Wu Deyi*
[* Professor and Senior Engineer, International Training and Research and Training Centre on Erosion and Sedimentation (ITRCES), Beijing. China.]
Abstract
Introduction
Methodology
Description of Wuhua County
Mechanisms of people's participation
Soil and water conservation strategy
Wuhua county is located at the mid-eastern part of Guangdong Province, China. The county has serious erosion and watershed degradation problem. Population density is 280/km2, and the average arable land per capita is only 0.1 ha. Soil and water erosion in the county is responsible for weak geo-morphology, poor soils and vegetation, hydrological problems, irrational land-use and many socio-economic problems.
Although the soil and water conservation work in the province began in 1949, this sector received high priority only since 1982. Accordingly, the provincial Government passed many related resolutions to effectively execute soil and water conservation program in Wuhua county.
Comprehensive management system of small watersheds (5-40 km) has been very popular in Wuhua county. At present, the county has 62 small watersheds under the comprehensive management system. Planning and selection of these watersheds were carried out by a multi-disciplinary team of technicians, NGOs, village leaders and farmers. Under this system, local county Government and farmers provide financial support, where as Provincial Government provides necessary materials, tools and equipments to implement the program at a small watershed level. People's participation in land management is through various contractual arrangement such as Family Contract System, Collective or Group Contract System, Sub-lease Contract System, Professional Contract System and Specialized Contract System. Because of these systems of people's participation, soil and water conservation works in China have been carried-out successfully. These systems have significantly improved the rural economy and standard of living of farmers of Wuhua county. This is achieved by soil and water conservation techniques which give quick economic benefits.
The concept of small watershed based development is practised successfully in Wupi river watershed of Wuhua county. The overall plan for the management of a small watershed emphasizes on comprehensive erosion control measures including measures for hill slope and gully stabilization. regulating river system and rearranging farm lands. Principles of soil erosion control have been further developed by combining soil erosion control measures with the optimum utilization of biological measures. Under these principles, short-term, medium-term and long-term objectives have been formulated. Short-term objective is to upgrade agricultural production, medium-term objective is to increase fruit production and long-term objective is to develop forestry and eventually to combine ecological and economic benefits. The focus on economic benefits is based on the fact that the people would participate activity in soil erosion control works only if it results into quick economic benefits to them.
Wuhua county is located at the mid-eastern part of Guangdong Province, China. The county has serious erosion and watershed degradation problems. Population density is 280/km2, and the average arable land per capita is only 0.1 ha. Soil and water erosion in the county is responsible for weak geo-morphology, poor soils and vegetation, hydrological problems. irrational land-use and many socio-economic problems.
The study was undertaken with the following objectives:
- To study elements of successful watershed management e.g. level of people's participation, gender equity, conservation of natural resources, distribution of benefits, farmer based research, rural organization etc.- To summarize the experiences of Wuhua County in watershed management, its constraints and lessons learned and make the same available to other Asian countries.
Wuhua county of Guangdong Province was selected for this case study as it represents the host experiences of peoples' participation in watershed management in Sub-tropical region of China. Wuhua county has serious erosion problems, the types of erosion and its nature represent the vast hilly areas in sub-tropical region of South China. Hence, the successful experience need to he studied so that it can he replicated into other parts of South China which covers about nine provinces.
Wuhua county has large population but relatively little land. Hence, soil erosion and water loss control and their rational exploitation are strenuous and arduous. Abundant experience in erosion control. use of natural resources and impetus to people's participation have been gained in the county since 1985.
Research works on: different types of erosion. reforestation, agro-forestry, pastoral management, soil and water conservation, land use management, stream source and shore protection, fruit tree and horticultural management, natural forest regeneration management, community forestry, reserve forest and protected area management, income generating practices, watershed resources policies and people's participation have been conducted.
After the Ministry of Water Resources and Guangdong Provincial Government executed the afforestation strategy in Guangdong, more favorable conditions were created for soil and water conservation works. At the same time, the Provincial People's Congress executed the soil and water conservation program and enacted policies in nine river basins of Guangdong province. Since then, the People's Congress and the Provincial Government, together with the farmers' groups and the numerous cadres including universities, research institutes, State Land Regulation Bureau of Agriculture, Institute of Botany. Institute of Geography and Academia Sinica, have made great efforts at strengthening the technical cooperation in soil and water conservation. The Commission for Integrated Survey of Natural Resources, the Chinese Academy of Science and State Planning Committee have also been involved in the conservation tasks.
Appropriate management and use of degraded watersheds have obviously resulted in ecological, economical and social benefits to the farmers. Since 1980, the officers, the engineers and the farmers have been able to combine all kinds of soil and water conservation works and transform the unproductive lands into highly productive farmlands, which in turn, developed the small watershed economy. Soil and water conservation stations have made full use of local resources, developed plant-culture, aqua-culture. poultry and produced high class commodities at suitable scales. These efforts have brought about promising results and opened up a new prospect for activating the economy.
The demonstration area selected by Guangdong province has received more than 20 awards from the Central, Provincial and County Governments for their outstanding works. It is for these reasons that the county was selected for this study,
RRA method was used for which the following steps were required:
- Data collection from engineers, professors,researchers in field experimental stations,
universities and research institutes.- Selection of a successful watershed management
project from various on-going projects in the
country and review of the mechanisms used for
promoting, testing and demonstrating farmers'
participation.- Information collection through group meetings with
GO, NGO and PO of the watershed area.- Visits and survey of the households.
- Analysing the data and writing the findings in
Chinese and English languages.
Environmental and socio-economic conditions
Topography
Climate
Soil and water erosion
Vegetation
Relations between vegetation and soil erosion
Environmental damage
In Wuhua county, there are 30 communes and 400 districts with a total population of more than one million. The population density in the county is 280/km2. There are 950.000 people from peasant families in rural areas and among them 400,200 are laborers engaged in farm work. Paddy is the principal crop, which is followed by sweet potato. Cash crops include sugar cane, peanut, soybean, tobacco, tea, orange, litchi. shaddock, plum etc. The per capita cultivated area is only 0,61 mu (0.04 ha).
Factors affecting suit erosion are climatic, topographical, geological and social. These include torrential rainfall of long durations, weakly developed rock joints, poorly formed soil structure, barren mountain chains with steep slopes, irrational land use resulting into over exploitation of sloping lands and deforestation, etc.
