نتایج جستجو برای: point nitrogen pollution and soil erosion

تعداد نتایج: 16946384  

Journal: :انسان و محیط زیست 0
مهران مجرد آشناآباد هیات علمی گرایش اکولوژی، دانشگاه پیام نور علیرضا روحانی هیات علمی دانشگاه پیام نور.

in future, soil erosion will be a great challenge for biosphere. if the soils today are notprotected carefully hunger crises all over the world will be widespread. the present article endeavorsto survey soil erosion process and approaches to prevent it. furthermore the article tries to review therelation between soil character and soil production capability shedding light on the effect of erosi...

2016
Guoyong Yan Yajuan Xing Lijian Xu Jianyu Wang Wei Meng Qinggui Wang Jinghua Yu Zhi Zhang Zhidong Wang Siling Jiang Boqi Liu Shijie Han

As crucial terrestrial ecosystems, temperate forests play an important role in global soil carbon dioxide flux, and this process can be sensitive to atmospheric nitrogen deposition. It is often reported that the nitrogen addition induces a change in soil carbon dioxide emission in growing season. However, the important effects of interactions between nitrogen deposition and the freeze-thaw-cycl...

2002
Manzul Kumar Hazarika Kiyoshi Honda

*Manzul Kumar Hazarika, Institute of Industrial Science, Block-C, Ce-509, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 1538505, Japan; Kiyoshi Honda, Asian Center for Research on Remote Sensing, STAR Program, Asian Institute of Technology, P.O.Box 4, Khlong Luang, Pathumthani 12120 , Thailand. *Corresponding author: [email protected] ABSTRACT Soil erosion is a serious environmental p...

Journal: :اکو هیدرولوژی 0
فاطمه رجایی دانشجوی دکتری، دانشکدۀ منابع طبیعی دانشگاه تربیت مدرس، نور عباس اسماعیلی ساری استاد، دانشکدۀ منابع طبیعی دانشگاه تربیت مدرس، نور عبدالرسول سلمان ماهینی دانشیار، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان مجید دلاور استادیار، دانشکدۀ کشاورزی، دانشگاه تربیت مدرس، تهران علیرضا مساح بوانی دانشیار، پردیس ابوریحان، دانشگاه تهران، تهران

non-point pollution are an important factor in determining water quality and eutrophication of fresh water. the principle causes of this issue is high concentrations of nutrients in the water especially nitrogen and phosphorus. change of land use particularly affected on water nitrate load. therefore, understanding the correlations between land use and nitrate pollutant is a priority in order t...

2002
Renata Chmelová Bořivoj Šarapatka

According to a UN Environment Programme survey, topsoil is eroding faster than it forms on about one third of the world’s cropland, causing an estimated 85 % of the world s land degradation from human activities. Erosion of soil, mainly by water, is also a problem in the Czech Republic where 54 % of arable land is endangered by water erosion. The topic of this article is to describe contemporar...

2002
Yang Qinke Li Rui

Astract: This paper shows how recent situation of soil erosion evaluation and prediction on a regional scale based on the techniques of spatial information. The study, which was carried out in central China, identified sediment discharge, precipitation, soil composition, gully density and land use as erosion factors at the regional level. It showed that soil erosion can be assessed and predicte...

2013
Ligang Xu Hailin Niu Jin Xu Xiaolong Wang

Protecting water resources from nitrate-nitrogen (NO3-N) contamination is an important public health concern and a major national environmental issue in China. Loss of NO3-N in soils due to leaching is not only one of the most important problems in agriculture farming, but is also the main factor causing nitrogen pollution in aquatic environments. Three typical intensive agriculture farmlands i...

2016
Q. H. Hu

This paper estimates the soil erosion rate and erosion-induced carbon sink using a new approach, and distinguish the contribution from topsoil erosion, gully erosion and landslides. The role of conservation programs on reducing soil erosion is also assessed. Special comments: 1. The abstract is too long and needed to be simplified. Besides, as the soil erosion rate estimated in this paper is mu...

2004
Alexey Voinov Erica J. Gaddis Helena Vladich

Whereas point sources of nutrients are quite well known and controlled, there is growing concern about non-point sources, especially those that are related to individual homeowners and citizens' practices. They seem to be the hardest to manage and reduce. On-site sewage disposal systems (OSDS) are among the major contributors to the nutrient pollution of surface and ground waters. In Calvert Co...

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