Results 41 to 50 of about 2,114 (164)
ABSTRACT Groundwater governance is complex due to several externalities associated with groundwater being an invisible natural resource tied to the land with millions of extractors and limited means of exclusion. The paper traces the evolution of groundwater irrigation in India and the corresponding change in groundwater laws and policies to address ...
Anindita Sarkar, Amrita Sarkar
wiley +1 more source
根据水分穿透曲线和Poiseuille方程,定量研究桂东南花岗岩区6种(次生林、柑橘园、玉米地、杉木林、撂荒地和桉树林)不同土地利用方式土壤大孔隙半径范围、数量及分布情况,分析不同土地利用方式对土壤大孔隙特征的影响。结果表明:(1)不同土地利用方式土壤水分穿透速率存在差异,土壤水分出流速率短时间内可达到稳定状态,柑橘园不同土层之间稳定出流速率变化较大;(2)不同土地利用方式的土壤大孔隙半径为0.4~2.4 mm,主要集中分布在0.4~1.2 mm,均值为0.85 mm,
黄娟 +5 more
doaj
Read the free Plain Language Summary for this article on the Journal blog. Abstract In the Southwest Australian Biodiversity Hotspot, the greatest plant species diversity tends to occur on the most phosphorus (P)‐impoverished soils. Many plant species in this P‐impoverished environment release root carboxylates that mobilise soil P which is a more ...
Xue Meng Zhou +5 more
wiley +1 more source
土壤侵蚀是三峡库区紫色土坡地土壤退化的主因,并由此造成土壤粗骨沙化和酸化。利用土地特性系列比较法,通过野外调查和室内分析相结合,研究了三峡库区紫色土坡地土壤退化特征,结果表明:(1)与未退化样地相比,不同利用方式和不同坡度段土壤粗化现象明显,表明它们存在不同程度的侵蚀退化。各土地利用类型pH值均有所减少,表征该研究区紫色土向酸性方向发展,特别是园地和菜地。(2)不同利用方式下土壤沙化程度由高到低的顺序是:荒地>建设用地>耕地>草地>林地>菜地>园地。(3 ...
董杰 +4 more
doaj +2 more sources
Impacts of storm event on DOM composition and flux in two Jiulong Tributaries with different watershed features [PDF]
通过调查2014年7月"麦德姆"台风影响期间福建九龙江北溪(流域以林地为主)和西溪(农业流域和城市背景)下游定点站DOM的时间序列,测定样品的DOC含量及其吸收光谱和三维荧光光谱,以评估不同流域背景对河流DOM动力学降雨响应的差异性,并为流域-河口系统的一体化管理提供重要参考。降雨期间,两条河流DOC浓度、吸收系数aCDOM(350)以及总荧光强度均随径流量升高而增大,并在水位下降期持续增加,且西溪增加量明显高于北溪,说明受人类活动扰动大的流域河流有机质对暴雨事件的响应更为灵敏 ...
徐静 +5 more
core
Restoration of monoculture in protected and marginal areas can be organized into two phases (1) identification and prioritization of restoration sites based on remote sensing or field survey then assessing degradation level, and (2) implementation of appropriate restoration interventions.
Liang Song +9 more
wiley +1 more source
研究了次降雨过程中北京市不同土地利用方式下(草地、农田、林地和果园)土壤养分流失特征。结果表明:(1)在不同土地利用方式下,地表径流量的变化均随着降雨时间的增加呈对数变化趋势,在同一降雨时间内,地表径流量均表现为草地>农田>林地>果园。(2)草地泥沙流失量随降雨历时幅度较大,在降雨后期出现陡增陡降的变化趋势,其他3种土地利用方式下泥沙流失量的增加幅度较小;不同土地利用方式下泥沙流失量大小顺序为:草地>农田>林地>果园。(3)草地和农田地表径流量显著高于林地和果园(P<0.05 ...
史佳良, 王秀茹, 李淑芳, 李 宁
doaj
Field studies in Soil Nitrogen Mineralization in an Agriculture Catchment, South Fujian Province [PDF]
人类活动对地球系统的影响迅速扩大,大量氮肥的输入使得生态系统氮超载,土壤氮矿化作为土壤氮转化的一个内部过程,在氮循环过程中起着非常重要的作用。农民在施肥期间往往忽略了土壤氮矿化这部分氮输入,盲目的追加化肥,导致氮元素的大量流失,引发一系列的生态环境问题。因此系统分析农田不同土地利用方式下土壤氮矿化负荷,并在此基础上对五川流域氮的收支进行试验研究,对指导农民具体施肥,提高氮的利用率,减少氮流失,降低环境中过量氮存在的风险具有重要的理论和实践意义。 本文以南靖县五川流域为例,以环境科学、农业生态学、农艺学 ...
李大朋
core
Occurrences of dust storms and long‐distance movement of dust across landscapes is constantly increasing in south Asia. This dust is expected to have profound impact on vegetation health and sustainability as dust may contribute to nutrient budgets of the forest ecosystems, while it could impart various stresses to the plants.
Shree P. Pandey +2 more
wiley +1 more source
Abstract This article argues that social actors' media ideologies about digital interfaces are key to the enregisterment of online activities. Focusing on an online register emergent from user activities around Year, Hare, Affair (YHA)—a state‐aligned Chinese animation—I explore how different metadiscourses evaluate this register by entextualizing ...
Jiarui Sun
wiley +1 more source

