灌溉興利調(diào)節(jié)計(jì)算過程案例根據(jù)水量平衡原理，采用列表法分別對(duì)不計(jì)損失的、計(jì)入損失兩種情況進(jìn)行水庫興利和調(diào)節(jié)計(jì)算。分析水庫來水和用水過程，從水庫蓄水期開始（即灌溉末期開始）作為調(diào)節(jié)年度的開始，應(yīng)用水量平衡原理進(jìn)行逐時(shí)列表計(jì)算，分別算出算出余水量和虧水量，根據(jù)不同運(yùn)行情況，分析出這一調(diào)節(jié)年度內(nèi)所需興利庫容。水庫面積大小為148.5km2，來水量=水庫集水面積*徑流量，用水量即為全灌區(qū)灌溉用水量之和。故下面進(jìn)行不計(jì)損情況下水庫調(diào)節(jié)計(jì)算表1.16不計(jì)損下水庫調(diào)節(jié)分析單位：萬m3月旬徑流量水庫來水量毛灌溉用水量余水量虧水量水庫蓄水量棄水量1050743.5743.5742.411000742.4125.784.584.582715.581.681.6908.8234.9518.3518.31427.1335.5527.2527.21954.3412.9191.6191.62145.9517.6261.4261.42234.2173.26上4.769.869.82234.269.9中13.8204.75002951939下21.1313.130013.31952.57上0.11.4400398.51554中16.92512511804.8下0.57.4450442.61362.48上00550550812.4中19.7292.4128.5163.8976.3下00267267709.39上117.6678.3660.548.2中10151.220048.20查圖任務(wù)書所給的面積-庫容曲線確定所對(duì)應(yīng)的面積，如下所示表1.17不計(jì)損庫容表變量對(duì)應(yīng)庫容相應(yīng)庫面面積（km2）相應(yīng)水位（m）興利庫容大小2234.2死庫容大小8003.6619總庫容大小3034.27.9623.105計(jì)損情況下水庫調(diào)節(jié)計(jì)算水庫建成后，形成水庫，導(dǎo)致水庫面積大于河面面積。因此一部分原來是陸面蒸發(fā)的地方變成了水面蒸發(fā)，所以要考慮水庫建成后所增加的水量蒸發(fā)損失，另外水庫來水時(shí)經(jīng)過壩、建筑物和地基還會(huì)有各種滲漏損失。在興利庫容確定的情況下由于蒸發(fā)、滲漏損失常使調(diào)節(jié)流量減少，若調(diào)節(jié)流量確定，則所需興利庫容將大增，所以水流損失必須考慮水庫水量損失包括蒸發(fā)和滲漏兩個(gè)方面，下面分別計(jì)算：蒸發(fā)損失是指建庫后的水面蒸發(fā)量大于原來蒸發(fā)量的的蒸發(fā)損失，計(jì)算公式如下：?W蒸=式中：ΔW蒸——年蒸發(fā)損失量，萬m3；E水——多年平均水面蒸發(fā)量，mm；有E水E測(cè)——水文站多年計(jì)算平均年蒸發(fā)量，mm；E陸——多年平均陸面蒸發(fā)量，平均年徑流深，mm；A——水庫平均水面面積，km2。蒸發(fā)損失計(jì)算過程如下：E水=KE測(cè)=0.85*1104.8=940mmΔW蒸=（?W蒸式中：K——折減系數(shù)取0.85；滲漏損失計(jì)算按照非灌溉期按當(dāng)月蓄水量0.01計(jì)，灌溉期按當(dāng)旬蓄水量的0.003計(jì)算分析表1.17計(jì)損條件下分析月份旬年蒸發(fā)量比例關(guān)系蒸發(fā)損失不計(jì)損時(shí)庫容滲漏量總損失量10740.0813.95742.46.22011660.0712.45742.46.21912380.046.658277.1141330.045.65908.87.9142270.034.451427.113.1183620.0711.551954.318.3304680.0712.852145.920.2335780.0814.952234.221.1366上470.058.452234.25.614中350.046.0519394.711下230.033.651952.54.787上450.058.1515543.512中440.057.951804.84.312下470.058.551362.43128上430.057.55812.41.39中650.0711.25976.31.814下640.0711.95709.31139上220.023.3548.203中170.022.45002下290.034.85005合計(jì)9281167.7298得到損失量為298萬m3考慮到之前來水量為3720萬m3，用水量為3474.1萬m3，計(jì)算得到來水量去除損失水量為3420m3幾乎持平于灌溉用水量，無需采用減少作物灌溉面積等方式方式降低。表1.18調(diào)節(jié)庫容計(jì)算月旬典型年蒸發(fā)量比例系數(shù)蒸發(fā)損失滲漏量總損失量10740.081462011660.07126.21912380.0477.1141330.0467.9142270.03413.1183620.071218.3304680.071320.2335780.081521.1366上470.0585.614中350.0464.711下230.0344.787上450.0583.512中440.0584.312下470.0593128上430.0581.39中650.07121.814下640.07121139上220.02303中170.02202下290.03505典型年水庫來水量凈來水量毛灌溉用水量余水量虧水量水庫蓄水量棄水5074373573573500-887285.78576768045.582737387634.9518504504138035.5527508508188912.9192173173192114117.626124324319212434.770646419216413.8205199450251167021.13133082703817070.12-3360363134416.925124624615890.573405402118800-349549869019.729329011617486400-22402436221.218186115932910.215215218029000000