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Discussion on irrigation water quota problem

Author: LiMing JiChunYe From: www.yourpaper.net Posted: 2010-06-22 16:12:15 Read:
Abstract: irrigation water quota is the implementation of basic irrigation "total control, quota management" and the optimal allocation of water resources, is to determine the agricultural planting structure and the scale of development on the basis of science.In order to promote the development of water-saving irrigation project, to further determine the irrigation water quota, this paper briefly discusses the meaning of irrigation water quota, and puts forward the influence factors of irrigation water, finally puts forward some suggestions on establishment of irrigation water quota.
Keywords: irrigation water quota in
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One, the connotation of
irrigation water quota
On the norm concept originally irrigation technology, namely the irrigation quota, and the net irrigation quota and irrigation quota of hair.Irrigation water quota and irrigation quota are closely linked, but there is a fundamental difference between.Net irrigation quota is based on crop water requirement, the effective rainfall, underground water amount determined, is to meet the crop to replenish soil moisture requirements of the scientific basis, it pays attention to the scientific irrigation.
Gross irrigation quota is the net irrigation quota basis, considering water loss and water loss, conversion of the canal was the first of the irrigation water demand, it also takes into account the irrigation water in the transport, loss occurs in the process of the allocation of law.Can be seen from the above analysis, irrigation quota pay more attention to the law, scientific irrigation itself, not according to the irrigation is reasonable and advanced, often do not have extensive, objective comparability.
Another difference between irrigation water quota and irrigation quota, irrigation quota is the basis of programming and design, and the irrigation water quota assessment index of agricultural water management.In the planning of irrigation system design, in order to consider whether to meet the crop water requirements, the use of net irrigation quota, in order to carry out the headworks, pumping station design, need to gross irrigation quota, visible to irrigation quota's role is to meet the needs of planning and design.But the net irrigation quota cannot be measured directly, gross irrigation quota and cannot be used for management of water a irrigation unit, see the irrigation quota management is not operable from agricultural water management function.Irrigation water quota is stipulated in evaluation position per unit of water indicators, can be determined directly, can the objective appraisal is one of the basic requirements.

two influence factors, irrigation water quota
Irrigation water use is affected by many factors, if we do not distinguish between, for each kind of situation to determine the irrigation water quota, although can be a scientific, reasonable, but are not comparable, thus losing significance.The effects of irrigation water use factor distinguishing factors, influencing factors and basic factors of hard soft effect.
1, the basic factors of
Crop variety of agricultural products agricultural activities, in order to obtain some kind of agricultural people to certain agricultural activities.The objective status of agricultural products and different crop water requirement in different crops, the crop species is to formulate the basic factors of irrigation water quota.Although for some reason can give up planting a crop replant other crop, but as long as there is for the crop demand, should it develop irrigation water quota.Considering the crop variety, first proposed the selection of seeding area crops to irrigation water quota, other crops can refer to.
Regional is making another basic factor of irrigation water quota, but the geographical condition is complicated.In general, the scope is too large, the irrigation water quota is universal; water household production scale is too small, the quota is not realistic for different water users make different irrigation water; the author thinks county range is more appropriate, although the water, water resources in the basic conditions are different preparation and supervision, but can rely on the Water Conservancy Bureau, ideal.The natural condition difference is too large, can also further refine the regional factors.2, the hard conditions of water resources factor
The basic conditions of water resources is not available, but the utilization of water resources and has a condition can be improved, for example, through the development of water-saving irrigation to improve water resources carrying capacity in a certain extent.Water-saving needs certain investment, also have certain economic benefits, different conditions in different regions, the investment and benefit is different.The shortage of water resources and economic conditions are good areas can be used to lower irrigation water quota, in order to facilitate the status of agricultural water right transfer to water efficiency high industry and sector; on the contrary, is rich in water resources but poor economic conditions of the region in a certain period of time with higher irrigation water quota, gradually to improve water use efficiency and use efficiency, to reduce the current development of agricultural economy pressure.
