A landscape view of stoneline technology constructed along a contour line in Lower Mbeere South District, Kenya (Paul Kahiga (8444-00300 Nairobi))

Stonelines (肯尼亚)

Miraini ya maviga

描述

Stonelines are constructed along the contours to slow down the speed of runoff, filter the soil and enhance water infiltration.

In Kenya stone lines are mostly practiced in areas that receive 200-750 mm of annual rainfall with a spacing of 15-30 m between them. They are particularly common in areas where rocks are readily available, such as Mbeere, Laikipia, Baringo, Mwingi, Kitui and Tharaka. Since the stonelines are permeable they do not pond runoff water but instead, they slow down the speed, filter it and spread the water over the field, thus enhancing water infiltration and reducing soil erosion. They are built in series running along the slope. In addition, the stone barrier blocks and settles down the sediments transported from the upper slopes.

Purpose of the Technology: They are often used to rehabilitate eroded and abandoned land. The advantages of stonelines include; slowing down the runoff thereby increasing infiltration and soil moisture. They also induce a natural process of terracing, reducing erosion and rehabilitation of eroded lands by trapping silt. They are easy to design and construct and since the stone line structure is permeable there is no need for construction of spillways to drain the excess runoff water. When it rains, the soil builds up on the upslope side of the stonelines and over time a natural terrace is formed.

Establishment / maintenance activities and inputs: The stonelines are spaced 15-30 m apart, a shorter distance being used for the steeper slopes. Stonelines are normally suitable on gentle slopes. Slopes above 35% should be avoided. They are established in the following manner: first, the contour line are marked out with the help of a tube level or line levels. In this region here, it is done with the help of the frontline agricultural extension officers. Secondly, a shallow foundation trench is dug across the slope (5-10 cm to 30 cm deep) using basic farm equipments (jembes or hoes). As shown on the above photographs, the larger stones are put on the down slope side of the trench while the smaller stones are used to build the rest of the bund. The smallest stones are used to fill the gaps and increase the heights of the bunds up to the desired level. Farmers plant fruit trees (pawpaws) as show in the photograph above on the upper part. The trees utilises the moisture and rich sediments deposited on the upper part. The stonelines can be reinforced with earth, or crop residues to make them more stable. Maintenance of stonelines is done by repairing the already damaged /fallen stoneline that may have been knocked down or disarranged by livestock or by human beings. In this case animal access needs to be limited and/or the bund should be laid out in a way that allows the animals to pass through.

Natural / human environment: In the lower Mbeere South District where the stoneline technologies is largely practiced, unless there are stones in the individual farms, it might be difficult to import stones from other farms as the exercise can be labor intensive. In this catchment, the Ministry of Agriculture through the front line extension officers has taken a lead role in encouraging farmers to adopt the technology especially the farms which have many stones. Most of the farmers who have implemented this technology in the Lower Mbeere South District learn from the ones who are already practicing through field days or individual initiatives.

地点

地点: Mbeere South District, Eastern Province, 肯尼亚

分析的技术场所数量:

选定地点的地理参考
  • 37.73636, -0.6751

技术传播: 均匀地分布在一个区域 (approx. < 0.1 平方千米(10 公顷))

在永久保护区?:

实施日期: 10-50年前

介绍类型
Farmers constructing a stoneline technology along a contour line in the Lower Mbeere South District (Paul Kahiga (8444-00300 Nairobi))

技术分类

主要目的
  • 改良生产
  • 减少、预防、恢复土地退化
  • 保护生态系统
  • 结合其他技术保护流域/下游区域
  • 保持/提高生物多样性
  • 降低灾害风险
  • 适应气候变化/极端天气及其影响
  • 减缓气候变化及其影响
  • 创造有益的经济影响
  • 创造有益的社会影响
土地利用

  • 农田
    • 一年一作: 谷物类 - 玉米, 谷类 - 小米, 谷类 - 高粱, 豆科牧草和豆类 - 豌豆
    • 多年一作(非木材)
    • 乔木与灌木的种植: 芒果、山竹果、番石榴, 仁果类(苹果、梨子、柑橘等)
    每年的生长季节数: 2

供水
  • 雨养
  • 混合雨水灌溉
  • 充分灌溉

土地退化相关的目的
  • 防止土地退化
  • 减少土地退化
  • 修复/恢复严重退化的土地
  • 适应土地退化
  • 不适用
解决的退化问题
  • 土壤水蚀 - Wt:表土流失/地表侵蚀
SLM组
  • 引水和排水
SLM措施
  • 结构措施 - S2:堤、岸

技术图纸

技术规范
This is a technical drawing representing a cross-section view of how the stonelines are constructed by the emerging farmers in the lower Mbeere South District.

First, a small trench is dug along an established contour line, the farmer starts arranging the stones with reference to their sizes. The bigger ones are arranged on the lower side and the small ones on the upper side as shown on the technical drawing.

By so doing, the eroded soils are trapped on the upper side by the small pebbles, allowing the water to pass through at lower speed hence low erosive capacity.

