技术

Afforestation and Hillside Terracing [厄立特里亚]

technologies_1330 - 厄立特里亚

完整性: 69%

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

SLM专业人员:
SLM专业人员:

Bereket Tsehaye

Toker Integrated Community Development

厄立特里亚

有助于对技术进行记录/评估的项目名称(如相关)
Book project: SLM in Practice - Guidelines and Best Practices for Sub-Saharan Africa (SLM in Practice)
有助于对技术进行记录/评估的机构名称(如相关)
Toker Integrated Community Development - 厄立特里亚
有助于对技术进行记录/评估的机构名称(如相关)
Ministry of Agriculture of Eritrea (Ministry of Agriculture of Eritrea) - 厄立特里亚

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。:

2. SLM技术的说明

2.1 技术简介

技术定义:

Tree plantations in combination with hillside terracing to protect upper catchment areas are a widespread technology in the Central and Northern Highland Zone of Eritrea.

2.2 技术的详细说明

说明:

In the early 1990s a large area was treated in the Toker catchment, northwest of Asmara. The first step was to establish hillside terraces on the steeper slopes where it is essential to conserve soil and water for improved growth of trees and other vegetation. The terraces comprise earthen embankments laid out along the along the contour, reinforced with stone risers, combined with a trench on the upper side to harvest runoff water. The trenches are subdivided into basins (by ties) to avoid lateral flow of runoff water. In a second step, trees were planted at a spacing of 2 m (in the trenches). Mostly fast growing eucalyptus was used, with a very small percentage of the indigenous African olive (Olea africana) - which has good survival rates but grows very slowly. Afforested areas are closed for any use until the trees reach maturity: they are protected by guards. In 1995 the Ministry of Agriculture handed over user rights to communities allowing cut-and-carry of grass and cutting of trees (with permission of the government). The technology requires appreciable expense, labor and expertise, but if maintained well, it results in multiple ecological and economic benefits: Soil cover has improved, water is conserved, the severe problems of soil erosion have been reduced, and dams further downstream are protected from siltation. Trees have become an important source of income for the rural communities, wood is a valuable resource mainly needed for construction, and also as fuel. Since the 1960s, several afforestation campaigns have been initiated by the government, mainly using food-for-work or cash-for-work approaches as incentives. Nowadays, local tree planting initiatives (on community or individual level) without external support are dominant.

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:

厄立特里亚

区域/州/省:

Central Highlands

有关地点的进一步说明:

Serejeka

具体说明该技术的分布:
  • 均匀地分布在一个区域
如果技术均匀分布在一个区域,则指定覆盖的区域(单位为平方千米):

30.0

注释:

Total area covered by the SLM Technology is 30 km2.

2.6 实施日期

如果不知道确切的年份,请说明大概的日期:
  • 10-50年前

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

3. SLM技术的分类

3.1 该技术的主要目的

  • 减少、预防、恢复土地退化

3.2 应用该技术的当前土地利用类型

农田

农田

  • 乔木与灌木的种植
乔木和灌木种植 - 指定作物:
  • 橄榄树
森林/林地

森林/林地

  • 植树造林
树木类型:
  • 桉树树种
产品和服务:
  • 木材
  • 薪材
  • 放牧/啃牧
注释:

Major land use problems (land users’ perception): Surface and gully erosion; Decline of vegetation cover, diversity and biomass; Loss of surface water; Lowering of ground water level
Plantation forestry: Yes
Trees/ shrubs species: Eucalyptus, few Olea africana

3.4 供水

该技术所应用土地的供水:
  • 雨养

3.5 该技术所属的SLM组

  • 天然和半天然森林管理
  • 横坡措施

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
结构措施

结构措施

  • S1:阶地
注释:

Main measures: vegetative measures, structural measures

Type of vegetative measures: aligned: -contour

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
生物性退化

生物性退化

  • Bc:植被覆盖的减少
  • Bq:数量/生物量减少
  • Bs:质量和物种组成/多样性的下降
水质恶化

水质恶化

  • Hg:地下水/含水层水位的变化
注释:

Main type of degradation addressed: Wt: loss of topsoil / surface erosion, Wg: gully erosion / gullying, Bc: reduction of vegetation cover, Bq: quantity / biomass decline, Bs: quality and species composition /diversity decline, Hg: change in groundwater / aquifer level

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:
  • 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

技术规范(与技术图纸相关):

Technical knowledge required for field staff / advisors: moderate

Technical knowledge required for land users: high

Main technical functions: control of raindrop splash, control of dispersed runoff: retain / trap, reduction of slope angle, improvement of ground cover, stabilisation of soil (eg by tree roots against land slides), increase of infiltration, increase of groundwater level / recharge of groundwater, increase of biomass (quantity), promotion of vegetation species and varieties (quality, eg palatable fodder)

Aligned: -contour
Vegetative material: T : trees / shrubs
Vertical interval within rows / strips / blocks (m): 2.00

Trees/ shrubs species: Eucalyptus, few Olea africana

Terrace: bench level
Spacing between structures (m): 2.50
Depth of ditches/pits/dams (m): 0.50

Construction material (earth): digging out trenches and piling up risers

Construction material (stone): risers should be reinforced with stones

Vegetation is used for stabilisation of structures.

