棉桃收獲機(jī)的設(shè)計(jì)【梳指式棉桃收獲機(jī)】
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外文資料翻譯
學(xué)院名稱 工程技術(shù)學(xué)院
專業(yè)名稱 機(jī)械設(shè)計(jì)制造及其自動(dòng)化
年 級(jí) 05
學(xué)生姓名 張敏敏
學(xué) 號(hào) 13
指導(dǎo)教師 陳振宇
職 稱 副教授
2009年 06 月10日
譯文:
農(nóng)業(yè)節(jié)水技術(shù)采用的決定因素:研究中國(guó)的10個(gè)省份
1.介紹
中國(guó)正面臨著嚴(yán)重的水資源短缺。一方面,供水資源正在不斷減少。雖然我國(guó)水資源總量為2855×108m3,占全球水資源的6%,是世界上水資源大國(guó)。但人均占有量?jī)H1945立方米,小于世界平均人均水平的1 / 4,被列為水資源貧乏的國(guó)家。此外,水資源短缺的加劇,地下水資源總量趨于減少。另一方面,水資源總需求卻大大增加。自新中國(guó)成立以來(lái),水資源的總需求一直在快速增長(zhǎng)。
水資源的短缺導(dǎo)致各部門(mén)之間在減少水的消耗率中展開(kāi)激烈的競(jìng)爭(zhēng)。回到建立中華人民共和國(guó)初期,中國(guó)的農(nóng)業(yè)部門(mén)的耗水率高達(dá)97%,然而到2005年,這一比例已下降到69 %,但非農(nóng)業(yè)部門(mén)水的消耗率已超過(guò)30 %??梢灶A(yù)見(jiàn),隨著經(jīng)濟(jì)的快速發(fā)展,農(nóng)業(yè)部門(mén)水的消耗率在中國(guó)將進(jìn)一步減少。
然而,中國(guó)農(nóng)業(yè)灌溉用水的利用率是相當(dāng)?shù)偷?。研究表明,農(nóng)業(yè)灌溉用水利用系數(shù)為0.3-0.4 ,從研究發(fā)現(xiàn),灌溉水利用效率在中國(guó)遠(yuǎn)遠(yuǎn)低于發(fā)達(dá)國(guó)家。此外,王金霞和Lohma發(fā)現(xiàn),缺少投資,灌溉設(shè)備維修不及時(shí)和管理不當(dāng)造成低效率的灌溉用水。
面對(duì)日益嚴(yán)重的農(nóng)業(yè)灌溉用水條件,我國(guó)政府不斷增加農(nóng)業(yè)節(jié)水技術(shù)上的投資。從1985年開(kāi)始,財(cái)政部與水資源部門(mén)和銀行積極合作,批準(zhǔn)總額為1.69億元人民幣的貼息貸款用于節(jié)水灌溉。各級(jí)財(cái)政部門(mén)已累計(jì)貼息約2.0億元,吸引來(lái)自不同政黨的投資16億元,發(fā)展中國(guó)家的節(jié)水灌溉面積超過(guò)15萬(wàn)畝。為了加強(qiáng)中國(guó)的節(jié)水灌溉技術(shù),在1996年和1997年,中央財(cái)政出臺(tái)了節(jié)水灌溉技術(shù)。 2000年作為一個(gè)重要的籌資計(jì)劃,國(guó)家引進(jìn)先進(jìn)的農(nóng)業(yè)技術(shù)項(xiàng)目。同時(shí),推廣了先進(jìn)實(shí)用的節(jié)水技術(shù),財(cái)政部給技術(shù)推廣的宣傳和人員的培訓(xùn)撥了大量經(jīng)費(fèi)。此外,國(guó)家加大了基礎(chǔ)設(shè)施和農(nóng)田灌溉的投資。
雖然政府一直積極促進(jìn)節(jié)水技術(shù)的采用,但還是不了解現(xiàn)狀。同時(shí),研究節(jié)水技術(shù)在中國(guó)的學(xué)術(shù)界十分有限,文件稀少。該研究節(jié)水技術(shù)的采用,主要是個(gè)案研究和定性分析,缺乏定量分析。
因此,本文采用來(lái)自中國(guó)10個(gè)省份的數(shù)據(jù)進(jìn)行了定量分析,農(nóng)業(yè)節(jié)水技術(shù)的采用和其決定因素。目前地球上水資源的儲(chǔ)備程度,在中國(guó)應(yīng)該采取怎樣的節(jié)水技術(shù)?哪些因素可能有顯著影響?水資源短缺的情況分析和政府政策的發(fā)揮?具體說(shuō)來(lái),本文的目的有二:首先描述節(jié)水技術(shù)的變化趨勢(shì);第二,查明這一因素的影響。
本文安排如下:介紹數(shù)據(jù)來(lái)源,種類,現(xiàn)狀和采用節(jié)水技術(shù)的變化趨勢(shì)、采用節(jié)水技術(shù)的分析、計(jì)量分析成果、結(jié)論和采取的政策。
2. 數(shù)據(jù)、類型、現(xiàn)狀和采用節(jié)水技術(shù)的變化趨勢(shì)
節(jié)水技術(shù)是指充分合理地利用各種可用水源,采取工程、農(nóng)藝、管理等技術(shù)措施,是區(qū)域內(nèi)有限水資源總體利用率最高及其效益最佳的農(nóng)業(yè),即節(jié)水高效的農(nóng)業(yè)。同樣的定義,水分利用效率意味著單產(chǎn)作物輸入水的量。節(jié)水技術(shù)的采用在某些情況下是不成立的,是用水的凈使用量來(lái)衡量總體的灌溉系統(tǒng)或?qū)α饔蛎娣e規(guī)模。這是因?yàn)楣?jié)水性質(zhì)不僅取決于技術(shù)特點(diǎn),而且取決于其他因素,如輸水系統(tǒng)和經(jīng)濟(jì)調(diào)整的輸出。
2.1 數(shù)據(jù)來(lái)源
數(shù)據(jù)來(lái)源于實(shí)地調(diào)查的中國(guó)農(nóng)業(yè)政策中心(CCAP)的三個(gè)項(xiàng)目.
