燥程度具有较好的相关性,未盐渍化（正常）和中度盐渍化与农区有效灌溉面积和农作物播种面积分别呈相关系数较高的正相关和负相关。     

Determination of land salinization causes via land cover and hydrological process change detection in a typical part of Songnen Plain

Causes of land salinization were determined via land cover and hydrological process change detection in a typical part of Songnen Plain. The area of saline land increased from 4627 km² in 1980 to 5416 km² in 2000, and then decreased to 5198 km² in 2015. The transformation between saline land and other land covers happened mainly before 2000, and saline land had transformation relationship mainly with cropland, grassland, and water body. From 1979 to 2007, groundwater depth fluctuated to increase and was mainly deeper than 3.3 m. Spatially, the area of the region where groundwater depth was deeper than 3.3 m increased from 46.7% in 1980 to 84% in 2000, while the area of the region almost occupied the whole region after 2000. Precipitation and evaporation changed little, while runoff decreased substantially. Shallow groundwater, change of cropland, grassland, and water body induced from human activities and decrease of runoff and increase of irrigation and water transfer from outer basin were the main reasons for land salinization before 2000. After 2000, groundwater with relatively great depth could not exert great influence on land salinization. Protection of grassland and wetland prevented the increase of the area of saline land.     

Land use change and its ecological effect in Qian＇an County of Jilin Province

Based on GIS and statistical methods, with the help of searching historical literatures and calculating the landscape indices, the land use changes of Qian‘an County in both spatial and temporal aspects from 1945 to 1996 has been analyzed in this paper. And the driving forces of land use changes and their ecological effects are discussed too. The main findings of this study are as follows: (1) Land use changed greatly in Qian‘an during 1945-1996, characterized by a decrease in grassland, wetland and water bodies, and an increase in cultivated land, saline-alkali land, and the land for housing and other construction purposes. Grassland decreased by 175,828.66 ha, and cultivated land increased by 102,137.23 ha over the half century. Accordingly, the main landscape type changed from a steppe landscape to a managed agricultural ecosystem. (2) Results of correlation analysis show that the land use change in the study area was mainly driven by the socioeconomic factors. (3) The ecological effects of land use change in the area are characterized by serious salinization, degression of soil fertility and the weakening, of landscaoe suitability.