title: Flood risk and property value: A case study analysing the effect of disclosed flood risk maps on the housing market in Hamilton, New Zealand

authors: Li, Chao

abstract: Flooding is among the most financially devastating natural disasters globally and in New Zealand. To manage flood risk, educating the public about its potential dangers is widely recognised as a necessity worldwide. However, in New Zealand, building development and property sales continue to thrive in officially designated flood risk areas, suggesting that published flood risk information may not be achieving its intended impact. This raises alarming concerns about whether the public effectively receives published flood risk information and to what extent it influences their decision making. However, empirical research on this topic is scarce in New Zealand, and the few existing studies only cover small portions of a case study area, lacking broader geographical representation and transferrable insights into long-term behavioural responses to flood risk information. This leaves local governments without reliable evidence to assess the effectiveness of flood risk disclosures and informed land-use decisions. One of the key reasons is the lack of nationally consistent flood risk mapping and the fragmented flood risk management approach across localities and regions, making flood risk information scattered, inconsistent, and difficult to access.
This research aims to address this gap by conducting a comprehensive empirical analysis in Hamilton City, New Zealand. Specifically, I focus on the holistic timeline of flood risk information released within the city since the first flood map was officially adopted in 2012. Specifically, Hamilton City Council (HCC) released flood risk maps and adopted them in the 2012 District Plan, followed by the introduction of online Floodviewer maps in 2020. Publishing flood risk information through two different platforms covering various urban spaces makes this a unique case study for examining the effects of flood risk on property prices. This research combines rigorous causal inference methods, including Difference-in-Differences (DID), Repeat-Sales models, and Hedonic modelling, to examine whether the release of flood risk information influences property sales in officially designated flood zones. The Results show that flood risk information has a limited impact on property prices in Hamilton City’s flood risk areas. However, in repeat sales analysis, disclosing flood risk information positively impacts housing value in these areas. These findings align with most historical research in New Zealand, indicating that it is not rare for people to disregard flood risk information in this country. This may be attributed to the absence of a unified national standard for published flood risk information and the lack of effective communication mechanisms.

text: Flood risk and property value: A case study analysing the effect of disclosed flood risk maps on the housing market in Hamilton, New Zealand Flooding is among the most financially devastating natural disasters globally and in New Zealand. To manage flood risk, educating the public about its potential dangers is widely recognised as a necessity worldwide. However, in New Zealand, building development and property sales continue to thrive in officially designated flood risk areas, suggesting that published flood risk information may not be achieving its intended impact. This raises alarming concerns about whether the public effectively receives published flood risk information and to what extent it influences their decision making. However, empirical research on this topic is scarce in New Zealand, and the few existing studies only cover small portions of a case study area, lacking broader geographical representation and transferrable insights into long-term behavioural responses to flood risk information. This leaves local governments without reliable evidence to assess the effectiveness of flood risk disclosures and informed land-use decisions. One of the key reasons is the lack of nationally consistent flood risk mapping and the fragmented flood risk management approach across localities and regions, making flood risk information scattered, inconsistent, and difficult to access.
This research aims to address this gap by conducting a comprehensive empirical analysis in Hamilton City, New Zealand. Specifically, I focus on the holistic timeline of flood risk information released within the city since the first flood map was officially adopted in 2012. Specifically, Hamilton City Council (HCC) released flood risk maps and adopted them in the 2012 District Plan, followed by the introduction of online Floodviewer maps in 2020. Publishing flood risk information through two different platforms covering various urban spaces makes this a unique case study for examining the effects of flood risk on property prices. This research combines rigorous causal inference methods, including Difference-in-Differences (DID), Repeat-Sales models, and Hedonic modelling, to examine whether the release of flood risk information influences property sales in officially designated flood zones. The Results show that flood risk information has a limited impact on property prices in Hamilton City’s flood risk areas. However, in repeat sales analysis, disclosing flood risk information positively impacts housing value in these areas. These findings align with most historical research in New Zealand, indicating that it is not rare for people to disregard flood risk information in this country. This may be attributed to the absence of a unified national standard for published flood risk information and the lack of effective communication mechanisms.

