Hydrological System of the Plitvice Lakes—Trends and Changes in Water Levels, Inflows, and Losses

The Plitvice Lakes National Park is inscribed on UNESCO’s World Heritage List. The lake system is composed of 16 cascading lakes of different sizes separated by tufa barriers, which are the park’s key phenomenon. The lakes are characterized by highly diverse trends of the characteristic hydrological indicators—mean annual water levels, discharges, and tufa barrier growth. The analyses carried out in this paper identified that in the period before the early 1990s, Kozjak Lake had a trend of decreasing discharges, together with a trend of increasing water levels and growing tufa barriers. In contrast to this, in the period after 2001, a trend of increasing discharges was recorded, as well as a trend of decreasing water levels and decreasing tufa barriers. A potential cause of the barriers decreasing in size were the extremely high discharges during the last decade, which resulted in increased erosion of the tufa barriers. Losses of water due to the sinking from the lake system as well as the upper Korana course were confirmed, and it was identified that during the analyzed period the losses had not changed significantly. It was determined that the losses of water from Kozjak Lake occurred during low-water periods; however, they depended not only on the quantity of water flowing through the lakes but also on the hydrological conditions underground. The analyses carried out and the methodological procedures used in the analyzed area of the Plitvice Lakes are useful examples for the performance of analyses at similar lakes in karst formed by tufa deposition processes.

Paleoenvironmental reconstruction of Triassic floras from the Central North Sea

The Triassic sediments of the Central North Sea (CNS) are considered to have been deposited in a continental environment under a semi-arid climate. The Skagerrak Formation in particular, comprises an alternation of sandstone and mudstone members, the development of which is considered to be climatically driven. However, conflicting models exist as to how climate influences member deposition. Here we analyse the climatic signal using a multivariate statistical approach in which de-trended correspondence analysis (DCA) is applied to palynological observations to quantify environmental reconstruction. Using DCA it has been possible to define paleoecological groups and construct a relative hydrological state trend showing hydrological conditions within the centre of the CNS basin during the Triassic. The resultant trends reveal that the relationship between hydrological conditions in the basin and the development of individual sandstones and mudstone members is perhaps not a simple as indicated by existing models. In particular our data suggest that whilst influenced by broader climate trends, in the basin centre, there is no simple relationship between climate change and sandstone/mudstone development. The data also indicates that the Julius and Jonathan mudstone members were deposited under differing hydrological conditions. The DCA trends shown here also suggest that the Carnian Pluvial Episode (CPE) documented from the South Permian Basin and Tethys is not expressed in the CNS.

Impact of land use change on hydrological conditions in the Karajae watershed, South Sulawesi Province

Land use is a representation of activities and utilization of land resources by the community. Land use has a big influence on the hydrological condition of a watershed. One of the small watersheds, in general, is the Karajae watershed, but it has a very large impact on the City of Pare-Pare, and the surrounding community. The Karajae watershed is the main water source for the people of Pare-Pare and agriculture. This study aims to analyze land use patterns that have a major impact on hydrological conditions in the Karajae watershed. The analysis begins with remote sensing methods to interpret land use using Landsat 7 image data in 2010 and Landsat 8 imagery in 2020. Next, analyze the pattern of land use change in detail in each forest area with a geographic information system approach. Analysis of hydrological conditions using the Soil and Water Assessment Tools approach with the input of the land use data. Land use Change 2010-2020 in the Karajae watershed shows additional land use in the form of settlements, rice fields, and dryland agriculture as a form of community activity. There are two forest areas in the Karajae watershed, namely production forest and protected forest. Production forest is dominated by dryland agriculture in the form of corn, beans, and horticulture, while the protected forest is dominated by and secondary dryland forest. This has an impact on hydrological conditions that there are fluctuations in discharge and an increase in sediment a decade ago. Optimal application of forest functions reduces discharge and sediment. Different forest planning for each forest function and land use within. Production forest with many activities directed towards community-based forest management such as community forest and village forest. As for the Protected Forest, which is dominated by grassland and shrubs, forest rehabilitation is carried out.