Wuhua county (115°18'-116°02' E, 23°23'-24° 12' N) is located at the upper reaches of Hanjiang river. The county is spread over a length and width of 71.59 km from east to west and 87.99 km from north to south, respectively. Its total area is 322,610 ha. There are 33,200 ha of cultivated land among which paddy fields occupy 25.900 ha, and the rest is rainfed farmland. The landform of the county is complex with various slope ranges and steep terrains. Mountain slopes with the percentage of the total area are shown in Table 1.
There are 13 mountains in the west of the county with elevations of > 1,000 in AMSL, among which Qimuzhang Mountain is the highest. Its peak is 1318 in AMSL. Small basins lie along the mountains. The eastern part of Wuhua county has gentle undulated hills. Wuhua and Qingjiang rivers are the main rivers in the county which create an alluvial plain in the lower reaches of the two rivers.
Guangdong province is in the south-eastern region of China, and Wuhua is located at the mid-eastern pan of the province. The Tropic of Cancer (2.5°) passes over the province. At low latitudes, solar radiation is high. Annual solar radiation totals 4.3952.2 MW/m2. The mean annual air temperature is 21.2° C, with the annual maximum and minimum average of 38 and -1.8° C, respectively. The summer is long and winter is short. The winter begins when the 5-day mean temperature falls below 10° C.
Wuhua county is situated at the sub-tropics and northern edge of the tropical areas in China bordering the South China Sea. Influenced by the oceanic climate and typhoonic rainstorms, it receives an average annual rainfall of 1,525 mm with high intensity. This is the main cause of soil erosion. The major landform types are mountains and hills. Thin layers of purple and red soils are formed in the weathered granite crust and purple sandy shale. If the vegetation is damaged and the land is irrationally over exploited, soil erosion easily occurs. Some soil erosion is also artificially caused by the destruction of forests and grasses in the sleep slopes, mining, rock quarries, for building roads and houses, and for other infra-structural constructions. In recent years, with the growth of population and continuously accelerating economic development in the region, real estates have been developed on a large scale. This is damaging erstwhile vegetation and landform and large quantities of silt and excavated stones are dumped into rivers and reservoirs. All these activities have accelerated the process of soil erosion in the county.
Guangdong province faces the South China Sea and possesses a 4,300 km long coast line. Wuhua is only about 200 km from the coast and is clearly influenced by maritime conditions. In spring and early summer, the cold air mass from the north is weakened considerably when it reaches Wuhua as it meets the warm moist maritime air mass. The first rainy period ends when the sub-tropical ridge shifts northward, it is immediately followed by typhoon season. The entire rainy season lasts from April to September. During the winter, the north air dominates, and this period is characterized by low temperature, dry air, and sunny days.
Table 1: Mountain slopes and their area in % of the total area of the county
|
Mountain slopes |
Percentage of the total area |
|
0° - 5 ° |
17.9 |
|
6° - 10° |
10.80 |
|
11° - 15° |
17.9 |
|
16° - 25° |
34.9 |
|
26° - 35° |
12.7 |
|
> 35° |
5.8 |
Although Guangdong is one of the high rainfall areas of China, its spatial distribution is uneven because of the disposition of the land and the sea, the orientation of the mountain chains, and the topography. Wuhua is situated between the heavy rainfall zone of Qingyuan (annual precipitation of 2,216 mm) and the low rainfall zone of Loding (annual precipitation of 1,343 mm). Based on 1966-1986 precipitation records, average annual rainfall was 1525.5 mm. The highest and the lowest annual rainfall was 2587 mm and 909 mm which was recorded in 1981 and 1977, respectively. The highest and lowest one-hour rainfall on record were 65 mm and 31.8 mm, respectively. Although, the historical peak value occurred in September, May has the highest average one-hour maximum rainfall followed by July and August.
Types of soil erosion
Some important features of soil erosion
In Wuhua county, there are two types of soil erosion: water erosion and gravitational erosion. Water erosion is surface erosion which include sheet erosion and rill erosion. Gravitational erosions include landslides, debris flows and slope collapses. Slope collapses have several patterns: arc-shaped, strip-shaped, ladle-shaped and fan or compound shaped. Some irrational activities have also aggravated various forms of soil and water loss. Anthropogenic erosion includes various forms of soil erosion and water loss, caused by human activities such as mining, stone quarrying, road building, steep slope reclamation etc. Serious problems of soil erosion in Wuhua have long been recorded in the official history of the county. Since 19th century, the practices of burning and culling of branches and roots of trees for lime and fuelwood, have continued. These practices have greatly aggravated hill slope erosion during the rainy season. Loss of prime farmlands have resulted from erosion. Since 1930's, serious problems of gully erosion and slope collapse have been recorded. Soil erosion aerial survey of 1983 showed that 875.83 km2 of the county was seriously affected by erosion. Of this area. 644.08 km2 was affected by surface erosion and 159.38 km2 by gully erosion. Slope collapses were observed in 19,719 locations, covering an area of 72.37 km2. The rates of gully erosion and slope collapses were in the order of 48.000 and 85.000 ton/km2, respectively. Different types of erosion and the area covered by them, is shown in Table 2.
Table 2. Different types of erosion and affected area
|
Erosion types |
Surface erosion |
gully erosion |
slope erosion | |||
|
Status |
slight |
serious |
slight |
serious |
slight |
serious |
|
Area covered (Km2) |
408.8 |
235.3 |
111.6 |
47.5 |
29.4 |
43.0 |
|
subtotal |
6440.1 |
159.1 |
72.4 | |||
- According to remote sensing survey in 1986, the area covered by erosion in Wuhua county was 875.83 km2 (about 1/10 of the total erosion area in Guangdong province). It is spread over 62 watersheds covering 30 communes.
- The proportion of severely eroded areas is high with 231.03 km2 of gully and slope collapsed areas amounting to 26.3% of the total eroded area in the region.
- There are two reasons for the formation of slope collapse. One of them is the erosion caused by runoff in the valley, in which slope collapse is caused by gully head retrogressive erosion. The second is the erosion caused by streams in which erosion is developed from down reaches and progresses to upper reaches of the stream.
- Slope collapse and gully erosion occur in coarse grain granite bedrock areas. This is because the granite deep weathered areas, with a thick mantle of red and deep red soils, have a high water holding capacity and are easy to be dissolved, as they contains abundant sand. Once the water holding capacity of the soil is exceeded, landslide and slope collapse occur.
