Archive: Waiology June 2014

Landscapes shaped by water

Waiology • Oct 30, 2014

• deposition,
• erosion,
• fluvial,
• geomorphology,
• landforms,
• landscape,
• sediment

By Daniel Collins New Zealand is both a pluvial and fluvial country. A lot of water falls on, moves through, and runs off the landscape to the surrounding seas. At each step along the way water can play a role in shaping the landscape, whether by resisting or facilitating erosion or by providing environments where eroded sediment is deposited. Read More

Southern Alps groundwater sheds light on the Alpine Fault

Waiology • Oct 28, 2014

• Alpine Fault,
• eartyquakes,
• Groundwater,
• Southern Alps,
• tectonism

By Simon Cox During the spring months of 2014, international attention will be drawn to the Alpine Fault along the western side of the Southern Alps, as the Deep Fault Drilling Project (DFDP) enters its second phase. Scientists from around the world aim to complete a 1.5 km drill hole near Whataroa, recover fault rocks for testing, and install … Read More

Thirsty trees and water yields: Vegetation, water and a changing climate

Waiology • Oct 23, 2014

• canopy,
• climate change,
• Drought,
• Ecohydrology,
• Evaporation,
• kauri,
• physiology,
• transpiration,
• water yield

By Cate Macinnis-Ng Future climate projections predict that some parts of New Zealand will become drier with droughts being more severe and frequent. This is particularly true for the north and eastern parts of the country. We know that soil moisture availability will decline due to reductions in rainfall and increased evaporative demand will lead to faster transfer of … Read More

Tussocks – a fundamental component of New Zealand’s water cycle

Waiology • Oct 20, 2014

• canopy,
• fog,
• interception,
• Runoff,
• tussock,
• water cycle,
• water yield

By Alice Trevelyan, Sarah Mager and Peter Wilson The significance of fog deposition to increased water yield has been contested for many years, especially across the Otago region. Determining the importance of the role of tussock grasslands in the hydrological system is becoming increasingly important, especially over the summer periods when the demand for water for irrigation, recreation and domestic … Read More

A pluvial and fluvial country

Waiology • Oct 14, 2014

• discharge,
• flow,
• fluvial,
• Pluvial,
• rain,
• Rivers

By Daniel Collins As Sir Geoffrey Palmer once remarked, New Zealand is a pluvial[1] country. It rains a lot. On average, 2.3 metres of water falls across New Zealand each year, or 610,000 million m3 in volumetric terms (about 10 times the volume of Lake Taupo). This is more than most countries, but not all. Values vary from source to … Read More

Weather and water in New Zealand – where do our storms come from?

Waiology • Oct 13, 2014

• atmospheric circulation,
• Climate,
• New Zealand,
• Rainfall,
• storms

By James Renwick New Zealand sits astride the middle latitudes in western Pacific Ocean, exposed to wind and weather from all quarters. Yet we do not usually receive our rain and storms from all quarters. Because the flow of the winds is normally from the west, most of the rain New Zealand experiences arrives from somewhere to the west or … Read More

The natural history of New Zealand’s freshwaters: Series introduction

Waiology • Oct 09, 2014

• natural history; water; freshwater

By Daniel Collins Freshwater issues are among the most important environmental issues facing New Zealanders and receive frequent news coverage. Degraded water quality and its link to dairying in particular is a case in point. Examining the policy and the policy-relevant science are important in order to resolve these issues, and are frequent topics here at … Read More

Full citizen science flood map for Christchurch, March 2014

Waiology • Sep 04, 2014

• Canterbury,
• Christchurch,
• citizen science,
• Data,
• Flooding,
• Risk

By Daniel Collins As a follow-up to Waiology’s article in June, here is a full map for the flooding of Christchurch on 5 March 2014. The map is derived from photos sent in by the public which were generally taken within a few hours of peak inundation. The blue colours represent the depth of water above the ground surface … Read More

NIWA revising national flood statistics

Waiology • Jul 16, 2014

• Data,
• floods

By Daniel Collins As we have seen in Northland in recent days and in Christchurch in March, severe floods pose a significant threat to rural and urban lives and livelihoods. One person drowned in the Waitangi River on Saturday, and the cost of the flooding will likely be in the millions. As a point of comparison, … Read More

Reviews coming in on new policy for freshwater management

Waiology • Jul 11, 2014

• freshwater management,
• limit-setting,
• policy,
• Water governance

By Daniel Collins The Government recently released the National Policy Statement for Freshwater Management (2014). The policy provides the most comprehensive instructions to regional councils yet on how our freshwaters – rivers, lakes, wetlands, and aquifers – are to be managed. Amendments made in the new policy include numerical thresholds and bottom-lines for a range of water quality attributes … Read More