Ratih Fitria Putri



Wednesday, April 21, 2010

Geomorphology & Hydrology Aspect Analysis (Geographic Location and Government Administration) of Pacarejo & Mangunan, Bantul Regency, Yogyakarta


Geographic Location
A. The Village of Mangunan
The village of Mangunan belonging to the Dlingo Sub District, The Regency of Bantul, D.I.Y Province is a region located in southern slope of Mount Merapi. Its height above sea level is 400 m. Based on the Digital RBI Map 1 : 25.000, year 2000 and 2001, Imogiri sheet, Mangunan village has astronomic location in 110024’20” BT – 110026’30” BT dan 8055’05” LS – 8058’00” LS.
The village of Mangunan, Dlingo Sub District, Bantul Regency has the width of approximately ± 952.3715 Hectares, consisting of 6 subvillage (sub village) with administrative boundaries:




a. Western side : Girirejo village
b. Northern side : Wukirsari village
c. Eastern side : Muntuk village
d. Southern side : Sriharjo village

The village of Mangunan is located at 6 kilometers from the centre of Sub District, while from the peoplel of regency is 14 kiometers, and from D.I.Y province peoplel is 21 kilometers. The village is divided into six subvillage, they are Subvillage Cempluk, Subvillage Kanigoro, Subvillage Mangunan, Subvillage Sukorame, Subvillage Lemahbang, dan Subvillage Kediwung.

B. The Village of Pacarejo

Pacarejo village which belongs to Semanu Sub District, Gunung Kidul Regency, D. I .Y Province is a region situated in the southern side of the city of Wonosari. This region is located at 381 meters above sea level. Based on Digital RBI map 1 : 25.000, year 2000 and 2001,Semanu sheet, Wonosari, Karangduwet, and Karangmojo, Pacarejo village has the astronomic location at 110035’30” BT – 110038’30” BT and 08003’30” LS – 08003’30” LS.

The village of Pacarejo and Semanu Sub District, Gunung Kidul Regency has the width of ± 3693,181 Hectares, consisting of 29 subvillage with the adminitrative boundaries as below :

a. Western side : Mulo vilage and Duwet village, Wonosari Sub District
b. Northern side : Baleharjo village and Semanu village
c. Eastern side : Semanu village and Candirejo village
d. Southern side : Hargosari village, Tanjungsari Sub District

The village of is located 5 km from the village government centre, while from the regency peoplel is km, and the distance from the province peoplel D.I.Y is 49 km. The village is divided into 29 subvillage, they are Subvillage Banyumanik, Peyuyon, Serpeng Lor, Serpeng Wetan, Pacing Lor, Pacing Kidul, Tekik, Dorogayung, Ngampo, Dengok Kidul, Dengok Lor, Kuwon Kidul, Kuwon Tengah, Kuwon Lor, Trukanngampo, Kwangen Kidul, Kwangen Lor, Jasem lor, Jasem Kidul, Wilayu, Jetis Kulon, Kenteng, Jelok, Jonge, Jetis Wetan, Cempluk, Kuwangen Lor, Kuwangen Kidul, and Subvillage Tonggor.

Climatology of Mangunan Village

The climatic condition influences soil, rock, groundwater and area vegetation condition or. Rain is an influencing factor of land slide. The classification of rain use the classification from Schmidt dan Ferguson.
The calculation of region climate type of the study region is done by comparing the average rate of dry month and the average rate of wet moon. Dry moon are months with monthly rain rate of less than 60mm, while wet moon are months with rain rate of more than 100mm.
The climate condition of the study area is known through the calculation of rain rate data for 10 years, that is from year 1989 – 1999 from five rain gauge station located closest to the research area, they area Terong (200 mdpal), Barongan (60 mdpal), Playen (200 mdpal), Dogongan/Siluk (286 mdpal), and Giriwungu (264 mdpal).

Based on Q value, Schmidt and Ferguson determine type of rain in Indonesia as shown in picturer 3.2. Based on rain type classification from Schmidt dan Ferguson, Q value in the research region is about 0, 5 – 1, 5 . Therefore, type of climate A (very humid) and B (humid).

Based on the analysis using Koppen method, the region, in fact, belongs to the region with Aw climate type, that is humid – dry climate. Type A means that the temperature in the lowest month is more than 18ÂșC , while Aw means the amounts of rain in the wet months can not balance the lack of rain in the dry months, so in the dry season the region frequently lack in water. (meteorologically dry).



Topography dan Morphology

The morphology of Mangunan is varied from lowly flat terrains to steep slope.The difference of the height of the lowest point is 25 m above sea level, while the highest peak is 500 m above sea level. Lowly flat regions are situated in the south of the village and its topograpghy continue to rise up to the northern border of the Mangunan village. Generally, the morphology of the region is hilly, with slope inclination of 15-40%.

