In the Parangtritis Beach tourism area located in the Southern Mountain of Yogyakarta, karst hills were excavated to build the main accessing road and produce some of long and very steep slopes along the sides of the road. But still, there was none of the slope reinforcement installed along the road. Meanwhile, at several nearby locations within Southern Mountain, rockfall incidents have occurred many times even caused casualties. The potential of rockfall hazard also could be found in the main road of Parangtritis Beach as the study area. The purpose of this study is to determine the rockfall hazard assessment along the main road using Slope Mass Rating (SMR) analysis with the additional parameter of the slope height and the rock block size. The necessary data obtained by direct measurement and laboratory test. Geomechanics analysis, stereographic projection analysis, and hazard parameters weighting were carried out to produce the Rockfall Hazard Zonation Map of the study area. Based on 17 measurement stations, there are 4 (four) rockfall hazard classes in the study area, i.e., very low, low, moderate, and high. The class of very low, which also included road segments without slope, has the largest percentages of 83.83%, followed by the classes of moderate, low, and high with the percentage of 7.16%, 4.28%, and 4,19%, respectively. SMR was assumed as the most significant parameter that influences the rockfall hazard zonation. Historical rockfall points were overlaid over the Rockfall Hazard Zonation Map to validate the predicted hazard zones. Since 91.23% of the rockfall occurred in the moderate and high hazard classes, the zonation map considered reliable to predict future rockfall. This study also identified several landslide potential zones and provides the recommendation of slope reinforcement to be installed in the study area.

中文翻译：

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基于坡度质量评估的分析，评估印度尼西亚日惹南部山区的崩塌危险

在日惹南部山区的Parangtritis海滩旅游区，开挖了岩溶丘陵，以建造主要的通行道路，并在道路两侧产生了一些长而陡峭的斜坡。但是，沿路没有安装任何斜坡加固。同时，在南山附近的几个地点，发生了多次崩塌事故，甚至造成人员伤亡。在Parangtritis Beach的主要道路上也有可能发生崩塌的危险。这项研究的目的是使用坡度质量等级（SMR）分析以及坡度高度和岩块大小的附加参数来确定主干道上的塌方危险性评估。通过直接测量和实验室测试获得的必要数据。地质力学分析 进行了立体投影分析和危害参数加权，以生成研究区域的落石危险区划图。基于17个测量站，研究区域中有4（四）种落石危险等级，即极低，低，中和高。非常低的类别（也包括不带坡度的路段）的比例最高，为83.83％，其次是中等，低和高的类别，分别为7.16％，4.28％和4,19％ 。SMR被认为是影响落石灾害分区的最重要参数。历史落石点被覆盖在落石危险区划图上，以验证预测的危险区域。由于91.23％的落石发生在中高危险等级，分区图被认为可以可靠地预测未来的崩塌。这项研究还确定了几个滑坡潜在带，并提出了建议在研究区域安装边坡加固的建议。