第一個(gè)項(xiàng)目是研究中國(guó)水利制度和管理小組的數(shù)據(jù)。本次調(diào)查分為兩個(gè)階段:第一階段,是在河南、河北、寧夏,調(diào)查期間分別為1990年, 1995年和2001年。第二階段,是在2004年9月的河南,河北省后續(xù)調(diào)查。另一后續(xù)調(diào)查是在2005年8月的寧夏。這一項(xiàng)目的調(diào)查了77個(gè)村莊的的水資源稀缺程度
第二個(gè)項(xiàng)目是對(duì)水資源的調(diào)查,2004年12月在中國(guó)北部的6個(gè)省進(jìn)行了調(diào)查,包括河南,河北,陜西,山西,內(nèi)蒙古,遼寧。投資期限為1995年至2004年,我們通過(guò)分層隨機(jī)抽樣的方式選取中國(guó)北部農(nóng)村的樣本。首先,我們選定每個(gè)省的樣本,然后根據(jù)其灌溉面積分成4類,即嚴(yán)重缺水,部分缺水,正常的和絕對(duì)水資源短缺(山區(qū)和沙漠地帶)。我們隨機(jī)抽取2個(gè)鄉(xiāng)鎮(zhèn)的縣和4個(gè)村莊,第二次調(diào)查收集了401個(gè)村莊的樣本。
第三個(gè)項(xiàng)目是于2006年7月調(diào)查了3個(gè)省的水資源消費(fèi)狀況,包括甘肅,湖北,湖南。我們?cè)?995年和2005年分別通過(guò)隨機(jī)分層抽樣的基礎(chǔ)上調(diào)查了水資源的稀缺程度。共有60個(gè)村莊被選定為樣本。
三次調(diào)查獲得了60個(gè)樣本村。因此,總共有538個(gè)樣本作為樣品最后調(diào)查的數(shù)據(jù)。
2.2節(jié)水技術(shù)的類型
根據(jù)調(diào)查10個(gè)省的538個(gè)村莊,我們發(fā)現(xiàn)在農(nóng)村地區(qū)有不同類型的節(jié)水技術(shù)。為了便于分析,我們按照資本需要、可分性和通過(guò)時(shí)間把它們歸為三類。
第一類是傳統(tǒng)的節(jié)水技術(shù),包括畦灌,溝灌和土地平整。我們把這些技術(shù)歸為同一個(gè)類型。大部分村領(lǐng)導(dǎo)反映,他們是在農(nóng)業(yè)改革之前就已運(yùn)用。而且,這些技術(shù)的固定費(fèi)用相對(duì)較低,每個(gè)家庭可獨(dú)立運(yùn)作。
第二類是以家庭為基礎(chǔ)的節(jié)水技術(shù),其中包括地面管道(薄膜塑料管或水袋) ,塑料薄膜覆蓋,使茬避免犁(小麥秸稈覆蓋),間歇灌溉和使用抗旱品種。通常這種類型的技術(shù)可以通過(guò)一個(gè)單一的家庭(而不是村民委員會(huì)或農(nóng)民家庭組)。此外,他們還具有相對(duì)較低的固定費(fèi)用。在與傳統(tǒng)技術(shù)相比,這種類型的技術(shù)出現(xiàn)的時(shí)候晚。
第三類是以社區(qū)為基礎(chǔ)的節(jié)水技術(shù),其中包括地下管道,噴灌,滴灌,防滲渠道。這些類型的技術(shù)通常是通過(guò)社區(qū)或農(nóng)民群體而不是個(gè)別農(nóng)戶的需求而設(shè)立的,因?yàn)樗鼈兊墓潭ㄙM(fèi)用相對(duì)較高,并要求集體或大多數(shù)農(nóng)戶合作。相對(duì)于前兩種類型,這些技術(shù)直到最近幾年才開(kāi)始運(yùn)用。
2.3節(jié)水技術(shù)的現(xiàn)狀及變化趨勢(shì)
一般來(lái)說(shuō),鄉(xiāng)村所采用的節(jié)水技術(shù)在中國(guó)分布廣泛且分散迅速??梢钥闯觯?79 %的村莊采用節(jié)水技術(shù),并在1995年,這一數(shù)字上升到95 % , 2005年增加了16%。從1995年到2005年,節(jié)水技術(shù)的普及率平均為87%,也就是說(shuō),在10年間,只有13 %的村莊沒(méi)有采取任何形式的節(jié)水技術(shù)。
然而,實(shí)際的節(jié)水面積在每一個(gè)村莊是相當(dāng)小的。在1995年的比率為11 %,在2005年僅僅為16 %。雖然在一定程度上有所增長(zhǎng),但采取節(jié)水技術(shù)的地區(qū)仍然相當(dāng)少,遠(yuǎn)遠(yuǎn)低于村莊所需的節(jié)水技術(shù)。這表明,該地區(qū)實(shí)際上運(yùn)用的節(jié)水技術(shù)是非常小的,盡管節(jié)水技術(shù)在中國(guó)的空間分布廣泛。這也意味著節(jié)水技術(shù)有很大的發(fā)展空間。
