青海省那棱格勒河下游绿洲区生态环境现状评价

采用归一化植被指数、景观多样性指数、景观均匀度指数等技术指标,评价那棱格勒河下游绿洲的生态环境现状。结果表明:那棱格勒河下游绿洲区主要为中植被覆盖(覆盖度30%~60%)区域,占绿洲区总面积的42.83%;低植被覆盖类型(覆盖度10%~30%)和高植被覆盖类型(覆盖度60%)次之。极低植被覆盖(覆盖度10%)区域最少,占绿洲区总面积的3.96%。稀疏草地和荒漠为该区域的优势景观,自然生产力等级低,生态系统受外界干扰后难以恢复,极易发生退化与沙化,系统的恢复稳定性与阻抗稳定性都较弱。     

塔里木河下游植被指数的遥感监测

为了了解塔里木河下游9次应急输水的生态环境效益，利用MODIS—NDVI最大合成法、差值法，分析了塔里木河下游植被指数的年际变化情况，结果表明：（1）塔里木河下游地区植被覆盖度变化中增加区面积呈增加趋势。（2）2002年与输水初期相比，植被覆盖度增加区主要分布于上段和中段的老塔里木河及其文阔尔河河道两侧，下段河道覆盖度增加区仅零星分布于距河道0．3km左右的地势低洼区域。2003年以后，下段植被覆盖度增加区面积已达84．30km^2，是2002年的3．16倍，主要分布在距离河道0．5km左右的河道两侧。至2007年塔里木河下游河道两侧植被覆盖度增加区的变化是比较显著的，特别是下段植被覆盖增加区呈带状分布于距河道1．5km左右的范围内。植被指数遥感监测说明塔里木河下游地区的生态环境得到明显改善。     

基于遥感和像元二分模型的新疆植被覆盖度格局动态监测

利用MODIS归一化植被指数(NDVI)资料反演了2006—2015年新疆植被覆盖状况,获取不同时期的植被覆盖度图,并进一步分析了植被覆盖度变化的原因。结果表明:新疆植被覆盖度呈现北部高于南部、西部高于东部的分布特征,其中西部和西北部的山地森林、草地以及天山北坡绿洲农作物、草地区域植被覆盖情况最好。过去10年间,新疆植被覆盖度总体呈上升趋势,2015年植被覆盖度达到最高,为16.68%。生态恢复工程、降水和气温等是影响植被覆盖度变化的主要因素。     

基于RS与GIS的水土保持生态功能区生态状况评估

以河南省大别山水土保持国家重点生态功能区为研究区,基于RS与GIS获取2012年和2017年研究区植被覆盖、土地利用、土壤侵蚀等遥感解译数据,从生态功能、生态结构和生态压力3个方面,采用综合指数法,对研究区生态状况进行动态监测与评价。结果表明,2012—2017年间,研究区土地利用结构发生较明显的变化,林草地覆盖率上升9.85%,耕地和建设用地面积比上升13.23%,水域湿地面积比变化不大;植被覆盖指数上升 62.74%,中度以上土壤侵蚀面积比略有增加;生态状况变化度ΔF=4.95,整体生态状况等级由良变为优,生态状况变化度评级为显著变好。     

基于TM影像的桂林市植被覆盖时空动态监测与分析

以西部地区中等规模城市——桂林市为例,利用1991、2006年两期TM卫星影像数据,在对原始数据预处理的基础上,提取归一化植被指数(NDVI)。依据混合像元二分模型,生成桂林市所辖5城区的两期植被覆盖度监测分类图像,对区域植被覆盖状况进行时空动态变化分析。结果表明,1991年~2006年间,城市植被覆盖区面积总体呈现下降趋势;在划分的3类植被覆盖类型中,低植被覆盖区面积减少幅度最为明显,中、高植被覆盖区面积有不同程度增长;低植被覆盖区主要分布在城市建成区与一些村镇外围区域,中、高植被覆盖区集中分布在城市远郊地带。此外,随着城市化的迅速发展,城乡各类建设用地面积不断增加,城市边缘地带的绿色植被正逐步被人工景观所取代。     