- Gully erosion and slope collapse are closely associated with the elevation and the orientation of slope faces.
- Topographic factors include the steepness of the slope and its direction. The slope collapse features are only found on about 50 % of the hilly lands having a slope range of 10-25 % and deep weathered granite bedrock with thick mantle of red and deep red soils. The orientation of 221 slope collapses in the Maxu River basin were analyzed and it was found that 56.1 % of the collapses were facing south, while only 1.8 % faced north. All other orientations had a frequency ranging from of 9-11 %. It is hypothesized that the high intensity of erosion in a drier south-facing slope was due to low density of vegetation cover.
Fifteen plant communities are found in the area. These are: Schefflera octophylla. Euodia lepta. and Lophatherum gracile:, Schima superba, Baeckea frutescens and Dicranopteris linearis; Lingnania chungii and Dicranopteris linearais: Acacia auriculieformis and Ottochloa nodosa: Pinus massoniana, Schima superba, Rhodomyrtus tomentosa and Eriachne pallescens; Pinus massoniana and Indolamus longiauritus; Pinus massoniana, Euodia lepta and Dicranopteris linearis: Pinus massoniana. and Dicranopteris linearis: Pinus massoniana, Baeckea frutescens and Eriachne pallescens, Cunninghamia lanceolata and Dicranopteris linearis; Baeckea frutescens, Lepironia articulara and Eleocharis atropururea. Baeckea frutescens, Lepironia articulata. and Eleocharis atropururea; Eragrostis perennans and Eriocaulon sexangulare; Lepironia articulata and Hydrilla vertibillata.
Specimens of these plant species are preserved in thelaboratory of the Department of Geography, South China Normal University
The existing vegetation is a result of a series of "reverse successions", where the climax vegetation was replaced by secondary growth, some time in the past. Much of this secondary vegetation has been replaced by the present range of species. Some remnants of the climax vegetation belonging to the monsoon broad-leaf evergreen types are also found. During the period of climax vegetation, the impact of raindrops on soil and detachments of soil particles by overland flow were minimum due to high canopy density and ground cover provided by the broad-leaf trees. The existing plant communities at present are inferior in providing dense canopy cover and protecting soil from raindrop erosion. Most of the existing tree species such as Schima superba, Pinus massoniana, Cunninghamia lanceolata, Pinus elliotescens, and the dominant xerophytic grass species are not adequate to provide complete ground cover. Hence the surface soil is easily eroded. When deep gullies and slope collapse features develop, the area becomes more favourable for the invasion of other hydrophilic plants like bracken fern. Thus. on shady slopes, bracken ferns are dominant. However, their fibrous roots have a strong binding effect and hence surface erosion is minimal. But, where the fern is frequently removed by people, his growth is retarded and the ground is not adequately covered, often resulting into surface erosion and slope collapse.
Based on the erosion types and the degree of human interference, lateritic red earth is associated with slope collapse features. These soils are mostly located in the lower slopes of the basin where a deep weathering 55-70 m thick mantle exists.
Annual average surface runoff of Wuhua country is 1.468 billion m3. In high runoff years (p= 10 %). the discharge reaches to 2.055 billion m3. In a dry year, the value of discharge is about 939.5 million m3. Water originating from the upper part of the river basin (excluding 225.7 billion m3) amounts to about 103.3 million m3. Thus, the total discharge is about 1.571 billion m3. In terms of cultivated land, 89.520 m3 of water is available for each hectare of farmland. In each year. the runoff is concentrated in the monsoon season from April to September, during which 71.3% of the total annual discharge occurs. Runoff has a double maxima, peaking in both June and August. However, from September to March, low flow predominates.
Sediment transported by rivers is related to the erosive power of the running water and the nature of the underlying material. High sediment yield occurs mainly in areas underlying with weathered granite. The average river sediment concentration is 0.66 kg/m3 where the surface material is predominantly weathered granite. The maximum sediment concentration is measured at 22.2 kg/m3. The seasonal variation of sediment concentration shows high value (exceeding 0.6 kg/m3) in the high flow period, peaking in April and May, while low concentration of 0.015 to 0.3 kg/m3 occurs in the low flow season.
On the other hand, with the same discharge. the sediment concentration is higher in the earlier rather than the later parts of the high flow season. During the early part of the season, the sediment concentration peaks before runoff takes place. This is due to sediment storage during October-March period and sediment flushing by the first storm runoff. The peak sediment load occurs in August reaching 364,000 tonnes and the minimum load occurs in December and January (2.000 tonnes). The peak in August is the combined product of high sediment yield averaging 494 ton/km2/yr. Based on the data, the rates of erosion are calculated as follows; inter rill erosion 600 ton/km2/yr, rill erosion 11.823 ton/km2/yr. and gully erosion 113.733 ton/km2/yr.
Although the area with soil erosion and water loss in Wuhua county is only 36 % of the total area. This area is widely distributed and the amount of soil loss ranges from 48,000-85,000 ton/km2/yr. Once the vegetation in the earth's surface is destroyed, the topsoil gets severely eroded and the earth surface turns into bare hills, mountains and barren ground. Silt discharged due to erosion will often silt up farmlands, chock lakes, reservoirs and canals clog up and raise river beds, block navigation passes, decrease the benefits of water conservancy facilities, and aggravate flood and waterlogging. All of these havocs seriously restrict the development of the economy and production in the county. In Guangdong province, soil erosion and water loss have not only caused runoff and soil erosion problems but also caused severe damage of soil fertility. It is estimated that more than 460,000 tones of organic matter is lost each year because of soil erosion and water loss. This is equivalent to 26,000 tones of N, 10,000 tones of Super P and 580,000 tones of P. In Wuhua, the rate of soil loss reaches to 6,488,900 ton/yr, of which the annual average rate is 7,409 ton/km2. In addition the siltation causes innumerable other damages to agricultural land, reservoirs and property.
Family contract system
Collective or group contract system
Sub-Lease contract system
Professional contract system
Specialized contract system
Soil and water conservation works in China have been carried out successfully, since China started the policy of economic reform 10 years ago. Although the land ownership belongs to the state, the present Government policy is to award 20-50 years land use titles to farmers for land management for economic benefits. This has resulted in better standard of living of the farmers and an improved rural economy. Main reason for such a success is the implementation of such soil and water conservation work plans which result into short and long-term economic benefits to the farmers. In addition, all farmers use soil and water conservation techniques under different contract systems of land management. These contract system are the main vehicle for facilitating people's participation in watershed management.
