نتایج جستجو برای: irrigation demand

تعداد نتایج: 187456  

2010
y. F. huang t. S. lee

Rivers are the main sources of water for agricultural purposes in Malaysia. The Seberang Perai Rice Irrigation Scheme in the state of Penang is one of the eight main rice growing areas in Malaysia. The scheme consists of five (5) sub-schemes and irrigation water for each sub-scheme are supplied from either the Muda river, Jarak river, Kulim river or the Kerian river with pumping or gravity inta...

2004
E. Humphreys Craig Meisner Raj Kumar Gupta Jagadish Timsina Yong Lu Yadvinder Singh M. A. Gill I. Masih Zheng Jia Guo J. A. Thompson

Water shortage is a major constraint to sustaining and increasing the productivity of rice-wheat systems. Saving water can be elusive in that reducing seepage, percolation and runoff losses from fields does not necessarily save water if it can be recaptured at some other temporal or spatial scale, for example by groundwater pumping. Many technologies appear to save substantial amounts of water ...

1998
Peter Oram

World population was about 2.5 billion in 1950; by 1988 it had doubled. Despite this unprecedented population explosion, global food supply kept pace with the additional demand for food. A technological revolution after World War II in the agriculture of the industrialized countries initially made this achievement possible. In the developing countries, where growth of food production had relied...

2005
A. ElMahdi B. Barnett T. Kennedy

Groundwater is a vital resource in Australian agriculture. Increased demand for water resulting from rapid economic development accompanied by poor climatic conditions (e.g. low rainfall levels) has induced an increased reliance on groundwater harvesting to sustain intensive irrigation practices. Overdraft of groundwater as a result of reduced surface water availability, increased economic viab...

2009
Rodrick D. Lentz Robert E. Sojka Charles W. Robbins Dennis C. Kincaid Dale T. Westermann

Furrow irrigation systems have a greater application capacity, are less costly, and use less energy than sprinkler systems but furrow irrigation produces greater runoff, erosion, and deep percolation losses. Phosphorus (P) and nitrogen (N) losses are associated with runoff sediment, and can be minimized by eliminating irrigationinduced erosion. Excessive leaching of inorganic and organic solute...

Journal: :Food chemistry 2016
Vanessa Cardeñosa Amadeo Girones-Vilaplana José Luis Muriel Diego A Moreno José M Moreno-Rojas

Demand for and availability of blueberries has increased substantially over recent years, driven in part by their health-promoting properties. Three blueberry varieties ('Rocío', V2, and V3) were grown under two cultivation systems (open-field and plastic tunnels) and subjected to two irrigations regimes (100% and 80% of crop evapotranspiration) in two consecutive years (2011-2012). They were e...

2008
H. Md. Azamathulla Fu-Chun Wu Aminuddin Ab Ghani Sandeep M Narulkar Nor Azazi Zakaria Chun Kiat Chang

There is an increasing awareness among irrigation planners and engineers to design and operate reservoir systems for maximum efficiency to maximise their benefits. Accordingly, significant work has been done on reservoir operation for known total irrigation demand and on the optimal allocation of water available to crops at the farm level. This present paper deals with the development and compa...

2011
Aadil Nabi Adrian H. Gallardo Shakeel Ahmed

Groundwater is one of the most valuable resources for drinking water and irrigation in the Maheshwaram Catchment, Central India, where most of the local population depends on it for agricultural activities. An increasing demand for irrigation and the growing concern about potential water contamination makes imperative the implementation of a systematic groundwater-quality monitoring program in ...

2002
Jinhua Zhao

Most structural and some nonstructural water projects require significant sunk costs and lead to uncertain economic and ecological outcomes. For instance, building irrigation or flood control dam requires sizable sunk cost, an investment that is difficult to recover later. The dam faces uncertainties in terms of future rainfall, the performance of the dam’s structures and downstream levees, the...

Journal: :محیط شناسی 0
تورج نصرآبادی استادیار گروه برنامه ریزی، مدیریت و آموزش محیط زیست، دانشکدۀ محیط زیست دانشگاه تهران الهام عرب کارشناس ارشد برنامه ریزی و مدیریت محیط زیست، دانشکدۀ محیط زیست دانشگاه تهران فرزام پوراصغر سنگاچین دکترای برنامه ریزی و مدیریت محیط زیست، دانشکدۀ محیط زیست دانشگاه تهران

introduction the average annual precipitation in iran is about 250 mm that is not regularly distributed spatially and temporally. more than 70 percent of total precipitation is not accessible due to evapotranspiration. total renewable water resources of the country are estimated to be around 130 billion cubic meters. in spite of limitation in water resources, they are not used properly. agricul...

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