由以上可知,這三種類型的節(jié)水技術(shù)的有效利用是非常低的。可以看出,即使是最早和最廣泛的傳統(tǒng)的節(jié)水技術(shù),通過(guò)的耕地面積也僅僅占28 % 。在2005年,以家庭為基礎(chǔ)和以社區(qū)為基礎(chǔ)的技術(shù),僅僅是占了12 %和9 %。我國(guó)運(yùn)用節(jié)水技術(shù)的耕地面積只占世界耕地面積平均水平的1 / 10,遠(yuǎn)遠(yuǎn)低于發(fā)達(dá)國(guó)家。
這三個(gè)類型的節(jié)水技術(shù)在其增長(zhǎng)趨勢(shì)和現(xiàn)狀上有顯著性的差異。一方面,在傳統(tǒng)技術(shù)的發(fā)展上,是以家庭和社區(qū)為基礎(chǔ)的類型。從1995年到2005年,傳統(tǒng)技術(shù)只是增加了47 % ,而以家庭和社區(qū)為基礎(chǔ)的技術(shù)分別增長(zhǎng)了200 %和300 % 。這表明,現(xiàn)代節(jié)水技術(shù)正在迅速發(fā)展。另一方面,雖然傳統(tǒng)技術(shù)正處于低增長(zhǎng),但是仍有很高的普及率。 2005年,傳統(tǒng)技術(shù)領(lǐng)域的普及率為28 % ,而這些家庭和社區(qū)為基礎(chǔ)的技術(shù),均小于15 % 。這意味著,節(jié)水技術(shù)在中國(guó)的發(fā)展還比較落后。
3 .對(duì)影響采用節(jié)水技術(shù)因素的描述性分析
我們對(duì)節(jié)水技術(shù)的采用和兩種類型的因素進(jìn)行相關(guān)性分析,在這個(gè)分析中,按照地區(qū)抽樣的方法將三種節(jié)水技術(shù)分為5組,并以此為基礎(chǔ)進(jìn)行等距分組。
3.1采用節(jié)水技術(shù)與水資源匱乏的的相關(guān)性
從理論上講,水已經(jīng)成為稀缺資源,所以必須通過(guò)節(jié)水技術(shù)來(lái)保存這個(gè)資源。以往的實(shí)證研究也表明,水資源匱乏與節(jié)水技術(shù)的采用是呈正相關(guān)。我們的調(diào)查數(shù)據(jù)顯示,這三種類型的節(jié)水技術(shù)的三個(gè)變量在反映水資源稀缺基本上呈正相關(guān)的。例如,以地下水作為灌溉用水的比例增加至43 %和45 %。雖然以社區(qū)為基礎(chǔ)的技術(shù)與水資源匱乏之間的相關(guān)性是積極的,整體相關(guān)性是積極的。其他兩個(gè)變量,如地表水和地下水也呈正相關(guān)。
3.2政府的支持政策和節(jié)水技術(shù)采用的相關(guān)性
一般來(lái)說(shuō),政府對(duì)節(jié)水技術(shù)采用更多的支持政策,,就越有可能是普及它們。然而,很難分析政府支持的一個(gè)又一個(gè)有關(guān)的政策有沒(méi)有必要這么做。因此,我們把這些政策分為三個(gè)方面的要求,即推廣,資金和示范?,F(xiàn)有的研究表明,通過(guò)政策支持推廣節(jié)水技術(shù)具有重大的積極影響。數(shù)據(jù)顯示,政府政策支持很可能對(duì)節(jié)水技術(shù)的采用有突出影響。由于政府的支持政策節(jié)水技術(shù)分別由22 % 、 24 %和28 %延長(zhǎng)增加至45 % 、45 %和62 % ,該地區(qū)的三種類型的節(jié)水技術(shù)也有所增加,這表明政府的支持政策與節(jié)水技術(shù)的采用有巨大的正相關(guān)關(guān)系。同樣,政府資助分別由4 % 、5 %和5 %增加至13 % 、13 %和17 % ,也顯示了該地區(qū)三種類型的節(jié)水技術(shù)有明顯的積極關(guān)系。
可以肯定的是,節(jié)水技術(shù)的采用可能會(huì)受其他因素(比如經(jīng)濟(jì)作物的種植面積, 農(nóng)業(yè)類型 ,非農(nóng)業(yè)人口就業(yè)率,教育水平,人均耕地)的影響。由于政府的支持政策節(jié)水技術(shù)的普及分別由22 % , 24 %和28 %延長(zhǎng)增加至45 % , 45 %和62 % ,該地區(qū)的三種類型的節(jié)水技術(shù)也有所增加,這表明政府的支持政策與節(jié)水技術(shù)的采用有巨大的正相關(guān)關(guān)系。同樣,政府資助分別由4 % 、5 %和5 %增加至13 % 、13 %和17 %,也顯示了該地區(qū)三種類型的節(jié)水技術(shù)有明顯的積極關(guān)系,通過(guò)地區(qū)的三種類型的節(jié)水技術(shù)。此外,該變量在建立示范村也具有積極的關(guān)系。
