The Green Barrier to Free Trade

The Green Barrier to Free Trade

C. P. Chandrasekhar, Jayati Ghosh and Parthapratim Pal

At the end of the latest round of meetings of the agricultural negotiations committee of the WTO, the optimism that negotiators would manage to come at a consensus on numerical targets, formulas and other “modalities” through which countries can frame their liberalisation commitments in a new full-fledged round of trade negotiations has almost disappeared. In a report by the negotiations’ chairperson to the Trade Negotiations Committee, circulated to WTO member governments on 7 July 2003, the chairperson Stuart Harbinson says: “Achieving the objective of establishing modalities as soon as possible has continued to remain elusive. … As matters stand, collective guidance and decisions are required on a number of key issues in order to clear the way for reaching [the goal set out in the Doha mandate]”. Establishing modalities before the Cancun ministerial was important for two reasons. First, it is now becoming clear, that even more than was true during the Uruguay Round, forging an agreement in the agricultural area is bound to prove extremely difficult. Progress in the agricultural negotiations was key to persuading the unconvinced that a new ‘Doha Round’ of trade negotiations is useful and feasible.

Second, the Doha declaration made agricultural negotiations one part of a ‘single undertaking’ to be completed by January 1, 2005. That is, in a take ‘all-or-nothing’ scheme, countries had to arrive at and be bound by agreements in all areas in which negotiations were to be initiated in the new round. This means that if agreement is not worked out with regard to agriculture, there would be no change in the multilateral trade regime governing industry, services or related areas and no progress in new areas, such as competition policy, foreign investment and public procurement, all of which are crucial to the economic agenda of the developed countries.

The factors making agriculture the sticking point on this occasion are numerous. As in the last Round, there is little agreement among the developed countries themselves on the appropriate shape of the global agricultural trade regime. There are substantial differences in the agenda of the US, the EU and the developed countries within the Cairns group of agricultural exporters. When the rich and the powerful disagree, a global consensus is not easy to come by.

In this round of negotiation, the complexity of the situation is likely to increase because a number of developing country including Cuba, Chile, Kenya, India, Nigeria, Pakistan, Sri Lanka, Uganda and Zimbabwe has taken a very pro-active role in the negotiations and have often expressed vies which are significantly different from the views expressed by the big three. The extent of disagreement among different country groups can be gauged from a recent paper by the Chairman of WTO Agriculture Committee Stuart Harbinson. This paper is based on the country proposals submitted during the current round of agricultural negations and the follow up consultations among the WTO Members conducted after Doha ministerial. The objective of this paper is to summarize the main features and results of the consultations and to provide a basis for working towards the establishment of modalities for the further commitments. This paper shows that not only there are still wide gaps in the positions among participants regarding fundamental aspects of the further negotiations but there also exist significant differences in the level of ambition among the member countries. What is even more worrying for the future of the agricultural negotiation is that even the latest round of talks, countries are not showing any inclination towards reconciliation. According to reports published in the International Trade Daily, after a negotiating group session held during 22-24th January 2003, Harbinson noted that the meeting was intended to "build bridges" between opposing camps and push the WTO talks forward as members head towards their March 31

deadline for finalizing negotiating modalities. Instead, he adds, "we have made very little headway in building bridges”. It is expected that with members failing to mend their differences, the first draft of a methodology framework for agricultural negotiations will be chair driven and is expected to be circulated before a mini-Ministerial scheduled for Tokyo Feb. 14-16. Given the progress so far, it seems virtually impossible that the March 31st deadline of finalizing the modalities will be met.

But that is not all. Even if an agreement is stitched up between the rich nations, through manoeuvres such as the Blair House accord, getting the rest of the world to go along would be more difficult this time. This is because the outcomes in the agricultural trade area since the implementation of the Uruguay Round (UR) Agreement on Agriculture (AoA) began have fallen far short of expectations. In the course of Round, advocates of the UR regime had promised global production adjustments that would increase the value of world agricultural trade and an increase in developing country share of such trade.

As Chart 1 shows, global production volumes continued to rise after 1994 when the implementation of the Uruguay Round began, with signs of tapering off only in 2000 and 2001. As is widely known, this increase in production occurred in the developed countries as well.

Not surprisingly, therefore, the volume of world trade continued to rise after 1994 (Chart 2). The real shift occurred in agricultural prices which, after some buoyancy between 1993 and 1995, have declined thereafter, and particularly sharply after 1997. It is this decline in unit values that resulted in a situation where the value of world trade stagnated and then declined after 1995, when the implementation of the Uruguay Round began.

As Table 1 shows, there was a sharp fall in the rate of growth of global agricultural trade between the second half of the 1980s and the 1990s, with the decline in growth in the 1990s being due to the particularly poor performance during the 1998 to 2001 period.

Price declines and stagnation in agricultural trade values in the wake of the UR Agreement on Agriculture were accompanied and partly influenced by the persisting regionalisation of world agricultural trade. The foci of such regionalisation were Western Europe and Asia, with 32 and 11 per cent of global agricultural trade being intra-Western European and intra-Asian trade respectively (Chart 3). What is noteworthy, however, is that agricultural exports accounted for a much higher share of both merchandise and primary products trade in North America and Western Europe (besides Latin America and Africa) then it did for Asia. Thus

despite being the developed regions of the world, agricultural production and exports were important influences on the economic performance of North America and Western Europe.

It is therefore not surprising that Europe is keen on maintaining its agricultural sector through protection, while the US is keen on expanding its role in world agricultural markets by subsidising its own farmers and forcing other countries to open up their markets. The problem is that the US has been more successful in prising open developing country markets than the large EU market. Thus out of $104 billion worth of exports from North America in 2001, $34 billion went to Asia and $15 billion to Latin America, whereas exports to Europe amounted to $14 billion (Table 2).

The Cairns group of exporting countries (Argentina, Australia, Bolivia, Brazil, Canada, Chile, Colombia, Costa Rica, Guatemala, Indonesia, Malaysia, New Zealand, Paraguay, Philippines, South Africa, Thailand and Uruguay), for some of who at least agricultural exports are extremely important, want world market to be freed of protection as well as the surpluses that result from huge domestic support in the US and the EC. We must note that $35 billion of the $63 billion of exports from Latin America went to the US and the EU. More open markets and less domestic support in those destinations is therefore crucial for the region.

