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1.
Snow cover variation and streamflow simulation in a snow-fed river basin of the Northwest Himalaya 总被引：3，自引：2，他引：1
Snowmelt is an important component of any snow-fed river system.The Jhelum River is one such transnational mountain river flowing through India and Pakistan.The basin is minimally glacierized and its discharge is largely governed by seasonal snow cover and snowmelt.Therefore,accurate estimation of seasonal snow cover dynamics and snowmeltinduced runoff is important for sustainable water resource management in the region.The present study looks into spatio-temporal variations of snow cover for past decade and stream flow simulation in the Jhelum River basin.Snow cover extent(SCE) was estimated using MODIS(Moderate Resolution Imaging Spectrometer) sensor imageries.Normalized Difference Snow Index(NDSI) algorithm was used to generate multi-temporal time series snow cover maps.The results indicate large variation in snow cover distribution pattern and decreasing trend in different sub-basins of the Jhelum River.The relationship between SCE-temperature,SCE-discharge and discharge-precipitation was analyzed for different seasons and shows strong correlation.For streamflow simulation of the entire Jhelum basin Snow melt Runoff Model(SRM) used.A good correlation was observed between simulated stream flow and in-situ discharge.The monthly discharge contribution from different sub-basins to the total discharge of the Jhelum River was estimated using a modified version of runoff model based on temperature-index approach developed for small watersheds.Stream power - an indicator of the erosive capability of streams was also calculated for different sub-basins. 相似文献
2.
Air temperature and snow cover variability are sensitive indicators of climate change. This study was undertaken to forecast and quantify the potential streamflow response to climate change in the Jhelum River basin. The implications of air temperature trends (+0.11°C/decade) reported for the entire north-west Himalaya for past century and the regional warming (+0.7°C/decade) trends of three observatories analyzed between last two decades were used for future projection of snow cover depletion and stream flow. The streamflow was simulated and validated for the year 2007-2008 using snowmelt runoff model (SRM) based on in-situ temperature and precipitation with remotely sensed snow cover area. The simulation was repeated using higher values of temperature and modified snow cover depletion curves according to the assumed future climate. Early snow cover depletion was observed in the basin in response to warmer climate. The results show that with the increase in air temperature, streamflow pattern of Jhelum will be severely affected. Significant redistribution of streamflow was observed in both the scenarios. Higher discharge was observed during spring-summer months due to early snowmelt contribution with water deficit during monsoon months. Discharge increased by 5% 40% during the months of March to May in 2030 and 2050. The magnitude of impact of air temperature is higher in the scenario-2 based on regional warming. The inferences pertaining to change in future streamflow pattern can facilitate long term decisions and planning concerning hydro-power potential, waterresource management and flood hazard mapping in the region. 相似文献
3.
With changing climatic conditions and snow cover regime, regional hydrological cycle for a snowy basin will change and further available surface water resources will be redistributed. Assessing snow meltwater effect on runoff is the key to water safety, under climate warming and fast social-economic developing status. In this study, stable isotopic technology was utilized to analyze the snow meltwater effect on regional hydrological processes, and to declare the response of snow hydrology to climate change and snow cover regime, together with longterm meteorological and hydrological observations, in the headwater of Irtysh River, Chinese Altai Mountains during 1961-2015. The average δ~(18) O values of rainfall, snowfall, meltwater, groundwater and river water for 2014–2015 hydrological year were-10.9‰,-22.3‰,-21.7‰,-15.7‰ and-16.0‰, respectively.The results from stable isotopes, snow melting observation and remote sensing indicated that the meltwater effect on hydrological processes in Kayiertesi River Basin mainly occurred during snowmelt supplying period from April to June. The contribution of meltwater to runoff reached 58.1% during this period, but rainfall, meltwater and groundwater supplied 49.1%, 36.9% and 14.0% of water resource to annual runoff, respectively. With rising air temperature and increasing snowfall in cold season, the snow water equivalent(SWE) had an increasing trend but the snow cover duration declined by about one month including 13-day delay of the first day and 17-day advancement of the end day during 1961–2016. Increase in SWE provided more available water resource. However, variations in snow cover timing had resulted in redistribution of surface water resource, represented by an increase of discharge percentage in April and May, and a decline in Juneand July. This trend of snow hydrology will render a deficit of water resource in June and July when the water resource demand is high for agricultural irrigation and industrial manufacture. 相似文献
4.