year: 2025

title: Annual carbon balance of an intensively grazed pasture: magnitude and controls

authors: Mudge, Paul Lawrence

subjects: Eddy covariance

abstract: Soil carbon (C) is important because even small changes in soil C can affect atmospheric concentrations of CO₂, which in turn can influence global climate. Adequate soil carbon is also required to maintain soil quality, which is important to if agricultural production is to be sustained. The soil carbon balance of New Zealand's pastoral soils is poorly understood, with recent research showing that soils under dairy pasture have lost large amounts of C during the past few decades. The main objective of this research was to determine an annual farm scale C budget for an intensively grazed dairy farm, with a second objective being to determine the amount of CO₂-C lost following cultivation for pasture renewal, and soil pugging by dairy cattle. A third objective was to investigate the environmental controls of CO₂ exchange in a dairy farm pasture system. Net ecosystem exchange (NEE) of CO₂ was measured using an eddy covariance (EC) system from 15 December 2007 to 14 December 2008. Closed chamber techniques were used to measure CO₂ emissions from three cultivated paddocks and three adjacent pasture paddocks between 26 January 2008 and 5 March 2008. CO₂ emissions were also measured using chambers from pugged and control plots between 25 June and 5 August. Coincidentally this research was carried out in a year with a severe summer/autumn drought and a wetter than usual winter. Annual NEE measured with the eddy covariance system was -1,843 kg C ha⁻¹ (a C gain by the land surface). Accounting for C in supplement import, milk export, pasture export and losses in methane, the dairy pasture system was a net sink of -880±500 kg C ha⁻¹. This C sequestration occurred despite severe drought during the study, which was in contrast to other studies of grasslands during drought. Cultivation under dry conditions did not increase cumulative CO₂-C emissions compared to adjacent pasture paddocks. However, when C inputs to pasture paddocks via photosynthesis were included in calculations, net C loss from the cultivated paddocks (during the 39 day study) was estimated to be 622 kg C ha⁻¹ more than the pasture paddocks. CO₂ emissions were lower from pugged plots compared to control plots, probably caused by decreased microbial and root respiration due to wetter soil conditions, and lowered root respiration as a result of lower pasture production. Volumetric soil moisture content (soil moisture) had a dominant effect on CO₂ exchange at a range of temporal scales. Respiration and photosynthesis were both reduced when soil moisture was below 43% (~the lower limit of readily available water) and photosynthesis virtually ceased when soil moisture declined below 24% (~wilting point). Soil moisture also influenced the relationship between temperature and respiration and photosynthetic flux density (PPFD) and NEE. These results suggest that management related soil disturbances of occasional cultivation for pasture renewal and soil pugging, are unlikely to cause large losses of soil C. Further, a severe drought also did not cause CO₂-C losses from the land surface to the atmosphere on an annual scale, in contrast to previous studies.

text: Annual carbon balance of an intensively grazed pasture: magnitude and controls Soil carbon (C) is important because even small changes in soil C can affect atmospheric concentrations of CO₂, which in turn can influence global climate. Adequate soil carbon is also required to maintain soil quality, which is important to if agricultural production is to be sustained. The soil carbon balance of New Zealand's pastoral soils is poorly understood, with recent research showing that soils under dairy pasture have lost large amounts of C during the past few decades. The main objective of this research was to determine an annual farm scale C budget for an intensively grazed dairy farm, with a second objective being to determine the amount of CO₂-C lost following cultivation for pasture renewal, and soil pugging by dairy cattle. A third objective was to investigate the environmental controls of CO₂ exchange in a dairy farm pasture system. Net ecosystem exchange (NEE) of CO₂ was measured using an eddy covariance (EC) system from 15 December 2007 to 14 December 2008. Closed chamber techniques were used to measure CO₂ emissions from three cultivated paddocks and three adjacent pasture paddocks between 26 January 2008 and 5 March 2008. CO₂ emissions were also measured using chambers from pugged and control plots between 25 June and 5 August. Coincidentally this research was carried out in a year with a severe summer/autumn drought and a wetter than usual winter. Annual NEE measured with the eddy covariance system was -1,843 kg C ha⁻¹ (a C gain by the land surface). Accounting for C in supplement import, milk export, pasture export and losses in methane, the dairy pasture system was a net sink of -880±500 kg C ha⁻¹. This C sequestration occurred despite severe drought during the study, which was in contrast to other studies of grasslands during drought. Cultivation under dry conditions did not increase cumulative CO₂-C emissions compared to adjacent pasture paddocks. However, when C inputs to pasture paddocks via photosynthesis were included in calculations, net C loss from the cultivated paddocks (during the 39 day study) was estimated to be 622 kg C ha⁻¹ more than the pasture paddocks. CO₂ emissions were lower from pugged plots compared to control plots, probably caused by decreased microbial and root respiration due to wetter soil conditions, and lowered root respiration as a result of lower pasture production. Volumetric soil moisture content (soil moisture) had a dominant effect on CO₂ exchange at a range of temporal scales. Respiration and photosynthesis were both reduced when soil moisture was below 43% (~the lower limit of readily available water) and photosynthesis virtually ceased when soil moisture declined below 24% (~wilting point). Soil moisture also influenced the relationship between temperature and respiration and photosynthetic flux density (PPFD) and NEE. These results suggest that management related soil disturbances of occasional cultivation for pasture renewal and soil pugging, are unlikely to cause large losses of soil C. Further, a severe drought also did not cause CO₂-C losses from the land surface to the atmosphere on an annual scale, in contrast to previous studies.