The fact that Europe has been successful in its effort at retaining its agricultural space with the help of a Common Agricultural Policy that both supports and subsidises its agricultural producers is clear from Chart 4, which shows that intra-EC trade which accounted for 74 per cent of EU exports in 1990, continued to account for 73 per cent of total EU exports in 1995 and 2001. But North America, with far fewer countries in its fold, has also been quite insular. Close to a third of North American exports are intra-regional. Little has changed since the Uruguay Round Agreement on Agriculture.

As far as developing countries are concerned, a WTO secretariat paper published in 20001 asserts that the agricultural exports of developing countries have expanded more rapidly than those of the developed countries in the post WTO period. However, data presented in the paper show that the share of developing countries in global agricultural exports has increased by only 1 percent during the period of 1994 to 1998 (Table 3). This minimal increase should be viewed against the fact that more than 75 percent of WTO Member countries are from the developing world and foreign trade in a large number of developing countries is dominated by agricultural products. And yet, these countries together account for less than 50 percent of the global agricultural trade and even after 5 years of implementation of the Agreement on Agriculture the situation remains virtually unchanged for them. Secondly, the paper also mentions “developing countries' import markets (and in some cases transition economies) are becoming increasingly important as outlets for agricultural exports from developing countries”. This, on one hand shows that developing countries are progressively opening up their agricultural sector but on the other hand, it also implies that the Agreement on Agriculture has not yet helped developing countries to gain increased market access in developed countries.

1 “Agricultural Trade Performance by Developing Countries 1990-98” –WTO Secretariat, WTO Document Number: G/AG/NG/S/6

Note: Data for Africa exclude South Africa.

The figures for "Other" include European developing economies as defined by the

WTO Statistics Division: Malta, Turkey, Bosnia and Herzegovina, Croatia, the

Former Yugoslav Republic of Macedonia, Slovenia, Yugoslavia and territories in

Western Europe n.e.s..

The shares are expressed in per cent of world agricultural exports excluding intra-EU

trade.

Source: WTO Document Number G/AG/NG/S/6

It is widely accepted that three sets of actors account for this failure of the AoA. The first, is that in order to push through an agreement when there were signs that the Uruguay Round was faltering, the liberalisation of agricultural trade in the developed countries was not pushed far enough. Second, is the ability to use “loopholes”, especially those in the form of inadequately well-defined Green and Blue Box measures, in the AoA, to continue to support and protect farmers on the grounds that such support was non-trade distorting. Finally, there are violations of even the lax UR rules in the course of implementation, which have been aided by the failure of the agreement to ensure transparency in implementation.

Not surprisingly, some countries, especially the Cairns group of exporting countries have proposed an ambitious agenda of liberalisation in the agricultural area. Tariffs are to be reduced sharply, using the “Swiss formula”, which would ensure that the proportionate reduction in the tariffs imposed by a country would be larger, the higher is the prevailing bound or applied tariff in that country. The formula arrives at the level to which tariffs in a country would be reduced by multiplying the existing (bound or applied) tariff by a numerical factor, and dividing the result by the sum of the current tariff rate and the numerical factor. The factor for developed countries proposed by the Cairns group is 25. Thus, a country with a tariff rate of 100 per cent on a particular product would have to reduce the rate to 20 per cent (2500/125), whereas a country with a 75 per cent tariff rate would have to reduce it proportionately less to 18.75 per cent (1875/100). Further, in keeping with the Special and Differential treatment requirement, the factor for the developing countries is proposed at 50, making their reduction requirements much smaller (to 33.3 and 30 per cent respectively in the case of a 100 and 75 per cent tariff).

Besides tariff reduction, the Cairns group has called for an enhancement of the minimum import levels of particular commodities by using lower tariffs (tariff rate quotas), argued for a sharp reduction in the aggregate support that can be provided using impermissible support measures, supported the scrapping of the so-called Blue Box measures fashioned during the Uruguay Round to appease the EU countries, and recommended stricter guidelines for assessing whether particular measures of support fall under fully permissible Green Box provisions.

These ambitious demands notwithstanding, it is clear that an agreement on modalities in time for the March 31 deadline is unlikely to materialise. Around the time of the January 22-24 meetings of the agricultural negotiators, the European Union Agricultural Commissioner Franz Fischler made it clear that that the late March deadline will be missed. Fischler reportedly declared that the March 31 deadline set at Doha was for the chairman of the agricultural negotiating group to present his proposal for modalities and that did “not mean automatically that the next day all members of the WTO will agree to that proposal.” In any case, with discussions on the reform of the EU’s Common Agricultural Policy expected to continue well into the summer, the EC does not yet have a fully formulated position to adopt in the course of the negotiations. Thus, the March 31 deadline cannot be met.

Till such time as these issues are cleared it is not at all certain that an agreement on agriculture, which is a prerequisite for the launch and completion of the ‘Doha Round’ of trade negotiations, can be ensured by 2005. Those in a hurry to get to that goal are in for a disappointment. But that prospect is not new. WTO members have already missed a December deadline for an agreement on patents and the supply of essential commodities, because of US intransigence. They have also missed the deadline to work out modalities for special and differential treatment of developing countries.

In the media’s blame game seeking to identify the culprit holding up progress towards an agreement on agriculture, once again the lead contender is the European Union. The grounds for this focus on the EU are, however, shaky. The United States too offers substantial support to its farmers, and has significantly hiked this support through the Farm Security and Rural Investment Act of 2002. Outlays on farm programmes in the US, principally income and price support programmes, averaged more than $15 billion a year between 1996 and 2002, and had touched a high of $32.3 billion in 2000. The 2002 Act promises on paper to keep this high support going, by authorising expenditures totalling $118.5 billion over a six-year period ending 2007. The actual figure is expected to be much higher. It is well known that this support goes disproportionately in favour of a few large commercial farms, which are the ones accounting for a majority of supplies to the US and international markets.

