Potential and Challenges of Karst Water Resources in Sumbermanjing Wetan District of Malang Regency

Abstract

Water is one of the primary needs of all living things. In order to figure out the potential of water resources, we need to conduct a study about water supply. This study of water resources was conducted in Sumbermanjing Wetan district located in the southern part of Malang Regency. This study is limited to the initial review of the existence of potency water resources in the study area, without including a quantitative aspect of the water resources. The first identification was collecting the data of water resources found in Sumbermanjing Wetan, and then analyze them descriptively. This step was to figure out the potential and challenges of water resources in Sumbermanjing Wetan. The result of this study showed that there were water resources in the form of spring, surface water, and subterranean river. The big volume of spring had been used by the people to fulfill their daily needs. However, the changing of the karst landscape had produced pollution around the settlement. Besides, there was volume decreasing of the spring, and so was the water supply for the people. The people could make use of other water resources such as the subterranean river that flow a whole year to overcome the problem. The most potential subterranean rivers are in Mbah Wajib Cave, Limbah Cave, Krompyang Cave, Kedung Pitu Cave, and Emas Cave.

Initial evaluation of land use potential using geospatial analysis at Sendang Biru Beach, Malang Regency, East Java Province, Indonesia

“…In addition, this area is also in a sedimentary rock area with rock ages in the late Miocene Tertiary type [27,28], having karst water sources from springs, surface runoff in the form of rivers and lakes and underground rivers. The distribution of water resources; 36 springs are found in the southern part, springs in the Sendang Biru karst area are in valleys, basins, and slopes [2]. Sendang Biru spring has a flow rate fluctuation during the rainy and dry seasons that is not too large, including perennial flow (flow throughout the year), the increase in flow rate, which is not too large, indicates that it is a spring that has diffuse and fissure types.…”

“…Land use in the Sendang Biru spring catchment area is heterogeneous, dominated by shrubs and forests that grow irregularly. The use of unspoiled land and the presence of quite a lot of Karren formations indicate that karst development is quite massive [29]; having karst springs looks like a natural reservoir that holds rainwater, releasing water on the ground indicates a large enough water source in residential areas, water output from natural reservoirs, excess karst springs, the length of time delay between rainwater coming out to springs so that some karst springs will issue large discharges in the dry season [2].…”

“…Recharge comes from the overflow of rainfall and flow and seepage from the Qas formation (swamp and river deposits), dominated by gravel, sand, clay, plant sides in the west and north, and Tomm (Mandalika Formation), which is dominated by andesite lava, Basalt, trachyte, dacite, propitiate, andesite breccia in the east. Sendang Biru has water resources in the form of a karst aquifer [2], with a gravity system flow that can be explored and exploited to meet the need for clean water with water quality still within normal limits.…”

“…Sendang Biru Beach is located in Tambak Rejo Village, Sumber Manjing Wetan District, Malang Regency, has the potential for fisheries resources and the Sempu Island nature reserve as well as it has karst water sources originating from springs, surface flows in the form of rivers and lakes [1]. Furthermore, underground rivers and the increasing population, consequently there is pressure on coastal areas, especially the opening of new residential areas, excessive use of resources, and land conversion resulting in changing the function of the ecosystem [2].…”

Potensi Laboratorium Alam Sumbermanjing Wetan dalam pembelajaran Geografi berbasis kerja lapangan (fieldwork)

“…Pada bentang alam vulkanik terdiri dari punggung gunung tidak beraturan yang membentang dari utara dan selatan wilayah kajian. Sumbermanjing Wetan merupakan daerah yang rawan bencana banjir, longsor, dan tsunami serta kekeringan (Sahrina et al, 2020). Ekosistem pesisir memiliki nilai kerentanan rendah dilihat dari aspek fisik, namun kerentanan tinggi di daerah pesisir karena adanya aktivitas manusia (Handartoputra et al, 2015).…”