Improving water use efficiency as part of integrated catchment management

Sustainable agricultural development requires technologies and practices that make more efficient and productive use of resources and an enabling environment that encourages the adoption of these technologies. Many institutions and international agencies are showing considerable interest in integrated catchment management (ICM) as a practical means of improving the management of water resources, reducing environmental degradation and promoting sustainable agricultural development. This paper outlines some of the main components of ICM and lists some of the prerequisites for establishing collective responsibility for, in particular, groundwater resources. This paper also discusses the extent to which programmes of ICM can be used as a means of conserving water resources and improving water use efficiency and productivity at the farm and catchment scales.     

复合坡度下雨水高效集蓄利用模式研究

通过复合坡面人工模拟降雨径流冲刷试验,研究了2种雨强下4种下垫面模式的坡面径流调控效应,从产流时间、侵蚀量、径流量以及泥沙含量等方面分析了径流调控的机理。结果表明:帕特草+PAM是一种理想的措施,其坡面径流量和侵蚀量均最小,较裸地对照(CK)分别提高了93.02%和98.13%,其次是帕特草+地孔,PAM+地孔;单纯在裸地上打地孔的坡面径流调控效果较裸地对照效果不明显。坡度对不同下垫面复合措施的影响甚微,而降雨强度对其影响却极为显著。坡面雨水的集蓄利用复合措施与水土保持综合治理模式改变了坡面的小地形状况,增加了植物(作物)覆盖度,加大了降水的入渗速率和数量,对黄土高原的水资源有效利用具有理论指导作用。     

流域“健康”诊断指标——一种生态环境评价的新方法

介绍了澳大利亚学者建立的流域环境质量评价指标体系及其评价过程。该方法利用１０项环境背景指标来分析流域的总体质量或功能水平,１０项环境趋势指标以及９项土地生产力和经济效益指标来分析流域环境质量变化的趋势。通过这些指标体系所揭示主要的环境问题,为环境管理提供依据。     

基于集水区法的森林生态系统影响径流研究进展

森林生态系统结构复杂, 具有减少地表径流、调节河川流量、减小土壤侵蚀等一系列保护环境的功能。森林植被变化对森林水文过程的影响会改变水量平衡方程的各个变量, 从而影响森林流域的水分分配和河川径流量, 进而对陆地生态系统水分循环起到重要的调节作用。从森林结构、森林类型、森林覆盖率和森林经营4个方面总结了国内外基于集水区法研究森林生态系统影响径流的结论, 即小流域的研究结果认为森林的减少将增加河川径流量, 而大流域的研究结果认为森林的减少将减少河川径流量。最后指出, 在研究单位和研究项目合作研究的基础上, 结合各相关学科的新兴技术和研究设备, 通过整合相关学科的研究成果, 阐明森林生态系统水土保持过程与机理, 是今后森林生态系统水文服务功能研究的发展方向。     

国内主要流域侵蚀产沙模型评述

流域侵蚀产沙模型是国际土壤侵蚀研究的重点领域之一,国内以往进行了较多研究,建立了许多模型。正确分析和评价这些模型对于合理地使用它们进行流域侵蚀产沙预报和水土保持规划等工作具有重要意义。从研究方法、模型结构、模型中各参数的确定等方面对我国主要流域侵蚀产沙经验模型和具有一定成因的模型进行了分析,并在此基础上对各模型进行了评价。     

Water balance characteristics of Kashima plateau basins assuming variable areas of underground catchments

Agricultural water use on upland fields depends mainly on precipitation and irrigation by small wells in the Kashima plateau basins. To establish a stable supply of water for irrigated upland fields, an evaluation of water-cycle mechanisms on an arable plateau near plain lakes is important. Previous research suggests that groundwater catchments do not necessarily coincide with the corresponding surface catchments in the plateau basins. However, a physical mechanism of groundwater movement has not yet been clearly demonstrated. In this paper, therefore, we aimed to estimate the areas of groundwater catchments that did not coincide with their corresponding surface catchments, by observing groundwater flow in boreholes and by evaluating water balances of four small basins on the Kashima plateau. As a result, hydrological and groundwater observations in the Kashima-Kohoku basin showed: (1) the groundwater catchment was larger than the surface catchment, as inferred from continuous groundwater observations and the observed directions of groundwater flow, (2) groundwater potential may change after intensive rains, especially after precipitation events of more than 50 mm, and (3) estimates of the long-term water balance confirmed that groundwater flowed into the surface catchment from the outside. The area of the Kashima-Kohoku groundwater catchment was 1.3–2.4 times the area of the surface catchment. Furthermore, the same result was obtained for two other basins.     