20年间艾比湖流域植被覆盖度景观格局变化

选取艾比湖流域1990年、2001年、2011年同期（9月）3期I．and．satTM遥感影像，基于归一化植被指数NDVI，提取植被覆盖等级图，利用ArcGIS9．3和Fragstas3．3对该流域植被景观的变化进行了分析研究。结果表明：1990—2011年，该流域植被覆盖度变化明显，低植被覆盖区和较低植被覆盖区都有所减少，分别由1990年的34．05％和32．94％减少到2011年的32．8％和24．06％；较高植被覆盖区和高植被覆盖区有所增加，分别由8．49％和5．20％增长到15．13％和9．83％，但水域面积退化明显，由1990年的525．9765km2缩小至494．9876km2，减少了30．9889km2，退缩幅度达O．4％；最大斑块指数（LPI）由17．04上升到21．10，香农多样性指数（SHDI）和香农均势度指数（SHEI）分别由1．5387和0．8588增长到1．6395和0．9150。表明艾比湖流域景观格局混杂程度愈来愈高，空间异质性在逐年加强，总体空间格局向破碎化趋势发展。     

应用遥感监测技术分析扬州市五年植被覆盖状况

利用扬州市2006—2010年间卫星遥感数据,对扬州市植被覆盖状况进行了研究。首先对遥感影像进行几何校正,其次对遥感影像进行解译,提取植被覆盖信息,计算扬州市植被覆盖指数,同时对扬州市近5年植被覆盖进行了动态变化分析。研究表明,扬州市近5年林地面积大幅度提高,植被覆盖指数逐年增加,生态环境状况逐年好转。     

基于RS和GIS技术的贵州省植被生态环境监测分析

为阐明贵州省植被生态环境变化的整体状况，基于RS和GIS技术，应用美国国家航空航天局最新的全球植被指数变化研究数据（GIMMS），通过计算月归一化植被指数（NDVI）变化率，并对研究区一元线性回归模拟，分析了贵州省1982年-2003年的地表植被覆盖。结果表明：22年来，研究区植被覆盖呈增加趋势，表明贵州省植被生态环境向好的方向发展；贵州省平均植被覆盖在春季和秋季呈上升趋势，夏季和冬季呈下降趋势，其中春季对植被覆盖总变化量的贡献最大；植被覆盖程度增减因区域不同而异，变化程度呈增加的区域主要位于贵,ki-I省的中部地区；变化程度呈减小的区域分布在贵州省的四周边缘。     

基于“天-空-地”一体化的生态保护红线区监管评价体系构建及应用ADDINCNKISM.UserStyle

科学监管评价生态保护红线区生态环境是合理利用自然资源和充分保护生态环境的基础,对推动国家生态文明建设具有重要意义。该研究基于“天-空-地”一体化获取多源数据,结合GIS和RS空间分析,从生态系统格局和质量、人类活动、环境限制4个方面选取25个指标,构建了生物多样性维护生态保护红线区监管评价体系,并以泰山生态保护红线区为例进行分析研究。结果表明:2000—2015年,研究区生态系统格局、生态系统质量、人类活动状况3个分指数得分及生态环境综合得分均呈现先降后升的趋势,就综合得分而言,2000—2005年、2005—2010年得分降幅分别为18.73%和5.24%,2010年得分最低(41.97分),而2010—2015年得分增幅为81.63%,2015年得分为76.23分,生态环境综合得分评价等级由Ⅱ级升为Ⅰ级。其中城乡居民和工矿用地面积占比、生态系统破碎度和分离度、植被生物量是影响研究区生态环境的关键指标,相关部门应加强对研究区边界处人类活动的监管,并注重生态系统完整性和植被生长状态的保护。该监管评价体系具有较强的实践性、科学性和可操作性,可为生态保护红线区的监管评价提供新思路。     

