Prehradní nádrž Nýrsko EarthCache
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Nyrsko Dam was built on the river Uhlava about 4 km south of Nyrsko. The water Reservoir used for drinking water for Plzen and Domažlicko. The dam was built between 1965 and 1969th on the foothills of the National Park Sumava.
Nyrsko Dam was built on the river Uhlava about 4 km south of Nyrsko and 19 km southwest of Klatovy. The water Reservoir
is used for drinking water for Plzen and Domažlicko. The dam was built between 1965 and 1969th on the foothills of the National Park Sumava.
The water tanks are recreational activities and swimming are prohibited. For the dam created a lake with a maximum volume of 21 million cubic meters. Sprinkled dam of
leading the indoor concrete, is 36 m high and the crown is 337 m long. Area of the lake is 148 ha and holds 16 million cubic meters of water, which are accumulated for the needs of the group drinking tap water supplies Nyrsko and surrounding communities. Lice extends 3 km upstream Uhlava. The greatest depth of water in the tank is 34m.
Bilding a dam results in a big geographical change in the nearby area. If you look at both sides of the dam you can see the difference (geographical change) as result of placing the dam. You can imagine the type of landscape, and the big change for humanity and nature by placing the dam. After the dam and around the western
bank of the dam results in yellow-marked tourist trail. In order to protect sources of drinking water is another movement of tourists in the vicinity of the dam restricted to designated routes. Route yellow marked trail leads around the tank from the dike along the western shore to Hojsova Guard. Along the eastern side leads (in the southern part of) the route of the green trail.
Uhlava river.
Uhlava river rises on the western slope Shield (1,241 m) at an altitude of 1.110
m above sea From the spring flows northwest for Nyrsko its flow turns northeast. Mouth of the river Radbuza in Pilsen at a height of 303 m. Uhlava is 108 km long and drains an area of 919 km
square.
Summer 2009 we have spent our holidays in the mansion across the lake. This cache is made as to pay tribute to this beautiful region. It is a wonderful area for walking or cycling or for fun excursions. You find yourself here in the foothills of the
National Park Sumava.*1
Czech Republic is one of our favorite
holiday destinations where we already have 11 times spent our summer holidays. We also did some geocaching and had a lot of fun.
*1 National Park Sumava. (visit link)
National Park Šumava
As a Czech-German transboundary locality the National park Šumava was selected, mainly for two following reasons:
1) It is a specific and unique natural unit, which is characteristic by series of problems, connected with its protection (these problems consist mainly in changes of ecosystems caused by preceding management and generally negative interventions of inhabitants into the natural environment).
2) Majority of land, where the National Park Šumava is situated, is state owned, and the land is not fully exposed to the process of privatization and parceling. This enables orientation of its management without taking the production approach as a basic motive for his activity in the area of the National Park Šumava. The forest and agricultural production is performed at about three quarters of the NP Šumava area, only as a secondary effect of care of the ecosystems; its protection, maintenance, or coordination.
NP Šumava was established by Regulation of the Government of the Czech Republic No. 163/1991 Coll., by which the National Park Šumava is established, and conditions are determined for its protection (dated March 20, 1991). The main subject for protection in the NP Šumava is: the typical ecosystems in all of their components, and process of their natural development.
The land of NP Šumava is located along the South border of the Czech Republic. Main part of NP is located at the territory of the districts Klatovy and Prachatice; the smaller one is at a part of the district Ceský Krumlov. The protection zone of the National Park was not determined, but its role is played by the Protected Landscape Area, which is surrounding land of the national park. Total area of the NP Šumava is about 680 km2.
Šumava belongs among largest and oldest mountains in the Central Europe, with extensive relicts of high plains, located in several levels at 1,000 m above mean sea level. In the mountains Šumava, which have a distant geomorphologic position against the main European erosion bases, the European water divide between the Black and North Sea is located. Present-day relief of Šumava is a result of intensive impact of processes of tropical weathering during the preceding denudation cycles. In Pleistocene period the prevailing processes were cryogenic and glacial ones.
The study area shows two climatic zones. The apical parts belong among slightly cool to cool climate with enhanced precipitation. Precipitation at elevations above 1000 m a.s.l. exceeds in long-run monitoring 1000 mm. Due to relatively low mean temperature around 5 °C), the precipitation remains in form of snow for considerable part of the year. The foothills are warmer with mean temperatures around 7 °C and average rainfall around 600 mm.
From the of regional geology point of view, territory of the National park Šumava is built by two basic geological units - moklanubicum and moldanubic plutonic rock. The term moklanubicum is used for a group of medium and strongly reworked rocks, with prevalence of paralueses and migmatites, often with intercalated beds of quartzites and erlans. In the given territory they are assigned to so called subdued unit. The moldanubic plutonic rock is in the Šumava branch represented by several larger granite massifs of Variscan age. Quaternary sediments are represented mostly by diluvial (slope) sediments of gelifluction origin. Very frequent are here turfs, less frequent then fluvial and deluvium-fluvial sediments, rarely also sediments of glacial origin. Stratigraphically the belong mostly to Pleistocene and partly to Holocene till Recent. Composition of slope sediments is quite fluctuating and ranges from clays through clayish sands to clayish stone sediments up to block sediments of various thicknesses. The seas of rock are usually based at frost cliffs. Significant tectonic systems are the fault zones, oriented WNW-ESE, NNW-SSE (up to N-S) and NNE-SSW. Their age is considered to be young Paleozoic to tertiary.
