Silting of Togo inshore sedimentary basin rivers and protection measures: Case of Zio river

5 SOLUTION APPROACHES OF RIVER SILTING UP AND BASIN

DEGRADATION

Zio basin can be considered as a territorial entity, ecologically rich which would have known in the pass an environmental stability. But, nowadays, the situation of strongly increasing population it undergoes a considerable degradation of its natural resources such as forest formations. The major environmental problems in the basin are:

· Deforestation about culture, charcoal and wood production;

· Soil impoverishment by hydrous erosion and human factors;

· River banks instability (degradation);

· Zio River silting up and water resources lacking;

· Eutrophication;

· Air and hydrous pollution;

· Biological diversity in loss;

· Desertification (soil degradation ...).

Solution of these problems requires urgent measures of environmental protection and dispositions go from defense to respect basin dynamics function. In fact, the problem of management of the basin environment and natural resources arise in term of prevention and conservation: prevention of the damage which can inflict the combined effects of poverty and development efforts and rare resources conservation and fragile forest ecosystems.

This study proposes to make a global and integrated solution of the environmental problems. Thus, it considers a multitude effective solution experimented in the country or in the West Africa to fight in general against erosion and river silting. Process, regarding basin reforested by »Taungya system» with idea to promote agroforestry, and to manage effectively bush fires practice, to protect the biodiversity, to sensitize the bordering populations, to limit or control eutrophication, to practice inexpensive anti-erosive measurements and control soil erosion.

Agroforestry, an innovative farming approach includes the culture of the trees and shrubs providing, fruits, nuts, fibres, medicinal substances, heating and work wood. Experiences show that this mode improves peasant food, also other existing conditions. Tongya technical allows the peasants to associate crop and wood production.

5.1 Basin reforestation and fire management

Reforestation is replanting and maintaining the trees, keystone of fight against deforestation, desertification and soil impoverishment. Basin vegetable cover degradation appears like thorough that the idea of a systematic prohibition of any form of exploitation comes at to mind. Also, the regulation is the legal way to submit the wood owners to the principles of environmental and natural resources protection.

However, it will be more judicious to intensify the national policy of reforest instituted since 1977 (1 st June, Tree Day) in the basin. Rehabilitation of the old clearings is an alternative to be considered.

In a general way, efforts of reforestation are far from compensating the fires destruction often practiced by the peasant breeders to facilitate herbaceous carpet pushes back for the pasture. In addition to the suitable regulation for the practice of fire, restraint measures considered relate to the massive introduction of fodder species of substitution making allow herds to wait the first rains and the new vegetable.

For this forest settlement or natural vegetation restoration, several objectives can be associated through the wood production or firewood for other uses, such as agroforestry, timbering of the village tributary of the river regarding Taungya principles following the strategy proposed in Table 7 below:

Table 7: Agroforestry strategy to limit erosion effect in basin

Agroforestry practice	Category Species		Propagation Method	Uses
Live-fencing and basin boundaries	Chosen following soils taxation (vocation, study)	Exotic (E)	Cuttings Cutting/seed Seed, Suckers	Protection, Fibre Fruit, Timber/Poles Fuelwood & Windbreak Protection
		Indigenous (In)	Truncheons Truncheons/Seed Seed left to grow	Protection, Fruit, Firewood, Timber, Medicinal, Fodder, Seed, Shade Nutrients Alleviation Protection
Trees in Pasture Land
Vegetable Garden/Homesteads		E	Left to Grow/Planted Left to Grow	Shade, Fodder, Fertilizer, Fruit, Timber, Fuelwood
		In	Left to Grow/Planted	Timber, Shade, Seed
Trees in Cropland Conservation Structures
		E	Seed/Buds Seed, Sucker Seed/Graft Cutting	Fruit, Fuelwood, Poles Medicine
		In	Left to Grow Left to Grow/Planted	Fruit, Fuelwood, Poles Medicine, Timber Nuts, Sculpture
		E	Seed/Graft, Seed Planted	Fruit, Shade, Poles Timber, Fuelwood
		In	Left to Grow/Planted Left to Grow	Live fencing & Medicine, Poles Fuelwood, Fodder Carvings, Shade, Food, Fruit, Fertilizer