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Infiltration ditches and ponding banks [纳米比亚]

Ovala

technologies_2989 - 纳米比亚

完整性: 96%

1. 一般信息

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

关键资源人

土地使用者:

Kahl Uwe

+264 67 290004 / +264811486666

uwe2008@iway.na

Farm Middelplaats

P.O. Box 213 Otjiwarongo

纳米比亚

SLM专业人员:
SLM专业人员:

Pringle Hugh

+61 418415269

hpringle1@bigpond.com

Ecosystem Management Understanding

P.O. Box 8522 Alice Springs NT 0871

澳大利亚

有助于对技术进行记录/评估的项目名称(如相关)
Southern African Science Service Centre for climate change and Adaptive Land management (SASSCAL)
有助于对技术进行记录/评估的机构名称(如相关)
Namibia University of Science and Technology ( NUST) - 纳米比亚
有助于对技术进行记录/评估的机构名称(如相关)
German Federal Ministry of Education and Research (BMBF) - 德国

1.3 关于使用通过WOCAT记录的数据的条件

(现场)数据是什么时候汇编的?:

2017

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。:

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?:

1.5 请参阅有关SLM方法的问卷

2. SLM技术的说明

2.1 技术简介

技术定义:

Construction of contour ditches and ponding banks to trap and infiltrate rainwater for improved growth of plants and replenishment of ground water, while gently spilling any excess water safely over wide areas to avoid erosion during intense rain. It must be integrated with other technologies that treat the root causes of rangeland degradation rather than used as a stand-alone technology to treat symptoms.

2.2 技术的详细说明

说明:

The technology is applied in rangeland where runoff occurs during and soon after rain, where the soil is deep enough to dig contour ditches and construct ponding banks, where there is sufficient gentle slope over a wide enough area for safely spilling excess water during intense rain, where valuable plants can establish themselves or be grown to benefit from the extra infiltrated rainwater, where the costs of earthmoving can soon be recovered through sale of extra production from the valuable plants and, most importantly, where the root causes of rangeland degradation have been addressed, usually through management of grazing and fires. At the appropriate area, contour lines are marked out by any available technology such as laser or dumpy level or mapped by drone. Where bushes grow densely, it may be necessary to clear narrow contour strips while leaving larger trees in place. Ditches can be dug to any depth down to approximately 50cm by mechanised grader or backhoe (a loader or digger attached to a tractor), or manually by pick and spade. The soil should ideally first be ripped where dug soil for the bund will be heaped, to ensure a firm foundation for the heaped soil to form a bund. To stabilise the bund, it should be compacted and creeping herbaceous plants should be encouraged to grow on it. Where water is to be spilled if ditches are full, either less soil needs to be heaped there or, if the ditch is deep enough, the natural ground surface can serve as spillway by avoiding to heap soil on it. In situations where excess water can safely be spilled from outward curves of the down-slope side of a long ditch, the dug soil can be placed as a bund below the long sections of ditch where water does not need to spill. In situations where excess water should rather be spilled evenly over the whole length of ditch, then either a second ditch can be graded below the first ditch, with the dug soil heaped upslope, or all of the dug soil needs to be moved and put to use elsewhere. Such soil could be used for building humps to divert flowing water out of tracks and back into natural flow paths, or to construct banks that divert water flowing down shallow gullies into contour ditches. Since it is almost impossible to dig exactly on contour, water starts to spill over the slightly lower edges of the ditch before the volume of water flow increases sufficiently to spill over the whole edge of the ditch. This results in self reinforcement over successive rainfall periods because herbaceous plants grow more densely at the slightly lower edges due to the greater amount of water that previously spilled there, resulting in more sediment being trapped there and consequent raising of the soil level, also by puffing up of the soil from their root growth and exudates which feed soil organisms. Eventually the previously lower sections are raised higher than other sections of the ditch edge, where subsequent spills wet the soil more for denser plant growth, and this slow self-reinforcing effect continues indefinitely. To avoid spillage over the end of each ditch, a short upward curve is built in when digging the ditch and heaping the bund. Organic material can also be placed in the ditch, or in larger settling ponds along the ditch, to improve nutrient cycling. Infiltration ditches were constructed at intervals of 0.5m height on a 30ha densely bushed portion of Farm Middleplaats and trees were planted below the ditches to grow into a fruitful landscape. Species included large canopy trees such as Faidherbia albida and Acacia erioloba, shorter thornless trees for “chop and drop” mulching, such as Peltophorum africanum and Bolusanthus speciosus, and trees that produce fruits, such as Sclerocarya birrea and Berchemia discolor, or edible leaves, such as Moringa oleifera. The tree seedlings were raised in a nursery on the farm, and he fence around the 30ha had to be strengthened to protect the planted seedlings from oryx. In addition, it was necessary to water the seedlings in the landscape for the first year or two until well established, On another portion of the farm where bushes had previously been cleared and the soil was consequently less fertile, ponding banks of approximately 1m height were constructed, especially in locations where it appeared that water had ponded naturally in the past. The ponded water encourages growth of herbaceous plants, especially where soil is scraped from below the bank so that the soil on its upper side remains undisturbed. A few grasses were dug from a wetland and brought to the farm for later transplanting of propagules into the ponded areas.