In this paper,the performance of the classic snowmelt runoff model(SRM)is evaluated in a daily discharge simulation with two different melt models,the empirical temperature-index melt model and the energy-based radiation melt model,through a case study from the data-sparse mountainous watershed of the Urumqi River basin in Xinjiang Uyghur Autonomous Region of China.The classic SRM,which uses the empirical temperature-index method,and a radiation-based SRM,incorporating shortwave solar radiation and snow albedo,were developed to simulate daily runoff for the spring and summer snowmelt seasons from 2005 to 2012,respectively.Daily meteorological and hydrological data were collected from three stations located in the watershed.Snow cover area(SCA)was extracted from satellite images.Solar radiation inputs were estimated based on a digital elevation model(DEM).The results showed that the overall accuracy of the classic SRM and radiation-based SRM for simulating snowmeltdischarge was relatively high.The classic SRM outperformed the radiation-based SRM due to the robust performance of the temperature-index model in the watershed snowmelt computation.No significant improvement was achieved by employing solar radiation and snow albedo in the snowmelt runoff simulation due to the inclusion of solar radiation as a temperature-dependent energy source and the local pattern of snowmelt behavior throughout the melting season.Our results suggest that the classic SRM simulates daily runoff with favorable accuracy and that the performance of the radiation-based SRM needs to be further improved by more ground-measured data for snowmelt energy input. 相似文献
5.
The dynamics of snow cover differs greatly from basin to basin in the Songhua River of Northeast China, which is attributable to the differences in the topographic shift as well as changes in the vegetation and climate since the hydrological year (HY) 2003. Daily and flexible multi-day combinations from the HY 2003 to 2014 were produced using Moderate Resolution Imaging Spectroradiometer (MODIS) from Terra and Aqua remote sensing satellites for the snow cover products in the three basins including the Nenjiang River Basin (NJ), Downstream Songhua River Basin (SD) and Upstream Songhua River Basin (SU). Snow cover duration (SCD) was derived from flexible multiday combination each year. The results showed that SCD was significantly associated with elevation, and higher SCD values were found out in the mountainous areas. Further, the average SCDs of NJ, SU and SD basins were 69.43, 98.14 and 88.84 d with an annual growth of 1.36, 2.04 and 2.71 d, respectively. Binary decision tree was used to analyze the nonlinear relationships between SCD and six impact factors, which were successfully applied to simulate the spatial distribution of depth and water equivalent of snow. The impact factors included three topographic factors (elevation, aspect and slope), two climatic factors (precipitation and air temperature) and one vegetation index (Normalized Difference Vegetation Index, NDVI). By treating yearly SCD values as dependent variables and six climatic factors as independent variables, six binary decision trees were built through the combination classification and regression tree (CART) with and without the consideration of climate effect. The results from the model show that elevation, precipitation and air temperature are the three most influential factors, among which air temperature is the most important and ranks first in two of the three studied basins. It is suggested that SCD in the mountainous areas might be more sensitive to climate warming, since precipitation and air temperature are the major factors controlling the persistence of snow cover in the mountainous areas. 相似文献
6.
1INTRODUCTION Snow is an important component of the Earth's surface. Up to 50×106km2(34%) ofthe Earth's land surface is sea- sonally snow-covered (VIKHAMAR and SOLBERG, 2002).Comparedtootherlandcovers,snowcoverextent varies dramatically on very short time scales (hours- months). Its presence affects physical, chemical and bio- logical processes at many spatial scales and has impor- tant social impacts. At the global scale, its high albedo strongly influences the Earth's radiation … 相似文献
7.
1INTRODUCTIONIntheHuanghe(Yellow) Riverbasin, soilerosionisaseriousproblem,whilerunoffandsedimentyieldsim-ulation hasnotbeenextensivelystudiedonthebasisofGIS(GeographicInformationSystem) and dis-tributedhydrologicalmodel.Inthisstudy,theLushiwatershed,whichislocatedattheupstreamoftheLushiHydrologicalStationintheLuoheRiver—thebiggesttributary oftheHuanghe Riveranddown-streamofXiaolangdiDam,isselectedasthestudyarea.ThelevelofsoilerosioninLushiwatershedismoderatein theHuangheRiverbas… 相似文献
8.