3, soft factors influencing
Operation management, irrigation, crop varieties, agronomic measures of field water and soil management, traditional irrigation habits also affected to a certain extent, irrigation water, but eliminate, control these effects generally do not need large investment, but also belongs to the production, management of the normal work, the formulation of irrigation water quota for the effect of control in unity and the relative reasonable range, no longer consider its influence.
Three,
recommended quota of methods for the preparation of irrigation water
For domestic water quota, industrial water quota have attached great importance to investigate the actual water process, test data of these areas the cause was not inadequate, theoretical analysis method of incomplete, but based on water quota is an assessment index, only in accordance with the actual conditions of local, the smooth implementation of talent.The same reason, making irrigation water quota should also get water survey and typical sample survey as the main method, and to survey the local situation as the analysis and determination of irrigation water quota basis.Since 1980 the national grain, vegetables, fruit total output increased substantially, but the farmland irrigation water volume did not increase.This fact not only confirmed the water-saving irrigation technology and popularization, and that with the advancement of agricultural technology, great changes have taken place in crop water consumption and water production function, so the irrigation experimental data based on the calculation and analysis of past irrigation water quota, it has the very big limitation.On the other hand, with the increasing shortage of water resources, many areas of real net irrigation water was significantly lower than that of traditional crop water requirement, but also due to the promotion of resistant variety, improve the rate of actual utilization of rainfall, due to the promotion of covering technology and many areas decrease irrigation frequency, reduce the evaporation and so on, these factors are present it is difficult to use the quantitative relation between the universal description.Furthermore, the national accord with "standard" water-saving irrigation technology of water saving irrigation area of 250000000 mu, accounting for the effective irrigation area of 31%, this proportion in the north water shortage cities more.Including supporting measures, scientific management, water saving benefits of engineering, they provide water for irrigation practice in line with the scientific, reasonable, advanced requirements, should not only learn, but also learn, comparable.In conclusion, although irrigation test data for a long period of time, a "water-saving irrigation technology specification" as the calculation basis, but still should pay attention to the investigation of the present situation of water, and take it as the starting point for irrigation water quota, unless it is divorced from reality.
Four, the irrigation water amount and water quota of the relationship between
Irrigation water volume control objective is to achieve the optimal allocation of water resources, efficient utilization and effective management.According to this idea, should first determine the distribution of water control index, the index is mainly based on the carrying capacity of river basin water resources and water resources allocation principle.According to the index of comprehensive consideration of counties, various local advantage, reasonable adjustment of economic structure, optimize the allocation of resources, in accordance with the coordinated development of economy and population, resources, environment, determine a reasonable life, industrial, agricultural water use index.Agricultural water use index including irrigation and other agricultural production water, should also be gradually refined to agricultural water management unit (for example, township, town), mainly on the basis of assessment, such as management of agricultural water use and approval of new agricultural water.In the irrigation water quota according to determine the main factors affecting crop, irrigation water volume is crop planting structure and scale irrigation.Should see, intrinsic motivation of agricultural structural adjustment is the pursuit of comparative benefit.The value orientation of planting structure adjustment.
"The economic system from planned economy to market economy, the fundamental requirement of economic increase mode change" from extensive to intensive, so it should be the fundamental principles of optimal allocation of irrigation water.But the adjustment of planting structure must take full account of the bearing capacity of water resources, that is to say, the premise must be restricted in the irrigation water amount, the pursuit of efficiency improvement.The maximum efficiency is the target, irrigation water volume is the constraint condition, planting structure, irrigation, irrigation technique and scale are the decision variables, is a constrained optimization problem.In the index of total quantity control of irrigation water can not meet certain planting structure under irrigation scale, should not be simply attributed to the reduction of high water consuming crops, and should carry out specific analysis.Generally speaking, if the crop economic value difference, and irrigation water quota is obvious, should first consider reduce the high water consumption.
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