In as much as such support, even if provided in the form of direct income payments “decoupled” from actual production, indirectly affects farmers’ production and pricing decisions, they influence availability and prices in world markets. That is they do distort world trade, even if the UR round agreement claims they do not. What the 2002 Farm Act indicates is that the US has no intention of cutting back on such support, and is unlikely to accede to any agreement that warrants such a cut. The reason why this implicit stance of the US does not lead to its identification as a bottleneck in the current negotiations on agriculture is that almost all of this support is in the form of Green Box measures, or measures of support that are acceptable under the Uruguay Round agreement because they are ostensibly “non-trade distorting”.

Not surprisingly, the US proposals advanced in the course of the work programme that began in March 2002, combine (i) a plea for export subsidy abolition; (ii) recommendations for increased market access through quota abolition, tariff reduction and enhanced tariff-rate quotas (or a minimum level of imports of each commodity that needs to be ensured with lower tariffs); and (iii) a case for either doing away with domestic support that does not fall in the Green Box category or the substitution of such support with outlays on new Green Box measures. That is the US proposals are clearly not in the direction of reducing state support

for agriculture, but of manipulating the agricultural support regime in the direction of what was defined to be non-trade distorting in the course of the Uruguay Round.

Seen in this background the new stand on agricultural support still being discussed among EU members is by no means bizarre. The European Commission’s recently released proposals for reform of the Common Agricultural Policy (CAP) do not promise any cut in total spending. But they do not point to any substantial increase either, since the EU leaders agreed last year to a 1 per cent ceiling on annual increases in the farm budget. In addition, the proposals currently being discussed make an effort to link subsidies less directly with production, thereby rendering them non-trade distorting.

The difficulty the EU faces is that of mooting and then winning agreement among its members on doing away with export subsidies and on making a complete transition to Green Box measures. Since the support afforded to agriculture in EU countries is large and multifarious, a complete transition is not easy to achieve. France, for example, which receives more money from the CAP than any other country is vehemently opposed to that transition, with vocal support from President Chirac. As a result the EU in its proposals submitted in December to the agricultural negotiations committee has called for retaining the Blue Box and for continuing with the Peace Clause, which protected Blue Box measures from being challenged during the implementation period of the Uruguay Round. That is the EU wants the right to openly and transparently support and protect its farmers, and wants adequate elbowroom within the agreement to do so. But the fact that it is unwilling to go the US way, by opting for less transparent support measures that have been defined as acceptable helps those who paint it as the stumbling block on the road to free trade.

The reason for the peculiar situation is that through the manoeuvres made during the Uruguay Round, especially the famous Blair House accord, the rich nations managed to obtain Cairns group concurrence and developing country support for an agreement that provided inadequate market access and little reduction in protection in the developed countries in the agricultural area. This they did by holding out the threat of trade chaos if no agreement was reached and by promising (i) that this was an interim arrangement which would be assessed starting a year before the completion of the implementation period; (ii) that the worst form of domestic support such as the blue box measures would be dropped at that point; and (iii) liberalisation would be further intensified starting in 2000.

Unfortunately, not only has the experience with the implementation of the not-so-liberal Uruguay Round Agreement on Agriculture been wanting on many counts, but there is strong pressure to continue with the manoeuvring by dressing up all support measures in Green, as is the case with the US, or by just refusing to meet the Uruguay Round commitments, as is true of the EU. This makes it extremely difficult to once more win Cairns group concurrence and developing country support for a new Agreement on Agriculture, which offers merely a small advance along an older protectionist route.

Unfortunately for the developed countries they had gone for the “single undertaking”, all-or-nothing strategy with the hope that they can use small concessions in areas like agriculture, drug patents and Special and Differential treatment to win major battles in the areas of competition policy, foreign investment and public procurement. But with no agreement among them even on those concessions and an agreement on agriculture proving a stumbling block, those visions born of greed are threatening to blur. The threat to the forces of corporate globalisation comes not just from the anti-globalisation movement outside. An important enemy seems to lie within, as well.

农田水利学试题及答案

农田水利学课程考试试题及答案 姓名年级专业学号 一、名词解释（每小题2分共10分） 1.灌水率： 2.排涝模数： 3.平均排除法： 4.（排涝计算中的）设计内水位： 5.容泄区： 二．选择题（共10分） 1.灌溉设计标准是反映灌区效益达到某一水平的一个重要技术指标，一般以( )与( )表示？ A、灌溉设计保证率、抗旱天数。 B、水文年型、降水量。 C、设计灌溉用水量全部获得满足的年数、抗旱天数。 D、水源来水量、灌区需水量。 2.什么叫田间渠系的灌排相邻布置？（） A、灌溉渠道与排水沟道的规划布置。 B、田间各级渠道规划布置的形式。 C、田间灌排渠系并行相邻的布置形式。 D、田间灌排渠系交错的布置形式。

3.渠道的输水损失包括以下四个部分：（） A、干渠、支渠、斗渠及农渠等四级渠道的水量损失。 B、渠床土质、地下水埋深、渠道的工作制度及输水时间。 C、自由渗流、顶托渗流、渠床土质、与渠道的工作制度等。 D、渠道水面蒸发损失、渠床渗漏损失、闸门漏水与渠道退水等。 4.什么叫渠道水的利用系数？（） A、灌溉渠系的净流量与毛流量的比值。 B、某一级渠道的净流量与毛流量的比值。 C、田间实际灌入的有效水量与末级渠道的供水量之比。 D、实际灌入农田的有效水量和渠首引入的水量之比。 5.在渠道规划设计中，渠道最小流量有何作用？（） A、用以校核对下一级渠道的水位控制条件。 B、用以校核渠道不淤条件。 C、用以确定修建节制闸的位置。 D、用以校核对下一级渠道的水位控制条件和确定修建节制闸的位置，并按最小流量验算渠道不淤条件。 6.什么叫雨水径流集蓄灌溉工程？（） A、导引、收集雨水径流，并把它蓄存起来加以有效灌溉利用的工程技术措施。 B、田面、坡面、路面及屋面庭院等各类集水工程。

