Effects of Water Shortages: Climate, Health, Environment

1. Effects of Water Shortages: Climate, Health, Environment

2. Adaptations of plants and Animal species to Desert Climate: • Species limit activity entirely to moist periods of the year, while during dry periods they remain in a dormant form. For example, seeds in annual plants, the laying of eggs by some invertebrates, and pupae in the case of insects. Also limit activities to cool times, like dusk, night, dawn. • Species reduce, but do not stop their activity during droughts. For example, desert shrubs lose most of their foliage during the dry season. Also some rodents, snails, and other animals spend the dry season in estivation.

3. Species avoid drought by periodic migration to sources of water and developing mechanisms for absorbing water, or storing quantities of water in internal organs. • Other species are able to continue activity for long periods of time even in the absence of water supply. For example large mammals with specialized mechanisms for drought tolerance like the camel.

4. Drought: • The region is permanently arid because the warm tropical air masses descend to the earth’s surface and become hotter and drier. • Effects of drought are usually intensified by human activities and mismanagement of land such as increasing the desert by cutting down trees, building houses, and bad farming techniques. • Direct impact of droughts on environment are lower flows in rivers which mean lower levels of dissolved oxygen - which lowers the dilution capabilities of any waste discharges.

5. Main Env. results of water shortage: Over pumping of Aquifers • With recent drought aquifers being pumped at 10-40cm^3 per year. Term mining assigned because water-seemingly a renewable resource-being depleted making it unrenewable. • The lower water table resulting from over pumping results in a lower water pressure and permits lower quality of water to flow inward and contaminate fresh water in aquifers. • Large body of water being directly affected from over pumping is the Dead Sea. All of it’s fresh natural water sources are being diverted for agricultural uses.

6. The Dead Sea • Over pumping and mineral extraction by Israeli and Jordanian companies are drying up the dead sea at an alarming rate, close to 3 feet per year. • For millennia balance of the dead sea’s evaporation was maintained by the only source of fresh water, the Jordan river. Irrigation along the river by Jordan and Israel are robbing the sea of its only replacement water. • Without an intensive engineering effort the sea’s level will continue to recede, surrounding ground water will disappear, surrounding land will buckle and collapse and there will be a major loss of wildlife and vegetation.

7. Pollution of Watercourses • About 100 million acres of land are used for agriculture. Half of the land is irrigated, the other half rain-fed. • 95% of all land is sprayed with fertilizers and pesticides. Israel is one of the largest users of pesticides per hectare in the world. Runoff of these chemicals is very high and contributes to the non-point pollution sources in the water. Main non-point pollutants are chemicals such as phosphates, sediments, nitrogen, and pesticides.

8. Non-Point Source: Scattered or diffuse source of pollutants, such as runoff from fields, golf courses, construction sites, etc. • Point Source: A specific location of highly concentrated pollution discharge such as factories, power plants, sewage treatment plants, underground coal mines, and oil wells.

9. Irrigation: • Irrigation systems withdraw from surface and groundwater sources affecting the down flow hydrology. • Biggest problem is waterlogging and salinity. Salinity affects now 7% of the world’s irrigated land. The productivity of the land is significantly reduced. • Any pollution carried by the irrigation system will flow onto the fields when the water is distributed and pollution from pesticides and fertilizers can flow into the irrigation system.

10. Regulations on pesticide use is very relaxed and all but non-existent for agricultural runoff. • Some Irrigation water, which has much lower standards then drinking water, is now so contaminated with residues that it is unfit for use. • The entire governmental system for controlling pesticides is complicated by overlapping jurisdictions among the ministries of Agriculture, of Health, and Environment.

11. Drinking water and Sewage • As in North American cities, most of the sewage systems have begun to deteriorate or cannot handle growing demand. • Only 1/3 of sewage is treated to a high standard, 10% ends up in septic tanks, and 10% remains untreated. • The city of Jerusalem still discharges half of it’s wastewater into dry riverbeds (wadis) • The ministry of Health tests extensively for bacteriological contamination. Older sewage systems are being replaced but progress is slow because of budget constraints.

12. Health implications of Runoff and Chemicals • It is generally accepted that developed countries suffer from problems of chemical discharge into the groundwater sources. While developing countries face agricultural runoff in water sources. • Water polluted with chemicals leads to water borne diseases.

13. Waterborne diseases: • Hepatitis, cholera, dysentery, typhoid, and skin irritations are the more common water-borne diseases that affect large populations in the tropical regions. • Pesticides affect the endocrine and causes reproductive damage to wildlife. The organophospates and the carbonates present in pesticides affect and damage the nervous system and can cause cancer. • Nitrates in drinking water are fatal to infants that drink formula milk. It limits oxygen to the brain and can cause digestive tract cancers.