Managing Watershed
 human activities on land took place in a region called the Watershed ( DAS ) is the area of ​​land bounded by a topographic ridge separator that receives rainwater and releases it into downstream and empties into the sea . DAS consists of several sub - watershed is a tributary that empties into the reservoir , dam , lake or river . Sub-watershed is often also referred to as Catchment or Catchment Area . Flood and landslide events reported by the mass media , occurs in a region called the watershed .
Many people associate the events of floods and landslides with illegal logging . There is also a mention due to abnormal channels and rivers , the river is not able to accommodate runoff because full of garbage , riparian areas and catchment areas used as residential . Flooding and landslides have always been big news because the harm and hardship on the people living in low areas or inhabiting the banks of a river or a sub-watershed . Facts show 1955 Batang Hari river floods inundate areas of Jambi , and it was there still intact forests . However , because the population was still sparse , flooding is not a serious problem . Now the increasingly dense population and inhabit the plains area , an area of ​​low and steep terrain . Few serious social problem arises flood ; landslides claimed .
Land Use
Why floods and landslides occur ? Land use in the watershed divided into: a ) Forest , usually located in the upper , b ) Cultivation area , plantation , agricultural , c ) Settlement , d ) Swamp , a lake , river banks , e ) Land industries , other danlain . Rain water in the watershed areas will experience several different events .
First , the rain water that falls in the forest area will be re- steam ( eveporasi ) , flowing sequence stems ( stemflow ) falling down to the ground or directly from branches , twigs and leaves directly into the ground . Because in general the surface layer of the forest soil is composed of organic material ( horizon O ) derived from the decomposition of plant material , then to the ground water will be easy to sink into the ground . Water that falls to the ground will be retained by a layer of undergrowth , bushes and shrubs form , as well as the humus layer of soil particles so little damage .
Second , usually intensively cultivated agricultural land , weeded , fertilized so the plants under clean . As a result of rain falling to the ground can be directly scatters on the surface of soil particles and soil erosion . The rain that falls directly from the sky to the land surface would disperse soil particles with energies greater so that erosion will be higher.
Especially just before the planting season , the land is usually cleared so that when the rains come , but the plants have not been able to protect the soil erosion will occur . The water seeped into the ground a little more than a stream flowing on the surface of the ground ( run- off ) that is capable of causing erosion and sediment flow into the river along transported .
Plantation crops serve the same or almost the same as forest plants . Because the understory ground cover plants that are able to withstand the blows rain . Water that falls to the ground will soak into the soil . Similarly, the surface flow is inhibited by plant cover , the rest went into the river . The volume of run- off is inhibited by  plant stands , as well as sediment .
Third , especially in  settlement consists mostly of building watertight ; roof , yard concrete , asphalt streets , concrete channels , so that the water is not given the opportunity to soak into the ground . As a result, almost all the rain water to flow into the main river and ended at the sea , reservoirs , and lakes , including all forms of waste transported . The more extensive or greater percentage of residential areas in a watershed , the greater the water coming into the river and potentially increase the volume of river water and cause flooding in the rainy season . Despite this erosion in urban residential areas are relatively small compared with rural or farming areas .
Fourth , rainwater that falls onto the surface of the water in the reservoir , lake , dam , or river will increase the volume of water that is directly reflected by the rise in water level . Directly does not cause erosion , but if the water flow then the flow rate will be able to scrape the wall / cliff line / water bodies and transport them downstream .
Flood plains ( flood plain ) is an area of ​​the river flow reserve . Under no circumstances exceed the normal flow of water , the water flow will satisfy the riverbanks . In case of rain unusually large ( 50 years or more cycles ) , the water will overflow into low areas around the riverbanks , riverbanks when not reserved for settlement . Remember 1955, the Jambi region experienced significant flooding although not many residents and forest intact . Similarly Solo River overflowed in 1966 resulted in many cities , including Solo, flooded .
Flooding , erosion , landslides and drought became serious problems faced by the community and the Government . Some areas of stagnant water , landslides , mudslides , road lines broke , and people isolated villages in the rainy season terberitakan in various media . In the dry season , the media carried stories of the people clean water shortages , thousands of hectares of rice puso lack of water , hydroelectric power generation capacity decreases , reservoirs and irrigation channels dry . If an area threatened crop failure , food shortages threaten other regions , and the Bulog food stocks threatened unfulfilled due to crop failure , so it must import . Extreme events alternating between the dry and rainy seasons .
Although it is a normal phenomenon , in fact the two events is due to increased human activity in exploiting natural resources . Exploitation without regard to sustainability will disrupt the natural balance , causing damage to humans . The damage should be prevented . For those who have not already damaged we must prevent the occurrence of damage . For those who are already damaged or need to be improved in order to recover our rehabilitation or close like before it breaks .
The author is a nature conservationist
Last modified : 16/03/08Soil and Water Conservation Prevent Flooding
By Dwiatmo Siswomartono
una reduce and prevent environmental damage , such as erosion and flooding , soil and water conservation is needed . Given the ongoing cause of erosion is the transport by water flow and water conservation is done by controlling the flow surface ( run- off ) and infiltrate it into the ground as much as possible .