Impacts of Climatic Factors on Runoff Coefficients in Source Regions of the Huanghe River 总被引：4，自引：0，他引：4
CHEN Liqun LIU Changming LI Yanping WANG Guoqiang 《中国地理科学(英文版)》2007,17(1):047-055
Runoff coefficients of the source regions of the Huanghe River in 1956–2000 were analyzed in this paper. In the 1990s runoff of Tangnaihai Hydrologic Station of the Huanghe River experienced a serious decrease, which had at- tracted considerable attention. Climate changes have important impact on the water resources availability. From the view of water cycling, runoff coefficients are important indexes of water resources in a particular catchment. Kalinin baseflow separation technique was improved based on the characteristics of precipitation and streamflow. After the separation of runoff coefficient (R/P), baseflow coefficient (Br/P) and direct runoff coefficient (Dr/P) were estimated. Statistic analyses were applied to assessing the impact of precipitation and temperature on runoff coefficients (including Dr/P, Br/P and R/P). The results show that in the source regions of the Huanghe River, mean annual baseflow coefficient was higher than mean annual direct runoff coefficient. Annual runoff coefficients were in direct proportion to annual pre- cipitation and in inverse proportion to annual mean temperature. The decrease of runoff coefficients in the 1990s was closely related to the decrease in precipitation and increase in temperature in the same period. Over different sub-basins of the source regions of the Huanghe River, runoff coefficients responded differently to precipitation and temperature. In the area above Jimai Hydrologic Station where annual mean temperature is –3.9oC, temperature is the main factor in- fluencing the runoff coefficients. Runoff coefficients were in inverse relation to temperature, and precipitation had nearly no impact on runoff coefficients. In subbasin between Jimai and Maqu Hydrologic Station Dr/P was mainly affected by precipitation while R/P and Br/P were both significantly influenced by precipitation and temperature. In the area be-tween Maqu and Tangnaihai hydrologic stations all the three runoff coefficients increased with the rising of annual precipitation, while direct runoff coefficient was inversely proportional to temperature. In the source regions of the Huanghe River with the increase of average annual temperature, the impacts of temperature on runoff coefficients be-come insignificant. 相似文献
9.
GLACIER MELTWATER RUNOFF IN CHINA AND ITS NOURISHMENT TO RIVER 总被引：3，自引：0，他引：3
杨针娘 《中国地理科学(英文版)》1995,5(1):66-76
ＧＬＡＣＩＥＲＭＥＬＴＷＡＴＥＲＲＵＮＯＦＦＩＮＣＨＩＮＡＡＮＤＩＴＳＮＯＵＲＩＳＨＭＥＮＴＴＯＲＩＶＥＲ￥ＹａｎｇＺｈｅｎｎｉａｎｇ（杨针娘）（ＬａｎｚｈｏｕＩｎｓｔｉｔｕｔｅｏｆＧｌａｃｉｏｌｏｇｙａｎｄＧｅｏｃｒｙｏｌｏｇｙ，ｔｈｅＣｈｉｎｅｓ... 相似文献
10.
MECHANISM AND EFFECT OF CHANNEL EVOLUTION AT ESTUARY OF WEIHE RIVER TO HUANGHE RIVER 总被引：2，自引：0，他引：2
LI Jing-yi SHI Chang-wei XU Xi-bao FU Zhi-jun 《中国地理科学(英文版)》2006,16(2):122-126
1INTRODUCTION Physiognomycharacteristicofawatershedisasymbolof ground erosion and incision, and it has been one of the most important factors influencing soil erosion and sedi- ment in the drainage area. Therefore physiognomy char- acteristic of the watershed and its influences on hydro- logical bed load have been one important focus in the watershed research both domestic and abroad (SCHUMM, 1977; QIAN et al., 1987) since the classical study by Horton in 1942 (HORTON, 1954). In rec… 相似文献
11.
基于支持向量机理论的地下水动态遥感监测模型与应用 总被引：2，自引：0，他引：2
地下水是我国内陆干旱地区水资源的重要组成部分,也是极为敏感的生态环境因素之一。地下水动态变化影响着绿洲和湿地的演化,以及土地资源的开发。西北地区地下水监测网尚不完善,动态资料相对缺乏。遥感技术可以弥补传统地下水位监测手段的不足。由于降水极少,西北干旱区地表反射率与地下水水位埋深关系极其密切。选用归一化植被指数(NDVI)、地表温度(LST)数据,应用支持向量机回归方法,建立西北干旱地区地下水位遥感监测模型。提取MODIS影像中的NDVI和LST产品上的地表温度和植被指数信息,作为模型的输入,通过合理选择核函数进行支持向量机的回归分析,从而建立地表植被指数、地表温度与地下水位的相关数学模型,并分析了不同核函数所拟合结果。在河西走廊疏勒河流域的研究成果表明,运用MODIS数据开发地下水动态模型反演水位变化是可行的,模型拟合的结果比较符合实际情况,尤其是对于细土平原地下水浅埋地区模型应用效果更为理想。一次多项式核函数适合模拟埋深小于3m浅埋地下水,径向基函数RBF核函数和三次多项式核函数法则更适合模拟较大埋深情况。开发的地下水位遥感监测模型可为西北干旱区水循环研究和流域水资源管理提供技术手段。 相似文献
12.