采煤塌陷积水区时空动态变化监测研究

基于Landsat系列4个时相数据,利用谱间关系法提取NDVI、NDWI和缨帽变换指数,并采用决策树和分类后比较法研究淮南矿区采煤塌陷积水区时空变化。结果表明:1987—2015年淮南矿区塌陷积水区域面积为189.51 km~2,年均增加6.77 km~2。其中,2000—2005年塌陷积水区域面积变化较大,年均增加15.0 km~2,其水域数量变化动态度和空间变化动态度分别高达13.66%和53.61%。凤台矿区年均增加积水面积最大,为2.60 km~2,其次为新集、潘集和孔李沉陷区,9大沉陷区及其他矿区增幅较小。在"边塌陷边治理"下,除潘集和凤台矿区水域面积增加,丁集朱集矿基本持平外,其他矿区水域面积均有所减少。     

Estimation of Vegetation Coverage in Semi-arid Sandy Land Based on Multivariate Statistical Modeling Using Remote Sensing Data

The estimation of vegetation coverage is essential in the monitoring and management of arid and semi-arid sandy lands. But how to estimate vegetation coverage and monitor the environmental change at global and regional scales still remains to be further studied. Here, combined with field vegetation survey, multispectral remote sensing data were used to estimate coverage based on theoretical statistical modeling. First, the remote sensing data were processed and several groups of spectral variables were selected/proposed and calculated, and then statistically correlated to measured vegetation coverage. Both the single- and multiple-variable-based models were established and further analyzed. Among all single-variable-based models, that is based on Normalized Difference Vegetation Index showed the highest R (0.900) and R ² (0.810) as well as lowest standard estimate error (0.128024). Since the multiple-variable-based model using multiple stepwise regression analysis behaved much better, it was determined as the optimal model for local coverage estimation. Finally, the estimation was conducted based on the optimal model and the result was cross-validated. The coefficient of determination used for validation was 0.867 with a root-mean-squared error (RMSE) of 0.101. The large-scale estimation of vegetation coverage using statistical modeling based on remote sensing data can be helpful for the monitoring and controlling of desertification in arid and semi-arid regions. It could serve for regional ecological management which is of great significance.     

伊犁低山丘陵区小流域水土保持措施优化配置研究

在调查分析伊犁低山丘陵区水土流失特点的基础上，研究了该区小流域水土保持措施的空间配置。结果表明：伊犁低山丘陵区水土流失主要表现为以水力侵蚀为主的多种土壤侵蚀类型作用下的坡面侵蚀和沟道侵蚀。针对其水土流失特点，伊犁低山丘陵区小流域水土保持措施优化配置为：以生态修复为主，上游地区封禁保护；中游地区种植水保林和经济林带，建立生态缓冲带；下游水平沟种草。通过综合治理开展水土保持生态环境建设，至2012年底，伊犁低山丘陵区治理程度达到77．33％，林草覆盖率48％，改善了当地生态环境。     

Impacts of ecological water conveyance on groundwater dynamics and vegetation recovery in the lower reaches of the Tarim River in northwest China

The ecological water conveyance project (EWCP) in the lower reaches of the Tarim River provided a valuable opportunity to study hydro-ecological processes of desert riparian vegetation. Ecological effects of the EWCP were assessed at large spatial and temporal scales based on 13 years of monitoring data. This study analyzed the trends in hydrological processes and the ecological effects of the EWCP. The EWCP resulted in increased groundwater storage—expressed as a general rise in the groundwater table—and improved soil moisture conditions. The change of water conditions also directly affected vegetative cover and the phenology of herbs, trees, and shrubs. Vegetative cover of herbs was most closely correlated to groundwater depth at the last year-end (R?=?0.81), and trees and shrubs were most closely correlated to annual average groundwater depth (R?=?0.79 and 0.66, respectively). The Normalized Difference Vegetation Index (NDVI) responded to groundwater depth on a 1-year time lag. Although the EWCP improved the NDVI, the study area is still sparsely vegetated. The main limitation of the EWCP is that it can only preserve the survival of existing vegetation, but it does not effectively promote the reproduction and regeneration of natural vegetation.     

