Asmat District’s Territory and Boundaries

Asmat district is situated in the south area of Papua provice, 137-140 East longitude and 4-7 South latitude and 23,746 km² of width. Administratively, the government of Asmat district consists of 7 sub-districts and 139 villages. It borders on

• Jayawijaya and Yahokimo districts in North
• Arafuru sea and Mappi district in South
• Mimika district in West, and
• Mappi and Boven Digoel districts in East.

Geographically, the district is adjacent to Arafuru Sea that becomes the bridge connecting the district to Australia and other Pacific areas. The position is very advantageous in term of economic accessibility. The sub-district Sawa Erma is the widest one. It is 6,974 km² of width or 29.36% of the district and the sub-district Fayit is the smallest one. It is 967 km² or 4.07% of the district.

TOPOGRAPHY

The topographically, Asmat district lies in lowland area of 0-100 meters above sea level. It indicates that the majority of its territory is flooded all year long. The topographic condition of the district can be described on the basis of above sea level height and land slope below.

Above Sea Level Height

The above sea level height of an area does not significantly influence the growth of plants. However, climate change has a direct impact on the growth of plants because of the difference in the height that causes the difference in temperature.

The height of an area is closely related to the terrain configuration, rainfall, and water availability and hence it influences the use of the land in certain area. Concerning with the development in the use of land in Indonesia there are some primary heights that plays an important role in the use of land in Indonesia. Based on the topographic map, Asmat district is situated in 0 meter to 100 meters above sea level.

The table below summarizes the height of the areas of the district.

Land Slope

Land slope represents one of the influencing factors in the land management. Also, it has a significant influence on the erosion of wider area of land. The use of sloping land will cause the instability of water debit in the downstream areas. It is because the run off of the upper stream is uncontrolled. The table below summarizes the details of the areas based on the land slope in the sub-districts of Asmat district.

Area Width Based on the Land Slope in Asmat District

Texture

Texture is the rough or fine condition of organic solid materials determined on the basis of the comparison of the sand/clay and dust fractions. The content of each of the fractions influences the land processing and the growth of plants, especially in regulating the air content of the soil and the air supply of the soil. Land texture gives significant impact to the erosion rate of the land layers.

Concerning with the aforementioned classifications, the details of Asmat district according to the texture of its land are summarized in the table below.

Ground Effective Depth

Ground effective depth is the depth that can be penetrated by the roots of plants to absorb the nutrition necessary for their growth. The inability of the roots to penetrate the ground is caused by the presence of a layer impenetrable by the roots and it represents the limit of the ground effective depth. The depth is classified into 5, which are:

Based on the aforementioned classification, Asmat district is classified according to the ground effective depth as summarized in table below.

Drainage

Ground drainage is the velocity of water dissipation into ground. An area with a good drainage is the one with quick water dissipation into ground. On the contrary, an area with a bad drainage is the one with slow water dissipation into ground and the ground becomes water-saturated.

The term drainage includes surface drainage, saving water drainage and permeability drainage. However, it is the surface drainage data that is presented for the purpose of the preparation of Asmat district profile by determining the relative comparison of the water inundating durations of certain areas. The drainage classification is determined on the basis of the velocity of water dissipation into ground and it results in the followings: never inundated, periodically inundated, and constantly inundated.

Ground Acidity

The information of the ground acidity is useful in the preservation of the ground. The ground with high acidity is neutralized by calcifying it or adding alkaline fertilizer.

The ground acidity may be classified into:

Climate

The climate of an area is the life supporting factor on earth. It is one of the factors that can not controlled by human being. Therefore, human being has to adapt to it. It is also the case of crops and plants in agricultural area to enhance agricultural production.

For an area with hot climate as Indonesia, the climate and its change have significant influence on the growth of crops and plants. So, it is the difference in the above sea level height of an area that determined the climate and not the time.

The difference in the above sea level height results in the difference in the temperature. The average annual temperature of lowland is 26 ^oC and it decreases about 0.6 ^oC in every 100 increase in the height. The element of the climate that has a significant influence on the growth of crops and agricultural plants is rainfall. The climate of Asmat district varies from an area to another. There are dry areas that are situated in south coast because of the influence of dry wind blowing from Australia continent. The wet areas of the district are situated in the North with high rainfall.

Southeast monsoon wind blows in the period of May to November from Australia continent. It blows in the periods of the months in which the sun is north of the equator that causes the areas with low air pressure. The monsoon wind does not contain much humidity because it blows from the continent with savannah and infertile land. It is felt especially in the south coastal area of the district.

Northwest monsoon wind blows in the period of December to April and has the characteristics that are different from the Southeast monsoon wind. It blows from Asian mainland and the sun is south of equator and causes low air pressure in the area. The Northwest monsoon blows with high humidity because it blows through wide areas and most of the areas are ocean and sea. Therefore, it brings rain, especially in the North areas of Asmat district.

The Southeast and Northwest monsoon winds blows at the velocity from 0.5-1.5 meter/second in evening and morning, while at noon it blows at the velocity from 3-4 meter/second. Actually, Northwest monsoon wind blows at higher velocity than the Southeast monsoon wind. The Northwest monsoon influences the West areas and some South areas of Asmat district.

Considering the position of Asmat district, which is in equatorial area, it has the average temperatures from 26-27 ^oC with the maximum average temperature 30.1-32.2 ^oC and the minimum average temperature 20.1-24.6 ^oC.

The absolute maximum temperature is in the range of 32.6-38.8 ^oC, while the absolute minimum temperature is in the range of 14.8-22.4 ^oC with the decrease in the temperature that is proportional with the increase in the above sea level height.  Every 100 meters increase in the height causes 0.6 ^oC decrease in the temperature. The air humidity in the district is generally high. The causal factor of the high humidity is that the winds that blow to the areas of the district come from wide areas of ocean and sea surrounding the district. The high humidity is not balanced with low temperature and it has typical influence on the district.