Analysis of the prevalence of malaria cases based on time shows that the overall trend has decreased, as displayed in Table 1, with the most cases found in Kokap Sub-district (Fig. 1). Figure 1 demonstrates that the results of the cluster spatial analysis have revealed that the zone with the highest cases of malaria is the Kokap Sub-district area. The spatial analysis and buffering show that the radius of distribution of case location to the place potential as risk factors , . In this study, the buffering was performed with a radius < 250 meters to determine the approximate size limit or radius of the nearest or farthest location from the case with a potential breeding place for Anopheles sp mosquitoes , . Figure 2 depicts the results of this research, which show that the spatial pattern of the highest malaria case cluster in the Kokap Sub-district from 2015 to 2018 is adjacent to the river basin area.
The results of this study indicate that the spatial trend pattern of malaria cases is in the river flow area < 250 meters. Based on river buffers, rivers can be seen to be a risk factor for malaria transmission. It has been discovered that mosquitoes can lay their eggs in rivers, puddles, and dammed water bodies. Because water is required for the oviposition and breeding stages of mosquito larvae, mosquito density is higher during the rainy season than during the dry season, resulting in seasonal malaria epidemiology . Anopheles sp larvae breed in swamps, lagoons, ground pools, rivers, ditches, and wells, as well as habitat within a radius of 0.5 − 2 km of the homes of malaria-positive sufferers , . The reproductive habitat of Anopheles sp is in seepage or flow from the river to the surrounding environment and forms puddles , –. In other mountainous and hilly areas, springs and streams with water-filled rock basins can be breeding grounds for An. maculatus mosquitoes , , .
Furthermore, rice field buffer shows that malaria cases are mostly concentrated in the radius of the buffer < 250 meters from the rice fields in Kokap Sub-district, as displayed in Fig. 2. This is compliant with the breeding habitats for Anopheles sp larvae, which include rivers, ponds, and rice fields , . Rice field is a potential habitat area at high risk of malaria transmission with a buffer zone of 500 meters , .
All malaria cases were found < 250 meters from the garden area. Based on the flight distance of mosquitoes, which is 0.5 km, this means that the presence of the garden may be a risk factor for malaria transmission. During the day, the garden serves an important role as a resting place for Anopheles sp mosquitoes , . This means that the presence of shrubs/gardens near the house increases the risk of malaria , . Anopheles maculatus is a species of mosquito that is a vector of malaria and lives in habitats such as garden areas , . Gardens are a high-risk area for malaria transmission, with less than 10% of the area within 1 km .
The results of this study also show that majority of the malaria cases occurred > 250 meters from the forest. This signifies that based on the mosquito flight distance of 0.5 km, the presence of forests is not a risk factor for malaria transmission. Which reported that forest does not have a significant effect on the incidence of malaria, with a distance of 900 to 1,250 meters . However, several cases of malaria were discovered < 0.5 kilometers away from the forest area because the forest is a breeding site for Anopheles sp. Because of Indonesia's geographical location on the equator, it has a tropical climate, and the living environment in the forest will increase the incidence of malaria because it is classified as an endemic area. Activities such as leaving the house at night without long-sleeve clothes and repellents in mosquito breeding sites such as forests will increase the risk of transmission. According to research in Thailand, living near a mosquito breeding site increases the risk of transmission by 2.37 times, and living in a forest area with active transmission increases the risk of transmission by 7.19 times . Forest and bush areas are habitats for Anopheles balabacensis and Anopheles maculatus mosquitoes.
Some methods of prevention and control of Anopheles sp vectors are spatial monitoring, analysis of time trends, , , and environmental management such as cleaning the environment that has the breeding potential, for example clearing shrubs in the garden area near the house  and closing standing water which has the potential to become a breeding ground for mosquitoes. Wearing long-sleeve clothes when going out at night, using insecticide-treated mosquito nets, using repellants, putting on mosquito repellant gauze, and giving prophylactic treatment when entering or working in endemic areas are also the ways that can prevent and control the vector –.
The strength of this study lies in its focuses on the detection and analysis of the cluster of the distribution pattern and area coverage of a geosphere phenomenon based on breeding places for malaria mosquitoes in rivers , , garden , rice fields , , ,  and forests , ,  by buffering , –, which has not been implemented investigation thoroughly in the vulnerable areas in Kulon Progo District in 2015–2018. The findings of this study are projected to support stakeholders in making policy and providing representative management of malaria case elimination. However, this study has some limitations does not perform risk factor analysis and space-time permutation or space-time temporal analysis.