以前的分析表明,水資源稀缺和政府政策的支持在節(jié)水技術(shù)的采用上起著非常積極的作用。然而,上述分析只是反映了簡(jiǎn)單的相關(guān)性變數(shù),但是沒(méi)有考慮到其他影響因素。在進(jìn)一步分析的基礎(chǔ)上建立計(jì)量經(jīng)濟(jì)學(xué)模型,控制的其他因素并計(jì)算出所需的結(jié)果。
4 計(jì)量經(jīng)濟(jì)模型和結(jié)果
為了準(zhǔn)確分析上述現(xiàn)象的內(nèi)在關(guān)系,我們建立了以下計(jì)量經(jīng)濟(jì)模型來(lái)分析538個(gè)村莊在1995年和2005年通過(guò)節(jié)水技術(shù)采用的數(shù)據(jù)的決定因素。
4.1建立計(jì)量經(jīng)濟(jì)模型
節(jié)水技術(shù)的采用程度(不論灌溉用水是否完全為地下水還是地表水;政府是否提供了資金支持,是否已成立示范村莊或?qū)嶒?yàn)基地,采用節(jié)水技術(shù)的控制變量和其他因素) 。
通過(guò)地區(qū)的節(jié)水技術(shù)我們選擇的是百分比(%) ,以反映通過(guò)這些技術(shù)的程度。該指數(shù)是指地區(qū)之間分別采用三種節(jié)水技術(shù)的總耕地面積的比率。為了全面反映水資源的稀缺程度,我們從三個(gè)不同方面衡量水資源的匱乏,即灌溉水的資源,可靠的地表水和地下水的可靠性。 (1)灌溉用水是否來(lái)自地下水(0表示沒(méi)有,而1表示有) ; (2)地表水的不足率(%) ,該指數(shù)的計(jì)算方法是調(diào)查1993年至1995年以及2002年至2005年村莊的水渠道的水。同樣,我們也可以選擇三個(gè)變量,以反映政策可能會(huì)影響節(jié)水技術(shù)的采用: (1)政府是否已開(kāi)展了活動(dòng),以擴(kuò)大節(jié)水技術(shù)(0表示沒(méi)有,而1表示有) ; (2)是否政府已提供資金支持這個(gè)村采用節(jié)水技術(shù)(0表示沒(méi)有,而1是) ; (3)有否已成立了示范村或?qū)嶒?yàn)基地采用節(jié)水技術(shù)(0表示沒(méi)有,而1是)。為了避免任何問(wèn)題我們添加一些控制變量的模型。舉例來(lái)說(shuō),我們?cè)黾咏?jīng)濟(jì)作物的比例(%),土壤類型(砂土0-1)和壤土(0:1) ,并與黏土作為對(duì)照組,通過(guò)節(jié)水技術(shù)它們可能會(huì)影響到成本和效益。我們還控制其他一些村級(jí)的變量,包括人均耕地(畝/人) ,灌溉面積(%) ,人均純收入(元/人) ,非農(nóng)業(yè)人口就業(yè)率(%) ?,F(xiàn)有的研究表明,這些變數(shù)都會(huì)對(duì)節(jié)水技術(shù)的采用產(chǎn)生影響。因?yàn)椴捎眠@些技術(shù)需要成本,信息和知識(shí)。此外,實(shí)施節(jié)水技術(shù)也與村莊和上級(jí)政府之間的距離。更困難的是,要監(jiān)控使用該技術(shù)。
4.2選擇模型的估計(jì)方法
為因變量是有限因變量,許多實(shí)測(cè)值是零。例如, 658 , 306和264個(gè)觀測(cè)值為零的地區(qū)分別采用以社區(qū)為基礎(chǔ),家庭為基礎(chǔ)的技術(shù)和傳統(tǒng)技術(shù)。這樣的方法,普通最小二乘法(生命線行動(dòng))可能會(huì)導(dǎo)致無(wú)效傾斜的結(jié)果,所以我們使用托比特估算方法。此外,考慮到每個(gè)省有一些失控的因素,一個(gè)省級(jí)虛擬變量加入模型中。
4.3 解釋和估計(jì)結(jié)果
節(jié)水技術(shù)采用主要的影響因素歸納如下:首先,一般來(lái)說(shuō), Tobit模型試驗(yàn)是非常明確的系數(shù)符號(hào)的獨(dú)立變量,基本上符合預(yù)期。這表明,它是可以通過(guò)Tobit模型的估計(jì)。與此同時(shí),共同線性也是考驗(yàn)。由于變量之間條件數(shù)非常小,所以該模型基本上沒(méi)有共線問(wèn)題。
