Results 21 to 30 of about 17,994 (170)
根据长期定位水土流失与防护林效益观测资料 ,分析了黄土残塬沟壑区吉县的降雨侵蚀。研究结果表明 ,当降雨达到一定量级才能产生土壤侵蚀 ,侵蚀性降雨的雨量标准为 10 mm/次 ,产生严重土壤侵蚀的降雨标准为≥ 3 0 mm/次 ,造成极为严重侵蚀的是降水频率为 5 %的大暴雨和降雨强度≥ 1.0 mm/ min的降雨。场降雨量、降雨强度与小流域产沙模数呈线性相关。因此 ,防止暴雨侵蚀是防治水土流失的关键。
魏天兴
doaj +2 more sources
Predicting Democracy Support in the Middle East and North Africa
ABSTRACT Democracy support among Arab citizens has decreased noticeably in the past decade. The Arab Barometer data demonstrates more than an average of 15–30 points drop‐in democracy support depending on the country considered. The present research utilizes the seventh wave data set offered by the Arab Barometer conducted between October 2021 and July
Mehmet Onder, Malek F. Abduljaber
wiley +1 more source
基于Wischimeier关于降雨侵蚀力R=EI30的经典算法,以黄土高原南部杨凌天然降雨为研究对象,较详细地分析了一次降雨过程雨滴大小分布;拟合了雨滴中数直径、降雨动能与降雨强度的关系;分别以EI10、EI30、EI60为降雨侵蚀力R指标,计算了该地区6-9月降雨侵蚀力大小,研究分析了降雨侵蚀力与降雨量之间的关系。得出以下结论:雨滴大小分布满足Best提出的分布式;雨滴中数直径反映次降雨过程中雨滴大小的总体趋势,与降雨强度关系密切,其关系式可表示为D50=2.25I0.21 ...
吴光艳 +5 more
doaj
Upper left: Cyrtodactylus myintkyawthurai, upper right: Hemiphyllodactylus montawaensis, and bottom left: Gyiophis salweenensis, just recently described, microendemic taxa not yet covered by any protective measures. Bottom right: Geochelone platynota offspring from Cologne Zoo, an example for successful ex situ keeping and conservation breeding of ...
Carolin Scholten +7 more
wiley +1 more source
为探究引起三峡库区农业小流域土壤侵蚀的主要次降雨因子,通过天然降雨观测资料,分析忠县石盘丘小流域2019年侵蚀性降雨年内分布特征和典型次降雨条件下A和B 2个集水区产沙过程的变化规律,采用相关性分析方法,揭示次降雨产沙的主要影响因素。结果表明:(1)全年119场降雨资料中,有19场为侵蚀性降雨。全年侵蚀性中雨共发生10次,是侵蚀性降雨中最常见的降雨类型。暴雨及以上降雨是造成研究区产沙量最大的降雨类型。(2)在典型中雨、大雨和暴雨产沙事件中,B集水区产沙量分别是A集水区的5.13,1.66,7.56倍 ...
崔璨 +5 more
doaj
Threshold conditions for channel initiation in a humid forested mountain : an approach from hydro-geomorphic observations [PDF]
筑波大学University of Tsukuba博士(理学)Doctor of Philosophy in ScienceOne of the primary issues on landform evolution in mountainous terrains is what rainfall and topographic conditions affect the location of channnel heads.
34848 +2 more
core
This study provided information on the abundance, population demography and activity pattern of an endangered species of Gekko badenii at the type locality of Ba Den Mountain, southern Vietnam. Local and international use and trade in Gekko badenii for food consumption and as pet were investigated and conservation recommendations highlighted.
Hai Ngoc Ngo +8 more
wiley +1 more source
为研究降雨因子对粉煤灰产流产沙的影响,揭示粉煤灰产流产渣的规律,采用径流小区定位观测试验,研究雨季期粉煤灰径流小区在自然降雨条件下的产流产渣特征。结果表明:(1)观测期内总降雨量为1 160.0 mm,侵蚀降雨量为720.7 mm,7月份降雨、侵蚀降雨均为最多,分别为409.6 mm和217.1 mm,暴雨的侵蚀降雨量最大,为280.1 mm;(2)7月份产流产渣最多,3个小区的产流产渣量分别为0.72,1.06,0.67 m3和0.30,0.90,0.21 kg,暴雨的产流产渣量最大,分别为0.62 ...
张华明 +7 more
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