1.2 参与该技术评估和文件编制的资源人员和机构的联系方式

有助于对技术进行记录/评估的项目名称（如相关）

有助于对技术进行记录/评估的项目名称（如相关）

有助于对技术进行记录/评估的机构名称（如相关）

1.3 关于使用通过WOCAT记录的数据的条件

编制者和关键资源人员接受有关使用通过WOCAT记录数据的条件。:

是

1.4 所述技术的可持续性声明

这里所描述的技术在土地退化方面是否存在问题，导致无法被认为是一种可持续的土地管理技术？:

否

1.5 参考关于SLM方法（使用WOCAT记录的SLM方法）的调查问卷

Vu Gia Thu Bon River Basin Information Centre [越南]

The VGTB River Basin Information Centre (RBIC) offers decision support tools for stakeholders and aims at providing comprehensive information and consulting services to the water and land users according to their demands.

• 编制者： Justyna Sycz
• 07/28/2015 midnight

2.1 技术简介

技术定义:

Return flow from paddy fields is strategically collected before being lost to rivers and is reused as an effective source of agricultural water.

2.2 技术的详细说明

说明:

Return flow from paddy fields is defined as applied water that is not lost by evapotranspiration but returns to an aquifer or surface water body (Womach, 2005). The two types of return flow are surface and sub-surface. Surface return flow accounts for the major proportion. If surface return flow is strategically collected before entering rivers, it can be used as an ‘extra’ effective source of agricultural water supply (Phil King, 2008; Simons et al., 2015). Because paddies effectively purify water by absorbing nitrogen and phosphorus, this produces return flow of an acceptable quality for irrigation purposes. Return flow can be collected by drainage canals and stored in ponds and reservoirs, and then returned to pumps for reapplication. This technology offers one solution towards overcoming a deficit of irrigation water.

The goal of this technology is to store and reuse surface return flow from paddy farms to enhance irrigation efficiency. The purpose of constructing temporary barriers in drainage canals is to minimise water wastage and optimise the possibility of collecting and recycling surface return flow. Return flow from irrigation system is stored in surrounding ponds and reservoirs Return flow can only be used when it is captured in a storage structure or drain which has a hydraulic link to the irrigation source: thus an integrated framework for the reuse system consisting of both hydraulic, and management, links should be established. Within the scope of this study, the Water Management Unit (WMU) is understood as an integrated irrigation and drainage system consisting of four components: (i) the hydrological catchment which covers both non-irrigated and irrigated area; (ii) the source scheme generating return flow; (iii) the reuse scheme that is hydraulically connected with the source scheme; and (iv) a drainage system functioning as a harvesting as well as a supply structure.

Before implementing such a system it is recommended to analyse the correlation between irrigation efficiency and reuse of return flow, as well as developing a framework for managing and recycling return flow. Investigation aims at identifying the potential of return flow for irrigation; determining its quantity and quality; and developing an efficient and sustainable reuse framework. Water balance calculations, field measurements, water quality sampling and interviewing are all used for this purpose.

In the study area, long dry seasons cause severe water shortages and problems with saline intrusion. The study area is mainly covered by paddy, vegetables and other annual crops such as maize, sweet potatoes, peanuts and sugarcane. Paddy rice, which consumes a high proportion of the freshwater, is the dominant crop. Agricultural land in the downstream area is irrigated through gravity or pump irrigation systems. Here results indicate that the irrigation efficiency can be improved significantly: the irrigation efficiency of Tu Cau and Thanh Quyt irrigation schemes is projected to increase respectively by 1.8 and 1.4 times.

Reuse of return flow can be applied in all WMUs where the drainage canals are connected with storage tanks. Scientific and technical support tools are offered by the Vu Gia Thu Bon River Basin Information Centre. The centre was established in Danang providing a comprehensive information service to farmers and other water users – it includes capacity building and consulting services also.

