双牌灌区水管理信息化技术建设

湖南省双牌灌区水管理信息化系统的使用,使灌区水管理实现了遥测遥控。信息化系统的使用可依据水位变化和降雨情况合理调配供水量,既提高灌溉用水量测精度,又保障用水量和收费的准确性,实现了水资源的优化配置和高效利用。     

水肥模式对温室小型西瓜水分利用及光合特性的影响研究

通过田间试验，研究不同灌溉模式与施肥方式对设施栽培条件下小型西瓜水分利用、光合特性以及产量品质的影响。研究结果表明，节水灌溉处理W3可在实现节水50％的基础上获得较高的产量，并且糖分测定结果显示，减少灌水对提高西瓜品质也有益处。根据光合特性分析结果，适当范围内控制土壤水分可促进西瓜的光合速率、气孔导度和蒸腾速率，并提高计算水分利用率。不同施肥处理研究结果显示，适当减少氮肥可明显提高西瓜品质，而磷肥处理与西瓜产量品质的关系不明显，需进一步研究。     

灰色关联投影法在节水灌溉方案选择中的应用

文章提出了用于节水灌溉方案选择的多目标决策灰色关联投影法,介绍了该方法的基本原理,建立了综合考虑项目的安全性、可靠性、地形适应性、作物适应性、施工难易程度等因素的节水灌溉方案。选择多目标决策灰色关联投影模型,并用实例加以说明,所得结果与层次分析法的评价结果基本相同,说明该方法用于节水灌溉方案选择是有效的[1]。     

发展集雨节灌深化水利富民-考察甘肃发展集雨工程的几点启示

在对甘肃省集雨节灌考察的基础上，提出了推动北京市集雨节灌水利富民工程发展的思路和措施。甘肃省实施的集雨工程，总结出了雨水集蓄利用三条途径：修筑梯田，拦蓄雨水，发展雨养农业；利用庭院、场院和屋顶集雨，发展庭院经济；利用道路集雨，发展大田作物节水灌溉。同时，也探索出了三种集雨节灌水利富民综合开发模式：集雨节灌与设施农业相结合；集雨节灌与生态农业、流域治理相结合；集雨节灌与观光农业、休闲娱乐相结合。借鉴甘肃成功的做法和经验，发展集雨节灌，五小水利工程网络化，建设有北京特色的集雨节灌水利富民工程，是北京应当深入思考和认真实施的事情。     

气候变化下黑龙江省水稻灌溉需水量变化特征

基于黑龙江省8个典型站点60年(1956-2015)的历史气象资料,利用Penman-Monteith公式和水量平衡模型计算了黑龙江省水稻全生育期内,两种灌溉模式下(淹水和控制灌溉)的作物需水量(ETC)及灌溉需水量,并结合气象因素的变化特征,借助Mann-Kendall检验方法分析了ETC及灌溉需水量对气象因子的响应。结果表明:ETC方面,不同灌溉模式下同一站点ETC的变化趋势基本一致,其中安达和绥化站的ETC呈下降趋势,出现"蒸发悖论"现象,嫩江、尚志和孙吴站的ETC显著上升,其余各站无明显变化。灌溉需水量方面,只有尚志站点在两种灌溉模式下均显著增加,孙吴、富锦和嫩江站仅在控制灌溉模式下呈明显上升趋势,而其余站点并没有一致性规律。总体上,相对于淹水灌溉,控制灌溉模式下有效降雨量提高了20%,灌溉需水量降幅为44.9%~52.9%,有效减少了农业生产在气候变化条件下受到的不利影响。     

基于免疫遗传算法优化的投影寻踪灌区综合评价

通过对哈尔滨市郊5个灌区的各项功能参数指标资料的收集与整理,采用高维降维技术投影寻踪分类模型（PPC）,利用基于实码加速免疫遗传算法（RAIGA）优化其投影方向,将多维数据指标（样本评价指标）转换到低维子空间,根据投影函数值的大小评价出样本的优劣,从而做出决策,为各灌区进行评价排序,了解灌区的运行状况。     

