مقاله ها
نویسنده : prone areas
بازدید : 71

the pace of change in our world is speeding up accelerating to the
point where it threatens to overwhelm the management capacity of
political leaders. this acceleration in history comes not only from
advancing technology but also from unprecedented world
population growth even faster economic growth and the
increasingly frequent collisions between expanding human
demands and the limits of the earth’s natural systems.
lester r. brown 1996

abstract
since more than 6000 years man is using water to his advantage in many different ways or protects
himself against harmful effects of water in order to improve his living conditions. tremendous
successes have been obtained but in many regions water management systems function significantly
below what could be expected and many challenges are ahead of us. with respect to water
management related to agricultural production there are broadly speaking three agro-climatologic
zone’s being: temperate humid zone arid and semi-arid zone and humid tropical zone. in addition in
principle four types of cultivation practices may be distinguished being:
? rainfed cultivation without or with a drainage system;
? irrigated cultivation without or with a drainage system.
dependent on the local conditions different types of water management with different levels of service
will be appropriate. in drought prone regions agriculture is normally impossible without an irrigation
system. drainage systems may be applied for salinity control and the prevention of waterlogging.
the cultivated area on earth is 1500 million ha. at 1100 million ha agricultural exploitation takes
place without a water management system. presently irrigation covers more than 270 million ha. it is
however responsible for 40% of crop output and uses about 70% of waters withdrawn from global
river systems. in about 60 million ha of the irrigated lands there is a drainage system as well. the
sector vision of water for food and rural development indicates a required duplication in food
production over the forthcoming 25 years and gives general recommendations how this increase can
be achieved. the major part of the increase in production would have to come from already cultivated
land among others by water saving improved irrigation and drainage and increase in storages.
especially in the developing countries huge efforts are required to feed the growing population to
improve the standard of living in the rural area and to develop and manage land and water in a
sustainable way. the following issues are of major importance in drought prone regions:
? availability of water and availability in space and time;
? links between irrigation and food security protection of the environment sustainable rural
development and livelihood;
? need for increasing withdrawals combined with water saving and improved efficiency in irrigation;
? need for increasing storages with 10 - 15%;
? basin wide planning inter basin transfers shared rivers conflict management;
? governance legal institutional and environmental issues;
? financing integrated water resources development modernisation and replacement.
having in mind the required increase in food production in the forthcoming decades in combination
with the need for sustainable rural development a wide range of issues is of major importance. in this
contribution a review is given how the concerned issues may play a role in the future development of
irrigation and drainage with a focus on the conditions in the drought prone regions. in line with this
the strategy for action of the international commission on irrigation and drainage (icid) will be
presented showing what icid considers of relevance and which activities the commission is planning
to develop to contribute to the realisation of the future challenges.

introduction
since more than 6000 years man is using water to his advantage in many different ways or protects
himself against harmful effects of water in order to improve his living conditions. tremendous
successes have been obtained but in many regions water management systems function significantly
below what could be expected and many challenges are ahead of us.
having in mind the required increase in food production in the forthcoming decades in combination
with the need for sustainable rural development a wide range of issues is of major importance. in this
contribution a review will be given how the concerned issues may play a role in the future
development of irrigation and drainage with a focus on the conditions in the drought prone regions. in
line with this the strategy for action of the international commission on irrigation and drainage
(icid) will be presented showing what icid considers of relevance and which activities the
commission is planning to develop to contribute to the realisation of the future challenges.

طراحی وب سایتفروشگاه اینترنتیطراحی فروشگاه اینترنتیسیستم مدیریت تعمیر و نگهداریسامانه تعمیر و نگهداری PM سامانه جمع آوری شناسنامه کامپیوتر سیستم جمع آوری شناسنامه کامپیوتر سیستم مدیریت کلان IT طراحی وب سایت آزانس املاک وب سایت مشاورین املاک طراحی پورتال سازمانی سامانه تجمیع پاساژ آنلاین پاساژ مجازی

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