نتایج جستجو برای: catchments area

تعداد نتایج: 587685  

Journal: :Remote Sensing 2015
Dominik Jaskierniak George Kuczera Richard Benyon Luke Wallace

Managers of forested water supply catchments require efficient and accurate methods to quantify changes in forest water use due to changes in forest structure and density after disturbance. Using Light Detection and Ranging (LiDAR) data with as few as 0.9 pulses m−2, we applied a local maximum filtering (LMF) method and normalised cut (NCut) algorithm to predict stocking density (SDen) of a 69-...

Abstract The results of an integrated study aimed at restoring water quality in a large watershed including seven catchments in north east Iran are presented in this paper. This case study demonstrates how landscape metrics reflect direct or surrogate causes of the land use practices that are the determinants of water quality parameters. Water quality factors included EC, pH, Cl-1, HCO3-1, SO4-...

Journal: :Environmental pollution 2008
Z Gagkas K V Heal N Stuart T R Nisbet

Streamwater was sampled at high flows from 14 catchments with different (0-78%) percentages of broadleaf woodland cover in acid-sensitive areas in the UK to investigate whether woodland cover affects streamwater acidification. Significant positive correlations were found between broadleaf woodland cover and streamwater NO3 and Al concentrations. Streamwater NO3 concentrations exceeded non-marin...

Extended abstract   1- Introduction   The forests of the Zagros vegetation area cover about six million hectares (40%) of Iran's forest area, which is dominated by oak species. These forests are exposed to a number of threats, including land use change, deforestation, over grazing, deliberate and unintentional fires, pest and disease attacks, and climate change. Although accurate and timely...

2009
X. Zhang G. Hörmann N. Fohrer

The KIDS model (Kielstau Discharge Simulation model) is a simple rainfall-runoff model developed originally for the Kielstau catchment. To extend its range of application we applied it to a completely different catchment, the XitaoXi catchment in China. Kielstau is a small (51 km2) lowland basin in Northern Germany, with large proportion of wetland area. And XitaoXi is a mesoscale (2271 km2) mo...

2018
Taylor Smith Bodo Bookhagen

Snow meltwaters account for most of the yearly water budgets of many catchments in High Mountain Asia (HMA). We examine trends in snow water equivalent (SWE) using passive microwave data (1987 to 2009). We find an overall decrease in SWE in HMA, despite regions of increased SWE in the Pamir, Kunlun Shan, Eastern Himalaya, and Eastern Tien Shan. Although the average decline in annual SWE across ...

2013
Ursula Eisendle-Flöckner Christian D. Jersabek Martin Kirchmair

Glacier-fed rivers are among the most sensitive and endangered habitat types nowadays. Their upper reaches are located within areas of economic interest (e.g. skiing and glacier skiing, hydropower generation), but also within protected areas such as, for example, National Parks worldwide (e.g. Hohe Tauern, Pyrenees, Rocky Mountains). The majority of glacial river studies has focused on the macr...

Journal: :یافته های تحقیقاتی در گیاهان زراعی و باغی 0
علیرضا توکلی مرکز تحقیقات کشاورزی و منابع طبیعی استان سمنان، شاهرود

in order to investigate the effects of super absorbent material on water saving and increasing rain water productivity under micro catchments water harvesting systems, a field experiment was conducted in east azarbaijan. the treatments included two mcwh patterns (small basins and semi-circular bunds), three catchments sizes, three runoff area treatments (natural, cleared and smoothed, wetting a...

ژورنال: علوم آب و خاک 2000
اسلامیان, سیدسعید , سلیمی, والی , چاوشی بروجنی, ستار ,

Peak discharge is one of the basic parameters in the design of hydraulic structures. There are various methods for peak discharge determination. Regional flood frequency analysis is based on physical, climatological and hydrological characteristics of basins. The objective of this study is to examine different models for the estimation of quantiles for some catchments in western Iran (namely: G...

اسلامیان, سیدسعید , سلیمی, والی , چاوشی بروجنی, ستار ,

Peak discharge is one of the basic parameters in the design of hydraulic structures. There are various methods for peak discharge determination. Regional flood frequency analysis is based on physical, climatological and hydrological characteristics of basins. The objective of this study is to examine different models for the estimation of quantiles for some catchments in western Iran (namely: G...

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