Water Pricing and Sustainability of Self-Governing Irrigation Schemes

The sustainability of self-governingirrigation schemes is currently underpressure in many countries as publicfinancial support is decreasing.Furthermore, growing global concernregarding water scarcity means thatefficient water use is essential.Theoretically the choice and implementationof a water-pricing system should play acentral role in achieving this objective,both by recovering water costs and byencouraging farmers to adopt more efficientbehaviour. In the Senegal River Delta newlyestablished water users associations (WUAs)have chosen low water charges, which areaffordable for the majority of farmers butwhich underestimate long-term maintenancecosts. Combined with the difficulty ofcollecting and managing farmers' fees, thischoice has drawn them into a vicious circleleading to scheme deterioration and poorwater service. New alternatives have beendiscussed with them using a simulation toolthat takes into account both the watercosts and the farmers' incomes. Comparedwith the present fixed water charge basedonly on cultivated land, a two-part optionbased both on equipped and irrigated areasensures the recovery of fixed expenses suchas maintenance, while encouraging farmersto intensify their farming systems byadopting double cropping. Neverthelesschoosing a relevant water charge does notensure by itself the sustainability of anirrigation scheme. Combined supportproviding WUAS and farmers with efficientadvice regarding management andorganisational skills should alsocontribute significantly to achieve thisprime objective.     

宁蒙引黄灌区田间节水潜力计算方法分析

以黄河干流宁蒙大型自流引黄灌区为研究对象,采用分项法以及两种计算顺序对宁蒙引黄灌区田间节水潜力进行了计算,分析了不同计算顺序对田间节水潜力计算结果的影响,并采用综合法对分项法计算结果进行了验证,表明计算方法可靠。     

黄河流域典型灌区灌溉节水管理模型研究

以黄河流域上下游2个典型灌区为背景，针对灌区有其农业水管理现状，开发了灌溉节水策略分析决策支持系统（DSS）原型。DSS是一个规划工具，通过对不同策略下田间配水及供水系统的模拟分析及综合决策，寻求最优的策略集合，以达到节约灌溉用水量、提高农业用水效率及维持农业可持续发展的目的。该DSS系统主要用于黄河流域灌区提高农业水管理水平的策略分析，也可用于评估灌区续建配套及土地最佳利用方案等方面。     

加快洞庭湖区农机化发展 促进社会主义新农村建设

建设社会主义新农村是我党今后很长一段时期的重大历史任务。新农村建设使洞庭湖区农机化获得了发展良机,而农机化在新农村建设中的地位和作用显著,本文从湖南洞庭湖区新农村建设的要求出发,提出了大力推广水稻生产全程机械化技术,以促进洞庭湖区农村生产发展、农民生活宽裕;坚持依法行政,保障农机安全生产,以促进农村社会和谐,乡风文明;抓好农机部门自身建设,以适应社会主义新农村建设的需求等几项措施。     

荒漠化预警模型及其应用研究

分析了土地生产潜力的影响因子及其计算方法，从机理上分析各因子给未来荒漠化的发展趋势可能造成的影响，并从土地生产潜力退化基本原理出发，建立了荒漠化顸警模型。以疏勒河流域为背景，在GIS平台支持下，应用预警模型分析了该流域昌马灌区农业综合开发后的荒漠化趋势，对灌区荒漠化的发展趋势和潜在危险性进行了分析判断。     

利用Radon变换计算粮仓害虫图像的倾斜角度

针对无明显的直线特征的仓储害虫图像,提出了一种基于Radon变换算法定位图像区域和检测图像倾斜角度的方法.实验结果表明,该算法能快速、准确地测量出仓储害虫图像的倾斜角度,并具有很强的抗干扰性、应用适应性和抗随机噪声的特性.     

Incorporation of ridge and furrow method of rainfall harvesting with mulching for crop production under semiarid conditions

A plastic-covered ridge and furrow rainfall harvesting (PRFRH) system combined with mulches was designed to increase water availability to crops for improving and stabilizing agricultural production in the semiarid Loess region of northwest China. The system was built by shaping the soil surface with alternate ridges and furrows along the contour. The plastic-covered ridges served as a rainfall harvesting zone and furrows as a planting zone. Some materials were also used to mulch the furrows to increase the effectiveness of the harvested water. This system can make better utilization of light rain by harvesting rainwater through the plastic-covered ridge. The field experiment (using corn as an indicator crop) showed that grain yields in the PRFRH system with mulches in 1998 and 1999 were significantly higher than the controls, with an increase of 4010–5297 kg per ha (108–143%). In most treatments, the water use efficiencies (WUE) were in excess of 2.0 kg m⁻³. The WUE values of corn in this system were 1.9 times greater than the controls in 1998 and 1.4 times greater than the controls in 1999. The plastic-covered ridge led to a yield increase of 3430 kg per ha (92%) in 1998 and of 1126 kg per ha (21%) in 1999 compared with the uncovered ridge. On average, the additional mulches in the furrow brought about a yield increase of 8–25%. Based on the results of this study and other researches, this technique can increase corn grain yield by 60–95% in drought and average years, 70–90% in wet years, and 20–30% in very wet years. The PRFRH system had the potential to increase crop yield and produced greater economic benefit, therefore it could be used in regions dominated by light rainfall of low intensity where crops generally fail due to water stress.     

疏勒河灌区新垦盐碱地洗盐定额试

根据疏勒河灌区新垦盐碱地土壤含盐量高，需采用水平明沟排水冲洗改良的实际，开展了不同冲洗定额的洗盐效果试验研究，提出了排盐地区系数经验公式与冲洗定额对数函数计算公式。根据表层土壤含盐量高的特点，提出了以0~30cm土层作为冲洗改良盐碱地脱盐控制层的准则，并制定了相应的洗盐定额。     

单位线方法在沿渡河流域的应用研

单位线方法在水文计算及洪水预报中得到了广泛的应用，至今仍然是汇流计算的重要工具。以沿渡河流域为研究背景，分别采用分析法及矩法推求了该流域的时段单位线，并分别用这两种单位线模拟了该流域的同次洪水过程，模拟结果表明分析法得到的单位线更加适合该流域的洪水计算。最后，在详细分析两种方法误差来源的基础上，提出了相应的改进措施。     

“数字清江”实时水情调度联合计

为了快速、准确的分析水情实况、预测未来的发展趋势，结合清江流域防洪减灾工作实际情况，设计了实时水情调度联合计算方案。根据清江流域地理位置的特点，将其分为7个子流域，依次进行降雨径流预报、洪水演算，为防洪减灾提供真实有效的决策依据。通过对该方案的分析，探讨了设计思路，并给出了其实现机理。该方案已在“数字清江”项目中得到成功应用。