System of natural surface waters at NP Šumava consists of spring areas and moor lands, network of water streams and glacial lakes. This system is complemented by artificial waterworks, as shipping canals and headwater channels and artificial reservoir (former navigation pools, fishing reservoirs, or dams).
The whole territory of the National Park Šumava is included in Natural Water Accumulation Protected Area (NWAPA), which almost identically corresponds with boarder of Protected Landscape Area (PLA) Šumava (by Regulation of Government No. 40/1978 Coll.), according to the Law No. 138/1973 Coll. on waters. From the hydrological point of view, major part of territory belongs to drainage area of the North Sea, catchment of Labe with the main rivers Vltava and Otava. The river Otava is draining the West part of NP Šumava. It originates by junction of two significant rivers - Vydra and Kremelná. The river Vltava drains waters from the South Bohemian part of NP Šumava, and springs as Cerný stream on the East Side of the Cerná mountain. The specific hydrological phenomenon at Šumava are natural glacial lakes, appearing in the altitude of about 1,000 m. Their condition is currently influenced by degree of acidification, resulting from acid deposition and natural conditions of the lakes.
Territory of Šumava as a unit is characterized by relatively monotonous hydrogeological conditions, whose uniformity is given by the fact that the territory is built by consolidated, intensively plicated through metamorphic rocks of moldanubicum and migmatites of moldanubic pluton. This rock formation features by only fracture permeability. Interstitial water-saturation, with sources of ground water mainly of only local significance, is related to the weathering cover of rock massif, and to deluvial, deluvio-fluvial, and fluvial sediments.
History of design of cultivated landscape of Šumava may be divided into several relatively clear time blocks. Šumava did not suffer by primeval and early medieval deforestation. Anthropogenous creation of unstocked forest land is dated into 12th and 13th centuries, when the high-medieval colonization started. Until the year 1,500 the settlement network is thickening and stabilizing in the foreland of Šumava. Till the year 1,700, the settlement penetrated at several places into the inner part of Šumava, mainly along the former kingdom paths. Final wave of settling entered the "forest" approximately in the middle of 18th century, in connection with development of glass industry and timber harvesting. Total devastation on many places reached so far that in the 19th century a planned restoration and regeneration of forests of Šumava was started. The spill-over of inhabitants from Šumava was accelerated by migration of nations in time of WWII (withdrawal of Czechs before the war and Germans after the WWII). In this period, also due to the "Cold War", a special border zone and military areas were established at Šumava. In this area, the existing settlement structure was practically liquidated. Reduction of permanent settlement in the region of Šumava caused a shortage of manpower in agriculture, forestry, and some of branches of secondary industry. Displacement of inhabitants led also to substituting the manpower by large-scale production technologies with direct and indirect impact on the natural environment (processes of development of forest exploitation, merge of fields, higher concentration of animals, soil amelioration, soil fertilization, etc.). The basic part of so far agriculturally utilized landscape was left useless and in the current landscape, its covering by the woody plants (succession areas) prove existence of renaturalization process.
In the last years (after the year 1989 and after accessibility to the border zone) a great increase of recreational use of the land occurred. Pressure on recreational use of the land is still increasing, as well in summer and winter activities.
End of 20th century was lead by effort to complete settlement of some parts of Šumava (Prášily). In the year 1991 took place a population census. According to data from this time, at the territory of NP Šumava, there were 36 settlement communities of various size, administered by 7 villages inside of NP Šumava and by 4 villages on its limits. In the villages inside the NP, there were 877 inhabitants living. Density of inhabitants in NP did not exceed 1.3 inhabitants per square km. In case of including also villages on the border of NP, the total number of inhabitants in the year 1991 was equal to 2027.
Take a photo ( optional ) of you or a team member with the GPS in hand in front of the big bilbord and answer the questions below. Place the photo (optional ) in your log and if possible, photographs of the area. Send the answers to questions by e-mail to us.
On the spot and cache discription you will find information with you need to answer the questions. if the answers are wrong your log will be deleted. (you wil be informed by e-mail before.)
Questions.
1. With activities are forbidden on the lake? (name at least two)
2. The height above sea level of the water overflow to protect the dam for overflowing by water.
3. The total number of inhabitants including also villages on the border of NP in the year 1991.
4. What are the dimensions of the bilboard in cm (not the size of the frame)
Thank you for visiting our first geocache.
Additional Hints
(Decrypt)
Uvag: Lbh jvyy arrq fbzrguvat gb zrnfher.