We refer to the formula : E = f ( CTSVH ) . In this case , E = erosion , C = climate ( climate ) , T = topography ( degree of slope steepness and length ) , S = soil ( soil ) , V = vegetation ( ground cover ) , H = human ( human ) . That is , the size of the erosion is influenced by five factors , namely , the climate in this rainfall , topography , soil , vegetation , and human .
The greater the rainfall , the steep and long slopes or more , the easier tereroni ( erosip ) soil type , ground cover plants further apart , and increasingly intense man working the land without soil conservation measures , the greater will be the erosion and run- off . If the soil layer reaches saturation point of water especially in the lower layers are impermeable layer above the soil mass layer will float on the water , so it will be easy to slip as landslides . Conversely , if the rainfall is small , not steep topography , the soil is not easily crumbled , the meeting ground cover vegetation , and human land users are aware and know the importance of the conservation, erosion and run- off will be smaller reach the attrition rate allowed .
Soil and water conservation techniques implemented by adopting rain water can seep into the ground and not flowing at ground level . Mechanical control run- off and erosion can be divided into vegetatip soil conservation , soil conservation civil engineering , chemical and soil conservation .
Soil Conservation vegetatip implemented with the creation of the ground cover vegetation above ground . Basically all plants or vegetation plays provide good land cover . Based on a research report in the United States , the grass on the golf courses can serve as erosion control and run- off as well as forest cover . As long as the soil is not saturated soil water conservation vegetatip the very real control run - off , erosion , and landslides . But if the soil is already saturated water , the effect would be significant . Remember the flood at Edinburgh in 1955 where forests are still intact .
Soil conservation techniques implemented by the civil engineering building construction sepil a terrace ( gulud patio , terrace channels , credit porch , and patio benches ) to shorten the length of the slope and minimize the degree of slope . In buildings constructed sewer waterfall ( drop - structure of stone , wood , or bamboo ) . To accommodate sediment and run- off were already drifting or not restrained built retaining control dam and dam , so that sediment does not enter into the main river .
Chemical soil conservation carried out by means of chemicals , among others , for binding soil particles to resist abrasion , while providing fertility to the plants , so that the large and fast to be faster as planting soil surface protector . This method is more costly, so it is rarely applied .
Land Capability
Population density beyond the limit would lead to excessive exploitation of resources and the environment would destabilize and undermine the availability of resources . To that end , the carrying capacity of the land to be stabilized by reducing population pressure through transmigration .
As is known , the flooding in the Watershed ( DAS ) Solo childbirth government policy to rehabilitate the Upper Solo watershed in a comprehensive and integrated antarsemua stakeholders through the Integrated Project .
Its activities include the manufacture of Gajah Mungkur by the Department of Public Works , soil conservation and civil engineering vegetatip upstream catchment area that became Gajah Mungkur by the MoF and the Ministry of Agriculture , transmigration residents outside the watershed even outside the province by the Ministry of Transmigration and local governments , land titling agriculture by the land Board , as well as the provision of soft loans to farmers even without flowers participants soil conservation .
Watershed management is so that the utilization of natural resources is not beyond the limit , so that the carrying capacity of the land in the watershed to be maintained and not exceeded . Because human nature is the cause of damage to the person in charge of ensuring good watershed management is a society that manages the government and its watershed lands . Prevention of erosion , flooding , and landslides in the watershed becomes an obligation of all stakeholders .
The forestry sector should manage forests well , so it is always closed forest vegetation , and not the cause of the disaster . The agricultural sector to foster the use of land in agricultural and plantation areas to pay attention to the rules of conservation land , especially in dryland agriculture . Then , the public works sector in order to foster the flow of water does not overflow during the year , avoiding river banks for settlement , mapping flood-prone areas , and others .
Infiltration wells
In residential areas should be made much recharge wells that run- off water to seep into the soil to prevent erosion and increase soil water preparation . Open land should not be concreted , but with the construction of grass - block or porous construction . Building permit ( IMB ) shall require the construction of recharge wells each particular unit of land area . For the opening of large tracts of land by the developer required the manufacture of building soil conservation .
National Land Agency should include the obligation to preserve the land for rights holders on each certificate issued . Then open up the banking sector access to credit for farmers in the upper watershed to facilitate  in getting conservation farming , so that there is fairness between upstream and downstream farmers . During the floods and droughts in the downstream always addressed his guilt to farmers upstream .
Local governments should establish and remind its residents of the potential danger of flooding , erosion , landslides and drought . Industrial and mining sectors arranged for the use of firewood for burning lime and other industries with non - wooden replaced , for example , oil , residues , or other energy sources .
To try to get the surface water can seep into the ground as much as possible will increase the ground water reserves that will come to the surface as springs , so that flooding can be reduced , decreases erosion , and landslides do not occur .
The writer is an observer of nature conservation issues


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