GEOGRAPHY AND POPULATION
The Sultanate of Oman occupies the south-eastern corner of the Arabian Peninsula and has a total area of 312 500 km². It is bordered in the north-west by the United Arab Emirates, in the west by Saudi Arabia and in the south-west by Yemen. A detached area of Oman, separated from the rest of the country by the United Arab Emirates, lies at the tip of the Musandam Peninsula, on the southern shore of the Strait of Hormuz. The country has a coastalline of almost 1 700 km, from the Strait of Hormuz in the north to the borders of the Republic of Yemen in the south-west, overlooking three seas: the Persian Gulf, the Gulf of Oman and the Arabian Sea.
Oman can be divided into the following physiographic regions:
The cultivable area has been estimated at 2.2 million ha, which is 7% of the total area of the country. The cultivated area was 61 550 ha in 1993, of which 18 550 ha consisted of annual crops and 43 000 ha consisted of permanent crops. Over half the agricultural area is located in the Batinah Plain in the north which has a total area representing about 3 % of the area of the country.
The total population is about 2.16 million (1995), of which 87% is rural according to United Nations estimates.
According to the national population census of 1993, 28% of the total population was rural. The difference between the two figures is explained by the fact that the UN standards for Oman consider as rural all the inhabitants of the country, except those of the two cities: Muscat and Matrah. The annual demographic growth rate is estimated at 3.7%. While agriculture and fisheries employed about 37 % of the total labour force in 1993, they accounted for only 3.3% of GDP.
TABLE 1 - Basic statistics and population
|Area of the country||1995||31250000||ha|
|Cultivable area||1990||2 200 000||ha|
|Cultivated area||1993||61 550||ha|
|- annual crops||1993||18 550||ha|
|- permanent crops||1993||43 000||ha|
|Total population||1995||2 163 000||inhabitants|
|Water supply coverage:|
TABLE 2 - Water: sources and use
|Renewable water resources:|
|Internal renewable water resources||0.985||km³/yr|
|Total (actual) renewable water resources||1995||0.985||km³/yr|
|Total (actual) renewable water resources per inhabitant||1995||455||m³/yr|
|Total dam capacity||1996||58||106 m³|
|- agricultural||1991||1 148||106 m³/yr|
|- domestic||1991||56||106 m³/yr|
|- industrial||1991||19||106 m³/yr|
|Total water withdrawal||1 223||106 m³/yr|
|as % of total (actual) renewable water resources||124||%|
|Other water withdrawal||-||106 m³/yr|
|Average groundwater depletion||-||106 m³/yr|
|Wastewater - Non-conventional water sources|
|- produced wastewater||1991||58||106 m³/yr|
|-treated wastewater||1991||28||106 m³/yr|
|- reused treated wastewater||1991||26||106 m³/yr|
|Desalinated water||1995||34||106 m³/yr|
CLIMATE AND WATER RESOURCES
The climate differs from one region to another. It is hot and humid during summer in the coastal areas and hot and dry in the interior regions with the exception of some higher lands and the southern Dhofar region, where the climate remains moderate throughout the year. In the north and centre of Oman rainfall occurs during the winter (November-April), while in the south and some internal parts of the country it is a result of seasonal summer storms (June-September). Average annual rainfall has been estimated at 55 mm, varying from less than 20 mm in the internal desert regions to over 300 mm in the mountain areas.
A great deal of uncertainty lies in the assessment of Oman's water resources. Internal renewable water resources have been evaluated at 985 million m³/year. Surface water resources are scarce. In nearly all wadis, surface runoff occurs only for some hours or up to a few days after a storm, in the form of rapidly rising and falling flood flows. Since 1985, 15 major recharge dams have been constructed together with many smaller structures, in order to retain a portion of the peak flows, thus allowing more opportunity for groundwater recharge. In addition, several flood control dams produce significant recharge benefits. In 1996, the total dam capacity is 58 million m³. Groundwater recharge is estimated at 955 million m³/year.
Non-conventional water sources
In 1995, the total produced wastewater was estimated at 58 million m³. Only 28 million m³ was treated, of which 26 million m³ was reused. Also in 1995, the quantity of desalinated water was 34 million m³.
TABLE 3 - Irrigation and drainage
|1. Full or partial control irrigation: equipped area||1993||61 550||ha|
|- surface irrigation||1993||57 820||ha|
|- sprinkler irrigation||1993||1 640||ha|
|- micro-irrigation||1993||2 090||ha|
|% of area irrigated from groundwater||1993||100||%|
|% of area irrigated from surface water||1993||0||%|
|% of area irrigated from non-conventional sources||1993||0||%|
|% of equipped area actually irrigated||1993||100||%|
|2. Spate irrigation area||-||ha|
|3. Equipped wetland and inland valley bottoms (i.v.b.)||-||ha|
|Total irrigation (1 +2+3)||1993||61 550||ha|
|- as % of cultivated area||100||%|
|4. Flood recession cropping area||-||ha|
|Total water managed area (1 +2+3+4)||1993||61 550||ha|
|- as % of cultivated area||100||%|
|- increase over last 10 years||-||%|
|- power irrigated area as % of water managed area||1993||100||%|
|Full or partial control irrigation schemes: Criteria|
|Large-scale schemes > - ha||-||ha|
|Small-scale schemes < - ha||-||ha|
|Total number of households in irrigation||1993||62 411|
|Total irrigated grain production||1994||18 900||tons|
|as % of total grain production||1994||100||%|
|Harvested crops under irrigation (full or partial control)||1993||70 930||ha|
|- permanent crops: total||1993||43 000||ha|
|- annual crops: total||1993||27 930||ha|
|, fodder crops (mainly alfalfa!||1993||17 330||ha|
|. vegetables||1993||5 700||ha|
|. cereals||1993||4 900||ha|
|Drainage - Environment:|
|as % of cultivated area||-||%|
|- drained areas in full or partial control irrigated areas||-||ha|
|- drained areas in equipped wetland and i.v.b||-||ha|
|- other drained areas||-||ha|
|- total drained area with subsurface drains||-||ha|
|- total drained area with surface drains||-||ha|
|Area salinized by irrigation||-||ha|
|Population affected by water-borne diseases||-||inhabitants|
In 1995, total water withdrawal was 1 223 million m³, of which almost 94 % for agricultural purposes (Figure 1). The treated wastewater was reused mainly for the irrigation of trees along the roads, while the desalinated water was used for domestic purposes. At present, groundwater depletion is thus estimated at around 240 million m³/year.
