青藏高原逐日无云MODIS积雪面积比例数据集(2000-2015)

青藏高原逐日无云MODIS积雪面积比例数据集(2000-2015)是在MODIS逐日积雪产品—MOD10A1的基础上,采用一种基于三次样条函数插值的去云算法进行去云处理后得到。 该数据集采用UTM(横轴等角割圆柱)投影方式,空间分辨率500m,提供逐日的青藏高原地区积雪面积比例(Fractional Snow Cover-FSC)结果。数据集为逐日文件,从2000年2月24日到2015年12月31日。每个文件为当日的积雪面积比例结果,数值为0-100(%),为ENVI标准文件,命名规则为:YYYYddd_FSC_0.5km.img,其中YYYY代表年,ddd代表儒略日(001-365/366)。文件可直接用ENVI或者ARCMAP等软件打开察看。 进行去云处理的原始MODIS积雪数据产品来源于由美国国家雪冰数据中心(NSIDC)处理的MOD10A1产品,这一数据集为hdf格式,采用sinusoidal投影。 青藏高原逐日无云MODIS积雪面积比例数据集(2000-2015)属性由该数据集的时空分辨率、投影信息、数据格式组成。 时空分辨率:时间分辨率为逐日,空间分辨率为500m,经度范围为72.8°~106.3°E,纬度为25.0°~40.9°N。 投影信息:UTM(横轴等角割圆柱)投影。 数据格式:ENVI标准格式。文件命名规则:“YYYYddd”+“_FSC_0.5km”+“.img”,其中YYYY代表年,ddd代表儒略日(001-365/366),其中“.img”是为了方便在ARCMAP等软件打开察看而添加的文件后缀。例如2000055_FSC_0.5km.img代表2000年第55天的结果。其中该数据集的ENVI文件是由头文件和主体内容构成。头文件包括行数、列数、波段数、文件类型、数据类型、数据记录格式、和投影信息等;以2000055_FSC_0.5km.img 文件为例,其头文件信息如下: ENVI description = { ENVI File, Created [Sat Apr 27 18:40:03 2013]} samples = 5760 lines = 3300 bands = 1 header offset = 0 file type = ENVI Standard data type = 1 :代表byte型 interleave = bsq :数据记录格式为BSQ sensor type = Unknown byte order = 0 map info = {UTM, 1.500, 1.500, -711320.359, 4526650.881, 5.0000000000e+002, 5.0000000000e+002, 45, North, WGS-84, units=Meters} coordinate system string = {PROJCS["UTM_Zone_45N",GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Transverse_Mercator"],PARAMETER["False_Easting",500000.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",87.0],PARAMETER["Scale_Factor",0.9996],PARAMETER["Latitude_Of_Origin",0.0],UNIT["Meter",1.0]]} wavelength units = Unknown,band names = {2000055}

Integrated hydrometeorological – snow – frozen ground observations in the alpine region of the Heihe River Basin, China

Alpine region is an important contributor in riverine and watershed ecosystems, which supplies freshwater and stimulates specific habitats of biodiversity. In parallel, extreme events (such as flood, wildfire, early snowmelt, drought and etc.) and other perturbations may reformat the hydrological processes and eco-functions in the area. It is then critical to advance a predictive understanding of the alpine hydrological processes through data-model integration. However, several formidable challenges, including the cold and harsh climate, high altitude and complex topography, inhibit complete and consistent data collection where/when needed, which hinders the associated development of interdisciplinary research in the alpine region. The current study presents a suite of datasets consisted of long-term hydrometeorological, snow cover and frozen ground data for investigating watershed science and functions from an integrated, distributed and multiscale observation network in the upper reaches of the Heihe River Basin (HRB) in China. Gap-free meteorological and hydrological data were monitored from the observation network connecting a group of automatic meteorological stations (AMSs), wireless sensors network (WSN) and runoff measurement spots. In addition, to capture snow accumulation and ablation processes, with the state-of-the-art techniques and instruments, snow cover properties were collected from a snow observation superstation. High-resolution soil physics datasets were also obtained to capture the freeze-thaw processes from a frozen ground observation superstation. The up-to-date datasets have been released to scientists with multidisciplinary backgrounds (i.e. cryosphere, hydrology, and meteorology) and expected to serve as a testing platform to provide accurate forcing data, validate and evaluate remote sensing data and distributed models to a broader community.