2.3 技术照片

2.5 已应用该技术的、本评估所涵盖的国家/地区/地点

国家:

越南

区域/州/省:

Quang Nam

有关地点的进一步说明:

Dien Ban

Map

×

2.6 实施日期

如果不知道确切的年份，请说明大概的日期:

• 不到10年前（最近）

2.7 技术介绍

详细说明该技术是如何引入的:

• 通过土地使用者的创新
• 在实验/研究期间

3.1 该技术的主要目的

• 改良生产
• 保护生态系统

3.2 应用该技术的当前土地利用类型

农田

• 一年一作
• 多年一作（非木材）
• 乔木与灌木的种植

年作 - 具体指明作物:

• 谷物类 - 玉米
• 谷类 - 水稻（湿地）
• 根/块茎作物 - 红薯、山药、芋头/椰子，其他

• vegetables

多年生（非木质）作物 - 指定作物:

• 甘蔗

乔木和灌木种植 - 指定作物:

• 树坚果（巴西坚果、开心果、核桃、杏仁等）

每年的生长季节数:

• 2

具体说明:

Longest growing period in days: 130, Longest growing period from month to month: 20th December to 28th April; Second longest growing period in days: 110, Second longest growing period from month to month: 20th May to 06th September

注释:

Major land use problems (compiler’s opinion): The lowland part of Vu Gia Thu Bon is an intensive agricultural area. Rice cultivation, which consumes a high proportion of fresh water, accounts for 70% of total agricultural land (Ribbe et al., 2011). Since 2005, due to the impacts of droughts and saltwater intrusion, water for irrigation during the dry seasons has become an increasing problem in the lowland area of this basin. Simultaneously, the irrigation efficiency of this region is relative low. Various measures are applied to address water scarcity for irrigation. Reusing return flow is regarded as a potentially new measure to reduce the severity of the irrigation deficit in dry periods.
Major land use problems (land users’ perception): Based on the information provided by the Department of Natural Resources and Environment (DONRE) for Quang Nam Province, this basin now faces the problem of temporarily insufficient irrigation water. This situation is caused by droughts, insufficient reservoir capacity, salinity intrusion and ineffective irrigation management.

3.4 供水

该技术所应用土地的供水:

• 充分灌溉

3.5 该技术所属的SLM组

• 集水
• 地表水管理（泉、河、湖、海）

3.6 包含该技术的可持续土地管理措施

结构措施

• S5：大坝、集水斗、水池
• S6：墙、障碍物、栅栏、围墙

管理措施

• M2：改变管理/强度级别
• M6：废物管理（回收、再利用或减少）

3.7 该技术强调的主要土地退化类型

水质恶化

• Hs：地表水良变化

注释:

Main causes of degradation: crop management (annual, perennial, tree/shrub) (Paddy rice requires huge amounts of water. Meanwhile, the coefficient of irrigation return flow from paddy field is also quite high.), industrial activities and mining (Hydropower construction reduces water availability for irrigation), over abstraction / excessive withdrawal of water (for irrigation, industry, etc.) (It causes water waste and reduces irrigation efficiency.), change of seasonal rainfall (It affects the paddy water balance and actual irrigation need.), droughts (It causes saltwater intrusion.)
Secondary causes of degradation: change in temperature (It relates to evapotranspiration.), inputs and infrastructure: (roads, markets, distribution of water points, other, …), governance / institutional

3.8 防止、减少或恢复土地退化

具体数量名该技术与土地退化有关的目标:

• 减少土地退化

4.1 该技术的技术图纸

技术规范（与技术图纸相关）:

Methods of recycling return flow from paddy fields: The surface return flow can be captured by drainage canals and stored in tanks: return water from these reservoirs is pumped back into irrigation canals.
In 2012, the first on-farm irrigation structure was initially implemented in the Tu Cau WMU in order to use return flow for irrigation purposes. The existing Sen Pond was enlarged and a temporary pumping station was installed to pump water into the irrigation canal system.
According to the pumping diary of Tu Cau station (in Winter-Spring crop 2013), there were totally 7 irrigation periods (8-11 days/period). Total input water (including effective rainfall) during the measuring period from 01 March to 10 April was about 28,000 m3. Meanwhile the total volume of return flow of the Tu Cau site was 16,176 m3. This amount of return flow has the potential to irrigate the agricultural area for about 16 days, equivalent to one and a half irrigation periods. The overall efficiency of the irrigation system will be significantly improved.
Location: Lowland area of VGTB Basin. Quang Nam Province
Date: January 2014

Technical knowledge required for field staff / advisors: high
Technical knowledge required for land users: low
Main technical functions: water harvesting / increase water supply

Dam/ pan/ pond
Depth of ditches/pits/dams (m): 2
Width of ditches/pits/dams (m): 194.9
Length of ditches/pits/dams (m): 399.4

Wall/ barrier
Height of bunds/banks/others (m): 0.5
Width of bunds/banks/others (m): 0.25
Length of bunds/banks/others (m): 1.26

Construction material (other): Stone, sandy bags and bamboo sticks
Specification of dams/ pans/ ponds: Capacity 116764.59m3
Catchment area: 77860 m²m2
Beneficial area: 30 ham2
Other type of management: Return flow is the part of drainage flow, it is necessary to enhance the institutional link to develop the reuse framework for the study area. Think about reforming IMC to IDMC with D is drainage.