In this system, the land development with appropriate soil and water conservation works is performed by the Government. The Soil and Water Conservation office of each community or village distributes land to each household. Some lands belong to farmers themselves and are non-taxable, while other lands are managed by farmers under contract with the Soil and Water Conservation Office. While the area of land distributed to each farmer varies, the whole area belongs to the entire farmers' community. Although each household is ordered by the state to cultivate certain key products such as grain and cotton, the household is free to select remaining crops on both their own land and on contracted land. Because China is a country with a large population with limited land resources, the average arable land per capita is only 0.1 ha. Farmers have adopted many farming systems such as multi-layer agriculture-forest-animal husbandry, and farming combined with home gardens in order to optimize output per unit area. In Wuhua, for example, the comprehensive family farm has a common land management pattern. It consists of multi-storied protective forest belts with Taxodium sp. trees in the upper storey, fruit trees like litchi and guava in the middle-storey and banana or palm trees in the lower layer, established around irrigated rice fields. These protective forests are lucrative. Farmers report that they earn $29 from just one step along the length of such a forest belt. In addition, fish ponds and animal husbandry are also included in family farm land management system. All the income from these activities belong to the farmers themselves. Therefore, the farmers have expressed great interests in establishing this kind of comprehensive family farm management system.
This system is suitable for the use of waste lands. Since this system needs large investments, it is very difficult for an individual family to develop such lands. In this situation, several families join together to form a group and each group buys a share of the Government distributed waste lands. The land is managed with the collective effort, and economic benefits are distributed to each family according to a family's share of land. The actual situation varies in different areas.
This system is suitable for the land in which the landlord is reluctant to manage his lands. In this case, the Government allows sub-leasing of the land to a farm family who is willing to manage it. A contract is made between the landlord and a tenant farmer and benefits are shared according to the contract.
This system is suitable for developing a land-use system that needs special skills or techniques e.g. engineering methods for soil and water conservation. In this system, a commune invites tenders and a contractor with required funds having enough professional skills and interest in developing a suitable land-use system, is hired. This system is mostly used for developing waste mountainous lands.
This system is adopted inside collectives or communes or state-owned agriculture/forest farms or in upper reaches of watersheds of reservoirs.
Even after the economic reforms in China, collective, commune and state farms are still managed by collectives, communes or states. Farmers are provided with basic salary, free medical treatment and almost free housing. A farm is usually divided into different specialized groups according to the type of management and products required. The farm demands for certain production standards from each specialized group, therefore each group is provided with land and other basic investments as necessary. If the farmers meet these production quotas, they get their basic salaries only. But, if they surpass the quotas, they will get more allowances and a share of the extra income. The distribution of extra income varies from state farm to state farms. However, farmers receive 50-60 % as allowance and bonus and 20 % as funds for expanding production.
In Wuhua county, of the 6,600 households who have made contracts, 2,600 made family contracts, 2,100 made group or collective contracts, and 1,900 made professional contracts. All these contracts included soil and water conservation, maintenance and development of the land. Since these contracts ensure economic benefit to the farmers, they are often mobilized for land management and are encouraged to participate in the construction of engineering structures and forestry works. In fact, four professional teams of land managers were set up in each watershed for such activities. The first team is specialized in conservation which includes 10-15 professional engineers, technicians and experienced farmers. The team is responsible for constructing large engineering structures and projects and conducting forest engineering works in eroded areas.
The second team has professionals in controlling sloping land collapses. In area with slight collapse, control measures are usually implemented by households near the area. These households are also responsible for maintenance of structures and forest engineering works in their vicinity. After a slope collapse, economic forests and herbs are planted to develop the waste land and to get all the economic benefits possible from the area. For example, a farmer named Zhang Xiangan of Mianyang commune in the Mianyang river watershed made a contract with the Commune Government, in which he was responsible for using the measures to control the area with large scale slope collapse and to maintain the structures such as check dams, silt trap dams, paring slope collapse, etc. He built his house at the mouth of the collapsed area and planted more than 200 bamboo seedlings, 500 palm seedlings and other profitable fruit trees. His net income was 20,000 yuan/year (exchange rate, 1US$ = yuan 8.6 in Jan. 1995). He was very successful in converting the original waste area into an area with commodity production. Another example in Caotinggang watershed is the Dajiken Hedong Commune, which originally had a serious erosion problem but after implementing conservation works to control erosion, 67 households made contracts to maintain, manage and exploit the watershed. They planted orange, tangerine, palm, and shaddock trees. They earned 2,350,000 yuan RMB from the production of 430 tons of fruits in 1993. Each household earned 35,000 yuan RMB, two households earned 200,000 Yuan RMB, five households earned more than 100,000 Yuan RMB and 38 households earned more than 50,000 Yuan RMB, on an average. The third team is a commune forest protection team which takes a small watershed as a management unit in which rules and regulations are enacted for forest protection.
Strategic decisions of the provincial government
Strategies for implementing comprehensive management of small watersheds
Watershed management planning
Achievements
Administration for people's participation and research support
The case of benefits from land leasing contractual arrangements for people's participation in WUPI watershed
Since the founding of the people's Republic of China in 1949, a extensive soil and water conservation works have been carried out in Guangdong Province. In the beginning, it was neglected in the Guangdong Province, as it was thought that the Province did not need it due to its favourable sub-tropical warm climate and plenty of rainfall. In 1982, after the 4th National Conference on Soil and Water Conservation, the Provincial Government explicitly pointed out that soil and water conservation measures are needed to ensure economic development of mountainous regions, river training and for appropriate use of the land resources. In 1984, the success of the experimental small watershed management at Wuhua, accelerated the progress of conservation works in Guangdong Province.
In 1985, the Provincial Government accepted three important proposals submitted by the Provincial People's Congress. They were:
- control and management of seriously eroded areas in the upper reaches of the Hanjiang River;- prevention and control of soil and water losses in the upper reaches of the Beijing River;
- regulations for soil and water conservation in Guangdong Province.
The implementation of these three decisions played an important role in the natural resource conservation and economic development of the mountainous regions in Guangdong Province.