STREAMFLOW CHARACTERISTICS OF THE EASTERN QINGHAI-XIZANG PLATEAU 总被引：1，自引：0，他引：1
The eastern Qinghai-Xizang (Tibet) Plateau is the headwater area for many large Asian rivers. Permafrost occurs above 4,200 m a.s.l. and glaciers occupy the summits and high valleys of the east-west trending mountain chains. Annual runoff generally increases with precipitation which is augmented southward by the rise in topography. Rainfall, snow melt, glacier melt and groundwater are the primary sources of stream flow, and the presence of permafrost enhances the flashiness of runoff response to rainfall and snowmelt events. Peak flows are concentrated between June and September. And winter is low flow season. Three types of runoff patterns may be distinguished according to their primary sources of water supply: snowmelt and rainfall, glacier melt and snowmelt, and groundwater. Large rivers generally drain more than one environments and their runoff regime reflects an integration of the various flow patterns on the plateau. 相似文献
13.
14.
The Jinsha River Basin is an important basin for hydropower in China and it is also the main runoff and sediment source area for the Yangtze River,which greatly influence the runoff and sediment in the Three Gorges Reservoir.This study aims to characterize the spatial distribution,inter-annual variation of runoff and sediment load in the Jinsha River Basin,and to analyze the contribution of rainfall and human activities to the runoff and sediment load changes.The monitoring data on runoff,sediment load and precipitation were collected from 11hydrological stations in the Jinsha River Basin from1966 to 2016.The data observed at the outlet of the basin showed that 71.4%of the runoff is from the upper reaches of the Jinsha River Basin and the Yalong River,while 63.3%of the sediment is from the lower reaches(excluding the Yalong River).There is no significant increase in runoff on temporal scale in the Jinsha River Basin,while it has an abrupt change in runoff in both upstream and midstream in 1985,and an abrupt change in downstream in 1980 and2013.The sediment load demonstrated a significantincreasing trend in the upstream,no significant reducing trend in the midstream,but significant reducing trend in the downstream.The sediment load in upstream showed abrupt change in 1987,in midstream in 1978 and 2014,in downstream in 2012.Rainfall dominated runoff variation,contributing more than 59.0%of the total variation,while human activity,including reservoirs construction,the implementation of soil and water conservation projects,is the major factor to sediment load variation,contributing more than 87.0%of the total variation. 相似文献
15.
All characteristics of vegetation,runoff and sediment from 1960 to 2010 in the Xiliu Gully Watershed,which is a representative watershed in wind-water erosion crisscross region in the upper reaches of the Yellow River of China,have been analyzed in this study.Based on the remote sensing image data,and used multi-spectral interpretation method,the characteristics of vegetation variation in the Xiliu Gully Watershed have been analyzed.And the rules of precipitation,runoff and sediment's changes have been illuminated by using mathematical statistics method.What′s more,the influence mechanism of vegetation on runoff and sediment has been discussed by using the data obtained from artificial rainfall simulation test.The results showed that the main vegetation type was given priority to low coverage,and the area of the low vegetation coverage type was reducing year by year.On the country,the area of the high vegetation coverage type was gradually increasing.In a word,vegetation conditions had got better improved since 2000 when the watershed management project started.The average annual precipitation of the river basin also got slightly increase in 2000–2010.The average annual runoff reduced by 37.5%,and the average annual sediment reduced by 73.9% in the same period.The results of artificial rainfall simulation tests showed that the improvement of vegetation coverage could increase not only soil infiltration but also vegetation evapotranspiration,and then made the rainfall-induced runoff production decrease.Vegetation root system could increases the resistance ability of soil to erosion,and vegetation aboveground part could reduce raindrop kinetic energy and splash soil erosion.Therefore,with the increase of vegetation coverage,the rainfall-induced sediment could decrease. 相似文献
16.
