土地覆被及生态服务价值变化的多时间尺度模拟——以四川省渔子溪流域为例   总被引：16，自引：0，他引：16  

冉圣宏  李秀彬  吕昌河 《地理学报》2006,61(10):1113-1120

根据渔子溪流域1986年和1994年的遥感影像土地覆被解译资料为基础,建立了模拟渔子溪流域生态环境变化的Markov Chain模型和Patch-dynamics模型,并以2002年遥感影像资料作为验证数据对模型进行了误差分析。以此为基础,分别以1年和8年的时间尺度对渔子溪流域土地覆被及其生态服务价值的变化进行了模拟,结果表明,时间尺度对模拟结果具有显著影响：在1年和8年的模拟尺度下,以Markov Chain模型得到的流域生态服务价值在1986~2018年间变化的相对误差为20%;不同土地覆被类型在不同步长下模拟结果的相对误差不一样,表明不同土地覆被类型变化的特征时间尺度不一样,以Patch-dynamics模型的模拟结果为例,步长为1年比步长为8年的相对误差大的土地覆被类型为耕地 (-8.2%/-5.6%)、有林地 (-0.5%/-0.4%)、草地 (0.7%/0.4%) 和居民建设用地 (-29.9%/-16.4%),它们的年际变化较大,其变化趋势不稳定,受到人为偶然因素的影响明显;而相对误差较小的土地覆被类型为灌木林 (-1.5%/-1.7%) 和永久冰雪覆盖 (27.3%/41.9%),它们的变化趋势较为稳定,主要受比较稳定的自然因素的影响。研究还表明,采用Markov Chain模型的模拟结果与采用Patch-dynamics模型的模拟结果总体上是一致的,但后者的模拟结果更稳定、更可靠。  相似文献   

ENSO事件对淮河流域降水的影响   总被引：1，自引：0，他引：1  

信忠保  谢志仁 《海洋预报》2005,22(2):38-46

研究表明,ENSO事件和淮河流域降水异常之间有明显的相关性。功率谱分析显示ENSO的冷事件和暖事件有三个共同的明显周期,即18个月、26个月和47个月;淮河流域降水异常的周期成分复杂,但同样存在明显的26个月周期。对。ENSO事件年份淮河流域降水异常的年内分布规律的分析结果表明：EL Nino年份的春季和冬季降水明显增多,而在LA Nina年份降水普遍减少,尤其以7月减少最为显著：在SO指数偏高年份,淮河流域降水明显减少,尤其是9、10、11三个月,减少量都在30％以上：而在SO指数偏低年份,春季和冬季降水明显增多。时间序列的滞后分析发现淮河流域降水异常对ENSO事件有3个月左右的响应滞后时间,对EL Nino响应的滞后时间大约4～5个月。  相似文献   

A New Precipitation Index for the Spatiotemporal Distribution of Drought and Flooding in the Reaches of the Yangtze and Huaihe Rivers and Related Characteristics of Atmospheric Circulation     

ZONG Haifeng  ZHANG Qingyun 《大气科学进展》2011,28(2):375-386

Characteristics of the spatiotemporal distributions of precipitation anomalies in the reaches of the Yangtze River and Huaihe River (YHR) were studied using EOF method. Four main precipitation pat-terns for the YHR in summer identified by the first two modes: a region-wide flood over the entire YHR (RWF); a region-wide drought over the entire YHR (RWD); a flood in the south with a drought in the northern region of the Yangtze River (FS-DN); and a drought in the south with a flood in the northern region of the Yangtze River (DS-FN). Based on the first two modes and the actual precipitation departure percentage, a new precipitation index is defined in this paper. The typical flood/drought years associated with the various rainfall patterns defined by this precipitation index are more representative and closer to reality compared to some existing precipitation indexes which just use the area-mean precipitation or the EOF time components individually. The characteristics of atmospheric circulation in summer corresponding to the four main precipitation patterns over the YHR in summer show the features of atmospheric circulation differ in different precipitation pattern years. Although the different patterns share a common main influential circulation system, such as the blocking high over northeastern Asia, the low trough of westerly flows in the mid latitudes, the West Pacific Subtropical High (WPSH), and the high ridge over the Tibet Plateau, the difference in location and intensity of these systems can lead to different distributions of precipitation anomalies.  相似文献   