两种驱动力作用下植被调控堆积体坡面减水减沙效益

定量分析侵蚀驱动力的变化对于植被调控堆积体坡面水文和产沙过程的影响,对于深刻理解植被防护堆积体侵蚀及其水土保持效益具有重要作用。该研究以陡坡工程堆积体(30°)作为研究对象,采用野外模拟降雨和降雨+上方汇水试验研究苜蓿对工程堆积体侵蚀过程的影响及其减水减沙效益。结果表明:1)两种驱动力下苜蓿对工程堆积体坡面减沙和减流效益分别为57.28%～98.51%和13.17%～83.11%,加入上方汇水后减沙和减流效益分别减少17.01%和68.74%;2)降雨条件下苜蓿对堆积体坡面减流减沙效益随降雨强度增大降低,而加入上方汇水后减沙效益随降雨强度增大而增大,但减流效益减小。显著性差异分析表明降雨强度对裸坡和苜蓿堆积体的径流和产沙均有显著影响(P0.01),且上方汇水的作用大于降雨;3)两种驱动力下裸坡堆积体侵蚀速率总体随产流历时减少,而苜蓿堆积体在降雨条件下侵蚀速率总体增大。加入上方汇水后裸坡及苜蓿堆积体坡面侵蚀和径流随产流历时的波动性显著增强;4)裸坡堆积体在降雨和降雨+上方汇水条件下产流前期的平均侵蚀速率是后期的1.06～2.90倍,苜蓿堆积体在降雨条件下产流前期平均侵蚀速率小于后期。研究成果可为生产建设项目工程堆积体水土流失防治和植被措施布设提供科学指导,具有显著的科学意义和工程实践指导价值。     

Participatory soil and water conservation planning using a financial analysis tool in the West Usambara highlands of Tanzania

Despite decades of soil and water conservation (SWC) efforts in Tanzania, the adoption of the recommended SWC measures by farmers is minimal. In the past, SWC plans did not incorporate farmers' knowledge, and the economics of SWC was not given much attention at the planning stage. This research evaluated the applicability of two tools for participatory soil erosion mapping using farmers' indicators of soil erosion and financial analysis of SWC measures at the planning stage. The two tools were evaluated in Kwalei catchment in the West Usambara highlands, Tanzania. The participatory soil erosion‐mapping tool uses farmers' indicators of soil erosion to identify, classify and map soil erosion at the catchment level. The financial analysis tool involves farmers in a stepwise analysis of the costs and benefits of SWC measures before the implementation. The erosion‐mapping tool increased farmers' awareness on the severity of soil erosion problems, and they realised the need for SWC plans at both field and catchment scales. With the financial analysis tool farmers participated in the cost and benefits analysis and were able to select SWC options that were feasible under their socio‐economic situation. The two tools were able to demonstrate that farmers' participation in SWC planning increases the acceptance of SWC measures because they solve problems that are perceived by themselves. The financial analysis tool demonstrated how farmers could make selection of SWC measures that are feasible under their biophysical and economic condition if they are informed about the costs and benefits. Copyright © 2006 John Wiley & Sons, Ltd.     

滴灌条件下积水区特性的试验研究

滴灌条件下供水强度大于土壤入渗速率时,地表产生积水区,滴灌条件下地表的积水区与土壤质地和滴头流量有关,且积水区的运移是规律的。当供水与入渗达到平衡状态时,积水区稳定。通过试验,研究不同土质在相同滴头流量下积水区运移规律,同种土质在不同流量条件下积水区运移规律,分析其影响因素,得到滴灌条件下积水区的运动符合幂函数关系。     

Community participation in the development of the Ōngātoro/Maketū Estuary project: The socio‐ecological dimensions of restoring an interconnected ecosystem

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