此外,通過(guò)三種類型的節(jié)水技術(shù)的模型,其控制變量也具有顯著的影響。舉例來(lái)說(shuō),灌溉面積的利用率,教育變量(比率為村民與中等學(xué)校教育)和人均純收入等在預(yù)期的理論模型都有顯著的積極影響。此外,該地區(qū)經(jīng)濟(jì)作物的比例在以家庭以社區(qū)為基礎(chǔ)的節(jié)水技術(shù)具有顯著的積極影響。這可能被解釋為這樣一個(gè)事實(shí),即高收益的經(jīng)濟(jì)作物就可以補(bǔ)償以家庭和社區(qū)為基礎(chǔ)的節(jié)水技術(shù)的高投入成本。
值得一提的是系數(shù),人均耕地和非農(nóng)業(yè)人口就業(yè)率是消極的傳統(tǒng)技術(shù)模式,分別達(dá)到顯著水平的1 %和5 %。這表明,這兩個(gè)系數(shù)與采用傳統(tǒng)技術(shù)存在顯著的負(fù)相關(guān)。這一結(jié)果可能是由于這樣一個(gè)事實(shí),即相對(duì)落后的傳統(tǒng)技術(shù)往往需要更多的勞動(dòng)力。
其次,水資源匱乏促進(jìn)了節(jié)水技術(shù)的采用.
估算結(jié)果表明,該模型的三個(gè)變量表明水資源匱乏與節(jié)水技術(shù)的采用有顯著的影響。這符合以前的分析。然而,不同類型的節(jié)水技術(shù)與水資源匱乏有不同的反應(yīng),。
從回歸結(jié)果可知,三種類型的節(jié)水技術(shù)的灌溉用水來(lái)自地下水完全是積極的。這表明,村莊的灌溉用水來(lái)自地下水比灌溉用水來(lái)自地表水更傾向于采用節(jié)水技術(shù)。然而,從簡(jiǎn)單的系數(shù)分析,這一解釋程度不高,即分別為7.9 % , 2.1 %和6.4 %。
地表水的不足制約著傳統(tǒng)模式節(jié)水技術(shù)的運(yùn)用,并達(dá)到1 %顯著性的水平統(tǒng)計(jì)。這表明,地表水越稀少,就越有可能是采用傳統(tǒng)技術(shù)。這可能是原因是,傳統(tǒng)的節(jié)水技術(shù)極大地影響了地表水 。
同樣,以社區(qū)為基礎(chǔ)的地下水模型中節(jié)水技術(shù)達(dá)到10 %。這表明,地下水稀少的村莊更愿意通過(guò)以社區(qū)為基礎(chǔ)的節(jié)水技術(shù),這可能的原因是以社區(qū)為基礎(chǔ)的節(jié)水技術(shù)的使用主要來(lái)自地下水,因此,地下水的任何改變都可能極大地影響到通過(guò)以社區(qū)為基礎(chǔ)的節(jié)水技術(shù)。但影響程度不高于12.6 %。
以家庭為基礎(chǔ)的節(jié)水技術(shù),通常有兩個(gè)來(lái)源(地表水和地下水) ,因此變數(shù)不足。地表水和地下水都在以示范戶為基礎(chǔ)的節(jié)水技術(shù)和他們的積極系數(shù)達(dá)到顯著水平,高于1 % 。這表明,缺乏地表水和地下水都可能影響到通過(guò)這種類型的節(jié)水技術(shù)。但是,從一定程度的顯示,地下水和地表水不足的影響程度不足,分別是7.8 %和5.7 % 。
第三,政策支持明顯影響節(jié)水技術(shù)的采用。
可以從估計(jì)的結(jié)果得出結(jié)論,政策支持對(duì)節(jié)水技術(shù)的采用也具有明顯的影響。
政府的支持對(duì)三種類型的節(jié)水技術(shù)達(dá)成5 %以上的影響,這表明有政府支持的村莊相比,與那些沒(méi)有政府支持的,更傾向于采用節(jié)水技術(shù)。這可能被解釋為這樣一個(gè)事實(shí),即信息和技術(shù)推廣人員把促進(jìn)了節(jié)水技術(shù)的采用。這個(gè)變數(shù)程度分別在三種模式達(dá)到21.2 %、12.9 %和16.9 %。
政府補(bǔ)貼在以社區(qū)為基礎(chǔ)的節(jié)水技術(shù)模型中是起積極作用的,統(tǒng)計(jì)達(dá)到1 %的顯著水平的。這表明,有政府補(bǔ)貼的村莊相比,與那些沒(méi)有政府補(bǔ)貼的,更可能采取以社區(qū)為基礎(chǔ)的節(jié)水技術(shù)。這可能是原因是,以社區(qū)為基礎(chǔ)的節(jié)水技術(shù)往往需要大量的投資,從而對(duì)補(bǔ)貼政策更加敏感。一定敏感程度的變量高達(dá)24.8 % ,也就是說(shuō),政府分別在三個(gè)型號(hào)的補(bǔ)貼的1/4變化是通過(guò)以社區(qū)為基礎(chǔ)的節(jié)水技術(shù),其中大約20 %是采用的節(jié)水技術(shù)。