淮河干流径流量长期变化趋势及周期分析   总被引：5，自引：2，他引：3  

王振龙  陈玺  郝振纯  王式成  孙乐强  崔蕾 《水文》2011,31(6):79-85

基于淮河干流鲁台子站1951～2008年径流量资料,采用最小二乘法、PIII曲线法和小波分析方法系统分析鲁台子站径流量的变化特征。结果表明:汛期径流量占全年径流总量的64%,年际变化最大相差4.7倍;从线性趋势来看,年径流量减少速率为0.68×108m3/a,其中汛期径流量减少速率为0.24×108m3/a,非汛期径流量减少速率为0.44×108m3/a,汛期径流量丰枯变化跟全年径流量相似程度高,非汛期径流量的年际波动较平稳;三种小波母函数对年径流序列周期分析结果略有差异,Mexcian hat小波检测结果偏宏观,Morlet小波和cmor2-1小波检测兼顾微观周期,cmor2-1小波更加准确全面反映径流周期变化,综合分析得出鲁台子年径流序列2年左右的主周期和8年左右的次周期。  相似文献   

气候变化下淮河流域极端洪水情景预估   总被引：3，自引：0，他引：3       下载免费PDF全文

郝振纯  鞠琴  王璐  王慧敏  江微娟 《水科学进展》2011,22(5):605-614

利用IPCC第4次评估公开发布的22个全球气候模式在A1B、A2和B1三种典型排放情景下的未来气温和降水预测结果,结合新安江月分布式水文模型,在对模型验证效果良好的基础上,参照集合预报方法,对未来90年(2010～2099年)气候变化下淮河流域的极端洪水进行预估。研究结果表明,从出现概率来看,淮河流域未来可能发生极端洪水年份的密集程度从大到小依次为A2情景、A1B情景、B1情景。A1B情景下,21世纪下半叶出现极端洪水的可能性增大,A2情景在2035～2065年以及2085年以后是极端洪水发生较为集中的时期。B1情景在21世纪70年代左右发生极端洪水的可能性较大。综合各种极端事件的定义方法,将极端洪水划定3个洪水量级。A2情景预估极端洪水的平均洪量在3种情景中最大,B1情景最小。3种情景未来一级极端洪水发生比例都比历史上偏大,A2情景下增加最多。二级极端洪水都较历史略有减少,三级极端洪水减少最显著。3种情景下各个量级极端洪水所占比例各不相同,A1B和A2情景二级以上极端洪水出现比例较大,B1情景下极端洪水量级多为三级,超1954年的一级极端洪水所占比例较小。  相似文献   

淮河流域能量和水分循环研究进展     

丁一汇  胡雯  黄勇  陈凤娇 《气象学报》2020,78(5):721-734

1998和1999年夏,中国与日本科学家合作在安徽省淮河流域进行了第一次大规模的能量与水循环试验（WCRP/GEWEX/GAME/HUBEX）,其重点是研究东亚梅雨锋系的多尺度,多系统结构、特征、生命史、发生发展机理及其引起洪涝灾害的原因。这是第一次中日合作的气象与水文联合观测试验,在此加强观测的基础上,双方进一步进行了长达5年的资料整理分析和科学研究工作,整个淮河流域能量与水循环试验与研究取得了全面和丰硕的成果。文中介绍了该计划所取得的主要成果,并以现在科学进展的视野重新评估这些成果的科学意义和不足,为进一步开展新的淮河与长江中下游梅雨科学联合试验提供经验和新的研究目标。   相似文献   