Experience has shown that comprehensive management of small watershed (5-40 km2) facilitates mobilization of people, ensures implementation of a household responsibility system, provides a unit to coordinate conflicts. Meanwhile, a small watershed which is a natural integral unit consisting of mountains, water and farmlands, is favourable for overall planning and comprehensive management for rational utilization of water and land resources to increase production. Comprehensive small watershed management consists of overall planning and development of hilly lands, water resources, farmland, forest, road, agriculture and fisheries, simultaneously. It also facilitates combination of forest and grasses as vegetative measures along with other engineering measures to control surface and gully erosion and to protect soil and water resources for short as well as long term economic benefits to the farmers. In Wuhua, the first effort at comprehensive small watershed management started in 1980 at its experimental pilot watershed area. Later, this experience was used for extension. In 1984, a workshop was held in Wuhua county to exchange experiences in the comprehensive management of a small watersheds. This provided an impetus to push comprehensive management works into a new stage. At present, 62 small watersheds (875.83 km2) in Wuhua County are under comprehensive management system.
The small as well as large watershed planning works are done for long term (10-20 years) as well as short-terms (5 years) duration. In Wuhua, the small watershed planning is made to be compatible with the large watershed management of the Province.
In the process of planning and management of soil, water and vegetation resources, practical measures to prevent the occurrence of soil erosion in new areas are imperative. Comprehensive planning, and land and water management is adapted to local Conditions. It is important to coordinate measures involving vegetative planting, engineering practices, conservation tillage and sheet and gully erosion control so as to secure the best integrated benefits of various conservation measures.
In the process of implementing soil conservation works, proper utilization and development of natural resources such as water, soil, plant, solar energy, etc. are taken into consideration, simultaneously.
Inter-linkages between ecological and economic benefits of soil conservation are considered. Soil conservation projects based on local natural resource base are selected for economic benefits through commodity production and for their ecological benefits.
Stipulation of planning scheme
The comprehensive planning scheme of a small watershed consists of: land-use planning, soil and water conservation planning, determination of eroded and controlled access areas, inputs, outputs and benefits.
The comprehensive control measures emphasize a combination of engineering measures, vegetative and tillage practices, and forest and grass planting. The efforts of the Wuhua County Government and its people for last 5-7 years (up to 1990) to improve the ecologogy, to increase the agriculture production, to promote economic development and to raise standard of living of its people, are found effective and highly commendable.
The new land use titling policy instituted in 1984, which permits people's participation in watershed management through five times of contractual arrangement (as explained earlier) between the state and the farmers, has brought significant improvement in natural resources and people's standard of living in Wuhua County. Some of the physical achievements by 1990, in Wuhua County, are highlighted here.
The total investments made are 35,582,000 Yuan and 18,418,000 labor days of work. Of the total investment for completion of vegetative and engineering measures, about 19,720,800 yuan (55%) was contributed by the Wuhua County Government, about 12,740,400 yuan (about 35%) was farmers' contribution and remaining 3,120,800 yuan (10 %) was bank loan on low interest.
Vegetative control measures include mixed planting of coniferous and broadleaf trees, combining arbour trees with bushes and grasses, grass-shrub vegetation, raising conservation forest, fuel woodlots and economic production forest by plantation and aerial sowing. They are used in bank slopes, collapsed hill slopes, bench terrace risers, and hill sides.
The areas above the middle mountain suffering from surface erosion are often planted with trees such as Pinus massoniana, Pinus elliotti, Taiwan acacia, Acacia confuss and Schima supperba. Similarly, plantation of shrubs like Tephrosia Candida, Rhodomyrtus tomentosa, Acacia mearnsii, Lespedeza bicolor, Dalbergia hupeana and Leucaena glauccu are propagated. Among grasses, Shrubby baeckea, Baeckea frutescena, Molasses grass, Melinis minutiflora, Chinese pennisetum and Pennisetum alopecuroides are popular.
The gully areas below the middle mountains are planted to arbors like Eucalyptus sp. with shrubs like Cajan pigeonpea, Cajanus cajan (L.), Salix myntillacea, Anderss sp., Largeleaf plemingra, White mulberry, and Lespedeza sp.. Among grasses, Milinis beauv, Thatch srewpine, Pandanus tectorius, Molasses grass, Tiger grass, Thysanolaena maxima (Roxb. Kuntze) are used on gullies along with bamboo species.
Up to 1990, the hill sides area planted by aerial sowing was 415 km2, conservation forest plantation was 218 km2, fuel woodlots was 166.5 km2, timber forest plantation was 35.6 km2 and area under economic forest and fruit trees gardens was 76.3 km2.
In engineering measures, 15,180 Check dams, 803 silt-trap dams and 2,992 no. level ditches were built with the total excavated volume of rock and earth work estimated at 10,663,000 m3.
These measures are used to control slope collapses, to improve the steep slope topography, to retard flood and sediment, and to create conditions for the growth of plants. The works consist of intercepting ditches, check dams, debris basins, and construction of bench terraces. These structures are designed for safe runoff disposal produced by 24 hours torrential rainfall of 10 year frequency. The national level policy legislation of 1993 has set the directions for these works (Deyi, 1995).
Legislation for preventing soil and water erosion was introduced by me Wuhua County Government based on the National Law of Soil and Water Conservation issued by the State Council on June 30, 1982 (Deyi, 1995).
The Wuhua County administrative organization responsible for soil and water conservation through various contractual arrangements with farmers includes: Soil and Water Conservation Office under the leadership of Soil and Water Conservation Committee of Wuhua County and the Department of Soil and Water Conservation of the Ministry of Water Resources of China through its Guangdong Provincial Bureau of Water Conservancy and Hydroelectric Power. The county magistrate heads the Committee which consists of representatives of the Bureaus of Water Resources, Forest, Soil and Water Conservation Office, Agriculture, Financial, Public Security, Transportation, and the Judicial and Mining Committee.
Soil and Water Conservation Office of the county is set up in the Bureau of Water Resources of the county and is directly responsible for county's soil and water conservation which include survey of soil and water losses, watershed planning and annual work plan preparation, monitoring and evaluation of the construction works, educations about legislative aspects, water and soil conservation, preventing new soil loss, organizing scientific and research works, summarizing the experience and their extension. A Soil and Water Conservation Office is also set up in each of the communities. A community head also is the leader of the Community Soil and Water Conservation Office while the water management head serves as vice leader of the community office. Members of the community office are me representatives from Water Management Division, Forest Station, Agriculture Station, Public Security Division, Financial Division, Judicial and Mining Division and Department of Soil and Water Conservation. The Community Soil and Water Conservation Office is responsible for soil erosion survey, implementation of soil erosion control measures and the development of local resources. The grass root unit of the organization is a Village Soil and Water Conservation Group which consists of a village group leader and farmers specialized fields. This group is responsible for the farmers' organization in the village, the construction related to various soil and water conservation projects, the development of local resources and for implementing a household contract systems for maintenance of these measures.