滴灌条件下干旱区农田水盐运移及调控研究进展与展望

以滴灌为代表的节水灌溉技术在我国干旱区大面积推广应用,提高了水肥利用效率,也改变了农田水盐运移模式。一方面,地下水位下降,土壤水与地下水之间的联系减弱,减少了潜水蒸发带来的盐分,使得土壤盐碱化减轻;另一方面,由于缺乏洗盐水量,导致积累在土壤表层的盐分不能及时淋洗入深层,表层土壤盐碱化加重。本文通过回顾滴灌技术在干旱区的应用和研究,系统分析了滴灌条件下干旱区农田土壤水盐运移特点和盐分累积规律,概括了不同作物的水盐响应特征,总结了不同滴灌条件下的土壤水盐数值模型,归纳了目前常用的土壤水盐调控方法。在此基础上提出了需要进一步研究的问题和方向,包括:进一步揭示滴灌条件下土壤水盐运移及累积特征,科学制定农田水盐调控方案;进一步揭示作物水盐耦合响应动力学机制,科学确定调控阈值;发展具有我国自主知识产权的水盐运移和作物生长耦合模拟软件;构建基于生态格局的农田排水和区域盐分处置模式。     

Grasses for biofuels: A low water-use alternative for cold desert agriculture?

In arid regions, reductions in the amount of available agricultural water are fueling interest in alternative, low water-use crops. Perennial grasses have potential as low water-use biofuel crops. However, little is known about which perennial grasses can produce high quantity, high quality yields with low irrigation on formerly high-input agricultural fields in arid regions. We monitored biomass production, weed resistance, rooting depth, and root architecture of nine perennial grasses under multiple irrigation treatments in western Nevada. Under a low irrigation treatment (71 ± 9 cm irrigation water annually), cool-season grasses produced more biomass and were more weed-resistant than warm-season grasses. With additional irrigation (120 ± 12 cm water annually), warm- and cool-season grasses had similar biomass production, but cool-season species remained more weed-resistant. Among species within each grass type, we observed high variability in performance. Two cool-season species (Elytrigia elongata and Leymus cinereus) and one warm-season species (Bothriochloa ischaemum) performed better than the other tested species. Root depth was not correlated with biomass production, but species with deeper roots had fewer weeds. Abundance of fine roots (but not large roots) was correlated with increased biomass and fewer weeds. Both L. cinereus and E. elongata had deep root systems dominated by fine roots, while B. ischaemum had many fine roots in shallow soil but few roots in deeper soil. Cool-season grasses (particularly E. elongata, L. cinereus, and other species with abundant fine roots) may be worthy of further attention as potential biofuel crops for cold desert agriculture.     

Irrigation Development and Rural Poverty in Gujarat,India: A Disaggregated Analysis

Abstract

There has been renewed interest during recent times in the impact of irrigation development on rural poverty. For long, researchers asked whether irrigation development reduces the poverty of irrigators. However, the question being asked now is: does investing in irrigation—rather than in other public works—help reduce rural poverty in a region? Using Government of Gujarat's 1997 census of Below Poverty Line (BPL) households as well as the Village Amenity Survey of the same year, this paper explores the interplay between irrigation development and rural poverty in 177 predominantly rural talukas, which is an administrative unit with a population of around 100,000-150,000 people, of Gujarat state in western India. Our analysis shows that for the design of poverty-targeting programs, two variables have the highest appeal: primary education infrastructure and improved land productivity through irrigation. It also suggests that, over the long run, irrigation benefits far transcend the command areas of irrigation systems. As a result, irrigation impact studies focused at farm or command area level seriously underestimate overall livelihood impacts of irrigation development. This is because intensively irrigated areas act as magnets that attract rural poverty from their surround, especially from other dry areas. Population pressure on farm lands thus tends to get redistributed according to the carrying capacity of farm lands. Across 177 predominantly rural talukas of Gujarat, we find: a) an inverse relationship between land use intensity and land-man ratio; and b) as land productivity (output/hectare of net sown area) declines, output per rural person declines too, but far more slowly than would have been the case without the “magnet effect.”     

Fertigation in Furrows and Level Furrow Systems. II: Field Experiments, Model Calibration, and Practical Applications

Furrow fertigation can be an interesting practice when compared to traditional overland fertilizer application. In the first paper of this series, a model for furrow fertigation was presented. The simulation model combined overland water flow (Saint-Venant equations), solute transport (advection-dispersion), and infiltration. Particular attention was paid to the treatment of junctions present in level furrow systems. In this paper, the proposed model is validated using five furrow fertigation evaluations differing in irrigation discharge, fertilizer application timing, and furrow geometry. Model parameters for infiltration and roughness were estimated using error minimization techniques. The error norm was based on observed and simulated values of advance time, flow depth, and fertilizer concentration. Model parameters could be adequately predicted from just one discharge experiment, although the use of more experiments resulted in decreased error. The validated model was applied to the simulation of a level furrow system from the literature. The model adequately reproduced irrigation advance and flow depth. Fertigation events differing in application timing were simulated to identify conditions leading to adequate fertilizer uniformity.