Prediction of vegetation anomalies over an inland river basin in north‐western China          下载免费PDF全文

Jing Fu  Jun Niu  Bellie Sivakumar 《水文研究》2018,32(12):1814-1827

Vegetation cover plays an important role in linking the atmosphere, water, and land and is deemed as a key indicator in the terrestrial ecological system. Therefore, it is of great importance to monitor vegetation dynamics and understand the mechanisms of vegetation change, including that driven by climate change. This study examines (a) the evolution of vegetation dynamics over the Heihe River Basin in the typical arid zone in north‐western China using nonparametric Mann–Kendall test and Thiel Sen's slope; (b) the relationships between remotely sensed vegetation indices (normalized difference vegetation index [NDVI] and enhanced vegetation index [EVI]) and hydroclimatic variables based on correlation analysis; and (c) the prediction of vegetation anomalies using a multiple linear regression model. For the analysis, the Moderate Resolution Imaging Spectroradiometer NDVI/EVI product and the gridded daily meteorological data at a spatial resolution of 0.125° over the period 2001–2010 are considered. The results indicate that vegetation cover improved over a large proportion during 2001–2010, with a significant trend towards warm and wet, characterized by an increase in average annual temperature and precipitation by 0.042 °C/year and 5.8 mm/year, respectively. We test the feasibility of NDVI and EVI in quantifying the responses of vegetation anomaly to climate change and develop a statistical model to predict vegetation dynamics in the basin. The NDVI‐based model is found to be more reliable than the EVI‐based model, partly due to the vegetation characteristics and geomorphologic properties of the study region. The proposed model performs well when there is no lag time between meteorological factors and vegetation indices for grassland and cropland, whereas 1‐month lead time prediction is found to be best for forest. The soil water content is introduced as an extra explanatory variable, which effectively improves the prediction accuracy for different land use types. In general, the predictive ability of the proposed model is stable and satisfactory, and the model can provide useful early warning information for regional water resources management under changing climate.  相似文献   

黑潮流域海温适应性观测敏感区诊断方法研究     

崔宝龙  笪良龙  过武宏  韩梅 《海洋科学》2018,42(7):80-86

敏感区诊断是适应性观测的关键问题,集合变换卡尔曼方法(EnsembleTransformKalmanFilter,ETKF)是目前主要的诊断方法之一。将集合变换卡尔曼方法应用于海洋环境适应性观测,根据ROMS海洋模式数据构建海表温度集合预报,以黑潮流域宫古海峡附近海域为验证区进行敏感区诊断计算,分析不同间隔时间条件下敏感区分布情况,结合模拟系统观测试验验证在敏感区进行适应性观测对预报质量的提升效果。结果表明,在诊断所得敏感区内添加观测能够提升预报质量;随时间间隔增大,敏感区向上游区域平移且预报质量提升效果减小;与在验证区整体添加观测相比,敏感区观测对预报质量提升效果基本相同并且观测成本明显减少。  相似文献   

基于熵权TOPSIS模型的海岛地区资源环境承载力研究——以舟山普陀区、定海区为例   总被引：2，自引：0，他引：2  

徐文斌  郭灿文  王晶  程义远  徐鹏杰  张宏晔 《海洋通报》2018,(1):9-16

随着海洋强国、"一带一路"、生态文明建设等国家战略的不断推进,海岛在国家政治、军事、经济、社会、生态中的地位不断提高,海岛开发、利用的规模越来越大,其生态保护也面临着新的挑战。本文依据资源环境承载力内涵,兼顾海岛资源环境特点,研究形成海岛地区资源环境承载力评价指标体系,综合应用熵权法、TOPSIS(逼近理想解排序方法)模型评价了典型海岛地区——普陀区与定海区2009-2015年间的资源环境承载力状况,结果表明:普陀和定海资源环境承载力水平呈稳步提升趋势,各个时期的环境保护政策和节能减排相关措施在环境保护与污染治理等方面起到了较为积极的作用。最后,在基于生态系统的海岛综合管理框架内提出了对策建议。  相似文献   