Flood hydrograph estimation from arid catchment morphology     

M. Nouh 《水文研究》1990,4(2):103-120

Data on performance of a geomorphologic rainfall-runoff model in simulating observed flash flood hydrographs in 32 arid catchments have been analysed. The catchments, which are located in the southwest region of Saudi Arabia, vary in their size, slope of land, and characteristics of soils, and are in zones of different rainstorm characteristics. The sensitivity of the model accuracy with various catchment and rainfall characteristics has been investigated. Size, followed by rate of infiltration and slope of land, are the most effective catchment characteristics affecting the accuracy. In addition, the accuracy varies with spatial and temporal rainfall variation, total rainfall depth, and length of the dry period between two successive rainstorms over catchment. It is sensitive to temporal rainfall variation more than spatial rainfall variation, and to the dry period more than total rainfall depth. Generally, the model did not display an accuracy approaching that of the observations, especially in simulating peak flowrates in large size infiltrating catchments having high temporal rainstorm variation. Guidelines on the best use of the model in arid catchments were proposed.  相似文献   

V: Daily catchment rainfall estimated from meteosat     

G. Dugdale  S. Hardy  J. R. Milford 《水文研究》1991,5(3):261-270

Meteosat data for 1986 to 1988 have been used to estimate the daily rainfall over catchments of tributaries of the river Senegal in Mail and Guinea. The technique uses the methodology of the TAMSAT group of the University of Reading, which involves the selection of an appropriate cloud top temperature threshold to determine whether the cloud is producing rain and the rainfall is estimated from the period during which storm clouds remain over a site. After calibration against all available raingauges in the catchments, the daily rainfall estimates derived by this technique were used as inputs to rainfall-runoff models. The results indicate that the streamflow models, which had themselves been calibrated using raingauge data, performed as well or better when the satellite derived estimates were used as inputs than when gauge data were used. An economical, automated operational system is described.  相似文献   

Hydrology and related changes after harvesting native forest catchments and establishing pinus radiata plantations. Part 3. Stream temperatures     

L. K. Rowe  C. H. Taylor 《水文研究》1994,8(4):299-310

Eight small steep south-west facing catchments (1-63-8-26 ha) have been monitored in Westland, New Zealand since 1974. Two catchments were retained in native mixed evergreen forest and the rest were subjected to various harvesting and land preparation techniques before being planted with Pinus radiata between 1977 and 1980. Stream temperatures were measured in all catchments for 11 years, including up to four years before harvesting. The streamwater temperature regime under the native forest cover has a seasonal cycle, with an annual mean of about 9°C and mean daily temperatures ranging between a winter minimum of about 5.8°C and a summer maximum of 12.S°C. After harvesting, the winter minimum stream temperatures in all trials were unchanged as topography exerts the major control over incoming solar radiation. The largest rises in mean summer stream temperatures, up to 5.5°C, were in the catchments that had been clearcut and burnt before planting. The maximum stream temperature recorded was 22.8°C in a clearcut catchment with no riparian reserve. Summer stream temperatures in this catchment were up to 11°C higher than in an adjacent control catchment. Summer stream temperature rises in catchments with riparian reserves were less than 1.5°C. Seven years after harvesting, stream temperatures were dropping towards pre-treatments levels in only two of the six treated catchments as revegetation of the riparian areas occurred and the plantations became established. As these small headwater streams discharge into streams with flows one or two orders of magnitude larger, the increases in summer stream temperatures will be rapidly dissipated. However, the cumulative impact of harvesting many small headwater catchments that discharge into a larger stream could have a noticeable effect on stream temperature if intact riparian reserves were not retained in both headwater and main streams.  相似文献   

淮河流域南部丘陵森林地区土壤-植被-大气相互作用:长期野外试验观测的初步分析          下载免费PDF全文

Qiudan Dai  Zhenhai Guo  Shufen Sun  Xia Xiao 《大气和海洋科学快报》2021,14(1):33-39

本文简要介绍了包括三部分观测的安徽淮南长期野外试验观测站,特别是土壤-植被-大气的集中观测,对小塔运行前三个月(2018年6月至8月)的数据,并结合同一时段大塔获得的数据,进行了初步分析.结果表明这些资料有合理的变化特征,日变化和夏季值特征显著,各月份间气象变化有明显差异.土壤水分和温度受降雨影响,在不同的下垫面条件下表现出不同的变化.土壤CO2日平均浓度在2 cm和10 cm处分别为1726和4481 ppm.2018年夏季土壤CO2浓度随土壤体积含水量的变化而变化,但与土壤温度呈弱相关.  相似文献