农田水利学试题及答案资料

农田水利学课程考试试题及答案 姓名 年级 专业 学号 一、名词解释（每小题 2 分 共 10 分） 1. 灌水率： 2. 排涝模数： 3. 平均排除法： 4. （排涝计算中的）设计内水位： 5. 容泄区： 二．选择题（共 10 分） 1. 灌溉设计标准是反映灌区效益达到某一水平的一个重要技术指标，一般以 （ ）与 （ ）表示？ A 、灌溉设计保证率、抗旱天数。 B 、水文年型、降水量。 C 、设计灌溉用水量全部获得满足的年数、抗旱天数。 D 、水源来水量、灌区需水量。 2. 什么叫田间渠系的灌排相邻布置？ （ ） 3. 渠道的输水损失包括以下四个部分： （ ） A 、干渠、支渠、斗渠及农渠等四级渠道的水量损失。 B 、渠床土质、地下水埋深、渠道的工作制度及输水时间。 C 、自由渗流、顶托渗流、渠床土质、与渠道的工作制度等。 D 、渠道水面蒸发损失、渠床渗漏损失、闸门漏水与渠道退水等。 4. 什么叫渠道水的利用系数？ （ ） A 、灌溉渠系的净流量与毛流量的比值。 B 、某一级渠道的净流量与毛流量的比值。 C 、田间实际灌入的有效水量与末级渠道的供水量之比。 D 、实际灌入农田的有效水量和渠首引入的水量之比。 5. 在渠道规划设计中，渠道最小流量有何作用？ （ ） A 、用以校核对下一级渠道的水位控制条件。 A 、灌溉渠道与排水沟道的规划布置。 B 、田间各级渠道规划布置的形 式。

B、用以校核渠道不淤条件。 C、用以确定修建节制闸的位置。 D、用以校核对下一级渠道的水位控制条件和确定修建节制闸的位置，并按最小流量验算渠道不淤条件。 6.什么叫雨水径流集蓄灌溉工程？（） A 、导引、收集雨水径流，并把它蓄存起来加以有效灌溉利用的工程技术措施。 B、田面、坡面、路面及屋面庭院等各类集水工程。 C、各类形式的水窖、水窑窖等蓄水工程。 D、各类最为有效节水的灌溉方式。 7.集流面的处理主要包括哪三类方法？（） A 、采用混凝土、水泥土、三七灰土进行表面处理。 B、采用塑料薄膜、或塑膜复沥青、复草泥。 C、植被管理；地表处理；化学处理。 D、采用钠盐、硅有机树脂及粗石蜡等化学处理方法。 8.蓄水工程有哪几种主要的类型？（） A 、引水渠沟或管道、入水口、拦污栅、沉沙槽、蓄水设施以及放水装置等。 B、涝池、旱井、田间蓄水池、水窖、水窑窖等。 C、引水渠、蓄水窑洞与放水暗管与放水暗渠。 D 、沉沙池、进水管、水窖等。 9.什么叫续灌方式？（） A 、类似于自来水管道可随机用水的供水方式。 B、输配水管道进行输水、配水和灌水的方式。 C、是指上一级管道按预先划分好的轮灌组分组向下一级管道配水的方式。 D 、是指上一级管道向所有的下一级管道同时配水的方式。 10.什么叫集水效率？（） A 、降水特征（次降雨量、降雨强度）和集水面质地、坡度、前期含水量与集水面尺寸。 B、集水面的处理材料、集水面积、集流路径和汇流时间。 C、随降水强度的增大而提高。 D、某时段内或某次降雨集水面的集水量占同一时期内的降雨量的比值。 三、简答题（每题6分，共30分） 1.四种地表取水方式的使用条件

农田水利学试题六

农田水利学课程考试试题 姓名年级专业学号 一、名词解释（每小题2分共10分） 1、渠道设计流量： 2、灌溉水利用系数： 3、最小流量： 4、田间净流量:： 5、不冲流速： 二．单向选择题（共10分） 1.地下水临界深度是指? （） A、地下水埋藏深度。 B、在一定的自然条件和农业技术措施条件下，为了保证土壤不产生渍害，所要求保持的地下水最小埋深。 C、在一定的自然条件和农业技术措施条件下，为了保证土壤不产生盐碱化和作物不受盐害，所要求保持的地下水最小埋深。 D、在一定的自然条件和农业技术措施条件下，为了保证土壤不产生盐碱化和作物不受盐害，所要求保持的地下水最大埋深。 2.对于控制一定地下水位要求的农田排水系统，下列哪种说法是正确的？（） A、在同一排水沟深度的情况下，排水沟的间距愈大，地下水位下降速度愈快，在一定时间内地下水位的下降值愈大，在规定时间内地下水位的下降值也愈大。 B、在允许的时间内要求达到的地下水埋藏深度ΔH一定时，排水沟的间距愈大，需要的深度也愈大。 C、在允许的时间内要求达到的地下水埋藏深度ΔH一定时，排水沟的间距愈小，需要的深度也愈大。 D、在同一排水沟间距的情况下，排水沟的深度愈小，地下水位下降速度愈快，在一定时间内地下水位的下降值愈大，在规定时间内地下水位的下降值也愈大。

3.设计排涝标准时，需选择发生一定重现期的暴雨，一般选择标准是？（） A、1-5年。 B、5-10年。 C、10-15年。 D、15-20年。 4.对渍害最不敏感的作物是？（） A、小麦； B、玉米； C、高粱； D、水稻。 5.特别适宜防治土壤次生盐碱化的农田排水方式是？（） A、明沟排水； B、竖井排水； C、暗管排水； D、暗沟排水。 6.在进行排水沟设计时，用来校核排水沟的最小流速的设计流量是？（） A、排涝设计流量； B、排渍设计流量； C、日常排水设计流量； D、排涝模数。 7.农田长期渍水不会造成下列后果？ A、土壤的透气性很差。 B、土层都处于强烈的氧化状态。 C、利于硫化氢等硫化物的形成，对作物根系产生永久性伤害。 D、有机质矿化程度低，分解释放的有效养分少，不能满足作物生长的需要。 8.防治土壤盐碱化的水利技术不包括？（） A、明沟排水 B、井灌井排 C、灌水冲洗 D、放淤改良 9.什么叫计划用水？（） A、灌溉水量的分配方法。 B、就是按作物的需水要求与灌溉水源的供水情况，结合渠系工程状况，有计划地蓄水、引水、配水与灌水。 C、是指灌溉水在灌区各级渠系调配、管理的方式。 D、是指灌溉水通过各级渠道流入田间的方法。 10.灌区用水计划一般来说有哪四种主要类型？（） A、水源引水计划、渠系配水计划与田间的用水计划等。 B、水权集中、统筹兼顾、分级管理、均衡受益。 C、年度轮廓用水计划、某灌季全渠系用水计划、干支渠段用水计划及用水单位的用水计划。 D、上下结合、分级编制，统一调度、联合运用。