不同于前兩次的政策支持,政府示威對(duì)三種類型的節(jié)水技術(shù)幾乎是沒(méi)有任何影響的。這表明,政府示威政策不會(huì)影響節(jié)水技術(shù)的采用。這可能是因?yàn)闆](méi)有真正實(shí)施這一示范政策。然而,政府政策的支持通過(guò)地區(qū)的節(jié)水技術(shù)對(duì)于水資源缺乏的問(wèn)題具有更大的影響。
5 結(jié)論和政策的影響
本文主要分析了中國(guó)農(nóng)業(yè)節(jié)水技術(shù)造成的影響。實(shí)地調(diào)查的數(shù)據(jù)來(lái)自三個(gè)項(xiàng)目中心所做的中國(guó)農(nóng)業(yè)政策( CCAP ),是在用于估計(jì)和分析的基礎(chǔ)上建立的計(jì)量經(jīng)濟(jì)模型。研究結(jié)果表明,雖然在中國(guó)節(jié)水技術(shù)迅速增加,但整體水平仍然相當(dāng)?shù)?,?jié)水技術(shù)的采用在中國(guó)是由多種因素影響的。其中包括水資源匱乏和政策干涉,這兩個(gè)主要因素影響了節(jié)水技術(shù)的采用。此外,作物結(jié)構(gòu),人均耕地面積,非農(nóng)業(yè)人口就業(yè)率和受教育程度也在不同程度影響到節(jié)水技術(shù)的采用。
上述研究的結(jié)果意味著,如果中國(guó)促進(jìn)整體采取節(jié)水技術(shù),推廣節(jié)水技術(shù),很可能是一個(gè)有效的政策工具,如果中國(guó)大力發(fā)展以社區(qū)為基礎(chǔ)的節(jié)水技術(shù),補(bǔ)貼政策的節(jié)水技術(shù)可能會(huì)更有效;調(diào)整作物結(jié)構(gòu),用高附加值的經(jīng)濟(jì)作物可能會(huì)鼓勵(lì)農(nóng)民和社區(qū)運(yùn)用現(xiàn)代節(jié)水技術(shù)。此外,由于缺乏一定程度的水資源利用方法,所以采取節(jié)水技術(shù)存在一定的阻礙,所以建立水權(quán)市場(chǎng)和完善的水的定價(jià)政策來(lái)促進(jìn)節(jié)水技術(shù)的運(yùn)用。
原文:
Determinants of agricultural water saving technology adoption: an empirical study of 10 provinces of China
1. Introduction
China is confronted with severe shortage of water resources. On the one hand, the supply of water resources is constantly decreasing. Although the national water resources total 2.5 trillion m3, listed as No. 6 in the world, the water resource per capita is merely 1,945 m3, less than 1/4 of the average world per capita listed among the 13 water-poor countries. Furthermore, the shortage is aggravating, especially the total underground water resources tends to decrease. On the other hand, the total demand for water resources is dramatically increasing. Since the establishment of the People's Republic of China, the total demand for water resources has been growing rapidly. Total water consumption of China increased from 103.1 billion m3 in 1949 to 543.5 billion m3 in
2005.