Location: Ntharawe. Lower Mbeere South District

Date: 2011-08-02

Technical knowledge required for field staff / advisors: moderate (In order to implement this technology, the farmers contact the front line agricultural extension officer in order to assist in making the contours.)

Technical knowledge required for land users: high (Stone required placement of a certain order. Big stone on the lower side and small stones on the upper side-Vertically)

Main technical functions: water spreading, sediment retention / trapping, sediment harvesting

Secondary technical functions: reduction of slope angle

Bund/ bank: graded
Spacing between structures (m): 15
Height of bunds/banks/others (m): 0.8
Width of bunds/banks/others (m): 1.2
Length of bunds/banks/others (m): 27.6

Slope (which determines the spacing indicated above): 8%

Lateral gradient along the structure: 8%
Author: W.Nguru, P.O.Box 12776-00100 Nairobi

技术建立与维护:活动、投入和费用

投入和成本的计算
  • 计算的成本为:每个技术单元 (单位:Stonelines)
  • 成本计算使用的货币:Kshs
  • 汇率(换算为美元):1 美元 = 80.0 Kshs
  • 雇用劳工的每日平均工资成本:2.50
影响成本的最重要因素
The system is labour intensive and hence will affect the cost of constructing the stonelines. However, availability of farm equipments like wheelbarrows, mattocks or oxen will help reduce the total cost and time required for construction and maintaining the stonelines. On steep slopes, the spacing between the lines is small as compared to a relatively gentle slope.
技术建立活动
  1. Establish a contour line and dig up a trench upon which the stones will be arranged (时间/频率: yearly)
  2. stones are collected and arranged along the established trench. The big boulders are reduced to the required sizes by the use of mattocks (时间/频率: once)
  3. The big stones are arranged on the lower side and the rest follows with respect to their sizes on the upper side (时间/频率: None)
  4. This formation is done per meter length. Mostly is charged 150Kshs per meter. (时间/频率: None)
技术建立的投入和成本 (per Stonelines)
对投入进行具体说明 单位 数量 单位成本 (Kshs) 每项投入的总成本 (Kshs) 土地使用者承担的成本%
劳动力
Establish a contour line Persons/day 0.5 3.76 1.88 100.0
Reduce stone size Persons/day 0.5 3.76 1.88 100.0
Arranging stones Persons/day 0.5 3.76 1.88 100.0
设备
Mattock pieces 1.0 18.75 18.75 100.0
Wheelbarrow pieces 1.0 20.0 20.0 100.0
施工材料
Stone no 1.0 1.88 1.88 100.0
技术建立所需总成本 46.27
技术建立总成本,美元 0.58
技术维护活动
  1. Repair/Rearrange stone on stone line after a rainy seasons or when people and animals have destroyed the stone line. (时间/频率: yearly during dry season)
技术维护的投入和成本 (per Stonelines)
对投入进行具体说明 单位 数量 单位成本 (Kshs) 每项投入的总成本 (Kshs) 土地使用者承担的成本%
劳动力
Repair/Rearrange stone mandays/acre 14.0 2.5 35.0 100.0
技术维护所需总成本 35.0
技术维护总成本,美元 0.44

自然环境

年平均降雨量
  • < 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
农业气候带
  • 潮湿的
  • 半湿润
  • 半干旱
  • 干旱
关于气候的规范
Annual rainfall: Also < 250 mm
Thermal climate class: tropics
斜坡
  • 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
海拔
  • 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.
......应用的技术
  • 凸形情况
  • 凹陷情况
  • 不相关
土壤深度
  • 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)
  • 中粒(壤土、粉土)
  • 细粒/重质(粘土)
土壤质地(地表以下>20厘米)
  • 粗粒/轻(砂质)
  • 中粒(壤土、粉土)
  • 细粒/重质(粘土)
表土有机质含量
  • 高(>3%)
  • 中(1-3%)
  • 低(<1%)
地下水位
  • 表面上
  • < 5米
  • 5-50米
  • > 50米
地表水的可用性
  • 过量
  • 中等
  • 匮乏/没有
水质(未处理)
  • 良好饮用水
  • 不良饮用水(需要处理)
  • 仅供农业使用(灌溉)
  • 不可用
水质请参考:
盐度是个问题吗?

洪水发生
物种多样性
  • 中等
栖息地多样性
  • 中等

应用该技术的土地使用者的特征

市场定位
  • 生计(自给)
  • 混合(生计/商业)
  • 商业/市场
非农收入
  • 低于全部收入的10%
  • 收入的10-50%
  • > 收入的50%
相对财富水平
  • 非常贫瘠
  • 贫瘠
  • 平均水平
  • 丰富
  • 非常丰富
机械化水平
  • 手工作业
  • 畜力牵引
  • 机械化/电动
定栖或游牧
  • 定栖的
  • 半游牧的
  • 游牧的
个人或集体
  • 个人/家庭
  • 团体/社区
  • 合作社
  • 员工(公司、政府)
性别
  • 女人
  • 男人
年龄
  • 儿童
  • 青年人
  • 中年人
  • 老年人
每户使用面积
  • < 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
规模
  • 小规模的
  • 中等规模的
  • 大规模的
土地所有权
  • 公司
  • 社区/村庄
  • 团体
  • 个人,未命名
  • 个人,有命名
土地使用权
  • 自由进入(无组织)
  • 社区(有组织)
  • 租赁
  • 个人
用水权
  • 自由进入(无组织)
  • 社区(有组织)
  • 租赁
  • 个人
进入服务和基础设施的通道
健康