扬州大学农科农田水利学计算题过程及答案

农田水利学计算题 1、某小型灌区作物单一为葡萄，某次灌水有600亩需灌水，灌水定额为25m 3/亩，灌区灌溉水利用系数为0.75，试计算该次灌水的净灌溉用水量和毛灌溉用水量。 解：W 毛=MA/η水=25*600/0.75=20000（m3） W 净=MA=25*600=15000（m3） 2、某灌区A =0.2万亩，A 蔬菜=0.16万亩，A 花卉=0.04万亩，m 蔬菜=20m 3/亩，m 花卉=15m 3/亩。求综合净灌水定额m 综及净灌溉用水量。 解：m 综=α1m 1+α2m 2=0.8*20+0.2*15=16+3=19（m3/亩） W=m 综*A=19*2000=38000（m3） 3、某小型提水灌区，作物均为果树，面积1000亩，用水高峰期最大灌水定额为25m3/亩，灌溉水利用系数为0.75，灌水延续4天，每天灌水20小时。试计算水泵设计流量。 解：Q 设= =25*1000/(3600*20*4*0.75)=0.12（m3/s ） 4、已知苏南某圩区，F=3.8Km2，其中旱地占20%，水田占80%。水田日耗水e=5mm/d ，水田滞蓄30mm ，旱地径流系数为0.6 。排涝标准采用1日暴雨200mm ，2天排除，水泵每天工作时间22小时。试求泵站设计排涝流量Q 和综合设计排涝模数q 。 解：R 水田=P-h 田蓄-eT=200-30-5*2=160（mm ） 水ηTt A m t T W Q k j j ij i i i 360036001∑==??=

R旱田=αP=0.6*200=120（mm） ∴Q=(R水田F水田+R旱田F旱田)/3.6Tt =(160*3.8*0.8+120*3.8*0.2)/3.6*2*22 =3.65(m3/s) ∴q =Q/F=3.65/3.8=0.96(m3/km2) 5、冬小麦播前土壤最大计划湿润层深度为0.6m，土壤平均孔隙率42.5%（占土壤体积百分比），土壤田间持水率为70%（孔隙百分比）。播前土壤含水率为45.0%（孔隙百分比）。计算冬小麦的播前灌水定额。解：M=667Hn(θmax-θ0)=667*0.6*0.425*(0.7-0.45) =42.5(m3/亩) 6、已知某渠系如图1-4-3所示，干、支渠采用续灌，设计灌水率q=0.78m3/（s·万亩），一支灌溉面积为2万亩，二支灌溉面积为2.4万亩，三支灌溉面积2.5万亩，支渠的灌溉水利用系数为0.82，干渠渠道水利用系数0.9。 【要求】 （1）计算各支渠设计流量； （2）计算干渠设计流量和灌区灌溉水利用系数。 解：（1）Q1=qA1/η支水=0.78*2/0.82=1.90(m3/s) Q2=qA2/η支水=0.78*2.4/0.82=2.28(m3/s) Q3=qA3/η支水=0.78*2.5/0.82=2.38(m3/s) （2）η水=η支水*η干=0.82*0.9=0.74 7、1）下图渠系干、支渠续灌

河海农水试题1

河海大学2002年攻读硕士学位研究生入学考试试题 名称:农田水利学 一:名词解释（每小题4分） 1、作物需水量 2、喷灌强度 3、灌溉水利用系数 4、作物水分生产函数 5、排渍水位 6、排水承泄区 二、判断题（每小题2分，共20分） 1、土壤中的毛管水是不能被植物根系吸收利用的水分（） 2、灌水定额是灌区的单位面积在单位时间内的灌水量（） 3、水库取水方式适用于河道水位和流量都满足灌溉引水要求的情况（） 4、规划固定式喷灌系统时，支管轮灌方式是否合理对于管的设计流量有显著影响（） 5、设计灌溉渠道时，如果糙率系数取值偏小，就会使渠道断面偏小，从而影响渠道过水能力（） 6、田间排水沟的间距取决于土壤性质和排水要求，和排水沟的深度无关（） 7、排渍模数是排水渠单位面积的排渍流量（） 8、灌溉渠道实行轮灌的主要目的在于减少渠道渗漏损失（） 9、喷灌工程不适用于地面坡度变化复杂的农田使用（） 10、用平均排出法计算的排涝设计流量比可能出现的排涝设计流量偏大（） 三、问答题（每小题8分，共40分） 1、灌溉渠道的设计流量、加大流量、最小流量在渠道设计中各有什么用途？ 2、排水沟道系统的规划布置要考虑哪些原则？ 3、局部灌溉包括哪些类型？渠道衬砌有何优缺点？ 4、渠道的水量损失包括哪些方面？渠道衬砌有何优缺点？ 5、灌溉管道系统的工作制度包括哪些内容？各自的适用条件是什么？ 河海大学2001年攻读硕士学位入学考试试题 名称：农田水利学 一：名词解释（每小题三分） 1. 凋萎系数2、作物需水量3、灌溉设计保证率 4、灌溉制度5、日常水位6、排水承泻区7、排渍模数8、轮灌 二、判断题（每小题而分） 对以下概念，你认为正确的在括号内填“+”号，你认为错误的在括号内填“-”号。 1、土壤中的吸湿水是可以被作物根系吸收利用的水分（） 2、鉴定土壤水分对作物生长是否有效的主要标志是土壤含水量（） 3、制定作物灌溉制度的基本原理是水量平衡（） 4、从河道引水灌溉时，如果河道流量大于灌溉引水流量，但枯水期水位偏低，饮水不足，应修筑水库调节径流（） 5、设计灌溉渠道时，如果糙率系数取值偏小，就会失渠道断面过大而增加工程量（） 6、上层滞水是停留在包气带土壤中的重力水（） 7、地下水的流量、流速、水位等运动要素随时间而变化的运动叫做地下水非稳定流动（） 8、田间排水沟的间距取决于土壤性质和排水要求，与排水沟深度无关（） 9、制定旱作物灌溉制度是作物地下水利用量指的是地面以下土层的储水量（） 10、用平均排出法计算的排涝设计流量比可能出现的排涝设计流量偏大（） 三、问答题（每小题6分）

