1.2 Contact details of resource persons and institutions involved in the assessment and documentation of the Technology

Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)

Department of Resources and Environmental Science, Beijing Normal University (Department of Resources and Environmental Science, Beijing Normal University) - China

1.3 Conditions regarding the use of data documented through WOCAT

When were the data compiled (in the field)?

16/05/2002

The compiler and key resource person(s) accept the conditions regarding the use of data documented through WOCAT:

Yes

1.5 Reference to Questionnaire(s) on SLM Approaches

2.1 Short description of the Technology

Definition of the Technology:

Auto-flowing slurry dams is filled with dense slurry by water flow from upland to maintain eroded soil particles and runoff.

2.2 Detailed description of the Technology

Description:

Falling water filled dams distribute widely in the middle reaches of the Yellow River, they are used to store water and wrap sediment which result from soil and water loss. On the Loess Plateau, in addition to the conditions of deep gully and steep slope, earth above the top of the dams can be used to build dams. First, soil is loosed with squirt guns, exploded or manually dug. Then, water is pumped up to the loose earth so as to rush the soil down along transporting ditch, turning the soil into dense mud to dam level surrounded by tamped banks. Under the press of gravity, the mud dehydrates, consolidates and becomes uniformly dense body of the dams. Compared with dams in other areas, the water power filled dams in the Yellow River basin are characterized by much denser mud, uniform particles and body texture, smaller transect of dams body, and wide applicability to soil materials such as sand soil, loess soil and weathering residue. The types of dams have widely applied to build moderate and small reservoirs and silt arresters in the middle reaches of the Yellow River, they play an important role in increase in agricultural production and reduction of sediment into the Yellow River.

2.3 Photos of the Technology

2.5 Country/ region/ locations where the Technology has been applied and which are covered by this assessment

2.6 Date of implementation

If precise year is not known, indicate approximate date:

• more than 50 years ago (traditional)

2.7 Introduction of the Technology

Specify how the Technology was introduced:

• as part of a traditional system (> 50 years)

Comments (type of project, etc.):

The technology was developed by local people during the conservation practice in 1950s.

3.1 Main purpose(s) of the Technology

• improve production

3.2 Current land use type(s) where the Technology is applied

Comments:

Major land use problems (compiler’s opinion): 1. Slope land is used as cropland
2. Too little ground cover to protect soil from erosion
3. Over grazing in wind erosion area

Major land use problems (land users’ perception): 1. Little cropland for food supply
2. The land productivity is too low
3. The benefit of returning cropland to graze land or woodland is not definite now except the compensate from government

3.3 Further information about land use

Number of growing seasons per year:

• 1

Specify:

Longest growing period in days: 165Longest growing period from month to month: May - Sep

3.4 SLM group to which the Technology belongs

• irrigation management (incl. water supply, drainage)

3.5 Spread of the Technology

Specify the spread of the Technology:

• evenly spread over an area

If the Technology is evenly spread over an area, indicate approximate area covered:

• > 10,000 km2

Comments:

Total area covered by the SLM Technology is 13062 m2.

Dams filled by water power are applied mainly in the middle reach of the Yellow River, including the provinces of Shanxi, Shaanxi, Inner Mongolia, Ningxia, Gansu, Qinghai, Henan, etc. The types of dams were used since 1950s, and most the dams being used were built in 1970s.

3.6 SLM measures comprising the Technology

Comments:

Main measures: structural measures

3.7 Main types of land degradation addressed by the Technology

Comments:

Main type of degradation addressed: Wg: gully erosion / gullying, Ha: aridification

Secondary types of degradation addressed: Wt: loss of topsoil / surface erosion, Et: loss of topsoil, Cn: fertility decline and reduced organic matter content

Main causes of degradation: other natural causes (avalanches, volcanic eruptions, mud flows, highly susceptible natural resources, extreme topography, etc.) specify, poverty / wealth (Lack of captial), education, access to knowledge and support services (Lack of knowledge)

3.8 Prevention, reduction, or restoration of land degradation

Specify the goal of the Technology with regard to land degradation:

• not applicable

4.2 Technical specifications/ explanations of technical drawing

Technical knowledge required for field staff / advisors: low

Technical knowledge required for land users: low

Main technical functions: control of concentrated runoff: retain / trap, water harvesting / increase water supply, sediment retention / trapping, sediment harvesting

Secondary technical functions: control of raindrop splash, control of dispersed runoff: retain / trap, control of dispersed runoff: impede / retard, control of concentrated runoff: impede / retard, control of concentrated runoff: drain / divert, reduction of slope angle, reduction of slope length, improvement of ground cover, increase of surface roughness, increase in organic matter, increase of infiltration, increase / maintain water stored in soil, water spreading, reduction in wind speed, increase in soil fertility, improvement of soil structure