作者:

Trinh Quoc Viet

4.2 有关投入和成本计算的一般信息

其它/国家货币（具体说明）:

VND

如相关，注明美元与当地货币的汇率（例如1美元=79.9巴西雷亚尔）：1美元=:

20828.0

4.3 技术建立活动

4.4 技术建立所需要的费用和投入

注释:

Duration of establishment phase: 12 month(s)

4.5 维护/经常性活动

4.6 维护/经常性活动所需要的费用和投入（每年）

4.7 影响成本的最重要因素

描述影响成本的最决定性因素:

Prices of the material and equipment; the approval procedure and disbursement process of the project of “Dredging and expanding Sen Pond”; the compensation cost for the farmers; the cost of operating and maintaining temporary pump; the cost of reinforcing the drainage canals.

5.1 气候

5.2 地形

5.3 土壤

5.4 水资源可用性和质量

5.5 生物多样性

5.6 应用该技术的土地使用者的特征

说明土地使用者的其他有关特征:

Land users applying the Technology are mainly common / average land users
Population density: > 500 persons/km2
Annual population growth: 1% - 2%
1% of the land users are very rich and own 3% of the land.
2% of the land users are rich and own 7% of the land.
70% of the land users are average wealthy and own 60% of the land.
25% of the land users are poor and own 20% of the land.
2% of the land users are poor and own 10% of the land.
Off-farm income specification: There is a large industrial park located near the study site and a large part of the working population in the region is earning income by working in the factories.

5.7 应用该技术的土地使用者使用的平均土地面积

5.8 土地所有权、土地使用权和水使用权

土地所有权:

• 州

• farmer, individual

用水权:

• 自由进入（无组织）

• farmer, individual

5.9 进入服务和基础设施的通道

6.1 该技术的现场影响

社会经济效应

生产

水资源可用性和质量

其它社会经济效应

社会文化影响

生态影响

水循环/径流

土壤

其它生态影响

6.3 技术对渐变气候以及与气候相关的极端情况/灾害的暴露和敏感性（土地使用者认为的极端情况/灾害）

渐变气候

渐变气候

气候有关的极端情况（灾害）

气象灾害

气候灾害

水文灾害

其他气候相关的后果

其他气候相关的后果

6.4 成本效益分析

技术收益与技术建立成本相比如何（从土地使用者的角度看）？

技术收益与技术维护成本/经常性成本相比如何（从土地使用者的角度看）？

6.5 技术采用

在所有采用这项技术的人当中，有多少人是自发的，即未获得任何物质奖励/付款？:

• 51-90%

注释:

By applying the technology, the potential reuse area of return flow is estimated about 33% of the study area (30.4ha of agricultural area is potentially irrigated by return flow). However, estimating the number of land user families that have implemented the technology is not the initial aim of the study. Therefore, it requires further detailed investigation and social survey as well.

6.7 该技术的优点/长处/机会

6.8 技术的弱点/缺点/风险及其克服方法

7.1 信息的方法/来源

7.2 参考可用出版物

标题、作者、年份、ISBN:

Kim, H. K. et al. (2009) Estimation of irrigation return flow from paddy fields considering the soil moisture

可以从哪里获得?成本如何?

Agricultural Water Management, 96(5), 875–882.

标题、作者、年份、ISBN:

Phil King (2008) Return Flow Efficiency

可以从哪里获得?成本如何?

New Mexico Water Resources Research Institute

标题、作者、年份、ISBN:

Simons, G.W.H. et al. (2015) Water reuse in river basins with multiple users: A literature review

可以从哪里获得?成本如何?

Journal of Hydrology. 558–571

标题、作者、年份、ISBN:

Ribbe et al. (2011) Annex 2 to Milestone Report 2011 - Description of the Study Region including an updated stakeholder analysis,

可以从哪里获得?成本如何?

LUCCi project. ITT, Cologne University of Applied Sciences