The above efforts are supported by the Wuhua Soil and Water Conservation Experiment and Extension Station which was set up in 1952. By now, it employs 114 staff. They include, 20 senior engineers and technicians in agriculture, forestry, hydrology, pedology, economics, and biology. This station has given impetus to the development of soil and water conservation technology. It has also played important role in extension and popularization of conservation works for comprehensive control of soil and water erosion. In 1985, about 15,000 mu (1,000 ha) of land was converted into soil and water conservation experimental area. The area included 17 runoff and sediment observation fields, 13 study fields -and laboratories, 7 metrological stations, 2 cross sections at the main stem of river for observing runoff and sediment flow and three demonstration sites for erosion controls. In addition, a ten year plan for the conservation of soil and water, and the development of the local resources in Wuhua County was made. To meet the manpower requirement in soil and water conservation, more than 100 trainees were sent to North-west University, Nanshang Water Conservancy and Electric Power School for advanced studies. Many of these trainees have become the technical backbone of the soil and water conservation team in Guangdong Province. At the same time cooperation among related research institutes, universities and colleges has also been intensified. Serious efforts have been made in research on subjects such as soil and water conservation, trees and grass plantations, small watersheds management, fruit orchard management in eroded and arid regions, and soil amelioration.
The Wupi small watershed
Comprehensive erosion control measures at Wupi watershed
Contractual arrangements for people's participation
Benefits of soil conservation
Results of improved land use management in Wuhua county
Acknowledgement
Bibliography
To illustrate the remarkable economic, social and environmental benefits derived from comprehensive watershed management by long term land use titling contractual arrangements for farmers participation, the case of Wupi Small Watershed is described here.
The Wupi river watershed (23.23 Km2) is located at 115°38' E to 115°42' E and 24°02' N to 24° 07' N in the Wuhua County. The altitude of the watershed ranges from 100-300 m. There are three small reservoirs built on the upper reaches of the watershed. The submerged and command area of these three reservoirs occupy one third of the watershed area. Most valleys are U-shaped. The density of the water course system is 1.9 km/km2. The Wupi River is a third order tributary of the Hanjing River, which originates in Xingling county and empties into the Wuhua River of the Hangjing River Watershed.
The total area of the watershed is 23.23 km2 of which hilly lands occupy 18.7 km2. About 20 % of the lands are within 10-15° slope, 50 % are within 16-35° slope and 30% of the slopes are steeper than 36°. In general, the geomorphology of the watershed is denuded low hills.
The Wupi River small watershed is under the jurisdiction of the Huacheng Township of Wuhua county. There are 1,365 households with total population of 6,328 persons. By the end of 1987, the population density was 272 people/km2. The agricultural area was 3,750 mu equivalent to about 10% of the total area of the watershed. Cultivated farmland per capita was 0.6 mu. Forest area was about 8,600 mu and the total crop yield was 2035.9 tons. The main crop was rice.
In last 10 years of comprehensive management, vegetative coverage has increased from 10 to 82 %, the river channel has deepened by 1.7 m, the per capita timber stock has increased to 3.13 m3, and the per capita mean annual crop yield has increased from 249 to 840 kg. The farmers per capita income has increased from 24,826 yuan in 1985 to 60,756 yuan in 1993 (Wuhua soil and water conservation office report, 1993).
Soil erosion in the Wupi watershed incorporates both water and gravitational erosion. According to a field investigation in 1954, eroded areas covered 22,499 mu (80 % of the total area). Aerial photography survey of 1981 and the standard classification of soil erosion types indicated that the surface erosion accounted for 6,064 mu (21.4 % of the total eroded area), gully erosion accounted for 7,582 mu (26.8 % of the total eroded area) and slope collapses accounted for 8,853 mu (31.3 % of the total eroded area). The extensive slope collapse in the Wupi watershed exhibited the following features:
- The sites of slope collapses were accompanied by deep gullies. Most landslides were located at foot hills, on steep rocky spurs and on the lower part of hill slopes. The depth of the gullies ranged from 10 m to 100 m. Within an area of 4.2 km2 in Yuangkeng reservoir site, there were 1,653 slope collapses.- The rate of soil erosion in the watershed was as high as 19,000 ton/km2/year.
- Coarse sediment particles were easily deposited in the river and in reservoirs. The annual average deposit of sediments in the Yuangkeng Reservoir amounted to 20,000 m3, rendering the reservoir into a debris basin.
- In the weathered granite zone, the top layers of the soil were completely eroded. The exposed parent materials of white and red sand were exposed to very high temperatures and characterized by very low soil moisture and nutrient contents. The average organic matter content was only 0.45 % at which no plant could grow well.
A brief history
Soil erosion control measures
Reduction in fuel-wood shortage
In 1952, an experimental station was set up to demonstrate and extend conservation measures in the Wupi River watershed. Primarily, the station was established to conduct field studies on soil erosion, however, it was also developed into demonstration centre to educate local inhabitants, to summarize experiences and to improve technical capabilities. From 1952 to 1966, the following structural measures were carried out to control erosion:
check dams, debris basins, terraces, ponds, reservoirs, horizontal ditches, fish-scale pits, and planting trees, shrubs and grasses.
In 1952, priority was given to gully treatment without an overall plan. In 1955, guiding principle for the gully and slope treatment were developed. Although slope treatments received priority, they had to be comprehensive and suit local conditions. Financial support and technical aid were to be concentrated to meet the limited key objectives. These principles were re-oriented in 1974, and the concept of small watersheds, as a planning unit determined by the natural sub-division of river systems came into practice. In this concept, the overall plan was to concentrate on comprehensive soil and water conservation measures including hill slope and gully stabilization, regulation of river systems and rearrangement of farmlands. After 1980, the guidelines for soil erosion control were further developed combining soil erosion control measures with the optimum utilization of natural resources. The short-term objective was to up-grade agricultural production, the medium-term objective was to increase fruit production, long-term objective was to develop forestry and eventually to combine ecological and economic benefits. The focus on economic benefits was given due to the fact that it would give tremendous motivation to people's participation in soil conservation.
