Dataset on beach dynamics and beach-casts appearance at the Northern coast of the Sambia Peninsula, the Baltic Sea (Kaliningrad Oblast, Russia)

Kaliningrad Oblast, the westernmost region of Russia, suffers from coastal erosion (Łabuz et al., 2018). Sandy beaches are narrow, especially at the Northern shore of the Sambia Peninsula, where the rate of coastal retreat is about 0.5–1.5 m/year (Karmanov et al., 2018), the width of the beach (10–25 m in average) varies in time, the shore is partly protected by old groins (Prushak et al., 2014). The issue of the beach cast is linked to the problems of marine litter and microplastic pollution (Chubarenko I. et al., 2020) and seegrass dumping (Chubarenko B. et al., 2021). To monitor the dynamics of the beach and the release of beach casts on it, the webcam was installed at the northern shore of the Sambia Peninsula (Kaliningrad Oblast, Russia). Primary information (the raw images) is not presented in the database. The secondary data developed after the processing of images are presented in a tabular table, it contains several sheets. Sheet 1 (named "Beach-Cast_data") shows the presence or absence of beach and beach cast; it has 5 columns: Date (shooting date, format YYYY-MM-DD), BeachW (beach present/absent west of groin), BeachE (beach present/absent east of groin), CastW (beach cast present/absent west of groin), CastE (beach cast present/absent east of groin). The absence of the beach or beach cast is designated as "0". The presence of the beach or beach cast is designated as "1", but if the beach cast occupied more the 25% of study area, then it is indicated as "2". Sheet 2 (named "Cast_areas") shows the area occupied by beach cast within the boundaries of the study area; it has 5 columns: Date (shooting date, format YYYY-MM-DD), CastWest means beach cast west of groin and presented by two columns "area" (m2) and percentage ("%"), the CastEast means beach cast east of groin and presented by two columns "area" (m2) and percentage ("%"). Sheet 3 (named "Legend") shows legend described above. References: Chubarenko B., Woelfel J., Hofmann J., Aldag S., Beldowski J., Burlakovs J., Garrels T., Gorbunova J., Guizani S., Kupczyk A., Kotwicki L., Domnin D., Gajewska M., Hogland W., Kołecka K., Nielsen J., Schubert H. Converting beach wrack into a resource as a challenge for the Baltic Sea (an overview). (2021) Ocean & Coastal Management, 200, 105413. Chubarenko I., Esiukova E., Khatmullina L., Lobchuk O., Grave A., Kileso A., Haseler M. (2020) From macro to micro, from patchy to uniform: Analyzing plastic contamination along and across a sandy tide-less coast. Marine Pollution Bulletin, 156, 111198. Łabuz T.A., Grunewald R., Bobykina V., Chubarenko B., Česnulevičius A., Bautrėnas A., Morkūnaitė R., Tõnisson H. (2018) Coastal dunes of the Baltic Sea shores: a review. Quaestiones Geographicae, 37(1), 47-71. Prushak Z., Ostrovsky R., Babakov A.N., Chubarenko B.V. (2014) The main principles of bank stabilization by the groins. Russian Journal of Geomorpholgy, 14(3), 91-105.

俄罗斯最西部的行政区加里宁格勒州（Kaliningrad Oblast）面临海岸侵蚀（coastal erosion）问题（Łabuz等，2018）。其沙滩普遍狭窄，尤以桑比亚半岛（Sambia Peninsula）北岸为甚，该区域海岸后退速率约为0.5–1.5 m/年（Karmanov等，2018）；沙滩平均宽度为10–25 m，且随时间动态变化，部分岸段由老旧丁坝（groins）防护（Prushak等，2014）。
海滩冲积物（beach cast）问题与海洋垃圾及微塑料污染（Chubarenko I.等，2020）、海草堆积物（seegrass dumping）密切相关（Chubarenko B.等，2021）。为监测沙滩动态及海滩冲积物的出现情况，研究人员在加里宁格勒州桑比亚半岛北岸架设了网络摄像头（webcam）。本数据库未收录原始图像（raw images）等一手数据，仅提供经图像处理后生成的二级数据（secondary data），该数据以表格形式存储，共包含3个工作表（sheet）。
工作表1命名为"Beach-Cast_data"，用于记录沙滩及海滩冲积物的存在状态，共设5列：Date（拍摄日期，格式为YYYY-MM-DD）、BeachW（丁坝西侧沙滩存在与否）、BeachE（丁坝东侧沙滩存在与否）、CastW（丁坝西侧海滩冲积物存在与否）、CastE（丁坝东侧海滩冲积物存在与否）。其中，沙滩或海滩冲积物缺失时记为"0"，存在时记为"1"；若海滩冲积物覆盖研究区域面积超过25%，则记为"2"。
工作表2命名为"Cast_areas"，用于统计研究区域内海滩冲积物占据的面积，共设5列：Date（拍摄日期，格式为YYYY-MM-DD）；CastWest代表丁坝西侧的海滩冲积物，包含"area"（面积，单位：平方米）与"percentage"（占比，%）两列；CastEast代表丁坝东侧的海滩冲积物，同样包含"area"（面积，单位：平方米）与"percentage"（占比，%）两列。
工作表3命名为"Legend"，用于展示上述数据的说明图例。

### 参考文献
1. Chubarenko B., Woelfel J., Hofmann J., Aldag S., Beldowski J., Burlakovs J., Garrels T., Gorbunova J., Guizani S., Kupczyk A., Kotwicki L., Domnin D., Gajewska M., Hogland W., Kołecka K., Nielsen J., Schubert H. 《将海滩海藻转化为资源：波罗的海面临的挑战（综述）》. (2021) *Ocean & Coastal Management*（《海洋与海岸管理》）, 200, 105413.
2. Chubarenko I., Esiukova E., Khatmullina L., Lobchuk O., Grave A., Kileso A., Haseler M. (2020) 《从宏观到微观、从斑块到均一：无潮沙质海岸沿线及跨岸塑料污染分析》. *Marine Pollution Bulletin*（《海洋污染公报》）, 156, 111198.
3. Łabuz T.A., Grunewald R., Bobykina V., Chubarenko B., Česnulevičius A., Bautrėnas A., Morkūnaitė R., Tõnisson H. (2018) 《波罗的海海岸沙丘研究综述》. *Quaestiones Geographicae*（《地理问题》）, 37(1), 47-71.
4. Prushak Z., Ostrovsky R., Babakov A.N., Chubarenko B.V. (2014) 《丁坝护岸的核心原则》. *Russian Journal of Geomorpholgy*（《俄罗斯地貌学杂志》）, 14(3), 91-105.