BEBERAPA SKENARIO PENGGUNAAN LAHAN UNTUK PERBAIKAN KONDISI HIDROLOGI DI DAERAH ALIRAN SUNGAI CIDURIAN (Land use scenarios for hydrological conditions improvement in Cidurian Watershed)

Daerah Aliran Sungai (DAS) Cidurian merupakan salah satu DAS di Pulau Jawa dengan kategori sebagai DAS yang dipulihkan. Kinerja DAS Cidurian secara umum dari hulu sampai dengan hilir termasuk dalam klasifikasi kategori buruk. Penelitian ini bertujuan untuk 1) mengkaji karakteristik hidrologi DAS Cidurian menggunakan model hidrologi SWAT; 2) mengkaji kinerja hidrologi berdasarkan skenario simulasi yang disusun; dan 3) menyusun strategi keberhasilan Rehabilitasi Hutan dan Lahan pada DAS Cidurian berdasarkan skenario terbaik. Berbagai skenario penggunaan lahan dan pengelolaannya diujicobakan menggunakan model SWAT (Soil and Water Assessment Tool) untuk menduga dampak penerapannya terhadap karakteristik hidrologi pada DAS Cidurian. Skenario yang diaplikasikan adalah sebagai berikut: 1) Implementasi RTRW (Rencana Tata Ruang Wilayah) Provinsi Banten dan Jawa Barat; 2) Implementasi Rehabilitasi Hutan dan Lahan dengan penanaman penanaman vegetative dan; 3). Implementasi Rehabilitasi Hutan dan Lahan penanaman vegetatif dan Konservasi Tanah dan Air secara vegetatif dan sipil teknis. Kalibrasi dan validasi dari model menunjukkan kategori memuaskan dengan nilai NSE (Nash-Sutcliffe Efficiency) 0,53 dan 0,50. Semua skenario menunjukkan peningkatan respon hidrologi dibandingkan dengan kondisi eksisting tahun 2020. Ketiganya memberikan respon limpasan permukaaan dan hasil sedimen yang menurun serta aliran lateral dan aliran dasar yang meningkat. Semua skenario ini menurunkan nilai Koefisien Aliran Tahunan (KAT) dan Koefisien Regim Aliran (KRA). Skenario penerapan kombinasi Rehabilitasi Hutan dan Lahan penanaman vegetatif dan Konservasi Tanah dan Air menjadi skenario terbaik dengan nilai KAT 0,27 (kategori rendah) dan KRA 22,40 (kategori rendah).

Factors determining the soil available water during the last two decades (1997–2019) in southern Spain

Assessing soil hydrological conditions can provide essential information for understanding the environmental processes that affect ecosystem services and, particularly in the context of ongoing climate change. This is key in areas affected by water scarcity such as the Mediterranean belt. Therefore, the main goals of this research are (i) to assess the main rainfall dynamics and trends of some representative hotspots along with southern Spain and (ii) to determine the impact on the soil available water content (AWC) over the last two decades. An analysis of daily precipitation and soil hydrological conditions was combined with soil sampling (543) and laboratory analyses to evaluate the properties related to the soil infiltration and retention capacity. The results show that the organic factors control soil properties and their hydrodynamics in southern Spain. Furthermore, a general declining trend in soil water availability is observed over the last two decades. This is more extreme in arid and semi-arid areas, where there have been several years in the last decade with more than 200 days without the available water content. Moreover, in these areas, heavy rainfall during specific moments of the year is the key factor that manifests a greater incidence in areas with steeper slopes, which in turn, also conditions the biological factors and the hydrodynamics of the soil. In short, in the context of climate change, the analysis of soil hydrological dynamics could be used to identify biodiversity thresholds in the Mediterranean area and even to detect phenological changes in specific plant species.