Management of the Wupi river watershed includes soil erosion control on hill slopes and gullies, regulation of river system and rearrangement of farmlands. Following measures have been adopted in the watershed:
Engineering measures
These measures on hill slopes include horizontal ditches and fish-scale pits. These were small-sized activities which were aimed to be effective in a short time. Afforestation, check dams, slope cutting and grading, terracing, shrub planting, grass planting, etc. are some of the other engineering measures used in eroded hill slopes, gullies, slope collapses, and flood control works in the watershed area.
Vegetative measures
The variation in elevation within the Wupi River watershed is only 100 m and there is no obvious climatic change vertically. Hence, altitude has no significant influence on the growth of vegetation. The main factors determining vegetative growth are soil and moisture, which are closely related to the slope and its orientation. A combination of trees, shrubs and grasses suited to the characteristics of a particular site are planted within the watershed. At the top and along the ridges of hills, pines and grasses are planted. Mixed forests of conifers, broad-leaved trees and grasses are planted on the slopes. At foothills, fruit and bamboo trees are planted. More specifically, Masson Pines, Slash Pines, Schima and Lespedaza shrubs sps. are planted on southern slopes and at the top of the hills. Fruits trees with high economic value also are planted at the foot hills.
In Wuhua county, soil loss is aggravated by deforestation caused by over logging of forests for fuel, and by scraping of grasses for soil fertility improvement. Population growth has made the shortage of fuel in rural areas even more acute. The fuel shortage problem is treated by:
- planting fuel trees around houses, along roads and near river banks;- combining afforestation for controlling soil erosion with afforestation for growing fuel trees;
- popularising biogas and coal supplies;
- renovating cooking stoves to save fuel; and closing off hill slopes and opening them at a fixed time for cutting.
Management measures
Management is strengthened by setting up authorized organizations for closing off afforested hills. A special team responsible for closing off afforested hills has been set up. The team teaches the people about the importance of protecting forests and conserving soil and water, the importance of ecological balance, and relevant laws and rules. The team helps local inhabitants work out detailed regulations for closing off hill slopes.
Three types of contracts are signed between local Governments (i.e. experimental station) and individual farmers to carry out soil erosion control measures. These contracts are: contracts with a single household, contracts with several united households and contracts with professional teams (here in referred as contractor). The poor families, who can not afford the initial expenditure, are provided with seeds, plant and tools by the Government. The works carried out by such families are inspected after one year. If seedling survival rate is over 80% and structural measures are implemented with required quality, then more grant-in-aid is given to the farmers. There are three units of implementation who assume separate responsibilities to carry out soil and water conservation tasks. Firstly, experiment stations are run by experimental stations on hills with the support of local Government or by contracted households. Experiment stations produce nursery stock and provide technical guidance to the farmers. They assume all the cost of their experiments. The contractor carries out the works and supervises the management under the supervision of the station. The income generated is distributed among the experimental station, the local Government (village) and the contractor on 3:2:5 basis. In fact 20% of the Wupi watershed budget comes from this income. Secondly, some experiments in the farm fields are performed by local inhabitants, and not run directly by the experimental station. In these cases, the experimental station works out a comprehensive plan for controlling soil erosion and providing technical guidance. The experimental station subsidizes the cost of nursery stock and provides some tools, where as, the contractor takes charge of the implementation and management. Income is distributed among the experimental station, the village and the contractor on a 2:1:7 basis, respectively. 50 % of Wupi watershed budget comes from this income.
Before the Wupi river watershed was treated, the height of the main river bed was higher than neighbouring fields. Beds of the tributaries were also higher than fields because of siltation. A series of engineering works, such as construction of reservoirs and ponds, have been built along the tributaries to control soil and water erosion and to reduce the number of disasters caused by droughts and floods. These activities reduced the flood by 30 % and the sediment flow by 40 %.
The width of the original Wupi river channel was not uniform. In the middle and lower reaches, it varied from 24-50 m. The slope of the longitudinal bed was 1/250-1/400. To improve the situation, the river was straightened and trained which shortened the river length by 282 m. The width of the river was reduced by one-third, thus enlarging the cultivated area by 82 mu. The river bed was deepened by 0.5 to 1 m. Its hanks were reinforced with masonry and six cascade weirs to prevent scouring. The slope of the river bed was reduced to 1/450.
Due to the serious problems of soil erosion. the agriculture production was low. Soils are sandy yellow, and clayey, and the areas are swampy and cold bed fields especially have low agricultural production. Measures taken to improve these lands include: regulating the irrigation and drainage systems; planting green manure crops; applying organic fertilizer: deepening the cultivated depth; improving the soil by mixing it with sand: rotating crops of rice and sweet potato: excavating cold spring and irrigation ditches: and removing shrubs and weeds around fields.
Remarkable benefits have been derived from comprehensive, concentrated and continuous erosion control measures in the Wupi river basin (Wuhua Soil and Water Conservation office. 1994).
Reduction in soil and water losses
According to the investigation of the Guangdong Provincial Bureau of Water Resources and Electric Power, the annual rate of erosion in the Wupi river basin was estimated at 6262 ton/km2/yr. The erosion control program carried out since 1982 has reduced the annual rate of erosion to be only 217 ton/km2, today. The height of the river bed decreased by an average of 1.7 m, and the river is now perennial. The flood flow regulation and the irrigation of crops have reduced drought (for 2 months period) on 1,300 mu of farm lands along the banks of the river. Thus, the soil loss has decreased and the threat of floods and droughts have been mitigated significantly. Also, crop production has increased and the standard of living of the people has improved.
Improvement in ecology and environment
Over 30 years of erosion control works, the area covered by vegetation increased from 10-80 %. In 1982, afforested land cover was only 6,775 ha. By the end of 1989, forest land cover was increased by 44.8% of the total hilly land. Vegetation management practices included planting forests on the top of mountains and planting fruit trees in the middle hill and in the lower part of the slopes.
Change in local climate
After constructing reservoirs, ponds and check dams, the conditions of the farmland have improved significantly. Change in local climate such as the changes in air temperature (summer temp. reduced by 14° C) and humidity (summer RH increased by 8.8%) has occurred after implementing soil erosion control works in the Wupi river watershed.
Soil fertility improvement
The soil fertility has improved from 14 to 47 times compared to that of hare mountains (total C+ -0.389%. total N - 0.015 %). depending on the type of forest or ground cover introduced.
