Dams and reservoirs play an essential role in regulating and managing water resources.Since the middle of the 20th century,the growing demand for water and hydropower has led to an unprecedented boom in reservoir cons...Dams and reservoirs play an essential role in regulating and managing water resources.Since the middle of the 20th century,the growing demand for water and hydropower has led to an unprecedented boom in reservoir construction worldwide[1,2].Meanwhile,reservoir construction has also resulted in a variety of ecological and socioeconomic impacts[3–5].Reservoirs transform natural flow regimes into conditions favored by human demand.The associated flow regulations,especially in reservoirs constructed in recent decades(e.g.,after 2000)with greater seasonal variability[6,7],represent a strong human-induced alteration of the hydrologic cycle.As reservoir construction continues to boom in many parts of the world,an up-to-date and openaccess inventory of reservoirs worldwide remains critically desired.展开更多
基金supported by the National Key Research and Development Program of China(2022YFF0711603)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA23100102,XDA19090120)+3 种基金the National Natural Science Foundation of China(42371399,42301431)the Science and Technology Planning Project of NIGLAS(2022NIGLAS-CJH04,2022NIGLAS-TJ18)supported by the NASA Surface Water and Ocean Topography(SWOT)Science Team(80NSSC20K1143)supported by the CNES TOSCA program of research for his role as PI of the Surface Water and Ocean Topography(SWOT)mission。
文摘Dams and reservoirs play an essential role in regulating and managing water resources.Since the middle of the 20th century,the growing demand for water and hydropower has led to an unprecedented boom in reservoir construction worldwide[1,2].Meanwhile,reservoir construction has also resulted in a variety of ecological and socioeconomic impacts[3–5].Reservoirs transform natural flow regimes into conditions favored by human demand.The associated flow regulations,especially in reservoirs constructed in recent decades(e.g.,after 2000)with greater seasonal variability[6,7],represent a strong human-induced alteration of the hydrologic cycle.As reservoir construction continues to boom in many parts of the world,an up-to-date and openaccess inventory of reservoirs worldwide remains critically desired.
文摘通过2014–2015年两次冬季野外调查,将收集的79处马鹿(Cervus elaphus)出现信息作为分布点数据,选取地形、景观类型、植被特征和人类干扰4类19种因子作为环境变量,利用最大熵(maximum entropy,Max Ent)模型,分析了小兴安岭铁力林业局辖区马鹿种群冬季潜在适宜生境分布特征和主要环境因子对马鹿分布的影响。结果显示:模型预测精度较高,训练集与验证集的平均AUC(area under the curve,受试工作者曲线下面积)值分别为0.949和0.958;Jackknife检验结果表明:景观类型因子对马鹿生境选择的影响较大;坡向、距大路距离、距混交林距离、距灌草地距离和距农田距离是影响马鹿生境分布的主要环境因子,其综合贡献值依次为27.8%、23.9%、19.5%、15.3%和10.4%;距小路距离对马鹿分布影响较小。我们依据Max Ent模型最大约登指数,找到最佳中断点0.22作为阈值将马鹿冬季栖息地划分为适宜和不适宜两个等级,其面积分别为663.49 km^2和1,378.85 km^2,分别占研究区总面积的32%和68%。马鹿的适宜生境主要分布在铁力林业局辖区的东部山地和中部林地等区域;南部地区接近铁力市区,人类活动频繁,不适宜马鹿栖息。对马鹿种群的保护管理措施提出3点建议:控制人为干扰;构建多样性景观;优先保护马鹿的潜在适宜生境分布区。
