植被的净初级生产力（NPP，Net Primary Productivity）是陆地植被通过光合作用固定太阳能，在单位时间内单位面积所获得生物量的净增加量。NPP作为陆地生态系统碳循环的一个重要组成成分，其对于控制大气中CO₂浓度的上升有着举足轻重的作用。它是植物自身生物学特性与外界环境相互适应的结果，不仅是异养生物生存的物质和能量基础，同时也是生物地球化学循环的关键环节，是评价生态结构功能稳定性的重要指标之一。由于光合作用直接影响植被的NPP，而归一化植被指数（Normalized Difference Vegetation Index,NDVI）又可以较为精准地反映植被的绿度和光合作用的强度，因此在区域和全球生态系统模型中，NDVI常被直接或间接地用于计算植被NPP。", "ds_source": "
该数据集的数据源为MOD17A3HGF.v006 版本数据，涉及分幅影像网格为h26v05，空间分辩率为500 m，时间分辨率为1年。", "ds_process_way": "
（1）运行MRT工具，生成MOD17A3HGF NPP数据拼接和投影转换的prm文件，利用MATLAB 语言程序生成调用MRT工具的批处理文件，并运行。\n
（2）利用泾河流域矢量边界，采用Python批量裁剪等步骤，最后采用GeoTIFF格式输出保存。", "ds_quality": "
本数据集与源数据集MODIS MOD17A3HGF.v006质量一致。NPP数据单位为kgC/m²/year，有效范围﹣30000—32700，放缩因子为0.0001，填充值范围32761—32767，其中：32761为未分类土地类型，32762为城镇建成区，32763为永久湿地或淹没的沼泽地，32764为常年积雪或覆盖冰的区域，32765为贫瘠稀疏的地区（如岩石、苔原和沙漠），32766为内陆淡水等覆盖区，32767为其他情况填充值。", "ds_acq_start_time": "2000-01-01 00:00:00", "ds_acq_end_time": "2021-12-31 00:00:00", "ds_acq_place": "泾河流域,甘肃省,宁夏回族自治区,陕西省", "ds_acq_lon_east": 108.86583333333333, "ds_acq_lat_south": 34.666666666666664, "ds_acq_lon_west": 106.19166666666668, "ds_acq_lat_north": 37.39888888888889, "ds_acq_alt_low": null, "ds_acq_alt_high": null, "ds_share_type": "login-access", "ds_total_size": 17156559, "ds_files_count": 265, "ds_format": "栅格", "ds_space_res": "500", "ds_time_res": "年", "ds_coordinate": "WGS84", "ds_projection": "", "ds_thumbnail": "eb7d013c-4d47-4745-8e98-0ce182221587.jpg", "ds_thumb_from": 2, "ds_ref_way": "", "paper_ref_way": "", "ds_ref_instruction": "用户在使用数据时请在正文中明确声明数据的来源，并在参考文献部分引用本元数据提供的引用方式。", "ds_from_station": null, "organization_id": "bf1ae243-c102-4b2d-a2f6-b698468f4401", "ds_serv_man": "敏玉芳", "ds_serv_phone": "0931-4967596 ", "ds_serv_mail": "ncdc@lzb.ac.cn", "doi_value": "10.12072/ncdc.JRiver.db1981.2022", "subject_codes": [ "170.4510" ], "quality_level": 3, "publish_time": "2022-04-08 10:16:58", "last_updated": "2025-06-30 15:52:31", "protected": false, "protected_to": null, "lang": "zh", "cstr": "11738.11.ncdc.JRiver.db1981.2022", "i18n": { "en": { "title": "NPP data of mod17a3hgf net primary productivity in Jinghe River Basin (2000-2021)", "ds_format": "Raster", "ds_source": "
The data source of this dataset is mod17a3hgf V006 version data, involving framing images, with grid h26v05, spatial resolution of 500 m and time resolution of 1 year.", "ds_quality": "
This data set is the same as the source data set MODIS mod17a3hgf V006 consistent quality. NPP data unit is KGC / m ²/ Year, the effective range is - 30000-32700, the shrinkage factor is 0.0001, and the filling value range is 32761-32767. Among them, 32761 is an unclassified land type, 32762 is an urban built-up area, 32763 is a permanent wetland or submerged swamp, 32764 is an area covered with perennial snow or ice, 32765 is a barren and sparse area (such as rocks, tundra and desert), 32766 is an inland freshwater and other covered area, and 32767 is a filling value under other circumstances.", "ds_ref_way": "", "ds_abstract": "
Net primary productivity (NPP) of vegetation is the net increase of biomass per unit area in unit time by fixing solar energy through photosynthesis. NPP, as an important component of carbon cycle in terrestrial ecosystem, plays an important role in controlling the rise of carbon monoxide concentration in the atmosphere. It is the result of the mutual adaptation between the biological characteristics of plants and the external environment. It is not only the material and energy basis for the survival of heterotrophic organisms, but also the key link of biogeochemical cycle. It is one of the important indexes to evaluate the functional stability of ecological structure. Because photosynthesis directly affects the NPP of vegetation, and the normalized difference vegetation index (NDVI) can accurately reflect the greenness of vegetation and the intensity of photosynthesis, NDVI is often directly or indirectly used to calculate the NPP of vegetation in regional and global ecosystem models.
", "ds_time_res": "年", "ds_acq_place": "Jinghe River Basin, Gansu Province, Ningxia Hui Autonomous Region, Shaanxi Province", "ds_space_res": "500", "ds_projection": "", "ds_process_way": "(1) Run the MRT tool to generate the PRM file of mod17a3hgf NPP data splicing and projection conversion. Use the MATLAB language program to generate the batch file calling the MRT tool and run it.\n
(2) Using the vector boundary of Jinghe River Basin, using Python batch cutting and other steps, and finally using GeoTIFF format to output and save.", "ds_ref_instruction": "When using the data, users should clearly state the source of the data in the text and quote the reference method provided by this metadata in the References section." } }, "submit_center_id": "ncdc", "data_level": 0, "license_type": "https://creativecommons.org/licenses/by/4.0/", "doi_reg_from": "reg_local", "cstr_reg_from": "reg_local", "doi_not_reg_reason": null, "cstr_not_reg_reason": null, "is_paper_in_submitting": false, "ds_topic_tags": [ "泾河流域", "MOD17A3HGF", "净初级生产力NPP" ], "ds_subject_tags": [ "自然地理学" ], "ds_class_tags": [], "ds_locus_tags": [ "泾河流域", "甘肃省", "宁夏回族自治区", "陕西省" ], "ds_time_tags": [ 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021 ], "ds_contributors": [ { "true_name": "张耀南", "email": "yaonan@lzb.ac.cn", "work_for": "中国科学院西北生态环境资源研究院", "country": "中国" } ], "ds_meta_authors": [ { "true_name": "李红星", "email": "lihongxing@lzb.ac.cn", "work_for": "中国科学院西北生态环境资源研究院", "country": "中国" } ], "ds_managers": [ { "true_name": "敏玉芳", "email": "myf@lzb.ac.cn", "work_for": "中国科学院西北生态环境资源研究院", "country": "中国" } ], "category": "生态" }