Monitoring the changes in impervious surface ratio and urban heat island intensity between 1987 and 2011 in Szeged,Hungary

Landsat time series data make it possible to continuously map and examine urban land cover changes and effects on urban environments. The objectives of this study are (1) to map and analyse an impervious surface and its changes within a census district and (2) to monitor the effects of increasing impervious surface ratios on population and environment. We used satellite images from 1987, 2003 and 2011 to map the impervious surface ratio in the census district of Szeged, Hungary through normalized spectral mixture analysis. Significant increases were detected from 1987 to 2011 in industrial areas (5.7–9.1%) and inner residential areas (2.5–4.8%), whereas decreases were observed in the city centre and housing estates due to vegetation growth. Urban heat island (UHI) values were derived from the impervious surface fraction map to analyse the impact of urban land cover changes. In 2011, the average value in the industrial area was 1.76 °C, whereas that in the inner residential area was 1.35–1.69 °C. In the city centre zones and housing estates, values ranging from 1.4 to 1.5 °C and from 1.29 to 1.5 °C, respectively, were observed. Our study reveals that long-term land cover changes can be derived at the district level from Landsat images and that their effects can be identified and analysed, providing important information for city planners and policy makers.     

Analysis of the changes of vegetation coverage of western Beijing mountainous areas using remote sensing and GIS

Mentougou District acts as a crucial component in the ecological buffer in western Beijing mountainous areas, Beijing, China. Using two Landsat MSS/TM images acquired on July 14, 1979 and July 23, 2005, the vegetation coverage of Mentougou District was calculated based on normalized difference vegetation index and spectral mixture analysis (NDVI-SMA) model. Its temporal and spatial changes were analyzed according to digital elevation model (DEM) image, social and economic data. The results showed that the vegetation coverage decreased from 76.4% in 1979 to 72.7% in 2005. Vegetation degradation was probably the result of human disturbance, such as outspreading of resident areas, and coal and stone mining activities, while vegetation restoration might be contributed by the combined effects of both natural processes and ecological construction effort. Vegetation changes were closely related to topographical characteristics. Plants at high altitude were more stable and less degraded than the plants at low altitude, while the plants on steep slope or northwest aspect were more vulnerable to degradation. During the period of 26 years, landscape appeared to become more fragmental, and ecological quality of the land seemed deteriorated sharply in that highly-covered vegetation area has been decreased by 24%.     

基于RS的徐州市区生态环境动态监测与评价分析

近年来,随着城市化进程推,城市生态环境正逐步恶化。徐州作为老矿业城市,情况尤其不为乐观,以徐州市区为例作生态评价分析。按照代表性、可操作性、适应性、可比性和方便性原则,选取了植被覆盖度、生物丰度、水网密度、人均绿地面积、城市环境污染负荷指数和环境质量综合指数作为评价指标来进行生态环境质量指数的计算。根据评价指标,选用1994年、2000年和2007年三个时相徐州市TM影像,对土地利用、河流水库、植被、人均绿地等方面进行遥感动态监测,然后对该地区13年来生态环境演变做了定量评价分析。评价结果表明,徐州市区生态环境质量由1994年的良好水平退化为一般水平,且有逐年下降恶化趋势,这与该区城市化进程一致。     

广西防城港市生态质量气象评价

以广西防城港市各区(县、市)为研究对象,应用生态质量气象评价方法,选取湿润指数、植被覆盖指数、水体密度指数、土地退化指数、灾害指数5个指标,通过计算生态环境综合指数,对防城港市生态质量进行评价。结果表明:防城港市最近10年生态质量评定级别为良好,植被覆盖度较好,降水充足,生物多样性较好,适合人类生存,评价结果与实际情况有较好的一致性,对城市建设和环境管理等方面具有一定的参考价值及科学依据。