本文利用格网技术(Fishnet),对龙门山地区"5.12"大地震震后的多期次遥感影像数据及基础地理信息数据进行评价、整合并实现了动态管理,在此基础上得到覆盖整个龙门山构造带的、能够反映不同地物信息的影像群.汶川地震造成了大量山体崩塌、滑坡、泥石流等地震场地灾害,这些灾害体表现为成群、成带分布的特征,并且单一的小灾害体... 相似文献
17.
光谱混合分析能够提取亚像元信息,被广泛地应用于遥感影像目标探测之中。本文针对MODIS积雪遥感影像,基于光谱混合分析框架,利用渐进辐射传输模型建立不同粒径大小的雪反射率光谱库,提出了一种考虑端元变化及二次辐射的雪盖面积反演算法。此算法首先利用渐进辐射传输模型建立不同粒径大小积雪的反射率光谱库,然后使用序贯最大角凸锥方法获取植被、土壤与岩石、阴影的光谱库。在建立各种地物反射率光谱库之后,利用均方根误差最小的方法获取最优端元组合。在此基础上,考虑端元独立辐射以及积雪与其它地物的二次辐射过程,利用稀疏光谱混合模型获取积雪面积与雪粒径大小。实验结果表明：此方法能够同时反演雪粒径与积雪面积,反演的雪粒径相比单波段的渐进辐射传输模型小,反演的积雪面积相比MOD10A1产品精度略微提高。 相似文献
18.
塔里木河流域综合治理生态要素变化的遥感分析 总被引：1，自引：0，他引：1
采用多种类、多时相遥感数据对塔里木河流域综合治理后的耕地变化和干流绿色走廊带的植被、沙质荒漠化和盐碱质荒漠化等主要生态要素进行了动态监测,结果表明:(1)1999-2008年间,流域耕地面积逐步扩大,从167.17万hm2增长到207.51万hm2。其中,塔里木河干流区耕地面积增加最快,叶尔羌河、开都河-孔雀河与和田河三流域稳步增加,而阿克苏河流域耕地面积先增加,后减少。除阿克苏河流域外,塔里木河流域等其他三流域和塔里木河干流,在2004-2008年间的面积增长速度明显大于1999-2002年和2002-2004年两个时段。(2)2002-2004年间,塔里木河干流绿色走廊带生态环境明显改善,主要表现为植被覆盖度的提高、沙质荒漠化土地面积的减小和强度减弱、盐碱质荒漠化土地的强度减弱等。耕地面积的大幅度增加引起的灌溉用水量的增大,对长期采用输水实现塔里木河的生态功能恢复具有长期性制约作用。 相似文献
19.
《山地科学学报》2021,(10)
Climate change has significantly affected hydrological processes and increased the frequency and severity of water shortage, droughts and floods in northeast China. A study has been conducted to quantify the influence of climate change on the hydrologic process in the Tao'er River Basin(TRB), one of the most prominent regions in northeast China for water contradiction. The Soil and Water Assessment Tool(SWAT) model was calibrated and validated with observed land use and hydro-climatic data and then employed for runoff simulations at upper, middle and lower reaches of the river basin for different climate change scenarios. The results showed that a gradual increase in temperature and decrease in annual precipitation in the basin was projected for the period 2020-2050 for both representative concentration pathways(RCP) 4.5 and 8.5 scenarios. The climate changes would cause a decrease in annual average runoff at basin outlet by 12 and 23 million m3 for RCP4.5 and 8.5, respectively. The future runoff in the upstream and midstream of the basin during 2020-2050 would be-10.8% and-12.1% lower than the observed runoff compared to the base period for RCP4.5, while those would be-5.3% and-10.7% lower for RCP8.5. The future runoff will decrease at three hydrology stations for the assumed future climate scenarios. The results can help us understand the future temperature and precipitation trends and the hydrological cycle process under different climate change scenarios, and provide the basis for the rational allocation and management of water resources under the influence of future climate change in the TRB. 相似文献
20.
自适应滤波的高分辨率遥感影像薄云去除算法 总被引：2，自引：0，他引：2
本文在借鉴遥感影像云雾去除相关研究基础上,提出了一种自适应滤波和非线性灰度变换的高分辨率遥感影像薄云雾消除方法,并与现有的几种效果较好的去云雾方法进行了对比研究。结果表明,本文提出的方法不仅能够有效降低薄云雾遮挡干扰影响,而且可以很好地保持原始影像真实的光谱特性,同时针对不同波段地物光谱特性做相应的灰度变换和融合处理,能够在很大程度上减少遥感影像的细节信息的丢失和保持图像的清晰度,是一种有效去除薄云雾覆盖的方法。 相似文献