Construction material (earth): Loess earth

Slope (which determines the spacing indicated above): 45%

If the original slope has changed as a result of the Technology, the slope today is: 30%

Lateral gradient along the structure: 60%

For water harvesting: the ratio between the area where the harvested water is applied and the total area from which water is collected is: 1:1

4.3 General information regarding the calculation of inputs and costs

Specify currency used for cost calculations:

• US Dollars

4.4 Establishment activities

	Activity	Type of measure	Timing
1.	preparing earth	Structural	n/a
2.	pumping water	Structural	n/a
3.	preparing base of the dam and its perimetric banks	Structural	n/a
4.	Flushing the prepared earth with water inside the banks of the dam	Structural	0.1~1
5.	After dehydration and consolidation of the earth, repeat 3 and 4.	Structural	n/a

4.5 Costs and inputs needed for establishment

Comments:

Duration of establishment phase: 540 month(s)

4.6 Maintenance/ recurrent activities

	Activity	Type of measure	Timing/ frequency
1.	Keeping the top of the dam level and free of crevice, water or rubbish	Structural	timely
2.	Keeping the top of the dam level and free of crevice, water or rubbish	Structural
3.	Keeping the slope of the dam compact and free of rill or weed.	Structural	timely
4.	Keeping the slope of the dam compact and free of rill or weed.	Structural
5.	Keeping the observation equipment work in order.	Structural	timely
6.	Keeping the observation equipment work in order.	Structural
7.	Preventing the base the dam from destroying by white ants and other animals.	Structural	April to October/once a year

4.7 Costs and inputs needed for maintenance/ recurrent activities (per year)

Comments:

The volume of structure.

4.8 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

Since the dam construction uses local materials, the most important factors affecting the cost are labor and equipment

5.1 Climate

5.2 Topography

Indicate if the Technology is specifically applied in:

• not relevant

Comments and further specifications on topography:

Landform: Also plateau/plain

5.3 Soils

If available, attach full soil description or specify the available information, e.g. soil type, soil PH/ acidity, Cation Exchange Capacity, nitrogen, salinity etc.

Soil fertility: low
Soil drainage / infiltration: medium - good
Soil water storage capacity: high - very high

5.6 Characteristics of land users applying the Technology

Indicate other relevant characteristics of the land users:

Population density: 50-100 persons/km2

Annual population growth: 0.5% - 1%

Relative level of wealth: rich, average, poor
There are almost no people very rich in the area.
Rich people are as same as average people.
40% of the land users are average wealthy and own 20% of the land (Average people in the area where the SWC is applied should offer labor for the construction.).
Poor people can offer labor for the construction.
Very poor people are relatively rare and they are often in poor health.

Off-farm income specification: Most young male farmers often go to the city or town to earn money

5.8 Land ownership, land use rights, and water use rights

Land ownership:

• state

Land use rights:

• open access (unorganized)
• communal (organized)

6.1 On-site impacts the Technology has shown

Ecological impacts

Water cycle/ runoff

Soil

6.4 Cost-benefit analysis

How do the benefits compare with the establishment costs (from land users’ perspective)?

How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?

6.5 Adoption of the Technology

• 1-10%

If available, quantify (no. of households and/ or area covered):

80'000 households (3 percent of the area)

Of all those who have adopted the Technology, how many have did so spontaneously, i.e. without receiving any material incentives/ payments?

• 10-50%

Comments:

5% of land user families have adopted the Technology with external material support

50000 land user families have adopted the Technology with external material support

Comments on acceptance with external material support: estimates

1% of land user families have adopted the Technology without any external material support

30000 land user families have adopted the Technology without any external material support

Comments on spontaneous adoption: estimates

There is a strong trend towards spontaneous adoption of the Technology

Comments on adoption trend: Although the local people adopt the SWC Technology willingly, it is usually invested, designed and constructed by the land owner, the local government.

7.2 References to available publications

Title, author, year, ISBN:

Special Planning Of Soil And Water Conservation in Xinzhou Region , Shanxi Province. 1986-1990.

Available from where? Costs?

Library of the Resource and Environmental Department, Beijing Normal University.

Title, author, year, ISBN:

How to design the dry masonry dam in the Hanjiachuan watershed. Tianyuzhu, Wangzuliang. Beijing. Water conservation in Beijing. 2000.

Available from where? Costs?

Library of the Resource and Environmental Department, Beijing Normal University.