نتایج جستجو برای: point source pollution

تعداد نتایج: 973664  

2010
Jinheng Zhang Junqiang Wang Yongliang Lv Jianting Liu Dapeng Li Zhenxuan Yao Xi Jiang Ying Liu

This research combined data from soil, terrain and meteorological surveys, with quantitative data from soil and water field studies to determine the leaching processes of nitrogen and phosphorus contaminants from field vegetation into the Dagu River. Using the Gray correlation analysis method, precipitation and irrigation were established as the major driving force behind leaching losses from c...

2005
T. Pohlert J. A. Huisman L. Breuer H. - G. Frede

We used the Soil and Water Assessment Tool (SWAT) to simulate point and non-point source pollution of nitrate in a mesoscale mountainous catchment. The results show that the model efficiency for daily discharge is 0.81 for the calibration period (November 1990 to December 1993) and 0.56 for the validation period (April 2000 to January 2003). The model efficiency for monthly nitrate load is 0.66...

2003
N. Turpin G. Rotillon P. Bontems T. Bioteau R. Laplana

We built a model of regulation for non point source water pollution through non linear taxation/subsidisation of agricultural production. Farms are heterogeneous along two dimensions: their ability to transform inputs into final production, and the available area they possess. We propose a framework for describing the ability of farmers, the cost and the emission joint functions from a populati...

2015
Qin Xu Gary Campbell Shiliang Wu Mark Roberts

.......................................................................................................................... 6 Chapter

Journal: :Environmental Modelling and Software 2007
V. Polyakov A. Fares D. Kubo J. Jacobi C. Smith

Impaired water quality caused by human activity and the spread of invasive plant and animal species has been identified as a major factor of degradation of coastal ecosystems in the tropics. The main goal of this study was to evaluate the performance of AnnAGNPS (Annualized NonPoint Source Pollution Model), in simulating runoff and soil erosion in a 48 km watershed located on the Island of Kaua...

2005
B. O. L. Demars D. M. Harper

In-river phosphorus retention alters the quantity and timings of phosphorus delivery to downstream aquatic systems. Many intensive studies of in-river phosphorus retention have been carried out but generally on a short time scale (2–4 years). In this paper, monthly water quality data, collected by the Environment Agency of England and Wales over 12 years (1990–2001), were used to model daily ph...

2002
Timothy N. Cason Lata Gangadharan Charlotte Duke

Non-point source pollution, such as nutrient runoff to waterways from agricultural production, is an environmental problem that typically involves asymmetric information. Land use changes to reduce pollution incur opportunity costs that are privately known to landholders, but these changes provide environmental benefits that may be more accurately estimated by regulators. This paper reports a t...

2000
A. Huber M. Bach H. G. Frede

Pesticide pollution of surface waters represents a considerable hazard for the aquatic environment. However, the mean amount of pesticides reaching the water resources varies considerably between regions and depends highly upon application rates, chemical characteristics of pesticides and natural conditions during application. In this study a model was developed which estimates loss of 42 activ...

2003
Timothy N. Cason Lata Gangadharan

Auctions allow regulators to identify land management changes with substantial environmental benefit and low opportunity cost. This paper reports an experiment in which seller subjects compete in sealed-offer auctions to obtain part of a fixed budget allocated by the experimenter-regulator to subsidize pollution abatement. One treatment employs uniform-price auction rules, whereas another treat...

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