贫瘠
教育

贫瘠
技术援助

贫瘠
就业(例如非农)

贫瘠
市场

贫瘠
能源

贫瘠
道路和交通

贫瘠
饮用水和卫生设施

贫瘠
金融服务

贫瘠

影响

社会经济影响
作物生产
降低
增加

生产故障风险
增加
降低

生产区域(耕种/使用中的新土地)
降低
增加

土地管理
妨碍
简化


Such that it hinders mechanisation tractors cannot operate due to the stone line arragement

工作量
增加
降低


The operation is labour intensive

Livelihood and human well-being
reduced
improved


Increased food security (the yield near the stoneline is better as compared to the situation that it was before implementation).

社会文化影响
SLM/土地退化知识
减少
改良

社会经济弱势群体的情况(性别、年龄、地位、种族等)
恶化
改良

生态影响
土壤水分
降低
增加

土壤流失
增加
降低

害虫/疾病控制
降低
增加


Snakes and scorpions

洪水影响
增加
降低

场外影响
下游洪水(不希望)
增加
减少

缓冲/过滤能力(按土壤、植被、湿地划分)
减少
改良

成本效益分析

与技术建立成本相比的效益
短期回报
非常消极
非常积极

长期回报
非常消极
非常积极

与技术维护成本相比的效益
短期回报
非常消极
非常积极

长期回报
非常消极
非常积极

气候变化

渐变气候
年温度 增加

非常不好
非常好
气候有关的极端情况(灾害)
局地暴雨

非常不好
非常好
局地风暴

非常不好
非常好
干旱

非常不好
非常好
比较和缓的(河道)洪水

非常不好
非常好

采用和适应

采用该技术的地区内土地使用者的百分比
  • 单例/实验
  • 1-10%
  • 11-50%
  • > 50%
在所有采用这种技术的人当中,有多少人在没有获得物质奖励的情况下采用了这种技术?
  • 0-10%
  • 11-50%
  • 51-90%
  • 91-100%
最近是否对该技术进行了修改以适应不断变化的条件?
什么样的变化条件?
  • 气候变化/极端气候
  • 不断变化的市场
  • 劳动力可用性(例如,由于迁移)

结论和吸取的教训

长处: 土地使用者的观点
  • By concentrating the stones along a contour, the farmer is able to make use of the land which otherwise is not possible if the stones are scatered.

    How can they be sustained / enhanced? Farmers should be encouraged to learn from one another but they should also seek advice from extension officers in making the contours.
  • The cost of replacement of farm equipments (jembes, forks and pangas) is reduced since they aren't broken by stones during land preparation.
长处: 编制者或其他关键资源人员的观点
  • The stones for constructing the technology are readily available in most of the farms.

    How can they be sustained / enhanced? Encouraging farmers to use the available stones to put up the technology.
  • Stoneline technology prevents soil loss due to erosion.

    How can they be sustained / enhanced? Modification of the technology to allow more infiltration.
  • No high level technical knowledge is required for construction of stoneline technology.

    How can they be sustained / enhanced? More farmers should be encouraged to adopt the technology since they dont need a high level of technical knowledge.
  • Stone lines technology can be modified to prevent soil and water from running off on the side of stone line ridge.

    How can they be sustained / enhanced? Construction of side ridges.
弱点/缺点/风险: 土地使用者的观点如何克服
  • Contour profiling is challenging. Assistance from the front line agricultural extension officers.
弱点/缺点/风险: 编制者或其他关键资源人员的观点如何克服
  • Labour intensive. When constructing, always move the stones downslope by gravity instead of moving upwards i.e. start from the contours from the upper side
  • The technology only allows the soil to deposit on the upper side of the stoneline but water passes through. Proper arrangement of the stones should be enhanced basing on their sizes.
  • Increased habitats for snakes and other dangerous creatures like scorpions that hide on the stonelines. Where there creatures are prone, the farmers should be careful.

参考文献

编制者
  • Paul Kahiga
Editors
审查者
  • David Streiff
  • Alexandra Gavilano
实施日期: June 13, 2013
上次更新: June 7, 2019
资源人
WOCAT数据库中的完整描述
链接的SLM数据
文件编制者
机构 项目
主要参考文献
  • Thomas, D.B. (eds) 1997. Soil and Water Conservation Manual for Kenya. Soil and Water Conservation Branch. Ministry of Agriculture, Livestock Development and Marketing. 210 p.:
  • Critchley W and Seigert K (1991) Water Harvesting. FAO:
This work is licensed under Creative Commons Attribution-NonCommercial-ShareaAlike 4.0 International