2.3 技术照片

2.4 技术视频

注释、简短说明:

https://www.youtube.com/watch?v=6C4V_Cib8ts
Only a short section in the film from 18m07s to 19m15s

日期:

08/04/2015

位置:

Farm Middelplaats and KAYEC campus, both in Namibia

摄影师的名字:

Andrew Botelle

2.5 已应用该技术的、本评估所涵盖的国家/地区/地点

国家:

纳米比亚

区域/州/省:

Otjozondjupa and Khomas Retions

2.6 实施日期

注明实施年份:

2014

2.7 技术介绍

详细说明该技术是如何引入的:
  • 通过项目/外部干预
注释(项目类型等):

Projects involving students

3. SLM技术的分类

3.1 该技术的主要目的

  • 改良生产
  • 减少、预防、恢复土地退化
  • 保持/提高生物多样性
  • 创造有益的经济影响

3.2 应用该技术的当前土地利用类型

牧场

牧场

粗放式放牧场:
  • 经营牧场
主要动物种类及产品:

Beef cattle and game animals

3.3 有关土地利用的更多信息

该技术所应用土地的供水:
  • 雨养
注释:

Except for Initial watering of planted tree seedlings, which was necessitated by drought

每年的生长季节数:
  • 1
牲畜密度(如相关):

10ha/LSU averaged out over time and not continuous

3.4 该技术所属的SLM组

  • 农业林学
  • 畜牧业和牧场管理
  • 集水

3.5 技术传播

具体说明该技术的分布:
  • 均匀地分布在一个区域
如果该技术均匀地分布在一个区域上,请注明覆盖的大致区域。:
  • 0.1-1 平方千米

3.6 包含该技术的可持续土地管理措施

植物措施

植物措施

  • V1:乔木和灌木覆盖层
  • V2:草和多年生草本植物
  • V3:植被的清理
结构措施

结构措施

  • S2:堤、岸
  • S4:平沟、坑
管理措施

管理措施

  • M2:改变管理/强度级别
  • M5:物种组成的控制/变化

3.7 该技术强调的主要土地退化类型

土壤水蚀

土壤水蚀

  • Wt:表土流失/地表侵蚀
  • Wg:冲沟侵蚀/沟蚀
水质恶化

水质恶化

  • Hg:地下水/含水层水位的变化

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:
  • 防止土地退化
  • 修复/恢复严重退化的土地

4. 技术规范、实施活动、投入和成本

4.1 该技术的技术图纸

作者:

Ibo Zimmermann

日期:

21/07/2017

4.2 技术规范/技术图纸说明

Contour strips were cleared by bulldozer at 0.5m height intervals on land with a gradient of approximately 1:100. A line was ripped approximately 0.6m deep, over which soil was heaped for a bund by a grader when digging a ditch on its upper side to hold rainwater at a depth of approximately 0.5m. The ends were hooked upwards by approximately 2m to avoid spillage there, while spillways were created by lowering a 10m length of the bund and staggered between ditches to zig-zag the spilled water slowly down the landscape. A variety of tree seedlings were planted below ditches to provide tall canopies, chop-and-drop mulching and edible leaves or fruits, at intervals of approximately 5m.