The shortage of water resources and fierce competition between various departments result in decreasing water consumption rate of agricultural sectors. Back to the early period after establishment of P.R.C,the water consumption rate of China's agricultural sectors was up to 97%; however, by 2005, that rate had decreased to 69% and the water consumption rate of non-agricultural sectors had exceeded 30% . It can be foreseen that the water consumption rate of agricultural sectors in China will further decrease along with the rapid economic development.
Nevertheless, the use efficiency of China's agricultural irrigation water is rather low. Researches demonstrate that the use coefficient of agricultural irrigation water is merely 0.3-0.4, with a difference of 0.4-0.5 compared with 0.7-0.9 of those developed countries; and the water use efficiency of crops averages 0.87 kg/m3, with a difference of 1.45 kg/m3 compared with Israel's 2.32 kg/m3. From similar studies we have found that the use efficiency of irrigation water in China is far lower than that of developed countries. In addition, studies of Wang Jinxia and Lohma have found that the shortage of investment, dilapidated condition without repair and improper management have resulted in the low use efficiency of irrigation water.
Confronted with increasingly severe condition of agricultural irrigation water, the Chinese government has been continuously increasing investment in agricultural water-saving technologies. Starting from 1985, Ministry of Finance, in active collaboration with sectors of water resources and banking, has granted a total of 1.69 billion yuan of discount interest loan for water-saving irrigation in successive years: finances at all levels has accumulated discount interest of approximately 0.2 billion yuan and attracted investment of 1.6 billion vuan from various parties, developing over 15 million mu of water-saving irrigation area. For the purpose of enhancing the water-saving irrigation technology of China, in 1996 and 1997, the Central Finance listed the technology of water-saving irrigation among. State Imported 1000 Advanced Agricultural Technologies Project, as a key funding program. Meanwhile, to popularize advanced and practical water-saving technologies, Ministry of Finance allocated technology extension outlay for technology publicity and personnel training. Besides, the state has increased investment in the infrastructure of farmland irrigation.
Although the government has been actively promoting water-saving technology adoption, it is ill-informed of the status of this adoption. Simultaneously, researches on water-saving technology adoption in China by the academic circles are quite limited. The scarce documents available, which study the water-saving technology adoption, are mainly cases study and qualitative analysis, lacking in quantitative analvsis.
Therefore, this paper employs data from ten provinces in China to carry out a quantitative analysis of the status quo of agricultural water-saving technology adoption and its determinants. What on earth is the current adoption extent of water-saving technology in China? Which factors may have remarkable effect on its adoption? What roles do shortage of water resources and governmental policy play? Specifically speaking, this paper has two purposes: firstly to describe the changing tendency of water-saving technology adoption and secondly to identify the determinants affecting this adoption
This paper is organized as follows: introduction data sources, types, status quo and changing tendency of water-saving technology adoption; descriptive analysis on water-saving technology adoption; econometric analysis and results; conclusion and policy implications.
2. Data, types, status quo and changing tendency of water-saving technology adoption
The water-saving technology defined by us refers to perceptible water-saving irrigation technology at field level. Likewise, the definition of water use efficiency also means crop yield per unit water input measured at field level, for water-saving technology adoption is found not water-saving in some conditions when the net water use amount is measured in the overall irrigation system or on the drainage area scale. This is because the water-saving nature of each technology is not only determined by technological characteristics but also by factors like hydrological system and economic adjustment of output .
2. l Data source
Data employed in this paper derives from field investigation of three projects done by the Center for Chinese Agricultural Policy (CCAP)
The first project was investigation on China's water right system and management panel data. This investigation is divided into two phases: during the first phase, investigation was done in Henan, Hebei and Ningxia in 2001 and the investigation period was respectively 1990, 1995 and 2001; during the second phase, follow-up investigation was performed in Henan and Hebei in September, 2004. To add data to2004, another follow-up investigation was completed in Ningxia in August, 2005. The investigation of this project randomly sampled 77 villages based on the scarcity degree of water resources.