农田水利学 复习参考答案

第1xx灌溉用水量 一、名词解释 1.吸湿系数 吸湿水达到最大时的土壤含水率称为吸湿系数。 2.凋萎系数 植物开始发生永久凋萎时的土壤含水率，也称凋萎含水率或萎蔫点。 3.田间持水率 农田土壤某一深度内保持吸湿水、膜状水和毛管悬着水的最大含水量。 4.作物需水量 指生长在大面积上的无病虫害作物，土壤水分和肥力适宜时，在给定的生长环境中能取得高产潜力的条件下为满足植株蒸腾、土壤蒸发及组成植株体所需的水量。 5.灌溉制度 按作物需水要求和不同灌水方法制定的灌水次数、每次灌水的灌水时间和灌水定额以及灌溉定额的总称。 6.灌水定额 一次灌水在单位灌溉面积上的灌水量。 7.灌溉定额 各次灌水定额之和。 8.灌水率(灌水模数) 单位灌溉面积上的灌溉净流量q 净。

9.灌溉设计保证率 是指灌区灌溉用水量在多年期间能够得到充分满足的机率，一般以正常供水的年数或供水不破坏的年数占总年数的百分比表示。 二、简答 1.简述农田土壤水分的存在形式。 按农田土壤水分存在的三种基本形式为地面水、土壤水和地下水。其中土壤水是与作物生长关系最密切的水分存在形式，按形态可分为气态水、吸着水、毛管水和重力水。 2.土壤含水量的表示方法有哪几种？它们之间的换算关系怎样？ 主要有四种： 质量百分数，以水分质量占干土质量的百分数表示；体积百分数，以土壤水分体积占土壤体积的百分数表示，或以土壤水分体积占土壤孔隙体积的百分数表示；相对含水率，以土壤实际含水率占田间持水率的百分数表示；水层厚度，将某一土层所含的水量折算成水层厚度，以mm计。 3.简述土壤水的有效性。 土壤水按是否能被作物利用而划分为无效水、过剩水和有效水。其中无效水是指低于土壤吸着水（最大分子持水率）的水分，过剩水是指重力水，有效水是指重力水和无效水之间的毛管水。 4.xx旱灾、洪灾、涝灾和渍害？ 农田水分不足引起作物产量减少或绝收的灾害称为旱灾。洪灾主要是指河、湖泛滥开形成的灾害。涝灾是指旱田积水或水田淹水过深，导致农业减产的现象。渍害是指由于地下水位过高或土壤上层滞水，因而土壤过湿，影响作物生长发育，导致农作物头疼或失收的现象。 5.何谓凋萎系数和田间持水率？两者各有什么用途？凋萎系数是指植物开始发生永久凋萎时的土壤含水率，也称凋萎含水率或萎蔫点。田间持水率是指农

农田水利学 复习参考答案

第1章灌溉用水量 一、名词解释 1.吸湿系数 吸湿水达到最大时的土壤含水率称为吸湿系数。 2.凋萎系数 植物开始发生永久凋萎时的土壤含水率，也称凋萎含水率或萎蔫点。 3.田间持水率 农田土壤某一深度内保持吸湿水、膜状水和毛管悬着水的最大含水量。 4.作物需水量 指生长在大面积上的无病虫害作物，土壤水分和肥力适宜时，在给定的生长环境中能取得高产潜力的条件下为满足植株蒸腾、土壤蒸发及组成植株体所需的水量。 5.灌溉制度 按作物需水要求和不同灌水方法制定的灌水次数、每次灌水的灌水时间和灌水定额以及灌溉定额的总称。 6.灌水定额 一次灌水在单位灌溉面积上的灌水量。 7.灌溉定额 各次灌水定额之和。 8."灌水率(灌水模数) 单位灌溉面积上的灌溉净流量q 净。

9.灌溉设计保证率 是指灌区灌溉用水量在多年期间能够得到充分满足的机率，一般以正常供水的年数或供水不破坏的年数占总年数的百分比表示。 二、简答 1.简述农田土壤水分的存在形式。 按农田土壤水分存在的三种基本形式为地面水、土壤水和地下水。其中土壤水是与作物生长关系最密切的水分存在形式，按形态可分为气态水、吸着水、毛管水和重力水。 2.土壤含水量的表示方法有哪几种？它们之间的换算关系怎样？ 主要有四种： 质量百分数，以水分质量占干土质量的百分数表示；体积百分数，以土壤水分体积占土壤体积的百分数表示，或以土壤水分体积占土壤孔隙体积的百分数表示；相对含水率，以土壤实际含水率占田间持水率的百分数表示；水层厚度，将某一土层所含的水量折算成水层厚度，以mm计。 3.简述土壤水的有效性。 土壤水按是否能被作物利用而划分为无效水、过剩水和有效水。其中无效水是指低于土壤吸着水（最大分子持水率）的水分，过剩水是指重力水，有效水是指重力水和无效水之间的毛管水。 4.何谓旱灾、洪灾、涝灾和渍害？ 农田水分不足引起作物产量减少或绝收的灾害称为旱灾。洪灾主要是指河、湖泛滥开形成的灾害。涝灾是指旱田积水或水田淹水过深，导致农业减产的现象。渍害是指由于地下水位过高或土壤上层滞水，因而土壤过湿，影响作物生长发育，导致农作物头疼或失收的现象。 5."何谓凋萎系数和田间持水率？两者各有什么用途？凋萎系数是指植物开始发生永久凋萎时的土壤含水率，也称凋萎含水率或萎蔫点。田间持水率是指