4.3 有关投入和成本计算的一般信息

具体说明成本和投入是如何计算的:
  • 每个技术区域
注明尺寸和面积单位:

30ha (contour ditches only)

其它/国家货币(具体说明):

NAD

注明雇用劳工的每日平均工资成本:

72 NAD

4.4 技术建立活动

活动 措施类型 时间
1. Marking of contour lines 结构性的 Dry season
2. Clearing of bush strips along contour 结构性的 Dry season
3. Ripping along contour 结构性的 Dry season
4. Digging ditch and heaping bund over ripline 结构性的 Start of rains
5. Raising tree seedlings in nursery 植物性的 Mostly dry season
6. Planting tree seedlings below ditches 植物性的 Rainy season
7. Watering tree seedlings 植物性的 Dry season
8. Strengthening fence around landscape to exclude oryx 结构性的 When needed

4.5 技术建立所需要的费用和投入

对投入进行具体说明 单位 数量 单位成本 每项投入的总成本 土地使用者承担的成本%
劳动力 Marking of contour lines Person days 6.0 72.0 432.0 100.0
劳动力 Raising tree seedlings in nursery Person days 20.0 72.0 1440.0 100.0
劳动力 Planting tree seedlings below ditches Person days 10.0 72.0 720.0 100.0
劳动力 Watering every 10 days in first year, except after rain Person days 150.0 72.0 10800.0 100.0
设备 Strengthening fence to exclude oryx (Labour) Person days 100.0 72.0 7200.0 100.0
设备 Bulldozer to clear strips and rip Bulldozer hours 89.0 850.0 75650.0 100.0
设备 Grader to dig ditches and heap bunds Grader hours 35.0 650.0 22750.0 100.0
设备 Diesel for bulldozer and grader Litres 1000.0 12.0 12000.0 100.0
设备 Tractor & 7000 lt water trailer every 10 days in first year, except after rain Tractor days 30.0 1250.0 37500.0 100.0
植物材料 500 Plastic bags / seeds with soil to raise seedllngs Filled growing bags 500.0 4.0 2000.0 100.0
施工材料 Fencing wire and posts to strengthen fence around fruitful landscape km of fencing 3.0 2200.0 6600.0 100.0
技术建立所需总成本 177092.0

4.6 维护/经常性活动

活动 措施类型 时间/频率
1. Maintenance of ditches and bunds by grader 结构性的 Rainy season

4.7 维护/经常性活动所需要的费用和投入(每年)

对投入进行具体说明 单位 数量 单位成本 每项投入的总成本 土地使用者承担的成本%
设备 Grader cost to maintain the swales every 3 – 4 years Grader hours 8.0 700.0 5600.0 100.0
技术维护所需总成本 5600.0

4.8 影响成本的最重要因素

描述影响成本的最决定性因素:

High cost of hiring or operating earthmoving machinery

5. 自然和人文环境

5.1 气候

年降雨量
  • < 250毫米
  • 251-500毫米
  • 501-750毫米
  • 751-1,000毫米
  • 1,001-1,500毫米
  • 1,501-2,000毫米
  • 2,001-3,000毫米
  • 3,001-4,000毫米
  • > 4,000毫米
有关降雨的规范/注释:

A single summer rainfall period over approximately four months per year

注明所考虑的参考气象站名称:

Otjiwarongo

农业气候带
  • 半干旱

5.2 地形

平均坡度:
  • 水平(0-2%)
  • 缓降(3-5%)
  • 平缓(6-10%)
  • 滚坡(11-15%)
  • 崎岖(16-30%)
  • 陡峭(31-60%)
  • 非常陡峭(>60%)
地形:
  • 高原/平原
  • 山脊
  • 山坡
  • 山地斜坡
  • 麓坡
  • 谷底
垂直分布带:
  • 0-100 m a.s.l.
  • 101-500 m a.s.l.
  • 501-1,000 m a.s.l.
  • 1,001-1,500 m a.s.l.
  • 1,501-2,000 m a.s.l.
  • 2,001-2,500 m a.s.l.
  • 2,501-3,000 m a.s.l.
  • 3,001-4,000 m a.s.l.
  • > 4,000 m a.s.l.
说明该技术是否专门应用于:
  • 不相关
关于地形的注释和进一步规范:

Scattered rocky outcrops

5.3 土壤

平均土层深度:
  • 非常浅(0-20厘米)
  • 浅(21-50厘米)
  • 中等深度(51-80厘米)
  • 深(81-120厘米)
  • 非常深(> 120厘米)
土壤质地(表土):
  • 粗粒/轻(砂质)
土壤质地(地表以下> 20厘米):
  • 粗粒/轻(砂质)
表土有机质:
  • 低(<1%)
如有可能,附上完整的土壤描述或具体说明可用的信息,例如土壤类型、土壤酸碱度、阳离子交换能力、氮、盐度等。:

A calcrete layer is occasionally exposed at the soil surfacce

5.4 水资源可用性和质量

地下水位表:

5-50米

地表水的可用性:

匮乏/没有

水质(未处理):

不良饮用水(需要处理)

水的盐度有问题吗?:

具体说明:

The water is only slightly brackish

该区域正在发生洪水吗?:

5.5 生物多样性

物种多样性:
  • 中等
栖息地多样性:
  • 中等

5.6 应用该技术的土地使用者的特征

定栖或游牧:
  • 定栖的
生产系统的市场定位:
  • 商业/市场
非农收入:
  • 收入的10-50%
相对财富水平:
  • 平均水平
个人或集体:
  • 个人/家庭
机械化水平:
  • 手工作业
  • 机械化/电动
性别:
  • 女人
  • 男人
土地使用者的年龄:
  • 中年人

5.7 应用该技术的土地使用者拥有或租用的平均土地面积

  • < 0.5 公顷
  • 0.5-1 公顷
  • 1-2 公顷
  • 2-5公顷
  • 5-15公顷
  • 15-50公顷
  • 50-100公顷
  • 100-500公顷
  • 500-1,000公顷
  • 1,000-10,000公顷
  • > 10,000公顷
这被认为是小规模、中规模还是大规模的(参照当地实际情况)?:
  • 大规模的

5.8 土地所有权、土地使用权和水使用权

土地所有权:
  • 个人,有命名
土地使用权:
  • 个人
用水权:
  • 个人

5.9 进入服务和基础设施的通道

健康:
  • 贫瘠
  • 适度的
教育:
  • 贫瘠
  • 适度的
技术援助:
  • 贫瘠
  • 适度的
就业(例如非农):
  • 贫瘠
  • 适度的
市场:
  • 贫瘠
  • 适度的
能源:
  • 贫瘠
  • 适度的
道路和交通:
  • 贫瘠
  • 适度的
饮用水和卫生设施:
  • 贫瘠
  • 适度的
金融服务:
  • 贫瘠
  • 适度的

6. 影响和结论性说明

6.1 该技术的现场影响

社会经济效应

生产

饲料生产

降低
增加
注释/具体说明:

Mainly Moringa oleifera

饲料质量

降低
增加
注释/具体说明:

Moringa leaves

畜牧生产

降低
增加
注释/具体说明:

Moringa heavily browsed

非木材林业生产

降低
增加
注释/具体说明:

Still saplings

产品多样性

降低
增加
注释/具体说明:

Moringa leaves and fruits of other species could be harvested

水资源可用性和质量

家畜用水的可用性

降低
增加
注释/具体说明:

Livestock need less water after feeding on lush forage

收入和成本

农业投入费用

增加
降低
注释/具体说明:

High initial cost of earthmoving

收入来源的多样性

降低
增加
注释/具体说明:

Potential from Moringa

工作量

增加
降低
注释/具体说明:

To water saplings

社会文化影响

食品安全/自给自足

减少
改良
注释/具体说明:

Nutritious Moringa leaves may be added to diets

健康状况

恶化
改良
注释/具体说明:

If nutritious Moringa leaves are eaten

SLM/土地退化知识

减少
改良
注释/具体说明:

Learning from action research

生态影响

水循环/径流

地表径流

增加
降低
注释/具体说明:

Slowed, spread and infiltrated by ditches and ponds

地下水位/含水层

下降
补水
注释/具体说明:

From improved infiltration

土壤

土壤水分

降低
增加
注释/具体说明:

Near ditches and banks

土壤覆盖层

减少
改良
注释/具体说明:

In ditches and ponds

养分循环/补给

降低
增加
注释/具体说明:

Below ditches and ponds

土壤有机物/地下C

降低
增加
注释/具体说明:

Through tree and grass roots

生物多样性:植被、动物

植被覆盖

降低
增加
注释/具体说明:

In ditches and ponds

生物量/地上C

降低
增加
注释/具体说明:

In ditches and ponds

植物多样性

降低
增加
注释/具体说明:

In ditches and ponds

栖息地多样性

降低
增加
注释/具体说明:

Along ditches and ponds

减少气候和灾害风险

干旱影响

增加
降低
注释/具体说明:

Along ditches and ponds

火灾风险

增加
降低
注释/具体说明:

Along ditches and ponds, due to increased grass

6.2 该技术的场外影响已经显现

下游洪水

增加
减少
注释/具体说明:

Through improved infiltration on the farm

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
季节 气候变化/极端天气的类型 该技术是如何应对的?
其他渐变气候 Increased variability in temperature and rainfall 增加

气候有关的极端情况(灾害)

气象灾害
该技术是如何应对的?
局地暴雨
局地雷暴
气候灾害
该技术是如何应对的?
热浪
寒潮
干旱
陆地火灾 适度
水文灾害
该技术是如何应对的?
山洪暴发
生物灾害
该技术是如何应对的?
昆虫/蠕虫侵扰

其他气候相关的后果

其他气候相关的后果
该技术是如何应对的?
缩短生长期

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)?
短期回报:

消极

长期回报:

积极

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)?
短期回报:

轻度消极

长期回报:

积极

6.5 技术采用

  • 单例/实验
在所有采用这项技术的人当中,有多少人是自发地采用该技术,即未获得任何物质奖励/付款?:
  • 0-10%

6.6 适应

最近是否对该技术进行了修改以适应不断变化的条件?:

若是,说明它适应了哪些变化的条件:
  • 气候变化/极端气候
具体说明技术的适应性(设计、材料/品种等):

After noticing death of tree seedlings from extreme drought, the decision was taken to irrigate them until sufficiently well established to care for themselves.

6.7 该技术的优点/长处/机会

土地使用者眼中的长处/优势/机会
Avoids wastage of rainwater lost as runoff from the farm and puts it to good use on the farm.
编制者或其他关键资源人员认为的长处/优势/机会
Improved water and nutrient cycling, resulting in better plant growth and higher animal production.
Reduced erosion of soil

6.8 技术的弱点/缺点/风险及其克服方法

土地使用者认为的弱点/缺点/风险 如何克服它们?
Death of many tree seedlings By irrigating tree seedlings until they are sufficiently well established to care for themselves, which may take one or two years.
编制者或其他关键资源人员认为的弱点/缺点/风险 如何克服它们?
High cost of earthmoving Growing of high value plants to recoup costs as quickly as possible, such as Moringa and dates.

7. 参考和链接

7.1 信息的方法/来源

  • 实地考察、实地调查
  • 与土地使用者的访谈

7.2 参考可用出版物

标题、作者、年份、ISBN:

Rainwater harvesting for drylands and beyond: Vol 2 – Water-harvesting earthworks, Lancaster, 0-977-246418

可以从哪里获得?成本如何?

https://www.amazon.com/Rainwater-Harvesting-Drylands-Beyond-Vol/dp/0977246418 $28

7.3 链接到网络上可用的相关信息

标题/说明:

Planning and managing farm roads Manual

URL:

www.sasscal.org/downloads/Planning_and_managing_farm_roads_in_Namibia.pdf

标题/说明:

Rangeland Rehydration Field Guide

URL:

https://emulandrecovery.org.au/~emulandr/files/Rangeland-Rehydration-Field-Guide.pdf

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