“海上丝绸之路”超大城市环境变化遥感分析     

冯素云  张凯选  鹿琳琳 《地球信息科学学报》2018,20(5):602-612

随着城市化进程的加快,如何及时、精确地对城市环境的变化做出评价,进而制定出合理的发展方案,对城市可持续发展至关重要。本文综合利用卫星遥感获取的PM_2.5浓度数据、地表温度数据（Land Surface Temperature,LST）、植被指数数据（Normalized Difference Vegetation Index,NDVI）及城市用地辅助信息数据,基于综合评价指标,分析海上丝绸之路沿线12个超大城市地区2000-2013年环境质量的动态变化。研究结果表明,2000-2013年,海上丝绸之路沿线约75%的超大城市呈现出不同程度的环境恶化现象。12个超大城市用地环境恶化及逐步恶化面积占研究区域总面积的31.33%（4732.39 km²）。2000-2013年,城市扩张用地恶化和逐步恶化面积约占总扩张用地的29.48%（3765.83 km²）。平均地表温度的上升、植被覆盖度的急剧下降及PM_2.5浓度的增加均对海上丝绸之路沿线超大城市环境质量变化产生影响。其中,空气中PM_2.5浓度的大幅度增加是2000-2013年海上丝绸之路沿线超大城市扩张用地环境退化的主要原因。  相似文献   

沿海城市经济-海洋生态环境-游艇旅游业耦合协调发展分析     

姚云浩  栾维新 《海洋通报》2018,(4):361-369

借鉴物理学中的耦合理论,分析沿海城市经济系统、海洋生态环境系统与游艇旅游业系统三者间的耦合协调作用机理;构建耦合评价模型与指标体系,并基于改进的熵值法,对沿海16个游艇旅游发展重点城市三者的耦合度及耦合协调度进行实证研究;运用皮尔逊相关系数法探讨各因素间相互关系。结果表明:沿海城市经济、海洋生态环境和游艇旅游业发展水平的综合评价值并不高,可进一步分为城市经济滞后型、生态环境滞后型和游艇旅游业滞后型三种制约类型;区域内三大系统耦合度较高,但耦合协调度较低且存在明显的区域差异;系统内部各因素间相互关联。鉴于此,提出游艇城市应因地制宜,协调开发与保护关系,深化产业融合等建议,以促进三大系统较高层次的耦合协调发展。  相似文献   

日照市露天开采矿山地质环境问题及恢复治理措施          下载免费PDF全文

汪继学  尹俊凯  陈鹏  张承斌 《山东国土资源》2018,34(12)

通过1∶5万矿山地质环境调查和遥感解译手段,对日照市矿山进行了全面的调查,查明各类矿山546处,主要集中在莒县和五莲县境内。除莒县刘官庄煤矿外,其余全部为露天开采矿山,主要选用直接开挖的方式,不仅破坏了地表环境,而且矿山生产活动产生的固体废弃物占用了大面积的土地。该文根据矿山地理位置及开采方式的不同,将相同类型的多个矿山划分为同一治理区,针对不同治理区的特点,采取科学有效的治理方法,建立健全矿山地质环境监督管理机制,切实解决矿山地质环境问题,改善生态环境。  相似文献   

新疆S214公路台特玛湖干涸湖盆段风沙危害及防治     

蔡东旭  李生宇  王海峰  俞祥祥  王世杰  徐新文 《中国沙漠》2020,40(1):1-11

新疆S214（考干-米兰，考米线）公路位于库鲁克塔格沙漠东南缘，穿越台特玛湖干涸湖盆。由于该区气候干旱，风力强劲，沙源丰富，流动沙丘广布且快速移动，风沙危害对公路运输构成严重威胁。通过对风沙环境和风沙危害定位观测和土壤水盐特征系统调查，确定了风沙危害极为严重的公路区段，提出了合理的风沙防护措施及防沙体系结构。结果表明：该区具有明显的单风向风况，主要盛行ENE和NE风，偶有反向风沙活动，起沙风频率、输沙势、输沙率极高，属于高能-大比率风能环境；受土壤水分、盐分含量影响，地表紧实度差异较大，部分地段为极疏松的沙层，部分地段为紧实的盐壳；S214公路风沙危害防护区段为K4+900~K18+200，设计建造的阻-固-输相结合的机械-植物复合防沙体系，防沙效果明显，保障了道路安全运营。这一强风沙、高盐区公路防沙体系建设模式可为类似环境地区工程防沙提供借鉴。  相似文献   