year: 2009

title: Ngā kura a Hineteiwaiwa: The embodiment of Mana Wahine in Māori fibre Arts

authors: Campbell, Donna

subjects: Mana Wahine

abstract: Imagine you are on a continuum of past present and future, in the present while connected to the past and creating for the future. Kairaranga  are constantly in this experience through engaging with the materiality of the practices of raranga and raranga whatu.  
The key focus of this thesis is to provide theoretical discussion of the raranga and whatu practices that are the creative component of this doctoral research.  The theories that inform the analysis are Kaupapa Māori and Mana Wahine both of which, like raranga, are organic to this place, Aotearoa , and have grown as descendants of Papatūānuku  and Ranginui . The connection between these theories and the creative practices of raranga and whatu form a cultural praxis through which I argue enables the transformative power of raranga and whatu practices.  This too is the essence of Te Whare Pora, a weaving house that embraces kairaranga both conceptually and materially and which provides the approach to the project. Te Whare Pora is a place of knowledge and a place of practice. Like Kaupapa Māori and Mana Wahine theories it is a cultural form and expression of praxis. As kairaranga we create taonga  informed by the creative genius of our tūpuna  from the native plants of the land. These ageless practices and the taonga we create are permeated with our own present realities. The taonga then carry this tūpuna knowledge into the future in multiple forms. To highlight this, I explore a range of practices that exemplify raranga and raranga whatu as cultural embodiment.  This is articulated through notions of raranga as an expression of cultural bodies of knowledge, creative practice and regenerative praxis that span the past, present and future.  As such, this thesis is an expression of the creative journey of theory and practice inspired by tūpuna knowledge in the art forms of raranga and raranga whatu. The practices of raranga and raranga whatu not only transform the materials the kairaranga is using, but also the kairaranga themselves. These practices become self-affirming, culturally affirming and ultimately decolonizing.

text: Ngā kura a Hineteiwaiwa: The embodiment of Mana Wahine in Māori fibre Arts Imagine you are on a continuum of past present and future, in the present while connected to the past and creating for the future. Kairaranga  are constantly in this experience through engaging with the materiality of the practices of raranga and raranga whatu.  
The key focus of this thesis is to provide theoretical discussion of the raranga and whatu practices that are the creative component of this doctoral research.  The theories that inform the analysis are Kaupapa Māori and Mana Wahine both of which, like raranga, are organic to this place, Aotearoa , and have grown as descendants of Papatūānuku  and Ranginui . The connection between these theories and the creative practices of raranga and whatu form a cultural praxis through which I argue enables the transformative power of raranga and whatu practices.  This too is the essence of Te Whare Pora, a weaving house that embraces kairaranga both conceptually and materially and which provides the approach to the project. Te Whare Pora is a place of knowledge and a place of practice. Like Kaupapa Māori and Mana Wahine theories it is a cultural form and expression of praxis. As kairaranga we create taonga  informed by the creative genius of our tūpuna  from the native plants of the land. These ageless practices and the taonga we create are permeated with our own present realities. The taonga then carry this tūpuna knowledge into the future in multiple forms. To highlight this, I explore a range of practices that exemplify raranga and raranga whatu as cultural embodiment.  This is articulated through notions of raranga as an expression of cultural bodies of knowledge, creative practice and regenerative praxis that span the past, present and future.  As such, this thesis is an expression of the creative journey of theory and practice inspired by tūpuna knowledge in the art forms of raranga and raranga whatu. The practices of raranga and raranga whatu not only transform the materials the kairaranga is using, but also the kairaranga themselves. These practices become self-affirming, culturally affirming and ultimately decolonizing.

year: 2019