农田水利学复习题目

农田水利学课程考试试题 四、计算题（20分） 某灌区冬小麦全生育期田间需水量E=380m3/亩，设计降雨量P=150㎜，降雨有效利用系数σ=，全生育期地下水补给量K=30m3/亩，生育初期土壤计划湿润层的深度取，生育后取。土壤孔隙率n=48%（占土体），田间持水率θ田=70%（占孔隙体积的百分数）。在冬小麦播种前进行灌溉，灌溉后使土壤最大计划湿润层范围内的含水率皆达到田间持水率，收割时可使土壤含水率降至田间持水率的80%。用水量平衡方程在式估算冬小麦全生育期的灌溉定额M2。 参考答案 一、名词解释 系统：将土壤-植物-大气看做一个连续体，即为SPAC系统。 2.作物需水量：植株蒸腾和株间蒸发的水量，又称腾发量。 3.作物灌溉制度：作物播种前（或水稻插秧前）及全生育期内的灌水次数，每次的灌水日期和灌水定额以及灌溉定额。 4.田间持水量（率）：当悬着毛管水达到毛细管最大持水能力时，悬着毛管水的平均含水量（率）。 5.作物水分生产函数：作物生长发育过程中，种作物产量与投入水量或者作物消耗水量之间的数量关系。 二、简答题 1.农田水分消耗的途径有哪些？各指什么? 植株蒸腾：作物根系从土壤中吸入体内的水分通过叶片的气孔扩散到大气中去的现象。 株间蒸发：植株间土壤或田面的水分蒸发。 深层渗漏：旱田中由于降水量或灌溉水量太多使土壤水分超过了田间持水量，向根系活动层以下的土层产生渗漏的现象。 2.简述作物实际需水量的计算过程。 （1）参照作物需水量的计算 （2）实际需水量的计算 3.简述灌水定额与灌溉定额的区别与联系。 灌水定额是一次灌水单位灌溉面积上的灌水量，灌溉定额是各次灌水定额之和。 4.如何计算管道式喷灌系统的设计流量和扬程？ 喷灌系统的设计流量就是涉及管线上同时工作的喷头流量之和，再考虑一定数量的损失水量；喷灌系统的设计扬程是在设计管线中的支管入口压力水头的基础上，考虑沿线设计管线的全部水头损失、水泵吸水管的水头损失，以及支管入口与水源水位的地形高差得到的。 5.喷灌的主要灌水质量指标有哪几个，如何定义？ 喷灌强度：单位时间内喷洒在单位面积土地上的水量 喷灌均匀度：在喷灌面积上水量分布的均匀程度 水滴打击强度：单位喷洒面积内水滴对作物和土壤的打击动能，一般采用水滴直径的 大小来衡量。 6.渠道设计时为什么要进行不冲不淤流速验算？

(完整版)农田水利学试题二

农田水利学课程考试试题姓名年级专业学号 一、名词解释（每小题2分共10分） 1.SPAC系统： 2.作物需水量： 3.作物灌溉制度： 4.田间持水量（率）： 5.作物水分生产函数： 二、简答题（每小题5分共40分） 1.农田水分消耗的途径有哪些？各指什么? 2.简述作物实际需水量的计算过程。 3.简述灌水定额与灌溉定额的区别与联系。 4. 如何计算管道式喷灌系统的设计流量和扬程？

5.喷灌的主要灌水质量指标有哪几个，如何定义？ 6.渠道设计时为什么要进行不冲不淤流速验算？ 7.在设计管道灌溉时，单口出流与多口出流时，管道水力计算有什么不同？ 8.简述排渍水位和排涝水位的区别？ 三、论述题（每小题15分共30分） 1.农田水分状况及其调节措施 2.试述非充分灌溉的基本原理。

四、计算题（20分） 某灌区冬小麦全生育期田间需水量E=380m3/亩，设计降雨量P=150㎜，降雨有效利用系数σ=0.8，全生育期地下水补给量K=30m3/亩，生育初期土壤计划湿润层的深度取0.3m，生育后取0.8m。土壤孔隙率n=48%（占土体），田间持水率θ田=70%（占孔隙体积的百分数）。在冬小麦播种前进行灌溉，灌溉后使土壤最大计划湿润层范围内的含水率皆达到田间持水率，收割时可使土壤含水率降至田间持水率的80%。用水量平衡方程在式估算冬小麦全生育期的灌溉定额M2。

参考答案 一、名词解释 1.SPAC系统：（soil-plant-atmosphere continum）将土壤-植物-大气看做一个连续体，即为SPAC系统。 2.作物需水量：植株蒸腾和株间蒸发的水量，又称腾发量。 3.作物灌溉制度：作物播种前（或水稻插秧前）及全生育期内的灌水次数，每次的灌水日期和灌水定额以及灌溉定额。 4.田间持水量（率）：当悬着毛管水达到毛细管最大持水能力时，悬着毛管水的平均含水量（率）。 5.作物水分生产函数：作物生长发育过程中，种作物产量与投入水量或者作物消耗水量之间的数量关系。 二、简答题 1.农田水分消耗的途径有哪些？各指什么? 植株蒸腾：作物根系从土壤中吸入体内的水分通过叶片的气孔扩散到大气中去的现象。 株间蒸发：植株间土壤或田面的水分蒸发。 深层渗漏：旱田中由于降水量或灌溉水量太多使土壤水分超过了田间持水量，向根系活动层以下的土层产生渗漏的现象。 2.简述作物实际需水量的计算过程。 （1）参照作物需水量的计算 （2）实际需水量的计算 3.简述灌水定额与灌溉定额的区别与联系。 灌水定额是一次灌水单位灌溉面积上的灌水量，灌溉定额是各次灌水定额之和。 4.如何计算管道式喷灌系统的设计流量和扬程？ 喷灌系统的设计流量就是涉及管线上同时工作的喷头流量之和，再考虑一定数量的损失水量；喷灌系统的设计扬程是在设计管线中的支管入口压力水头的基础上，考虑沿线设计管线的全部水头损失、水泵吸水管的水头损失，以及支管入口与水源水位的地形高差得到的。 5.喷灌的主要灌水质量指标有哪几个，如何定义？ 喷灌强度：单位时间内喷洒在单位面积土地上的水量 喷灌均匀度：在喷灌面积上水量分布的均匀程度 水滴打击强度：单位喷洒面积内水滴对作物和土壤的打击动能，一般采用水滴直径的 大小来衡量。 6.渠道设计时为什么要进行不冲不淤流速验算？ 7.在设计管道灌溉时，单口出流与多口出流时，管道水力计算有什么不同？ 8.简述排渍水位和排涝水位的区别 排渍水位是排水沟经常需要维持的水位，主要由控制地下水位的要求所决定（防渍或防止土壤盐碱化） 排涝水位是排水沟宣泄排涝设计流量（或满足排涝要求）时的水位。 三、论述题 1.农田水分状况及其调节措施 农田水分状况：一般是指农田土壤水、地面水和地下水的状况，及其在时间上的变化。 调节措施：

