Not A drop to drink in the land of the rivers is a long documentary, produced and written by Aziz Sanghur. Mr. Sanghur is documentary film-maker. The documentary shows that global warming is now a reality, as is evident from the increase in global average atmospheric and oceanic temperatures and widespread melting of snow and ice. Glaciers in Karakoram, Rakaphoshi and Nangaparbat are Pakistan's primary source of water. But some predict that global warming could consume the glaciers in as little as 40 years. In Pakistan, the most dangerous aspect of glacial melting is the large lakes left behind, potential sources of destructive flooding. The rainfall is greatly reduced and highly erratic. The drought and shrinking reservoirs also hurt agricultural productivity. Cotton, rice, sugarcane and maize yields fell by various degrees. The Indus Waters Treaty is a water-sharing treaty between the Republic of India and Islamic Republic of Pakistan, brokered by the World Bank. The Indus System of Rivers comprises three Western Rivers the Indus, the Jhelum and Chenab and three Eastern Rivers - the Sutlej, the Beas and the Ravi; and with minor exceptions, the treaty gives India exclusive use of all of the waters of the Eastern Rivers and their tributaries before the point where the rivers enter Pakistan. Similarly, Pakistan has exclusive use of the Western Rivers. Pakistan also received one-time financial compensation for the loss of water from the Eastern Rivers. In 1970s, India blocked entire waters of River Satluj, Ravi and Bias which was a violation of all international laws as well as Indus Basin Treaty. Pakistan's principal natural resources are arable land and water. About 25% of Pakistan's total land area is under cultivation and is watered by one of the largest irrigation systems in the world. Pakistan irrigates three times more acres than Russia. The Indus River Delta, forms where the Indus River flows into the Arabian Sea in Pakistan. The natural flow of water and fertile sediments from Indus River into the delta has been impeded due to the construction of dams along the river. The population of the delta was estimated at 900,000 in 2003 (the total population of Indus River Delta-Arabian Sea mangroves was 1.2 million). Within the river delta, about 140,000 (16% of the population) depended on the mangrove forests for their livelihood, and 60% depended on the forests for fuels. At least 75% of the population in the active delta depend on the fishing industry. The population suffers from the lack of health facilities and medical staff. Only about a third of the population has access to clean drinking water. The Indus River Delta-Arabian Sea mangroves are a large mangrove ecoregion on the Arabian Sea coast of India and Pakistan. These mangroves are found in the Indus River delta on the Arabian sea, an even saltier estuary than usual due to the salts brought to the coast by the Indus from the Thar Desert, a process that is ongoing as the river is increasingly used for irrigation and water supply. Mangroves are an important habitat where salt and fresh water mix and support a range of plants specialised to survive in this salty environment, and large numbers of fishes and crustaceans that find food, shelter and oxygen in the waters beneath the tree roots. The climate is hot. Formers have blamed the design of Left Bank Outfall (LBOD) spinal drainage for inundation of large swathes of land in Tando Mohammad Khan, Badin and Mirpurkhas districts and displacement of a large number of people in rural Sindh. Freshwater capture fisheries are dominated by the Indus River and its tributaries. The fish fauna of the Indus system in its northern part is cold-water type, while the greater middle and southern parts of the system are warm-water zones. Fisheries in rivers and reservoirs account for more than 80 percent of total inland fish production. The riverine fishery management system is operated mainly by provincial fisheries departments. They enforce regulatory laws that restrict catch by size of fish and establish closed seasons.