Figure 1 - Water withdrawal (total: 1.2 km³ in 1991)
IRRIGATION AND DRAINAGE
All agriculture in Oman is irrigated and since the 1970s the equipped area increased from about 28 000 ha to 61 550 ha in 1993 (Figure 2), of which 34 930 ha, or almost 57%, is located in the Al Batinah province in the north. Although 2.2 million ha are considered to be suitable for agriculture, there are no figure on the irrigation potential, as no reliable data are available on groundwater availability in the deep aquifers. At present groundwater depletion already takes place, especially in coastal areas, leading to sea water intrusion and a deterioration in the water quality.
Figure 2 - Evolution of the irrigated area
Figure 3 - Sources of water of the households involved in irrigation (total: 62 411 households en 1993)
The falaj system ('aflaj' in the plural) is the traditional method developed centuries ago for supplying water for irrigation and domestic purposes. Many of the systems currently in use are estimated to be over a thousand years old. The falaj comprises the entire system: the source, which might be a qanat, a spring or the upper reaches of flowing wadis from which water is diverted; the conveyance system, which is usually an open earth or cement-lined ditch; and the delivery system. The falaj has assumed social significance, and wellestablished rules of usage, maintenance and administration have evolved.
Originally, the falaj developed where higher elevation water sources such as springs, qanats or surface water could be intercepted by diversion or small catchment dams and then conveyed by gravity to the point of use. More recently, however, dug wells have been used to supplement the falaj water. This is especially the case in the coastal areas where many hand-dug wells and tubewells have been constructed. For 47% of the total number of 62 411 households involved in irrigation, wells are now the main source of water, 39% rely on falaj water, while the remaining 14% have access to both sources (Figure 3).
Figure 4 - Irrigation techniques f/p (total: 61 550 ha in 1993)
Of the total area of 61 550 ha equipped for irrigation, all of which is power irrigated using groundwater (wells, falaj), only 1 640 ha, or 2.7%, benefit from sprinkler irrigation and 2090 ha, or 3.4%, from micro-irrigation techniques (Figure 4). Although the Ministry of Agriculture and Fisheries (MAF) is making efforts to introduce modern irrigation techniques, the traditional flood system remains the most common irrigation technique. In order to encourage farmers to take up the new techniques, MAF has approved a financial subsidy varying between 75 % for small-scale schemes (less than 10 feddans or 4.2 ha), 50% for medium-scale schemes and 25% for large-scale schemes (more than 50 feddans or 21 ha). Most of the area consists of small schemes.
In 1996, the cost of irrigation development was estimated at $US 3 250/ha for medium and large schemes and $US 4 415/ha for small schemes. These costs represent the average cost of installing sprinkler irrigation and micro-irrigation systems. The average annual operation and maintenance costs are $US 845, 1 170 and 1 820/ha for large, medium and small schemes respectively.
Date palm is the main crop grown in Oman, occupying about half the total cropped area. Other crops are fodder crops (mainly alfalfa), other fruit trees (citrus, bananas, mangoes, coconuts) vegetables and cereals (mainly barley, wheat and sorghum) (Figure 5).
Figure 5 - Irrigated crops f/p (total: 70 930 ha in 1993)
No reliable information on the area salinized by irrigation is available. A study done in 1994 on the salinity of soils in general in Oman, states that an area of 11.7 million ha, which is 35 % of the total area of Oman, is affected by salinity. No drainage is practiced.
The Ministry of Water Resources (MOOR) is in charge of water resources assessment, whereas the Ministry of Agriculture and Fisheries (MAF) is in charge of irrigation.
In 1988, Royal Decree No. 83/88 declared the water resources of Oman a national resource. This is the most far-reaching and important piece of legislation on water resources. Oman has several laws on water resources and the main measures taken for water management and conservation are:
TRENDS TN WATER RESOURCES ASSESSMENT
Three broadly-based programmes have been set up by the government for:
In addition to the above measures taken for water management and conservation, the government has recently initiated programmes to relocate some of the large-scale farms in the Batinah and Salalah Plains, where the water resources are over-utilized, to areas with underutilized water resources. Several water conservation initiatives have been developed, like leakage control in municipal water supply schemes and the improvement of irrigation methods through subsidy programmes. Public awareness of water resources issues has created a general and focused understanding of the overall situation and of the specific contribution each citizen can make.
The main issues and strategies that the government will address in the coming years are:
MAIN SOURCES OF INFORMATION
Department of Agricultural Statistics. 1995. Agricultural Census 1992-93. Ministry of Agriculture and Fisheries.
Ministry of Agriculture and Fisheries. [?]. Development and optimization of the use of water resources in the Sultanate of Oman.
Ministry of Water Resources. 1991. National Water resources Master Plan. Oman.
World Bank. 1988. Sultanate of Oman: Recent economic developments and prospects. Report No 6899-OM. Washington DC.