4.3 技术建立活动

活动 时间(季度)
1. Dig planting pits (0.5 x 0.5x 0.5 m), at 2 m intervals, in the trenches
2. Plant tree seedlings (mainly eucalypts, some African olives); fill pit with top soil (optional: mix with 1 spade of manure)
3. Spot weeding and softening soil around the pits to improve percolation of water and soil aeration (during rainy season)
4. Supplementary irrigation during dry spells (using jerry / watering cans)
5. Prohibit open grazing: Area closure is done collectively
6. Mark contour lines using a line level. Spacing between terraces depends on slope, vegetation status, soil depth. In the case study area horizontal spacing between terraces is 2.5 m
7. Terraces are built (inward-sloping) by digging out trenches (0.5 m deep) and piling up risers (minimum 0.75 m high). Risers should be reinforced with stones (where available)
8. The trenches are separated into basins by ties at an interval of 2-5 m to avoid eventual lateral movement of water

4.4 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 Labour ha 1.0 1760.0 1760.0 73.0
设备 Tools ha 1.0 50.0 50.0 73.0
植物材料 Seedlings ha 1.0 600.0 600.0 73.0
技术建立所需总成本 2410.0
技术建立总成本,美元 2410.0

4.5 维护/经常性活动

活动 时间/频率
1. Replacement of missing plants at onset of rains (10% replacement of seedlings is expected in the 1st year) onset of rains
2. Spot weeding and softening soil
3. Supplementary irrigation
4. Maintenance of structures before onset of rainy season

4.6 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%
劳动力 Labour ha 1.0 480.0 480.0 83.0
植物材料 Seedlings ha 1.0 100.0 100.0 83.0
技术维护所需总成本 580.0
技术维护总成本,美元 580.0
注释:

Costs are calculated for gentle slopes with a terraces spaced at 2.5 m.

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:

Labour cost includes construction of hillside terrace, pitting, planting and spot weeding and cultivation. According to the work and payment norms of the Ministry of Agriculture the cost of 1 person-day is 2.66 US$. Production cost of one seedling is 0.2 US$. Maintenance costs include terrace maintenance, re-pitting and replanting of seedlings.

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
农业气候带
  • 半干旱

Thermal climate class: tropics

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.
关于地形的注释和进一步规范:

Landforms: Also hill slopes
Slopes on average are steep ( > 50%)
Soil fertility is low

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)
  • 中粒(壤土、粉土)
表土有机质:
  • 低(<1%)

5.6 应用该技术的土地使用者的特征

生产系统的市场定位:
  • 生计(自给)
  • 混合(生计/商业)
个人或集体:
  • 团体/社区
机械化水平:
  • 手工作业
  • 畜力牵引
说明土地使用者的其他有关特征:

Land users applying the Technology are mainly disadvantaged land users

Market orientation of production system: subsistence (self-supply), subsistence (self-supply), mixed (subsistence/ commercial, mixed (subsistence/ commercial

5.7 应用该技术的土地使用者使用的平均土地面积

  • < 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)?:
  • 小规模的

5.8 土地所有权、土地使用权和水使用权

土地所有权:
土地使用权:
  • 社区(有组织)

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:

cut-and-carry of grass

木材生产

降低
增加
收入和成本

收入来源的多样性

降低
增加
注释/具体说明:

selling timber and grass

社会文化影响

食品安全/自给自足

减少
改良

娱乐机会

减少
改良

社区机构

削弱
加强

SLM/土地退化知识

减少
改良

冲突缓解

恶化
改良

生态影响

水循环/径流

地表径流

增加
降低

地下水位/含水层

下降
补水
土壤

土壤水分

降低
增加

土壤覆盖层

减少
改良

土壤流失

增加
降低

土壤有机物/地下C

降低
增加
生物多样性:植被、动物

生物量/地上C

降低
增加

6.2 该技术的场外影响已经显现

旱季稳定可靠的水流

减少
增加

下游洪水

增加
减少

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)

气候有关的极端情况(灾害)

气候灾害
该技术是如何应对的?
干旱 不好
注释:

Sensitive to climatic extremes (e.g. rainfall decrease, especially in case of monocultures)

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:

轻度消极

长期回报:

非常积极

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:

中性/平衡

长期回报:

积极

注释:

Initial labour inputs payout on long term

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?:
  • 0-10%
注释:

100% of land user families have adopted the Technology with external material support

There is a moderate trend towards spontaneous adoption of the Technology

Comments on adoption: Acceptance of afforestation areas has increased, since user rights have been given to land users: Communities located in Toker upper catchment areas have taken the initiative to maintain and protect their woodlots. Moreover, there is a trend toward locally initiated hillside terracing and tree planting without external initiative/incentives, apart from the provision of seedlings (through Ministry of Agriculture). The afforestation area covers approx. 30 km2 with high potential to enlarge.

6.7 该技术的优点/长处/机会

编制者或其他关键资源人员认为的长处/优势/机会
Protection of slopes from erosion while at the same time providing an income source for the poor

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?
Establishment cost is high and labour intensiv provision of hand tools and demanded seedlings
Fast growing eucalyptus trees have a high rate of water consumption; Indigenous trees are not favoured encourage people to protect naturally regenerated indigenous trees, assist villagers to get market channels for products of indigenous trees
Community mobilization and high knowledge of land users is required awareness raising campaigns, strengthen village institutional arrangements, assist villages bylaws
Land use rights: because the afforestation area is communal, nobody feels responsible for maintenance promote plantations by individual households

7. 参考和链接

7.2 参考可用出版物

标题、作者、年份、ISBN:

Zeremariam I. 2001. Assessment of upper catchment development technologies in the Central High Land zone of Eritrea. MSc Thesis; The Royal Veterinary and Agricultural University, Denmark.

标题、作者、年份、ISBN:

Amanuel Negasi et al. 2002. Soil and water conservation Manual for Eritrea. RELMA.

标题、作者、年份、ISBN:

Zeremariam I.2001. Assessment of upper catchment Development Technologies and Approaches in the Central High Land zone of Eritrea. MSc Thesis; The Royal Veterinary and Agricultural University, Denmark

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