农田水利学 复习参考答案

第4章田间工程与灌水方法 一、名词解释 1.田间工程 田间工程通常指最末一级固定渠道（农渠）和固定沟道（农沟）之间的条田范围内的临时渠道、排水小沟、田间道路、稻田的格田和田埂、旱地的灌水畦和灌水沟、小型建筑物以及土地平整等农田建设工程。 二、简答 1.何为地面灌溉及其分类？ 地面灌溉（surface irrigation ）是指利用沟、畦等地面设施对作物进行灌水，水流沿地面流动，边流动边入渗的灌溉方法。一般分为漫灌、淹灌、畦灌和沟灌。 2.简述沟灌与畦灌的区别？ 畦灌（border irrigation）是用田埂将灌溉土地分割成一系列狭长地块——畦田（close-end border），水从输水沟或直接从毛渠引入畦田后，在畦田表面形成很薄的水层，沿畦长坡度方向均匀流动，边流边渗，润湿土壤。在流动过程中主要借重力作用，以垂直下渗的方式逐渐湿润土壤。 沟灌（furrow irrigation）是在作物行间开挖灌水沟，灌溉水由输水沟或毛渠进入灌水沟后，在流动的过程中，主要借毛细管作用从沟底和沟壁向周围渗透而湿润土壤。

3.简述常用节水灌溉措施？ 常用节水灌溉措施包括地膜覆盖、波涌灌溉、喷灌、微灌、滴灌、渗灌等。 4.喷头的种类有哪些？其基本参数包括哪些？ 按压力分：低压喷头、中压喷头及高压喷头。 按喷头的结构形式与水流形状分：旋转式、固定式和孔管式三种。 按喷洒特征分：散水式、射流式。 喷头的几何参数有：进水口直径、喷嘴直径、喷射仰角。 喷头的工作参数有：压力、喷水量、射程。 5.喷灌技术的“三要素”是指什么？其概念定义为何？ 喷灌强度是指单位时间内喷洒在单位面积上的水量，一般用mm/h或mm/min表示。又可细分为点喷灌强度、单喷头平均喷灌强度、系统组合平均喷灌强度、允许喷灌强度。 喷灌均匀度是指在喷灌面积上水量分布的均匀程度，它是衡量喷灌质量优劣的主要指标之一，直接关系到喷灌农作物的增产幅度。 水滴打击强度是指喷头喷洒范围内，单位受水面积上一定量的水滴对土壤或作物的打击动能，即单位时间内单位受水面积所获得的水滴撞击能量。实践中一般常用水滴直径或雾化指标来间接反映水滴打击强度。 三、计算题 1.某灌区种植小麦，灌水定额m=50m3／亩，土壤透水性中等。由土壤渗吸试 =150mm／h，α=0.5，地面坡度(畦田坡验资料得知：第1小时内平均渗吸速度i 方向)为0.002。 要求 （1）计算灌水时间(h)； （2）选择畦田长度和宽度(m)； （3）计算入畦单宽流量［L／(s·m)］。 解：1）由畦灌的延续时间公式可得：

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农田水利学考试试题及答案 一、名词解释（每小题2分共10分） 1.灌水率： 2.排涝模数： 3.平均排除法： 4.（排涝计算中的）设计内水位： 5.容泄区： 二．选择题（共10分） 1.灌溉设计标准是反映灌区效益达到某一水平的一个重要技术指标，一般以( )与( )表示？ A、灌溉设计保证率、抗旱天数。 B、水文年型、降水量。 C、设计灌溉用水量全部获得满足的年数、抗旱天数。 D、水源来水量、灌区需水量。 2.什么叫田间渠系的灌排相邻布置？（） A、灌溉渠道与排水沟道的规划布置。 B、田间各级渠道规划布置的形式。 C、田间灌排渠系并行相邻的布置形式。 D、田间灌排渠系交错的布置形式。 3.渠道的输水损失包括以下四个部分：（） A、干渠、支渠、斗渠及农渠等四级渠道的水量损失。 B、渠床土质、地下水埋深、渠道的工作制度及输水时间。 C、自由渗流、顶托渗流、渠床土质、与渠道的工作制度等。 D、渠道水面蒸发损失、渠床渗漏损失、闸门漏水与渠道退水等。 4.什么叫渠道水的利用系数？（） A、灌溉渠系的净流量与毛流量的比值。 B、某一级渠道的净流量与毛流量的比值。 C、田间实际灌入的有效水量与末级渠道的供水量之比。 D、实际灌入农田的有效水量和渠首引入的水量之比。 5.在渠道规划设计中，渠道最小流量有何作用？（） A、用以校核对下一级渠道的水位控制条件。 B、用以校核渠道不淤条件。 C、用以确定修建节制闸的位置。 D、用以校核对下一级渠道的水位控制条件和确定修建节制闸的位置，并按最小流量验算渠道不

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