The second project was investigation on water resources of Northern China in December, 2004. 6 provinces were investigated, including Henan, Hebei, Shannxi, Shanxi, Inner Mongolia, and Liaoning. The invested periods were 1995 and 2004 respectively.To make the research more representative, we adopted the way of randomly stratified sampling to select sample villages in Northern China. Firstly, we selected counties in each sample province and then divided them into 4 categories in accordance with their irrigation area, namely sever water shortage, partial water shortage, normal and absolute water shortage (mountain areas and deserts). We randomly sampled 2 townships in each county and 4 villages in each county. The second investigation collected 401 sample villages.
The third project was investigation on water-consuming consortiums of 3 provinces in July, 2006, including Gansu, Hubei and Hunan. We adopted the randomly stratified sampling based on scarcity degree of water resources in 1995 and 2005 respectively. Altogether 60 sample villages were selected.
Investigation of the first and second projects collected 478 sample villages and investigation of the third obtained 60 sample villages. Therefore, there are a total of 538 samples from the three investigations. As samples of the final investigation are data of 2005, we deal with all data of 2004 in accordance with those of 2005 in consideration of consistency.
2.2 Types of adopted water-saving technologies
Based on investigation of 538 villages in 10 provinces, we have found that there are various types of water-saving technologies in the rural area. To facilitate analysis, we categorize them into three types in accordance with capital needed, separability and time of adoption.
The first type is traditional water-saving technologies including border irrigation, furrow irrigation and land leveling. We categorize these technologies into the same type as they were adopted rather early and some were adopted in 1980s prior to agricultural reform as most village leaders reflected. Besides, these technologies have relatively low fixed cost and are separable for each household to operate independently.
The second type is household-based water-saving technologies which include ground pipes (film plastic pipe or water bags), plastic film cover, leaving stubble to avoid plough (wheat straw covering), intermittent irrigation and anti-drought breeds. Normally this type of technologies can be adopted by a single household (rather than village committees or farmer household group). In addition, they have relatively low fixed cost but high separability. In comparison with traditional technologies, these types of technologies were adopted later.
The third type is community-based water-saving technologies which include underground pipes, sprinkler irrigation, drip irrigation and anti-seepage channel. These types of technologies are usually adopted by the community or farmer group instead of individual farmer household as they demand equipment with relatively high fixed cost and require cooperation of the collective or the majority of farmer households. Compared with the previous two types, these technologies were not adopted by farmers until recent years.
2.3 Status quo and changing tendency of adopted water-saving technology
Generally speaking, villages adopting water-saving technologies in China are distributed widely and scattered rapidly. It can be seen that 79% villages adopted water-saving technologies in 1995 and that number increased to 95% in 2005 increasing by 16%. From 1995 to 2005, the adoption rate of water-saving technologies averaged 87%, that is to say, only 13% villages did not adopt any kind of water-saving technology during the 10 years.
However, the actual adoption area of water-saving technologies in each village was rather small. In 1995 the rate was 11% and merely 16% in 2005. Although there is a growth to some extent, the adoption area of water-saving technologies was still quite low, by far lower than the rate of villages adopting water-saving technologies. This indicates that the area which actually adopted water-saving technologies is very small in spite of the wide spatial distribution of adopted water-saving technologies in China. This also signifies that there is great development space for the adoption of water-saving technologies.
As the same of the overall adoption, the adoption degree of the three types of water-saving technologies is very low. It can be seen that even for the traditional water-saving technologies which were adopted the earliest and the most widely, the adopted area merely accounted for 28%
arable area in 2005,let alone the household-based and community-based technologies, which merely accounted for 12% and 9% respectively in 2005, accounting for 1/10 arable area in average, far below the adoption rate of developed countries like America and Israel.
But there is a remarkable difference in the growth tendency and status of these three types of water-saving technologies. On the one hand, the growth of traditional technologies is slower than that of household-based and community-based types. From 1995 to 2005, the traditional technologies merely increased by 47% whereas the household based and community-based technologies increased respectively by 200% and 300%. This indicates that modern water-saving technologies are developing rapidly. On the other hand, though traditional technologies witness low increase, they are still significant in terms of adopted area. In 2005, the adopted area of traditional technologies was 28% whereas those of household-based and community-based technologies were less than 15%. This implies that water-saving technologies adopted in China are still rather backward. In similar studies done by Lohmaret , similar conclusion was drawn.
3. Descriptive analysis on factors affecting water-saving technology adoption
We analyze the correlation between water-saving technology adoption and the two types of factors in this paper and classify the three types of water-saving technologies into five groups in accordance with rate of the adoption area in a method of sample-based isometric grouping.
3.1 Correlation between scarcity of water resources and water-saving technology adoption
Theoretically speaking, the scarcer a resource becomes, the more likely it is to adopt technologies to save this resource. Previous empirical studies also demonstrate that scarcity of water resources is in positive correlation with water-saving technology
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