The agricultural system has changed significantly since 1980, as has the economic structure. The ratio of income from agriculture:forest:pasture: other activities (include cash crops, livestock and fisheries) changed from 68:5:9:18 in 1980 to 45:2:5:48 in 1989, respectively. At present, the total forest land area is 17,860 mu which is about 65.7% of the total areas of the Wupi watershed. Economic forests are now spread over an area of 557 mu, or 3.5 % of the total forest lands. Thus, the ratio of agriculture income has decreased due to decrease in agriculture area while the income from other activities e.g. livestock, cash trees, fisheries and other economic activities has increased. Appropriate policies on people's participation through contractual arrangements have enhanced the participation of the people in the soil conservation works. Significant change also occurred in the development of specialized household systems. By the end of 1989, there were 7 brick kilns. 28 households specialized in animal breeding, and 67 households in transportation with 11 automobiles and 96 tractors.
Within eight years till 1994. trees and grasses have been planted on 26,885 ha of barren mountainous areas. Water conservation forests were planted on a total area of 13,296 ha, fuel forests on 12,960 ha and economic forests on 6,632 ha. About 1,626 ha of crop lands were converted into forest land and 91,333 ha of hills were closed off to protect the forest. Grasses were planted on 5,773 ha. The total vegetative area has increased from 108,826 ha (33.9%) to 277,333 ha (66 %). The accumulated forest volume increased from 1,238,000 m3 to 2,030,000 m3 and the volume of forest logging decreased from 45,300 m3 to 14,050 m3. Thus, the barren mountain slopes have disappeared practically from Wuhua County. The change in income due to over all land use change before (1985) and after (1993) soil conservation program was implemented through the family or other contract systems of people's participation is given in Table 4. The agriculture income decreased from 54.46% to 42.9% while all other income increased significantly (Table 4).
Total area treated from 1985-93 by engineering soil conservation measures and land use measures in the county is 846 Km2. This has checked a total soil loss of 1,419.300 tons. This includes 564,500 tons checked by terracing and level ditches, 261.800 tons from gully control by check dams, 573,000 tons checked from soil collapses by check dams. These measures are coupled with vegetative measures/cover. The relationship between the vegetation cover and soil loss is given in Table 5.
Table 4: Changes in income (in million Yuan, Y) due to change in land use practices before (1985) and after (1993) soil conservation program through various contract systems of people's participation
|
Year |
Total output (106 Y) |
Cash trees |
Forest |
Animal hush. |
Livestock |
Fisheries |
|
1985 |
24827 |
13522 |
1290.86 |
7874.41 |
419.7 |
419.7 |
|
1988 |
36880 |
16511 |
2386.51 |
13778 |
3861.5 |
544.9 |
|
1993 |
160759 |
26048 |
2372 |
26097 |
3747 |
2695 |
Table 5: Relationship between cover and soil loss
|
Items |
Barren land |
Vegetative coverage area |
||
|
50 % |
60% |
80% |
||
|
Annual precipitation (mm) |
434.7 |
434.7 |
434.7 |
434.7 |
|
Annual runoff (m3/km2) |
179340 |
153290 |
143920 |
126360 |
|
Annual soil loss (m3/km2) |
6262.2 |
1199.2 |
1016.4 |
268 |
|
Maximum soil loss (m3/km2) |
1868 |
566 |
312.3 |
116.5 |
Soil and water conservation program in the Wuhua county by various contractual arrangements with the farmers has transformed the small watersheds into marketable commodity production systems bases. In mountainous areas, cash crop trees are planted in terraced farmlands. Pineapple, plum, shatian, shaddock, litchi, pepper, mango, tea, banana, carambola, papaya, citrus, agro-forestry, livestock, and aquatic products have been produced with high market value. The per capita food produced has remained same due to reduction in agricultural area, but the per capita income has increased 4-5 folds. This is a result of the success of the various contractual arrangements made by the Governments for people' participation in the small watershed based natural resources management by leasing the lands from 20-50 years duration.
Table 6: Change in farmer's income before (1985) and after (1993) soil conservation program with farmer's contractual arrangement in Wuhua County
|
year |
total agricultural income |
total food output |
per capita food availability (kg) |
income per capita (yuan) |
|
1985 |
24827.60 |
5118292 |
283.5 |
280 |
|
1988 |
36881 |
5265870 |
275 |
531 |
|
1991 |
49312 |
5605880 |
301.5 |
763 |
|
1993 |
60756 |
5536920 |
292 |
1276 |
My sincere appreciation goes to the following institutes who were extremely helpful during this study: the Department of Water and Soil Conservation, the Guangdong Bureau of Water Resources and Hydroelectric Power, the Wuhua Water and Soil Conservation Office, the Water and Soil Conservation Office of Mezhou, the Experimental Stations in Wuhua, Hesi and Deqing Counties, Guangdong Province, the Institute of Geography, South China Institute of Botany, Academia Sinica, the South China Normal University, communities of Wuhua County, and Guangdong province. Special thanks to Mr. Prem. N. Sharma CTA/RC Watershed Management/FARM, RAS/93/063, who visited Wuhua to help initiate this study. In addition, I would like to express my sincere thanks to the all individuals who helped shape this study.
Deyi, Wu. 1994. Agro-forestry Applied in Watershed Management in China. Course on farm/agro-forestry technologies, extension, and marketing in the Asia. APAN/CAF.
Deyi, Wu. 1995. State of Art and Status of watershed Management in China. Published in The status of Watershed Management in Asia WMTUH/FARM Field Doc. # 1, pp 7-18.
Division of Soil and Water Conservation, Guangdong Bureau of Water Conservancy and Hydroelectric Power. 1994. "Report on Soil and Water Conservation, Guangdong, China.
Guo Tingfu. 1994. Report on Soil and Water Conservation in China.
Guanzhou Institute of Geography & University of Toronto. 1994. Report on Soil Erosion and Land Management in the Granite Region of Guangdong province South China.
Wuhua Soil and Water Conservation Office. 1994. Report on Soil Erosion and Its Control in Wuhua county.
Wang Zhuhao. 1994. Report on Ecosystem in Tropical and Sub-tropical Waste Lowland in Gangdong Province. South China Institute of Botany, Academia Sinica.
Wuhua Soil and Water Conservation Office. 1994. Report on Wupi River Watershed Management.