基于小震定位与震源机制解信息的阿尔金断裂带东段构造转换研究   总被引：1，自引：0，他引：1       下载免费PDF全文

刘亢  李海兵  王长在  张辉  肖根如  李红光  张凌 《地球物理学报》2018,61(11):4459-4474

阿尔金断裂带东段地区的造转换及其动力学机制研究一直是地学工作者关注的焦点.本文利用双差定位法获取研究区域2008—2017年间6013次地震事件的精确定位数据；整理筛选前人震源机制解36个，并采用P/S波振幅比方法计算获得221个以及CAP方法获得25个震源机制解信息.选择野马河—大雪山断裂作为研究区构造转换研究的突破口，综合小震定位数据与震源机制解信息，并开展野外地质调查进行验证，清晰刻画出该断裂的深部构造形态以及现今的运动特征：由阿尔金断裂带向祁连山方向过渡，断层产状由近直立逐渐转变为倾向南，倾角变缓，震源机制解由走滑性质为主转变为逆冲性质为主，是一个连续渐变的过程，为研究区的构造转换研究提供了直接证据.  相似文献   

Variation in the sediment deposition behind check‐dams under different soil erosion conditions on the Loess Plateau,China          下载免费PDF全文

Yanhong Wei  Zhong He  Juying Jiao  Yujin Li  Yixian Chen  Hengkang Zhao 《地球表面变化过程与地形》2018,43(9):1899-1912

To maintain a reasonable sediment regulation system in the middle reaches of the Yellow River, it is critical to determine the variation in sediment deposition behind check‐dams for different soil erosion conditions. Sediment samples were collected by using a drilling machine in the Fangta watershed of the loess hilly–gully region and the Manhonggou watershed of the weathered sandstone hilly–gully (pisha) region. On the basis of the check‐dam capacity curves, the soil bulk densities and the couplet thickness in these two small watersheds, the sediment yields were deduced at the watershed scale. The annual average sediment deposition rate in the Manhonggou watershed (702.0 mm/(km²·a)) from 1976 to 2009 was much higher than that in the Fangta watershed (171.6 mm/(km²·a)) from 1975 to 2013. The soil particle size distributions in these two small watersheds were generally centred on the silt and sand fractions, which were 42.4% and 50.7% in the Fangta watershed and 60.6% and 32.9% in the Manhonggou watershed, respectively. The annual sediment deposition yield exhibited a decreasing trend; the transition years were 1991 in the Fangta watershed and 1996 in the Manhonggou watershed (P < 0.05). In contrast, the annual average sediment deposition yield was much higher in the Manhonggou watershed (14011.1 t/(km²·a)) than in the Fangta watershed (3149.6 t/(km²·a)). In addition, the rainfalls that induced sediment deposition at the check‐dams were greater than 30 mm in the Fangta watershed and 20 mm in the Manhonggou watershed. The rainfall was not the main reason for the difference in the sediment yield between the two small watersheds. The conversion of farmland to forestland or grassland was the main reason for the decrease in the soil erosion in the Fangta watershed, while the weathered sandstone and bare land were the main factors driving the high sediment yield in the Manhonggou watershed. Knowledge of the sediment deposition process of check‐dams and the variation in the catchment sediment yield under different soil erosion conditions can serve as a basis for the implementation of improved soil erosion and sediment control strategies, particularly in semi‐arid hilly–gully regions. Copyright © 2018 John Wiley & Sons, Ltd.  相似文献   

广东省海洋生态环境现状及保护对策建议          下载免费PDF全文

胡平  严淑青  石萍  郑兆勇  林丽茹 《海洋开发与管理》2020,37(6):115-120

广东省作为海洋强省，海洋经济总量连续多年居全国首位，不断助力海洋强国建设。海洋生态环境的有效保护是海洋经济高质量发展的重要前提，文章在分析广东省近年来海洋生态环境状况、面临的机遇和挑战的基础上，提出海洋生态环境保护的建议，主要包括：健全源头管控，制定各类型入海排污口管控措施，实施动态监管；开展入海江河整治，减少入海营养盐负荷，逐步建立“河长制”和“湾长制”的衔接机制；加强用海风险防范，严控海洋环境风险，构建事前防范、事后管控、事后处置的全过程海洋生态风险防范体系；实施洁净海岸带工程，强化海洋生态修复，提升公众亲海岸线的生态空间品质；强化海洋资源高效利用，坚持海洋经济绿色发展，加快推动海洋经济高质量发展；推动人才队伍建设，保障监测技能提能增效，提升全省海洋环境监测信息化水平。  相似文献