Pacarejo village in the Semanu Sub District has varied topography from flat, hilly, to wavy with the slope inclination of 3-30%. Most of the village regions have wavy morphology, while the flat and hilly morphology can only be found in certain places within the region of the village. The flat region is located in the south of Pacarejo village, to be precisely in Subvillage Banyumanik and Subvillage Peyuyon. The slope map of Mangunan and Pacarejo village is presented in picture.

Geomorphology and Soil


Geomorphology condition describes the land form and the process which cause the creation of the land form. The development of land form is determined by the denudation process and soil development, erosion, soil mass movement and or rock mass movemet, flood, sedimentation, marine abrasion, climate, ocean wave, earth gravity, and biology including human.

The land form classification used in this research is based on the classification made by BAKOSURTANAL ( 1985 ) in Prapto Suharsono (1988), which emphasizes on the genesis and topography. Geomorphology process in the research region can be known from its topography visibility through the interpretation of aerial photo.

The land form which is found in the research region is the land form from structural process, such as escarpment, uplifted hills, folded mountains, and the valleys between hills. This land form is highly controlled by structural processes which happen like fault, fold, uplifting, and is deeply related with litology and geology structure in this region. Soil has the ability to store, release, and percolate rain water. The condition of soil which influences such ability is the solum depth, permeability, and texture. The soil condition in the research region is known from Semi Detailed Soil Map of D. I. Y scale 1 : 50.000, year 1994 from The Agroclimate and Soil Research Centre, Bogor.

Hydrology Condition

A. Mangunan Village
The Mangunan Village belongs to the system of Oyo River Stream. The Rivers which flows in Mangunan Village almostly rivers with order one and shape a radial stream pattern. The large intensity of rain in the research amounts to 1412,2 – 2592,5 mm/yrs. Providing water supply for Oyo River. The available geology and geomorphology conditions are able to store ground water, so in several places there are springs.
Springs in the research area flow all year round and are found at the upper until middle slope. The lack of effort of land and water conservation causes decrease in the springs discharge around the village. Springs are used for every activities of people, either domestic or farming activities are delivered through water pipes or storing tub to the people and settlement.

Oyo river is the main river which flows across The Baturagung Hills Zone. The river is an intermittent river, so in the dry season the river seldom experience lack of water or low discharge. The main function of Oyo River is as a sources of irrigation for the farm fields along the banks of Oyo River. The rocks forming the base of Oyo River belong to The Oyo Formation with the main rocks are napalm and limestone. Materials often brought by the stream of Oyo River are Alluvium Sediment which originate from massive platform. Colluvium Sediment as pebbles and gravel are used by the surrounding people as mine material class C. The small rivers in the research area are mostly the river which only flow in the rainy season because of the lack of water supply and also because of the high inclination of the river base. The existing rivers also function as the carrier of erosion sediment.

The availability of water in the lower slope is still be influenced by the springs, either from the lower slope or the middle and the upper slope, also the river water. The water is used for irrigating farm fields. Meanwhile, the existence of ground water is still few in several places, because the ground water in this place has 12- 15 meters from the land surface. The main sources of fresh water for the daily activities are wells and springs. The irrigation facilities in Mangunan village are reservoir (4),water pump (10) and water divider (10). There is no irrigation ditch in this village, so it entirely depends on on rain storage field and drill bor made around farm fields, which seldom contain high quality water.

B. Pacarejo Village
The rivers which flows the Pacarejo Village are mostly the rivers with order one and form irregular stream pattern, because they are related with their geology condition. The available geology and geomorphology conditions are not able to store ground water, so in certain places there are ponds which are unsaturated water surface. Being an area composed of limestone as bed rocks, the area has an intensive denudational process. This causes ground water to become more deeply located, causing the surrounding people to rely on ponds to access water for everyday’s use.
The rivers in the research area are mostly the rivers which flow only in the rainy season because of the lack of water supply, and also because of the great inclination of the river base. The available rivers has the function of being the transporter of of erosion sediment. Some of the rivers in Pacarejo village they are Kali Sureng, Kali Ngingrong, Kali Jirak, Kali Gunungringin, Kali Dengok, and Kali Ngrejeng. From the field survey result, every river in the area suffer from dryness in the dry season. Irigation facility in Pacarejo village are water pump (3 units), ponds (10 and windmills (1). In the village, there is an irigatino ditch for irigating farms, especially in the dry season.



*Read More ^_^ My Paper... on: http://chiba-u.academia.edu/RATIHFITRIAPUTRI
*) Paper presented at the GTZ Project (Germany - Gadjah Mada University Indonesia)


By: RATIH FITRIA PUTRI (Double Degree Master Programe Remote Sensing Chiba University, Japan and Watershed & Coastal Management Gadjah Mada University)

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