this point with an imaginary straight line until "km 160". Climate The temperature reaches 44 °C in summer and drops to 0 °C in winter, the average temperature is 26 °C. The average amount of precipitation is between 900 and 1,200 millimeters annually. Hydrography The Paraguay River forms one border of the department. The tributary rivers Pilcomayo, San Carlos, Siete Puntas, Negro, Verde, Montelindo, Aguaray Guazú, and Confuso also flow through the department but are not navigable for big ships. To the south lies the Patiño Swamp. The city of Villa Hayes floods frequently when the rivers overflow. The land elsewhere in the department is higher. Environment There are four ecosystems in the Chaco territory: the floodplain of the Paraguay River, Pozo Azul, Laguna Salada, and the Floodplain of the Pilcomayo River. The Pilcomayo River's deviation towards Argentina has produced several changes in the habits of the people; the drought causes the migration of the jacarés to most humid areas and spreads diseases. Endangered flora include timbó, samu'u, white and red quebracho, and karanday and endangered fauna include carpincho, jurumi, jacaré, and tapir. The east has saline soil and the south has calcareous soil. The hills Confuso, Siete Cabezas and Galván are small elevations. Economy Industry and business Presidente Hayes leads Paraguay in production of cattle, and is second in production of horses. The population is heavily involved in agriculture; the department is third place in production of sorghum. Cotton and sugarcane are also agricultural products of the area; Villa Hayes and Benjamín Aceval are notable for production of sugarcane. In Villa Hayes are the sugar factory Censi and Pirota. Sawmills, ceramic factories and steel mills are also in the city. ACEPAR, Aceros del Paraguay, is an important iron and steel industry and is also located in Villa Hayes. In addition, in Villa Hayes is Astillero Chaco Paraguayo S.A., a specialising in the construction of launches for heavy loads, fuel and vegetable oil transportation. There is also soap and lime factories and an ESSO plant of fuel and lubricants. Puerto Falcón trades heavily with Argentina and also sees a lot of tourism. Tinfunqué National Park is a major tourist attraction with an area of 280,000 hectares. Transportation and services The most important way of transportation is Route No. 9 "Carlos Antonio López" also known as "Transchaco", which cross the Paraguay River through the Remanso Bridge and extends to Bolivia. The